fix phpcs via phpcbf

fix: make in_array comparison strict

.distignore

@@ -8,12 +8,15 @@
 .data
 .svnignore
 .wordpress-org
+.php_cs
 Gruntfile.js
 LINGUAS
 Makefile
 README.md
 readme.md
 CODE_OF_CONDUCT.md
+FEDERATION.md
+SECURITY.md
 LICENSE.md
 _site
 _config.yml
@@ -21,6 +24,8 @@ bin
 composer.json
 composer.lock
 docker-compose.yml
+docker-compose-test.yml
+Dockerfile
 gulpfile.js
 package.json
 node_modules
@@ -33,3 +38,4 @@ phpunit.xml.dist
 tests
 node_modules
 vendor
+src

.github/FUNDING.yml

@@ -1,9 +0,0 @@
-# These are supported funding model platforms
-
-github: pfefferle # Replace with up to 4 GitHub Sponsors-enabled usernames e.g., [user1, user2]
-patreon: # Replace with a single Patreon username
-open_collective: # Replace with a single Open Collective username
-ko_fi: # Replace with a single Ko-fi username
-tidelift: # Replace with a single Tidelift platform-name/package-name e.g., npm/babel
-liberapay: pfefferle
-custom: https://notiz.blog/donate/ # Replace with a single custom sponsorship URL

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,90 @@
+name: Bug Report
+description: Helps us improve our product!
+labels: "Needs triage, [Type] Bug"
+body:
+  - type: markdown
+    attributes:
+      value: |
+        ### Thanks for contributing!
+
+        Please write a clear title, then fill in the fields below and submit.
+
+        Please **do not** link to image hosting services such as Cloudup, Droplr, Imgur, etc…
+        Instead, directly embed screenshot(s) or recording(s) in any of the text areas below: click, then drag and drop.
+  - type: markdown
+    attributes:
+      value: |
+        ---
+        ## Core Information
+  - type: textarea
+    id: summary
+    attributes:
+        label: Quick summary
+  - type: textarea
+    id: steps
+    attributes:
+      label: Steps to reproduce
+      placeholder: |
+        1. Start at `site-domain.com/blog`.
+        2. Click on any blog post.
+        3. ...
+    validations:
+      required: true
+  - type: textarea
+    id: expected
+    attributes:
+      label: What you expected to happen
+      placeholder: |
+        e.g. The post should appear.
+    validations:
+      required: true
+  - type: textarea
+    id: actual
+    attributes:
+      label: What actually happened
+      placeholder: |
+        e.g. The post did not appear.
+    validations:
+      required: true
+  - type: dropdown
+    id: users-affected
+    attributes:
+      label: Impact
+      description: Approximately how many users are impacted?
+      options:
+        - One
+        - Some (< 50%)
+        - Most (> 50%)
+        - All
+    validations:
+      required: true
+  - type: dropdown
+    id: workarounds
+    attributes:
+      label: Available workarounds?
+      options:
+        - No and the platform is unusable
+        - No but the platform is still usable
+        - Yes, difficult to implement
+        - Yes, easy to implement
+        - There is no user impact
+    validations:
+      required: true
+
+  - type: markdown
+    attributes:
+      value: |
+        <br>
+
+        ## Optional Information
+
+        The following section is optional.
+  - type: textarea
+    id: logs
+    attributes:
+      label: Logs or notes
+      placeholder: |
+        Add any information that may be relevant, such as:
+          - Browser/Platform
+          - Theme
+          - Logs/Errors

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,34 @@
+name: Feature Request
+description: Suggest an idea for the ActivityPub plugin!
+title: "Feature Request:"
+labels: ["[Type] Feature Request"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Please, be as descriptive as possible. Issues lacking detail, or for any other reason than to request a feature, may be closed without action.
+
+  - type: textarea
+    id: what
+    attributes:
+      label: What
+      description: Add a concise description of the feature being requested.
+      placeholder: eg. I would like a new dropdown at <xyz>...
+    validations:
+      required: true
+
+  - type: textarea
+    id: why
+    attributes:
+      label: Why
+      description: Add a description of the problem this feature solves.
+      placeholder: |
+        eg. This will solve my accessibility needs.
+    validations:
+      required: true
+
+  - type: textarea
+    id: how
+    attributes:
+      label: How
+      description: If applicable, add screenshots, mockup, animations and/or videos to help illustrate how the feature could be done.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,22 @@
+<!--- Provide a general summary of your changes in the Title above -->
+
+Fixes #
+
+## Proposed changes:
+<!--- Explain what functional changes your PR includes -->
+*
+
+### Other information:
+
+- [ ] Have you written new tests for your changes, if applicable?
+
+## Testing instructions:
+<!-- If you were reviewing this PR, how would you like the instructions to be presented? -->
+<!-- Please include detailed testing steps, explaining how to test your change. -->
+<!-- Bear in mind that context you working on is not obvious for everyone.  -->
+<!-- Adding "simple" configuration steps will help reviewers to get to your PR as quickly as possible. -->
+<!-- "Before / After" screenshots can also be very helpful when the change is visual. -->
+
+* Go to '..'
+*
+

.github/dependabot.yml

@@ -0,0 +1,15 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: "composer" # See documentation for possible values
+    directory: "/" # Location of package manifests
+    schedule:
+      interval: "daily"
+  - package-ecosystem: "npm" # See documentation for possible values
+    directory: "/" # Location of package manifests
+    schedule:
+      interval: "daily"

.github/workflows/deploy.yml

@@ -0,0 +1,17 @@
+name: Deploy to WordPress.org
+on:
+  push:
+    tags:
+    - "*"
+jobs:
+  tag:
+    name: New tag
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - name: WordPress Plugin Deploy
+      uses: 10up/action-wordpress-plugin-deploy@stable
+      env:
+        SVN_PASSWORD: ${{ secrets.SVN_PASSWORD }}
+        SVN_USERNAME: ${{ secrets.SVN_USERNAME }}
+        SLUG: activitypub

.github/workflows/gardening.yml

@@ -0,0 +1,50 @@
+# Repo gardening. Automate some of the triage tasks in the repo.
+name: Repo Gardening
+
+on:
+  pull_request_target: # When a PR is opened, edited, updated, closed, or a label is added.
+    types: [opened, reopened, synchronize, edited, labeled, closed]
+  issues: # For auto-triage of issues.
+    types: [opened, labeled, reopened, edited, closed]
+  issue_comment: # To gather support references in issue comments.
+    types: [created]
+concurrency:
+  # For pull_request_target, cancel any concurrent jobs with the same type (e.g. "opened", "labeled") and branch.
+  # Don't cancel any for other events, accomplished by grouping on the unique run_id.
+  group: gardening-${{ github.event_name }}-${{ github.event.action }}-${{ github.event_name == 'pull_request_target' && github.event.pull_request.head.ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  repo-gardening:
+    name: 'Automated repo gardening.'
+    runs-on: ubuntu-latest
+    if: github.event_name == 'pull_request_target' || github.event.pull_request.head.repo.full_name == github.event.pull_request.base.repo.full_name
+    timeout-minutes: 10
+
+    steps:
+     - name: Checkout
+       uses: actions/checkout@v3
+
+     - name: Setup Node
+       uses: actions/setup-node@v3
+       with:
+          node-version: lts/*
+
+     - name: Wait for prior instances of the workflow to finish
+       uses: softprops/turnstyle@v1
+       env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+     - name: 'Automate triage (add labels, clean labels, ...).'
+       uses: automattic/action-repo-gardening@trunk
+       with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          slack_token: ${{ secrets.SLACK_TOKEN }}
+          slack_team_channel: ${{ secrets.SLACK_TEAM_CHANNEL }}
+          slack_he_triage_channel: ${{ secrets.SLACK_HE_TRIAGE_CHANNEL }}
+          slack_quality_channel: ${{ secrets.SLACK_QUALITY_CHANNEL }}
+          tasks: 'addLabels,cleanLabels,assignIssues,flagOss,gatherSupportReferences,replyToCustomersReminder'
+          add_labels: '[
+              {"path": "src/followers", "label": "[Block] Followers"},
+              {"path": "src/follow-me", "label": "[Block] Follow Me"}
+            ]'

.github/workflows/phpcs.yml

@@ -0,0 +1,31 @@
+name: PHP_CodeSniffer
+on:
+  push:
+  pull_request:
+jobs:
+  phpcs:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '7.4'
+          coverage: none
+          tools: composer, cs2pr
+      - name: Get Composer cache directory
+        id: composer-cache
+        run: echo "::set-output name=dir::$(composer config cache-files-dir)"
+      - name: Setup cache
+        uses: pat-s/always-upload-cache@v1.1.4
+        with:
+          path: ${{ steps.composer-cache.outputs.dir }}
+          # Use the hash of composer.json as the key for your cache if you do not commit composer.lock.
+          key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.json') }}
+          #key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
+          restore-keys: ${{ runner.os }}-composer-
+      - name: Install dependencies
+        run: composer install --prefer-dist --no-progress
+      - name: Detect coding standard violations
+        run: ./vendor/bin/phpcs -n -q

.github/workflows/phpunit.yml

@@ -0,0 +1,44 @@
+name: Unit Testing
+on:
+  push:
+  pull_request:
+jobs:
+  phpunit:
+    runs-on: ubuntu-latest
+    services:
+     mysql:
+       image: mariadb:10.4
+       env:
+         MYSQL_ROOT_PASSWORD: root
+       ports:
+         - 3306:3306
+       options: --health-cmd="mysqladmin ping" --health-interval=10s --health-timeout=10s --health-retries=10
+    strategy:
+      matrix:
+        php-versions: ['5.6', '7.0', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2']
+        include:
+          - wp-version: latest
+          - wp-version: '6.2'
+            php-versions: '5.6'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-versions }}
+          coverage: none
+          tools: composer, phpunit-polyfills
+          extensions: mysql
+
+      - name: Install Composer dependencies for PHP
+        uses: "ramsey/composer-install@v1"
+
+      - name: Setup Test Environment
+        run: bash bin/install-wp-tests.sh wordpress_test root root 127.0.0.1 ${{ matrix.wp-version }}
+
+      - name: Unit Testing
+        run: ./vendor/bin/phpunit
+        env:
+          PHP_VERSION: ${{ matrix.php-versions }}

.github/workflows/stale.yml

@@ -0,0 +1,19 @@
+name: 'Close stale issues and PRs'
+on:
+  schedule:
+    - cron: '30 1 * * *'
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v8
+        with:
+          stale-issue-message: 'This issue is stale because it has been open 120 days with no activity. Remove stale label or comment or this will be closed in 5 days.'
+          days-before-stale: 120
+          days-before-close: 7
+          exempt-all-pr-assignees: true
+          exempt-all-assignees: true
+          exempt-all-pr-milestones: true
+          exempt-all-issue-milestones: true
+          start-date: '2019-02-01T00:00:00Z'

.github/workflows/update-assets.yml

@@ -10,7 +10,7 @@ jobs:
     steps:
     - uses: actions/checkout@master
     - name: WordPress.org plugin asset/readme update
-      uses: 10up/action-wordpress-plugin-asset-update@master
+      uses: 10up/action-wordpress-plugin-asset-update@stable
       env:
         SVN_PASSWORD: ${{ secrets.SVN_PASSWORD }}
         SVN_USERNAME: ${{ secrets.SVN_USERNAME }}

.gitignore

@@ -4,3 +4,6 @@ package-lock.json
 composer.lock
 .DS_Store
 .idea/
+.php_cs.cache
+.vscode/settings.json
+.phpunit.result.cache

.travis.yml

@@ -1,97 +0,0 @@
-sudo: false
-dist: trusty
-language: php
-notifications:
-  email:
-    on_success: never
-    on_failure: change
-cache:
-  directories:
-  - vendor
-  - "$HOME/.composer/cache"
-after_success: bash bin/deploy.sh
-env:
-  matrix:
-  - WP_VERSION=latest WP_MULTISITE=0
-  global:
-  - WP_TRAVISCI=travis:phpunit
-  - SVN_REPO: https://plugins.svn.wordpress.org/activitypub/
-  - GH_REF: https://github.com/pfefferle/wordpress-activitypub.git
-  - secure: "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"
-matrix:
-  include:
-  - php: 7.3
-  - php: 7.2
-  - php: 7.1
-  - php: 7.0
-  - php: 5.6
-  - php: 5.6
-    env: WP_PLUGIN_DEPLOY=1
-before_script:
-- |
-  # Remove Xdebug for a huge performance increase:
-  if [ -f ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/xdebug.ini ]; then
-    phpenv config-rm xdebug.ini
-  else
-    echo "xdebug.ini does not exist"
-  fi
-- |
-  # Export Composer's global bin dir to PATH:
-  composer config --list --global
-  export PATH=`composer config --list --global | grep '\[home\]' | { read a; echo "${a#* }/vendor/bin:$PATH"; }`
-- |
-  # Install the specified version of PHPUnit depending on the PHP version:
-  if [[ "$WP_TRAVISCI" == "travis:phpunit" ]]; then
-    case "$TRAVIS_PHP_VERSION" in
-      7.3|7.2|7.1|7.0|nightly)
-        echo "Using PHPUnit 6.x"
-        composer global require "phpunit/phpunit:^6"
-        ;;
-      5.6|5.5|5.4|5.3)
-        echo "Using PHPUnit 4.x"
-        composer global require "phpunit/phpunit:^4"
-        ;;
-      *)
-        echo "No PHPUnit version handling for PHP version $TRAVIS_PHP_VERSION"
-        exit 1
-        ;;
-    esac
-  fi
-  if [[ "$WP_TRAVISCI" == "travis:phpcs" ]] ; then
-      composer install
-  fi
-- mysql --version
-- phpenv versions
-- php --version
-- php -m
-- which phpunit
-- phpunit --version
-- curl --version
-- grunt --version
-- git --version
-- svn --version
-- locale -a
-before_install:
-- export PATH="$HOME/.composer/vendor/bin:$PATH"
-- |
-  if [[ ! -z "$WP_VERSION" ]] ; then
-    set -e
-    bash bin/install-wp-tests.sh wordpress_test root '' localhost $WP_VERSION
-    set +e
-  fi
-script:
-- |
-  if [[ ! -z "$WP_VERSION" ]] ; then
-    # Run the build because otherwise there will be a bunch of warnings about
-    # failed `stat` calls from `filemtime()`.
-    echo Running with the following versions:
-    php -v
-    phpunit --version
-    # Run PHPUnit tests
-    phpunit || exit 1
-    WP_MULTISITE=1 phpunit || exit 1
-  fi
-- |
-  if [[ "$WP_TRAVISCI" == "travis:phpcs" ]] ; then
-    ./vendor/bin/phpcs -p -s -v -n --standard=./phpcs.ruleset.xml --extensions=php
-  fi

CODE_OF_CONDUCT.md

@@ -0,0 +1,128 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+We as members, contributors, and leaders pledge to make participation in our
+community a harassment-free experience for everyone, regardless of age, body
+size, visible or invisible disability, ethnicity, sex characteristics, gender
+identity and expression, level of experience, education, socio-economic status,
+nationality, personal appearance, race, religion, or sexual identity
+and orientation.
+
+We pledge to act and interact in ways that contribute to an open, welcoming,
+diverse, inclusive, and healthy community.
+
+## Our Standards
+
+Examples of behavior that contributes to a positive environment for our
+community include:
+
+* Demonstrating empathy and kindness toward other people
+* Being respectful of differing opinions, viewpoints, and experiences
+* Giving and gracefully accepting constructive feedback
+* Accepting responsibility and apologizing to those affected by our mistakes,
+  and learning from the experience
+* Focusing on what is best not just for us as individuals, but for the
+  overall community
+
+Examples of unacceptable behavior include:
+
+* The use of sexualized language or imagery, and sexual attention or
+  advances of any kind
+* Trolling, insulting or derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or email
+  address, without their explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Enforcement Responsibilities
+
+Community leaders are responsible for clarifying and enforcing our standards of
+acceptable behavior and will take appropriate and fair corrective action in
+response to any behavior that they deem inappropriate, threatening, offensive,
+or harmful.
+
+Community leaders have the right and responsibility to remove, edit, or reject
+comments, commits, code, wiki edits, issues, and other contributions that are
+not aligned to this Code of Conduct, and will communicate reasons for moderation
+decisions when appropriate.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when
+an individual is officially representing the community in public spaces.
+Examples of representing our community include using an official e-mail address,
+posting via an official social media account, or acting as an appointed
+representative at an online or offline event.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported to the community leaders responsible for enforcement at
+https://developer.wordpress.com/contact/?g21-subject=Code%20of%20Conduct.
+All complaints will be reviewed and investigated promptly and fairly.
+
+All community leaders are obligated to respect the privacy and security of the
+reporter of any incident.
+
+## Enforcement Guidelines
+
+Community leaders will follow these Community Impact Guidelines in determining
+the consequences for any action they deem in violation of this Code of Conduct:
+
+### 1. Correction
+
+**Community Impact**: Use of inappropriate language or other behavior deemed
+unprofessional or unwelcome in the community.
+
+**Consequence**: A private, written warning from community leaders, providing
+clarity around the nature of the violation and an explanation of why the
+behavior was inappropriate. A public apology may be requested.
+
+### 2. Warning
+
+**Community Impact**: A violation through a single incident or series
+of actions.
+
+**Consequence**: A warning with consequences for continued behavior. No
+interaction with the people involved, including unsolicited interaction with
+those enforcing the Code of Conduct, for a specified period of time. This
+includes avoiding interactions in community spaces as well as external channels
+like social media. Violating these terms may lead to a temporary or
+permanent ban.
+
+### 3. Temporary Ban
+
+**Community Impact**: A serious violation of community standards, including
+sustained inappropriate behavior.
+
+**Consequence**: A temporary ban from any sort of interaction or public
+communication with the community for a specified period of time. No public or
+private interaction with the people involved, including unsolicited interaction
+with those enforcing the Code of Conduct, is allowed during this period.
+Violating these terms may lead to a permanent ban.
+
+### 4. Permanent Ban
+
+**Community Impact**: Demonstrating a pattern of violation of community
+standards, including sustained inappropriate behavior,  harassment of an
+individual, or aggression toward or disparagement of classes of individuals.
+
+**Consequence**: A permanent ban from any sort of public interaction within
+the community.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage],
+version 2.0, available at
+https://www.contributor-covenant.org/version/2/0/code_of_conduct.html.
+
+Community Impact Guidelines were inspired by [Mozilla's code of conduct
+enforcement ladder](https://github.com/mozilla/diversity).
+
+[homepage]: https://www.contributor-covenant.org
+
+For answers to common questions about this code of conduct, see the FAQ at
+https://www.contributor-covenant.org/faq. Translations are available at
+https://www.contributor-covenant.org/translations.

Dockerfile

@@ -0,0 +1,27 @@
+FROM php:7.4-alpine3.13
+
+RUN mkdir /app
+
+WORKDIR /app
+
+# Install Git, NPM & needed libraries
+RUN apk update \
+    && apk add bash git nodejs npm gettext subversion mysql mysql-client zip \
+    && rm -f /var/cache/apk/*
+
+RUN docker-php-ext-install mysqli
+
+#  Install Composer
+RUN EXPECTED_CHECKSUM=$(curl -s https://composer.github.io/installer.sig) \
+    && curl https://getcomposer.org/installer -o composer-setup.php \
+    && ACTUAL_CHECKSUM="$(php -r "echo hash_file('sha384', 'composer-setup.php');")" \
+    && if [ "$EXPECTED_CHECKSUM" != "$ACTUAL_CHECKSUM" ]; then >&2 echo 'ERROR: Invalid installer checksum'; rm composer-setup.php; exit 1; fi \
+    && php composer-setup.php --quiet \
+    && php -r "unlink('composer-setup.php');" \
+    && mv composer.phar /usr/local/bin/composer
+
+RUN curl -O https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar && \
+    chmod +x wp-cli.phar && \
+    mv wp-cli.phar /usr/local/bin/wp
+
+RUN chmod +x -R ./

FEDERATION.md

@@ -0,0 +1,38 @@
+# Federation in WordPress
+
+The WordPress plugin largely follows ActivityPub's server-to-server specification, but makes use of some non-standard extensions, some of which are required to interact with the plugin. Most of these extensions are for the purpose of compatibility with other, sometimes very restrictive networks, such as Mastodon.
+
+## Supported federation protocols and standards
+
+- [ActivityPub](https://www.w3.org/TR/activitypub/) (Server-to-Server)
+- [WebFinger](https://webfinger.net/)
+- [HTTP Signatures](https://datatracker.ietf.org/doc/html/draft-cavage-http-signatures)
+- [NodeInfo](https://nodeinfo.diaspora.software/)
+
+## Supported FEPs
+
+- [FEP-f1d5: NodeInfo in Fediverse Software](https://codeberg.org/fediverse/fep/src/branch/main/fep/f1d5/fep-f1d5.md)
+- [FEP-67ff: FEDERATION.md](https://codeberg.org/fediverse/fep/src/branch/main/fep/67ff/fep-67ff.md)
+- [FEP-5feb: Search indexing consent for actors](https://codeberg.org/fediverse/fep/src/branch/main/fep/5feb/fep-5feb.md)
+
+Partially supported FEPs
+
+- [FEP-1b12: Group federation](https://codeberg.org/fediverse/fep/src/branch/main/fep/1b12/fep-1b12.md)
+
+## ActivityPub
+
+### HTTP Signatures
+
+In order to authenticate activities, Mastodon relies on HTTP Signatures, signing every `POST` and `GET` request to other ActivityPub implementations on behalf of the user authoring an activity (for `POST` requests) or an actor representing the Mastodon server itself (for most `GET` requests).
+
+Mastodon requires all `POST` requests to be signed, and MAY require `GET` requests to be signed, depending on the configuration of the Mastodon server.
+
+More information on HTTP Signatures, as well as examples, can be found here: https://docs.joinmastodon.org/spec/security/#http
+
+## Additional documentation
+
+- Plugin Description: https://github.com/Automattic/wordpress-activitypub?tab=readme-ov-file#description
+- Frequently Asked Questions: https://github.com/Automattic/wordpress-activitypub?tab=readme-ov-file#frequently-asked-questions
+- Installation Instructions: https://github.com/Automattic/wordpress-activitypub?tab=readme-ov-file#installation
+- Upgrade Notice: https://github.com/Automattic/wordpress-activitypub?tab=readme-ov-file#upgrade-notice
+- Changelog: https://github.com/Automattic/wordpress-activitypub?tab=readme-ov-file#changelog

Gruntfile.js

@@ -24,7 +24,6 @@ module.exports = function(grunt) {
       files: {
         src:  [
           '**/*.php',         // Include all files
-          'includes/*.php', // Include includes
           '!sass/**',         // Exclude sass/
           '!node_modules/**', // Exclude node_modules/
           '!tests/**',        // Exclude tests/
@@ -42,25 +41,12 @@ module.exports = function(grunt) {
           'README.md': 'readme.txt'
         },
       },
-    },
-    makepot: {
-      target: {
-        options: {
-          mainFile: 'activitypub.php',
-          domainPath: '/languages',
-          exclude: ['bin/.*', '.git/.*', 'vendor/.*'],
-          potFilename: 'activitypub.pot',
-          type: 'wp-plugin',
-          updateTimestamp: true
-        }
-      }
     }
   });
 
   grunt.loadNpmTasks('grunt-wp-readme-to-markdown');
-  grunt.loadNpmTasks('grunt-wp-i18n');
   grunt.loadNpmTasks('grunt-checktextdomain');
 
   // Default task(s).
-  grunt.registerTask('default', ['wp_readme_to_markdown', 'makepot', 'checktextdomain']);
+  grunt.registerTask('default', ['wp_readme_to_markdown', 'checktextdomain']);
 };

LICENSE

@@ -1,6 +1,7 @@
 MIT License
 
 Copyright (c) 2019 Matthias Pfefferle
+Copyright (c) 2023 Automattic
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1,10 +1,9 @@
 # ActivityPub #
-**Contributors:** [pfefferle](https://profiles.wordpress.org/pfefferle)  
-**Donate link:** https://notiz.blog/donate/  
+**Contributors:** [automattic](https://profiles.wordpress.org/automattic/), [pfefferle](https://profiles.wordpress.org/pfefferle/), [mediaformat](https://profiles.wordpress.org/mediaformat/), [mattwiebe](https://profiles.wordpress.org/mattwiebe/), [akirk](https://profiles.wordpress.org/akirk/), [jeherve](https://profiles.wordpress.org/jeherve/), [nuriapena](https://profiles.wordpress.org/nuriapena/), [cavalierlife](https://profiles.wordpress.org/cavalierlife/)  
 **Tags:** OStatus, fediverse, activitypub, activitystream  
 **Requires at least:** 4.7  
-**Tested up to:** 5.3  
-**Stable tag:** 0.9.1  
+**Tested up to:** 6.4  
+**Stable tag:** 1.2.0  
 **Requires PHP:** 5.6  
 **License:** MIT  
 **License URI:** http://opensource.org/licenses/MIT  
@@ -13,53 +12,71 @@ The ActivityPub protocol is a decentralized social networking protocol based upo
 
 ## Description ##
 
-This is **BETA** software, see the FAQ to see the current feature set or rather what is still planned.
+Enter the fediverse with **ActivityPub**, broadcasting your blog to a wider audience! Attract followers, deliver updates, and receive comments from a diverse user base of **ActivityPub**\-compliant platforms.
 
-The plugin implements the ActivityPub protocol for your blog. Your readers will be able to follow your blogposts on Mastodon and other federated platforms that support ActivityPub.
+With the ActivityPub plugin installed, your WordPress blog itself function as a federated profile, along with profiles for each author. For instance, if your website is `example.com`, then the blog-wide profile can be found at `@example.com@example.com`, and authors like Jane and Bob would have their individual profiles at `@jane@example.com` and `@bobz@example.com`, respectively.
 
-The plugin works with the following federated platforms:
+An example: I give you my Mastodon profile name: `@pfefferle@mastodon.social`. You search, see my profile, and hit follow. Now, any post I make appears in your Home feed. Similarly, with the ActivityPub plugin, you can find and follow Jane's profile at `@jane@example.com`.
+
+Once you follow Jane's `@jane@example.com` profile, any blog post she crafts on `example.com` will land in your Home feed. Simultaneously, by following the blog-wide profile `@example.com@example.com`, you'll receive updates from all authors.
+
+**Note**: if no one follows your author or blog instance, your posts remain unseen. The simplest method to verify the plugin's operation is by following your profile. If you possess a Mastodon profile, initiate by following your new one.
+
+The plugin works with the following tested federated platforms, but there may be more that it works with as well:
 
 * [Mastodon](https://joinmastodon.org/)
-* [Pleroma](https://pleroma.social/)
-* [Friendica](https://friendi.ca/)
-* [HubZilla](https://hubzilla.org/)
+* [Pleroma](https://pleroma.social/)/[Akkoma](https://akkoma.social/)
+* [friendica](https://friendi.ca/)
+* [Hubzilla](https://hubzilla.org/)
 * [Pixelfed](https://pixelfed.org/)
-* [SocialHome](https://socialhome.network/)
+* [Socialhome](https://socialhome.network/)
 * [Misskey](https://join.misskey.page/)
+* [Firefish](https://joinfirefish.org/) (rebrand of Calckey)
+
+Some things to note:
+
+1. The blog-wide profile is only compatible with sites with rewrite rules enabled. If your site does not have rewrite rules enabled, the author-specific profiles may still work.
+1. Many single-author blogs have chosen to turn off or redirect their author profile pages, usually via an SEO plugin like Yoast or Rank Math. This is usually done to avoid duplicate content with your blog’s home page. If your author page has been deactivated in this way, then ActivityPub author profiles won’t work for you. Instead, you can turn your author profile page back on, and then use the option in your SEO plugin to noindex the author page. This will still resolve duplicate content issues with search engines and will enable ActivityPub author profiles to work.
+1. Once ActivityPub is installed, *only new posts going forward* will be available in the fediverse. Likewise, even if you’ve been using ActivityPub for a while, anyone who follows your site, will only see new posts you publish from that moment on. They will never see previously-published posts in their Home feed. This process is very similar to subscribing to a newsletter. If you subscribe to a newsletter, you will only receive future emails, but not the old archived ones. With ActivityPub, if someone follows your site, they will only receive new blog posts you publish from then on.
+
+So what’s the process?
+
+1. Install the ActivityPub plugin.
+1. Go to the plugin’s settings page and adjust the settings to your liking. Click the Save button when ready.
+1. Make sure your blog’s author profile page is active if you are using author profiles.
+1. Go to Mastodon or any other federated platform, and search for your profile, and follow it. Your new profile will be in the form of either `@your_username@example.com` or `@example.com@example.com`, so that is what you’ll search for.
+1. On your blog, publish a new post.
+1. From Mastodon, check to see if the new post appears in your Home feed.
+
+Please note that it may take up to 15 minutes or so for the new post to show up in your federated feed. This is because the messages are sent to the federated platforms using a delayed cron. This avoids breaking the publishing process for those cases where users might have lots of followers. So please don’t assume that just because you didn’t see it show up right away that something is broken. Give it some time. In most cases, it will show up within a few minutes, and you’ll know everything is working as expected.
 
 ## Frequently Asked Questions ##
 
+### tl;dr ###
+
+This plugin connects your WordPress blog to popular social platforms like Mastodon, making your posts more accessible to a wider audience. Once installed, your blog can be followed by users on these platforms, allowing them to receive your new posts in their feeds.
+
 ### What is the status of this plugin? ###
 
 Implemented:
 
-* profile pages (JSON representation)
+* blog profile pages (JSON representation)
+* author profile pages (JSON representation)
 * custom links
 * functional inbox/outbox
 * follow (accept follows)
 * share posts
 * receive comments/reactions
+* signature verification
 
 To implement:
 
-* signature verification
-* better WordPress integration
-* better configuration possibilities
 * threaded comments support
+* replace shortcodes with blocks for layout
 
 ### What is "ActivityPub for WordPress" ###
 
-*ActivityPub for WordPress* extends WordPress with some Fediverse features, but it does not compete with platforms like Friendica or Mastodon. If you want to run a **decentralized social network**, please use [Mastodon](https://joinmastodon.org/) or [GNU social](https://gnu.io/social/).
-
-### What are the differences between this plugin and Pterotype? ###
-
-**Compatibility**
-
-*ActivityPub for WordPress* is compatible with OStatus and IndieWeb plugin suites. *Pterotype* is incompatible with the standalone [WebFinger plugin](https://wordpress.org/plugins/webfinger/), so it can't be run together with OStatus.
-
-**Custom tables**
-
-*Pterotype* creates/uses a bunch of custom tables, *ActivityPub for WordPress* only uses the native tables and adds as little meta data as possible.
+*ActivityPub for WordPress* extends WordPress with some Fediverse features, but it does not compete with platforms like Friendica or Mastodon. If you want to run a **decentralized social network**, please use [Mastodon](https://joinmastodon.org/) or [GNU social](https://gnusocial.network/).
 
 ### What if you are running your blog in a subdirectory? ###
 
@@ -69,7 +86,7 @@ In order for webfinger to work, it must be mapped to the root directory of the U
 
 Add the following to the .htaccess file in the root directory:
 
-	RedirectMatch "^\/\.well-known(.*)$" "\/blog\/\.well-known$1"
+	RedirectMatch "^\/\.well-known/(webfinger|nodeinfo|x-nodeinfo2)(.*)$" /blog/.well-known/$1$2
 
 Where 'blog' is the path to the subdirectory at which your blog resides.
 
@@ -86,7 +103,235 @@ Where 'blog' is the path to the subdirectory at which your blog resides.
 
 ## Changelog ##
 
-Project maintained on GitHub at [pfefferle/wordpress-activitypub](https://github.com/pfefferle/wordpress-activitypub).
+Project maintained on GitHub at [automattic/wordpress-activitypub](https://github.com/automattic/wordpress-activitypub).
+
+### 1.2.0 ###
+
+* Add: Search and order followerer lists
+* Add: Have a filter to defer signature verification
+* Improved: "Follow Me" styles for dark themes
+* Improved: Allow `p` and `br` tags only for AP comments
+* Fixed: Deduplicate attachments earlier to prevent incorrect max_media
+
+
+### 1.1.0 ###
+
+* Improved: audio and video attachments are now supported!
+* Improved: better error messages if remote profile is not accessible
+* Improved: PHP 8.1 compatibility
+* Fixed: don't try to parse mentions or hashtags for very large (>1MB) posts to prevent timeouts
+* Fixed: better handling of ISO-639-1 locale codes
+* Improved: more reliable [ap_author], props @uk3
+* Improved: NodeInfo statistics
+
+### 1.0.10 ###
+
+* Improved: better error messages if remote profile is not accessible
+
+### 1.0.9 ###
+
+* Fixed: broken following endpoint
+
+### 1.0.8 ###
+
+* Fixed: blocking of HEAD requests
+* Fixed: PHP fatal error
+* Fixed: several typos
+* Fixed: error codes
+* Improved: loading of shortcodes
+* Updated: caching of followers
+* Updated: Application-User is no longer "indexable"
+* Updated: more consistent usage of the `application/activity+json` Content-Type
+* Removed: featured tags endpoint
+
+### 1.0.7 ###
+
+* Fixed: broken function call
+* Add: filter to hook into "is blog public" check
+
+### 1.0.6 ###
+
+* Fixed: more restrictive request verification
+
+### 1.0.5 ###
+
+* Fixed: compatibility with WebFinger and NodeInfo plugin
+
+### 1.0.4 ###
+
+* Fixed: Constants were not loaded early enough, resulting in a race condition
+* Fixed: Featured image was ignored when using the block editor
+
+### 1.0.3 ###
+
+* Fixed: compatibility with older WordPress/PHP versions
+* Update: refactoring of the Plugin init process
+* Update: better frontend UX and improved theme compat for blocks
+* Compatibility: add a ACTIVITYPUB_DISABLE_REWRITES constant
+* Compatibility: add pre-fetch hook to allow plugins to hang filters on
+
+### 1.0.2 ###
+
+* Updated: improved hashtag visibility in default template
+* Updated: reduced number of followers to be checked/updated via Cron, when System Cron is not set up
+* Updated: check if username of Blog-User collides with an Authors name
+* Compatibility: improved Group meta informations
+* Fixed: detection of single user mode
+* Fixed: remote delete
+* Fixed: styles in Follow-Me block
+* Fixed: various encoding and formatting issues
+* Fixed: (health) check Author URLs only if Authors are enabled
+
+### 1.0.1 ###
+
+* Update: improve image attachment detection using the block editor
+* Update: better error code handling for API responses
+* Update: use a tag stack instead of regex for protecting tags for Hashtags and @-Mentions
+* Compatibility: better signature support for subpath-installations
+* Compatibility: allow deactivating blocks registered by the plugin
+* Compatibility: avoid Fatal Errors when using ClassicPress
+* Compatibility: improve the Group-Actor to play nicely with existing implementations
+* Fixed: truncate long blog titles and handles for the "Follow me" block
+* Fixed: ensure that only a valid user can be selected for the "Follow me" block
+* Fixed: fix a typo in a hook name
+* Fixed: a problem with signatures when running WordPress in a sub-path
+
+### 1.0.0 ###
+
+* Add: blog-wide Account (catchall, like `example.com@example.com`)
+* Add: a Follow Me block (help visitors to follow your Profile)
+* Add: Signature Verification: https://docs.joinmastodon.org/spec/security/
+* Add: a Followers Block (show off your Followers)
+* Add: Simple caching
+* Add: Collection endpoints for Featured Tags and Featured Posts
+* Add: Better handling of Hashtags in mobile apps
+* Update: Complete rewrite of the Follower-System based on Custom Post Types
+* Update: Improved linter (PHPCS)
+* Compatibility: Add a new conditional, `\Activitypub\is_activitypub_request()`, to allow third-party plugins to detect ActivityPub requests
+* Compatibility: Add hooks to allow modifying images returned in ActivityPub requests
+* Compatibility: Indicate that the plugin is compatible and has been tested with the latest version of WordPress, 6.3
+* Compatibility: Avoid PHP notice on sites using PHP 8.2
+* Fixed: Load the plugin later in the WordPress code lifecycle to avoid errors in some requests
+* Fixed: Updating posts
+* Fixed: Hashtag now support CamelCase and UTF-8
+
+### 0.17.0 ###
+
+* Fix type-selector
+* Allow more HTML elements in Activity-Objects
+
+### 0.16.5 ###
+
+* Return empty content/excerpt on password protected posts/pages
+
+### 0.16.4 ###
+
+* Remove scripts later in the queue, to also handle scripts added by blocks
+* Add published date to author profiles
+
+### 0.16.3 ###
+
+* "cc", "to", ... fields can either be an array or a string
+* Remove "style" and "script" HTML elements from content
+
+### 0.16.2 ###
+
+* Fix fatal error in outbox
+
+### 0.16.1 ###
+
+* Fix "update and create, posts appear blank on Mastodon" issue
+
+### 0.16.0 ###
+
+* Add "Outgoing Mentions" ([#213](https://github.com/pfefferle/wordpress-activitypub/pull/213)) props [@akirk](https://github.com/akirk)
+* Add configuration item for number of images to attach ([#248](https://github.com/pfefferle/wordpress-activitypub/pull/248)) props [@mexon](https://github.com/mexon)
+* Use shortcodes instead of custom templates, to setup the Activity Post-Content ([#250](https://github.com/pfefferle/wordpress-activitypub/pull/250)) props [@toolstack](https://github.com/toolstack)
+* Remove custom REST Server, because the needed changes are now merged into Core.
+* Fix hashtags ([#261](https://github.com/pfefferle/wordpress-activitypub/pull/261)) props [@akirk](https://github.com/akirk)
+* Change priorites, to maybe fix the hashtag issue
+
+### 0.15.0 ###
+
+* Enable ActivityPub only for users that can `publish_posts`
+* Persist only public Activities
+* Fix remote-delete
+
+### 0.14.3 ###
+
+* Better error handling. props [@akirk](https://github.com/akirk)
+
+### 0.14.2 ###
+
+* Fix Critical error when using Friends Plugin and adding new URL to follow. props [@akirk](https://github.com/akirk)
+
+### 0.14.1 ###
+
+* Fix "WebFinger not compatible with PHP < 8.0". props [@mexon](https://github.com/mexon)
+
+### 0.14.0 ###
+
+* Friends support: https://wordpress.org/plugins/friends/ props [@akirk](https://github.com/akirk)
+* Massive guidance improvements. props [mediaformat](https://github.com/mediaformat) & [@akirk](https://github.com/akirk)
+* Add Custom Post Type support to outbox API. props [blueset](https://github.com/blueset)
+* Better hash-tag support. props [bocops](https://github.com/bocops)
+* Fix user-count (NodeInfo). props [mediaformat](https://github.com/mediaformat)
+
+### 0.13.4 ###
+
+* fix webfinger for email identifiers
+
+### 0.13.3 ###
+
+* fix: Create and Note should not have the same ActivityPub ID
+
+### 0.13.2 ###
+
+* fix Follow issue AGAIN
+
+### 0.13.1 ###
+
+* fix Inbox issue
+
+### 0.13.0 ###
+
+* add Autor URL and WebFinger health checks
+* fix NodeInfo endpoint
+
+### 0.12.0 ###
+
+* use "pre_option_require_name_email" filter instead of "check_comment_flood". props [@akirk](https://github.com/akirk)
+* save only comments/replies
+* check for an explicit "undo -> follow" action. see https://wordpress.org/support/topic/qs-after-latest/
+
+### 0.11.2 ###
+
+* fix inconsistent `%tags%` placeholder
+
+### 0.11.1 ###
+
+* fix follow/unfollow actions
+
+### 0.11.0 ###
+
+* add support for customizable post-content
+* first try of a delete activity
+* do not require email for AP entries. props [@akirk](https://github.com/akirk)
+* fix [timezones](https://github.com/pfefferle/wordpress-activitypub/issues/63) bug. props [@mediaformat](https://github.com/mediaformat)
+* fix [digest header](https://github.com/pfefferle/wordpress-activitypub/issues/104) bug. props [@mediaformat](https://github.com/mediaformat)
+
+
+### 0.10.1 ###
+
+* fix inbox activities, like follow
+* fix debug
+
+### 0.10.0 ###
+
+* add image alt text to the ActivityStreams attachment property in a format that Mastodon can read. props [@BenLubar](https://github.com/BenLubar)
+* use the "summary" property for a title as Mastodon does. props [@BenLubar](https://github.com/BenLubar)
+* support authorized fetch to avoid having comments from "Anonymous". props [@BenLubar](https://github.com/BenLubar)
+* add new post type: "title and link only". props [@bgcarlisle](https://github.com/bgcarlisle)
 
 ### 0.9.1 ###
 
@@ -230,9 +475,15 @@ Project maintained on GitHub at [pfefferle/wordpress-activitypub](https://github
 
 * initial
 
+## Upgrade Notice ##
+
+### 1.0.0 ###
+
+For version 1.0.0 we have completely rebuilt the followers lists. There is a migration from the old format to the new, but it may take some time until the migration is complete. No data will be lost in the process, please give the migration some time.
+
 ## Installation ##
 
-Follow the normal instructions for [installing WordPress plugins](https://codex.wordpress.org/Managing_Plugins#Installing_Plugins).
+Follow the normal instructions for [installing WordPress plugins](https://wordpress.org/support/article/managing-plugins/).
 
 ### Automatic Plugin Installation ###
 

SECURITY.md

@@ -0,0 +1,36 @@
+# Security Policy
+
+Full details of the Automattic Security Policy can be found on [automattic.com](https://automattic.com/security/).
+
+## Supported Versions
+
+Generally, only the latest version of the ActivityPub plugin has continued support. If a critical vulnerability is found in the current version of the ActivityPub plugin, we may opt to backport any patches to previous versions.
+
+## Reporting a Vulnerability
+
+[ActivityPub](https://wordpress.org/plugins/activitypub/) is an open-source plugin for WordPress. Our HackerOne program covers the plugin software, as well as a variety of related projects and infrastructure.
+
+**For responsible disclosure of security issues and to be eligible for our bug bounty program, please submit your report via the [HackerOne](https://hackerone.com/automattic) portal.**
+
+Our most critical targets are:
+
+* ActivityPub plugin (all within this repo)
+* wordpress.com -- hosted ActivityPub offering on WordPress.com.
+
+For more targets, see the `In Scope` section on [HackerOne](https://hackerone.com/automattic).
+
+_Please note that the **WordPress software is a separate entity** from Automattic. Please report vulnerabilities for WordPress through [the WordPress Foundation's HackerOne page](https://hackerone.com/wordpress)._
+
+## Guidelines
+
+We're committed to working with security researchers to resolve the vulnerabilities they discover. You can help us by following these guidelines:
+
+*   Follow [HackerOne's disclosure guidelines](https://www.hackerone.com/disclosure-guidelines).
+*   Pen-testing Production:
+    *   Please **setup a local environment** instead whenever possible. Most of our code is open source (see above).
+    *   If that's not possible, **limit any data access/modification** to the bare minimum necessary to reproduce a PoC.
+    *   **_Don't_ automate form submissions!** That's very annoying for us, because it adds extra work for the volunteers who manage those systems, and reduces the signal/noise ratio in our communication channels.
+    *   To be eligible for a bounty, all of these guidelines must be followed.
+*   Be Patient - Give us a reasonable time to correct the issue before you disclose the vulnerability.
+
+We also expect you to comply with all applicable laws. You're responsible to pay any taxes associated with your bounties.

activitypub.php

@@ -3,9 +3,9 @@
  * Plugin Name: ActivityPub
  * Plugin URI: https://github.com/pfefferle/wordpress-activitypub/
  * Description: The ActivityPub protocol is a decentralized social networking protocol based upon the ActivityStreams 2.0 data format.
- * Version: 0.9.1
- * Author: Matthias Pfefferle
- * Author URI: https://notiz.blog/
+ * Version: 1.2.0
+ * Author: Matthias Pfefferle & Automattic
+ * Author URI: https://automattic.com/
  * License: MIT
  * License URI: http://opensource.org/licenses/MIT
  * Requires PHP: 5.6
@@ -15,81 +15,203 @@
 
 namespace Activitypub;
 
-/**
- * Initialize plugin
- */
-function init() {
-	\defined( 'ACTIVITYPUB_HASHTAGS_REGEXP' ) || \define( 'ACTIVITYPUB_HASHTAGS_REGEXP', '(?:(?<=\s)|^)#(\w*[A-Za-z_]+\w*)' );
+use function Activitypub\is_blog_public;
+use function Activitypub\site_supports_blocks;
 
-	require_once \dirname( __FILE__ ) . '/includes/table/followers-list.php';
-	require_once \dirname( __FILE__ ) . '/includes/class-signature.php';
-	require_once \dirname( __FILE__ ) . '/includes/peer/class-followers.php';
-	require_once \dirname( __FILE__ ) . '/includes/functions.php';
-
-	require_once \dirname( __FILE__ ) . '/includes/class-activity-dispatcher.php';
-	\Activitypub\Activity_Dispatcher::init();
-
-	require_once \dirname( __FILE__ ) . '/includes/model/class-activity.php';
-	require_once \dirname( __FILE__ ) . '/includes/model/class-post.php';
-	\Activitypub\Model\Post::init();
-
-	require_once \dirname( __FILE__ ) . '/includes/class-activitypub.php';
-	\Activitypub\Activitypub::init();
-
-	// Configure the REST API route
-	require_once \dirname( __FILE__ ) . '/includes/rest/class-outbox.php';
-	\Activitypub\Rest\Outbox::init();
-
-	require_once \dirname( __FILE__ ) . '/includes/rest/class-inbox.php';
-	\Activitypub\Rest\Inbox::init();
-
-	require_once \dirname( __FILE__ ) . '/includes/rest/class-followers.php';
-	\Activitypub\Rest\Followers::init();
-
-	require_once \dirname( __FILE__ ) . '/includes/rest/class-following.php';
-	\Activitypub\Rest\Following::init();
-
-	require_once \dirname( __FILE__ ) . '/includes/rest/class-webfinger.php';
-	\Activitypub\Rest\Webfinger::init();
-
-	require_once \dirname( __FILE__ ) . '/includes/rest/class-nodeinfo.php';
-	\Activitypub\Rest\NodeInfo::init();
-
-	require_once \dirname( __FILE__ ) . '/includes/class-admin.php';
-	\Activitypub\Admin::init();
-
-	require_once \dirname( __FILE__ ) . '/includes/class-hashtag.php';
-	\Activitypub\Hashtag::init();
-
-	require_once \dirname( __FILE__ ) . '/includes/class-debug.php';
-	\Activitypub\Debug::init();
-
-	require_once \dirname( __FILE__ ) . '/includes/class-health-check.php';
-	\Activitypub\Health_Check::init();
-}
-add_action( 'plugins_loaded', '\Activitypub\init' );
+require_once __DIR__ . '/includes/compat.php';
+require_once __DIR__ . '/includes/functions.php';
 
 /**
- * Add rewrite rules
+ * Initialize the plugin constants.
  */
-function add_rewrite_rules() {
-	if ( ! \class_exists( 'Webfinger' ) ) {
-		\add_rewrite_rule( '^.well-known/webfinger', 'index.php?rest_route=/activitypub/1.0/webfinger', 'top' );
-	}
+\defined( 'ACTIVITYPUB_REST_NAMESPACE' ) || \define( 'ACTIVITYPUB_REST_NAMESPACE', 'activitypub/1.0' );
+\defined( 'ACTIVITYPUB_EXCERPT_LENGTH' ) || \define( 'ACTIVITYPUB_EXCERPT_LENGTH', 400 );
+\defined( 'ACTIVITYPUB_SHOW_PLUGIN_RECOMMENDATIONS' ) || \define( 'ACTIVITYPUB_SHOW_PLUGIN_RECOMMENDATIONS', true );
+\defined( 'ACTIVITYPUB_MAX_IMAGE_ATTACHMENTS' ) || \define( 'ACTIVITYPUB_MAX_IMAGE_ATTACHMENTS', 3 );
+\defined( 'ACTIVITYPUB_HASHTAGS_REGEXP' ) || \define( 'ACTIVITYPUB_HASHTAGS_REGEXP', '(?:(?<=\s)|(?<=<p>)|(?<=<br>)|^)#([A-Za-z0-9_]+)(?:(?=\s|[[:punct:]]|$))' );
+\defined( 'ACTIVITYPUB_USERNAME_REGEXP' ) || \define( 'ACTIVITYPUB_USERNAME_REGEXP', '(?:([A-Za-z0-9_-]+)@((?:[A-Za-z0-9_-]+\.)+[A-Za-z]+))' );
+\defined( 'ACTIVITYPUB_CUSTOM_POST_CONTENT' ) || \define( 'ACTIVITYPUB_CUSTOM_POST_CONTENT', "<strong>[ap_title]</strong>\n\n[ap_content]\n\n[ap_hashtags]\n\n[ap_shortlink]" );
+\defined( 'ACTIVITYPUB_AUTHORIZED_FETCH' ) || \define( 'ACTIVITYPUB_AUTHORIZED_FETCH', false );
+\defined( 'ACTIVITYPUB_DISABLE_REWRITES' ) || \define( 'ACTIVITYPUB_DISABLE_REWRITES', false );
+\defined( 'ACTIVITYPUB_DEFAULT_TRANSFORMER' ) || \define( 'ACTIVITYPUB_DEFAULT_TRANSFORMER', 'activitypub/default' );
+
+
+\define( 'ACTIVITYPUB_PLUGIN_DIR', plugin_dir_path( __FILE__ ) );
+\define( 'ACTIVITYPUB_PLUGIN_BASENAME', plugin_basename( __FILE__ ) );
+\define( 'ACTIVITYPUB_PLUGIN_FILE', plugin_dir_path( __FILE__ ) . '/' . basename( __FILE__ ) );
+\define( 'ACTIVITYPUB_PLUGIN_URL', plugin_dir_url( __FILE__ ) );
 
-	if ( ! \class_exists( 'Nodeinfo' ) ) {
-		\add_rewrite_rule( '^.well-known/nodeinfo', 'index.php?rest_route=/activitypub/1.0/nodeinfo/discovery', 'top' );
-		\add_rewrite_rule( '^.well-known/x-nodeinfo2', 'index.php?rest_route=/activitypub/1.0/nodeinfo2', 'top' );
-	}
-}
-\add_action( 'init', '\Activitypub\add_rewrite_rules', 1 );
 
 /**
- * Flush rewrite rules;
+ * Initialize REST routes.
  */
-function flush_rewrite_rules() {
-	\Activitypub\add_rewrite_rules();
-	\flush_rewrite_rules();
+function rest_init() {
+	Rest\Users::init();
+	Rest\Outbox::init();
+	Rest\Inbox::init();
+	Rest\Followers::init();
+	Rest\Following::init();
+	Rest\Webfinger::init();
+	Rest\Server::init();
+	Rest\Collection::init();
+
+	// load NodeInfo endpoints only if blog is public
+	if ( is_blog_public() ) {
+		Rest\NodeInfo::init();
+	}
+}
+\add_action( 'rest_api_init', __NAMESPACE__ . '\rest_init' );
+
+/**
+ * Initialize plugin.
+ */
+function plugin_init() {
+	\add_action( 'init', array( __NAMESPACE__ . '\Migration', 'init' ) );
+	\add_action( 'init', array( __NAMESPACE__ . '\Activitypub', 'init' ) );
+	\add_action( 'init', array( __NAMESPACE__ . '\Activity_Dispatcher', 'init' ) );
+	\add_action( 'init', array( __NAMESPACE__ . '\Collection\Followers', 'init' ) );
+	\add_action( 'init', array( __NAMESPACE__ . '\Admin', 'init' ) );
+	\add_action( 'init', array( __NAMESPACE__ . '\Hashtag', 'init' ) );
+	\add_action( 'init', array( __NAMESPACE__ . '\Mention', 'init' ) );
+	\add_action( 'init', array( __NAMESPACE__ . '\Health_Check', 'init' ) );
+	\add_action( 'init', array( __NAMESPACE__ . '\Scheduler', 'init' ) );
+
+	if ( site_supports_blocks() ) {
+		\add_action( 'init', array( __NAMESPACE__ . '\Blocks', 'init' ) );
+	}
+
+	$debug_file = __DIR__ . '/includes/debug.php';
+	if ( \WP_DEBUG && file_exists( $debug_file ) && is_readable( $debug_file ) ) {
+		require_once $debug_file;
+		Debug::init();
+	}
+
+	require_once __DIR__ . '/integration/class-webfinger.php';
+	Integration\Webfinger::init();
+
+	require_once __DIR__ . '/integration/class-nodeinfo.php';
+	Integration\Nodeinfo::init();
+}
+\add_action( 'plugins_loaded', __NAMESPACE__ . '\plugin_init' );
+
+/**
+ * Class Autoloader
+ */
+\spl_autoload_register(
+	function ( $full_class ) {
+		$base_dir = __DIR__ . '/includes/';
+		$base     = 'Activitypub\\';
+
+		if ( strncmp( $full_class, $base, strlen( $base ) ) === 0 ) {
+			$maybe_uppercase = str_replace( $base, '', $full_class );
+			$class = strtolower( $maybe_uppercase );
+			// All classes should be capitalized. If this is instead looking for a lowercase method, we ignore that.
+			if ( $maybe_uppercase === $class ) {
+				return;
+			}
+
+			if ( false !== strpos( $class, '\\' ) ) {
+				$parts    = explode( '\\', $class );
+				$class    = array_pop( $parts );
+				$sub_dir  = implode( '/', $parts );
+				$base_dir = $base_dir . $sub_dir . '/';
+			}
+
+			$filename = 'class-' . strtr( $class, '_', '-' );
+			$file     = $base_dir . $filename . '.php';
+
+			if ( file_exists( $file ) && is_readable( $file ) ) {
+				require_once $file;
+			} else {
+				// translators: %s is the class name
+				\wp_die( sprintf( esc_html__( 'Required class not found or not readable: %s', 'activitypub' ), esc_html( $full_class ) ) );
+			}
+		}
+	}
+);
+
+/**
+ * Add plugin settings link
+ */
+function plugin_settings_link( $actions ) {
+	$settings_link = array();
+	$settings_link[] = \sprintf(
+		'<a href="%1s">%2s</a>',
+		\menu_page_url( 'activitypub', false ),
+		\__( 'Settings', 'activitypub' )
+	);
+
+	return \array_merge( $settings_link, $actions );
+}
+\add_filter( 'plugin_action_links_' . plugin_basename( __FILE__ ), __NAMESPACE__ . '\plugin_settings_link' );
+
+\register_activation_hook(
+	__FILE__,
+	array(
+		__NAMESPACE__ . '\Activitypub',
+		'activate',
+	)
+);
+
+\register_deactivation_hook(
+	__FILE__,
+	array(
+		__NAMESPACE__ . '\Activitypub',
+		'deactivate',
+	)
+);
+
+\register_uninstall_hook(
+	__FILE__,
+	array(
+		__NAMESPACE__ . '\Activitypub',
+		'uninstall',
+	)
+);
+
+/**
+ * Only load code that needs BuddyPress to run once BP is loaded and initialized.
+ */
+add_action(
+	'bp_include',
+	function() {
+		require_once __DIR__ . '/integration/class-buddypress.php';
+		Integration\Buddypress::init();
+	},
+	0
+);
+
+/**
+ * `get_plugin_data` wrapper
+ *
+ * @return array The plugin metadata array
+ */
+function get_plugin_meta( $default_headers = array() ) {
+	if ( ! $default_headers ) {
+		$default_headers = array(
+			'Name'        => 'Plugin Name',
+			'PluginURI'   => 'Plugin URI',
+			'Version'     => 'Version',
+			'Description' => 'Description',
+			'Author'      => 'Author',
+			'AuthorURI'   => 'Author URI',
+			'TextDomain'  => 'Text Domain',
+			'DomainPath'  => 'Domain Path',
+			'Network'     => 'Network',
+			'RequiresWP'  => 'Requires at least',
+			'RequiresPHP' => 'Requires PHP',
+			'UpdateURI'   => 'Update URI',
+		);
+	}
+
+	return \get_file_data( __FILE__, $default_headers, 'plugin' );
+}
+
+/**
+ * Plugin Version Number used for caching.
+ */
+function get_plugin_version() {
+	$meta = get_plugin_meta( array( 'Version' => 'Version' ) );
+
+	return $meta['Version'];
 }
-\register_activation_hook( __FILE__, '\Activitypub\flush_rewrite_rules' );
-\register_deactivation_hook( __FILE__, '\flush_rewrite_rules' );

assets/css/activitypub-admin.css

@@ -0,0 +1,199 @@
+.activitypub-settings {
+	max-width: 800px;
+	margin: 0 auto;
+}
+
+.settings_page_activitypub .notice {
+	max-width: 800px;
+	margin: auto;
+	margin: 0px auto 30px;
+}
+
+.settings_page_activitypub .wrap {
+	padding-left: 22px;
+}
+
+.activitypub-settings-header {
+	text-align: center;
+	margin: 0 0 1rem;
+	background: #fff;
+	border-bottom: 1px solid #dcdcde;
+}
+
+.activitypub-settings-title-section {
+	display: flex;
+	align-items: center;
+	justify-content: center;
+	clear: both;
+	padding-top: 8px;
+}
+
+.settings_page_activitypub #wpcontent {
+	padding-left: 0;
+}
+
+.activitypub-settings-tabs-wrapper {
+	display: -ms-inline-grid;
+	-ms-grid-columns: auto auto auto;
+	vertical-align: top;
+	display: inline-grid;
+	grid-template-columns: auto auto auto;
+}
+
+.activitypub-settings-tab.active {
+	box-shadow: inset 0 -3px #3582c4;
+	font-weight: 600;
+}
+
+.activitypub-settings-tab {
+	display: block;
+	text-decoration: none;
+	color: inherit;
+	padding: .5rem 1rem 1rem;
+	margin: 0 1rem;
+	transition: box-shadow .5s ease-in-out;
+}
+
+.wp-header-end {
+	visibility: hidden;
+	margin: -2px 0 0;
+}
+
+summary {
+	cursor: pointer;
+	text-decoration: underline;
+	color: #2271b1;
+}
+
+.activitypub-settings-accordion {
+	border: 1px solid #c3c4c7;
+}
+
+.activitypub-settings-accordion-heading {
+	margin: 0;
+	border-top: 1px solid #c3c4c7;
+	font-size: inherit;
+	line-height: inherit;
+	font-weight: 600;
+	color: inherit;
+}
+
+.activitypub-settings-accordion-heading:first-child {
+	border-top: none;
+}
+
+.activitypub-settings-accordion-panel {
+	margin: 0;
+	padding: 1em 1.5em;
+	background: #fff;
+}
+
+.activitypub-settings-accordion-trigger {
+	background: #fff;
+	border: 0;
+	color: #2c3338;
+	cursor: pointer;
+	display: flex;
+	font-weight: 400;
+	margin: 0;
+	padding: 1em 3.5em 1em 1.5em;
+	min-height: 46px;
+	position: relative;
+	text-align: left;
+	width: 100%;
+	align-items: center;
+	justify-content: space-between;
+	-webkit-user-select: auto;
+	user-select: auto;
+}
+
+.activitypub-settings-accordion-trigger {
+	color: #2c3338;
+	cursor: pointer;
+	font-weight: 400;
+	text-align: left;
+}
+
+.activitypub-settings-accordion-trigger .title {
+	pointer-events: none;
+	font-weight: 600;
+	flex-grow: 1;
+}
+
+.activitypub-settings-accordion-trigger .icon,
+.activitypub-settings-accordion-viewed .icon {
+	border: solid #50575e medium;
+	border-width: 0 2px 2px 0;
+	height: .5rem;
+	pointer-events: none;
+	position: absolute;
+	right: 1.5em;
+	top: 50%;
+	transform: translateY(-70%) rotate(45deg);
+	width: .5rem;
+}
+
+.activitypub-settings-accordion-trigger[aria-expanded="true"] .icon {
+	transform: translateY(-30%) rotate(-135deg);
+}
+
+.activitypub-settings-accordion-trigger:active,
+.activitypub-settings-accordion-trigger:hover {
+	background: #f6f7f7;
+}
+
+.activitypub-settings-accordion-trigger:focus {
+	color: #1d2327;
+	border: none;
+	box-shadow: none;
+	outline-offset: -1px;
+	outline: 2px solid #2271b1;
+	background-color: #f6f7f7;
+}
+
+.activitypub-settings
+input.blog-user-identifier {
+	text-align: right;
+}
+
+.activitypub-settings
+.header-image {
+	width: 100%;
+	height: 80px;
+	position: relative;
+	display: block;
+	margin-bottom: 40px;
+	background-image: rgb(168,165,175);
+	background-image: linear-gradient(180deg, red, yellow);
+	background-size: cover;
+}
+
+.activitypub-settings
+.logo {
+	height: 80px;
+	width: 80px;
+	position: relative;
+	top: 40px;
+	left: 40px;
+}
+
+.settings_page_activitypub .box  {
+	border: 1px solid #c3c4c7;
+	background-color: #fff;
+	padding: 1em 1.5em;
+	margin-bottom: 1.5em;
+}
+
+.settings_page_activitypub .activitypub-welcome-page .box label {
+	font-weight: bold;
+}
+
+.settings_page_activitypub .activitypub-welcome-page input {
+	font-size: 20px;
+	width: 95%;
+}
+
+.settings_page_activitypub .plugin-recommendations {
+	border-bottom: none;
+	margin-bottom: 0;
+}

assets/js/activitypub-admin.js

@@ -0,0 +1,20 @@
+jQuery( function( $ ) {
+	// Accordion handling in various areas.
+	$( '.activitypub-settings-accordion' ).on( 'click', '.activitypub-settings-accordion-trigger', function() {
+		var isExpanded = ( 'true' === $( this ).attr( 'aria-expanded' ) );
+
+		if ( isExpanded ) {
+			$( this ).attr( 'aria-expanded', 'false' );
+			$( '#' + $( this ).attr( 'aria-controls' ) ).attr( 'hidden', true );
+		} else {
+			$( this ).attr( 'aria-expanded', 'true' );
+			$( '#' + $( this ).attr( 'aria-controls' ) ).attr( 'hidden', false );
+		}
+	} );
+	
+	$(document).on( 'wp-plugin-install-success', function( event, response ) {
+		setTimeout( function() {
+			$( '.activate-now' ).removeClass( 'thickbox open-plugin-details-modal' );
+		}, 1200 );
+	} );	
+} );

bin/deploy.sh

@@ -1,82 +0,0 @@
-#!/usr/bin/env bash
-
-set -e
-
-if [[ "false" != "$TRAVIS_PULL_REQUEST" ]]; then
-	echo "Not deploying pull requests."
-	exit
-fi
-
-if [[ ! $WP_PLUGIN_DEPLOY ]]; then
-	echo "Not deploying."
-	exit
-fi
-
-if [[ ! $SVN_REPO ]]; then
-	echo "SVN repo is not specified."
-	exit
-fi
-
-# Untrailing slash of SVN_REPO path
-SVN_REPO=`echo $SVN_REPO | sed -e "s/\/$//"`
-# Git repository
-GH_REF=https://github.com/${TRAVIS_REPO_SLUG}.git
-
-echo "Starting deploy..."
-
-mkdir build
-
-cd build
-BASE_DIR=$(pwd)
-
-echo "Checking out trunk from $SVN_REPO ..."
-svn co -q $SVN_REPO/trunk
-
-echo "Getting clone from $GH_REF to $SVN_REPO ..."
-git clone -q $GH_REF ./git
-
-cd ./git
-
-if [ -e "bin/build.sh" ]; then
-	echo "Starting bin/build.sh."
-	bash bin/build.sh
-fi
-
-cd $BASE_DIR
-
-echo "Syncing git repository to svn"
-rsync -a --exclude=".svn" --checksum --delete ./git/ ./trunk/
-rm -fr ./git
-
-cd ./trunk
-
-if [ -e ".distignore" ]; then
-	echo "svn propset form .distignore"
-	svn propset -q -R svn:ignore -F .distignore .
-
-else
-	if [ -e ".svnignore" ]; then
-		echo "svn propset"
-		svn propset -q -R svn:ignore -F .svnignore .
-	fi
-fi
-
-echo "Run svn del"
-svn st | grep '^!' | sed -e 's/\![ ]*/svn del -q /g' | sh
-echo "Run svn add"
-svn st | grep '^?' | sed -e 's/\?[ ]*/svn add -q /g' | sh
-
-# If tag number and credentials are provided, commit to trunk.
-if [[ $TRAVIS_TAG && $SVN_USER && $SVN_PASS ]]; then
-	if [[ ! -d tags/$TRAVIS_TAG ]]; then
-		echo "Commit to $SVN_REPO."
-		svn commit -m "commit version $TRAVIS_TAG" --username $SVN_USER --password $SVN_PASS --non-interactive 2>/dev/null
-		echo "Take snapshot of $TRAVIS_TAG"
-		svn copy $SVN_REPO/trunk $SVN_REPO/tags/$TRAVIS_TAG -m "Take snapshot of $TRAVIS_TAG" --username $SVN_USER --password $SVN_PASS --non-interactive 2>/dev/null
-	else
-		echo "tags/$TRAVIS_TAG already exists."
-	fi
-else
-	echo "Nothing to commit and check \`svn st\`."
-	svn st
-fi

bin/install-wp-tests.sh

@@ -25,7 +25,11 @@ download() {
     fi
 }
 
-if [[ $WP_VERSION =~ ^[0-9]+\.[0-9]+$ ]]; then
+if [[ $WP_VERSION =~ ^[0-9]+\.[0-9]+\-(beta|RC)[0-9]+$ ]]; then
+	WP_BRANCH=${WP_VERSION%\-*}
+	WP_TESTS_TAG="branches/$WP_BRANCH"
+
+elif [[ $WP_VERSION =~ ^[0-9]+\.[0-9]+$ ]]; then
 	WP_TESTS_TAG="branches/$WP_VERSION"
 elif [[ $WP_VERSION =~ [0-9]+\.[0-9]+\.[0-9]+ ]]; then
 	if [[ $WP_VERSION =~ [0-9]+\.[0-9]+\.[0] ]]; then
@@ -47,7 +51,6 @@ else
 	fi
 	WP_TESTS_TAG="tags/$LATEST_VERSION"
 fi
-
 set -ex
 
 install_wp() {
@@ -104,8 +107,8 @@ install_test_suite() {
 	if [ ! -d $WP_TESTS_DIR ]; then
 		# set up testing suite
 		mkdir -p $WP_TESTS_DIR
-		svn co --quiet https://develop.svn.wordpress.org/${WP_TESTS_TAG}/tests/phpunit/includes/ $WP_TESTS_DIR/includes
-		svn co --quiet https://develop.svn.wordpress.org/${WP_TESTS_TAG}/tests/phpunit/data/ $WP_TESTS_DIR/data
+		svn co --quiet --ignore-externals https://develop.svn.wordpress.org/${WP_TESTS_TAG}/tests/phpunit/includes/ $WP_TESTS_DIR/includes
+		svn co --quiet --ignore-externals https://develop.svn.wordpress.org/${WP_TESTS_TAG}/tests/phpunit/data/ $WP_TESTS_DIR/data
 	fi
 
 	if [ ! -f wp-tests-config.php ]; then
@@ -113,6 +116,7 @@ install_test_suite() {
 		# remove all forward slashes in the end
 		WP_CORE_DIR=$(echo $WP_CORE_DIR | sed "s:/\+$::")
 		sed $ioption "s:dirname( __FILE__ ) . '/src/':'$WP_CORE_DIR/':" "$WP_TESTS_DIR"/wp-tests-config.php
+		sed $ioption "s:__DIR__ . '/src/':'$WP_CORE_DIR/':" "$WP_TESTS_DIR"/wp-tests-config.php
 		sed $ioption "s/youremptytestdbnamehere/$DB_NAME/" "$WP_TESTS_DIR"/wp-tests-config.php
 		sed $ioption "s/yourusernamehere/$DB_USER/" "$WP_TESTS_DIR"/wp-tests-config.php
 		sed $ioption "s/yourpasswordhere/$DB_PASS/" "$WP_TESTS_DIR"/wp-tests-config.php
@@ -121,6 +125,23 @@ install_test_suite() {
 
 }
 
+recreate_db() {
+	shopt -s nocasematch
+	if [[ $1 =~ ^(y|yes)$ ]]
+	then
+		mysqladmin drop $DB_NAME -f --user="$DB_USER" --password="$DB_PASS"$EXTRA
+		create_db
+		echo "Recreated the database ($DB_NAME)."
+	else
+		echo "Leaving the existing database ($DB_NAME) in place."
+	fi
+	shopt -u nocasematch
+}
+
+create_db() {
+	mysqladmin create $DB_NAME --user="$DB_USER" --password="$DB_PASS"$EXTRA
+}
+
 install_db() {
 
 	if [ ${SKIP_DB_CREATE} = "true" ]; then
@@ -144,7 +165,14 @@ install_db() {
 	fi
 
 	# create database
-	mysqladmin create $DB_NAME --user="$DB_USER" --password="$DB_PASS"$EXTRA
+	if [ $(mysql --user="$DB_USER" --password="$DB_PASS" --execute='show databases;' | grep ^$DB_NAME$) ]
+	then
+		echo "Reinstalling will delete the existing test database ($DB_NAME)"
+		read -p 'Are you sure you want to proceed? [y/N]: ' DELETE_EXISTING_DB
+		recreate_db $DELETE_EXISTING_DB
+	else
+		create_db
+	fi
 }
 
 install_wp

build/follow-me/block.json

@@ -0,0 +1,47 @@
+{
+  "$schema": "https://schemas.wp.org/trunk/block.json",
+  "name": "activitypub/follow-me",
+  "apiVersion": 3,
+  "version": "1.0.0",
+  "title": "Follow me on the Fediverse",
+  "category": "widgets",
+  "description": "Display your Fediverse profile so that visitors can follow you.",
+  "textdomain": "activitypub",
+  "icon": "groups",
+  "supports": {
+    "html": false,
+    "color": {
+      "gradients": true,
+      "link": true,
+      "__experimentalDefaultControls": {
+        "background": true,
+        "text": true,
+        "link": true
+      }
+    },
+    "__experimentalBorder": {
+      "radius": true,
+      "width": true,
+      "color": true,
+      "style": true
+    },
+    "typography": {
+      "fontSize": true,
+      "__experimentalDefaultControls": {
+        "fontSize": true
+      }
+    }
+  },
+  "attributes": {
+    "selectedUser": {
+      "type": "string",
+      "default": "site"
+    }
+  },
+  "editorScript": "file:./index.js",
+  "viewScript": "file:./view.js",
+  "style": [
+    "file:./style-index.css",
+    "wp-components"
+  ]
+}

build/follow-me/index.asset.php

@@ -0,0 +1 @@
+<?php return array('dependencies' => array('wp-api-fetch', 'wp-block-editor', 'wp-blocks', 'wp-components', 'wp-compose', 'wp-data', 'wp-element', 'wp-i18n', 'wp-primitives'), 'version' => '2a185b1c488886051601');

build/follow-me/style-index.css

@@ -0,0 +1 @@
+.activitypub-follow-me-block-wrapper{width:100%}.activitypub-follow-me-block-wrapper.has-background .activitypub-profile,.activitypub-follow-me-block-wrapper.has-border-color .activitypub-profile{padding-left:1rem;padding-right:1rem}.activitypub-follow-me-block-wrapper .activitypub-profile{align-items:center;display:flex;padding:1rem 0}.activitypub-follow-me-block-wrapper .activitypub-profile .activitypub-profile__avatar{border-radius:50%;height:75px;margin-right:1rem;width:75px}.activitypub-follow-me-block-wrapper .activitypub-profile .activitypub-profile__content{flex:1;min-width:0}.activitypub-follow-me-block-wrapper .activitypub-profile .activitypub-profile__handle,.activitypub-follow-me-block-wrapper .activitypub-profile .activitypub-profile__name{line-height:1.2;margin:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.activitypub-follow-me-block-wrapper .activitypub-profile .activitypub-profile__name{font-size:1.25em}.activitypub-follow-me-block-wrapper .activitypub-profile .activitypub-profile__follow{align-self:center;background-color:var(--wp--preset--color--black);color:var(--wp--preset--color--white);margin-left:1rem}.activitypub-profile__confirm.components-modal__frame{background-color:#f7f7f7;color:#333}.activitypub-profile__confirm.components-modal__frame .components-modal__header-heading,.activitypub-profile__confirm.components-modal__frame h4{color:#333;letter-spacing:inherit;word-spacing:inherit}.activitypub-follow-me__dialog{max-width:30em}.activitypub-follow-me__dialog h4{line-height:1;margin:0}.activitypub-follow-me__dialog .apmfd__section{margin-bottom:2em}.activitypub-follow-me__dialog .apfmd-description{font-size:var(--wp--preset--font-size--normal,.75rem);margin:.33em 0 1em}.activitypub-follow-me__dialog .apfmd__button-group{align-items:flex-end;display:flex;justify-content:flex-end}.activitypub-follow-me__dialog .apfmd__button-group svg{height:21px;margin-right:.5em;width:21px}.activitypub-follow-me__dialog .apfmd__button-group input{background-color:var(--wp--preset--color--white);border:1px solid var(--wp--preset--color--black);color:var(--wp--preset--color--black);flex:1;padding:6px 12px}

build/follow-me/view.asset.php

@@ -0,0 +1 @@
+<?php return array('dependencies' => array('wp-api-fetch', 'wp-components', 'wp-compose', 'wp-dom-ready', 'wp-element', 'wp-i18n', 'wp-primitives'), 'version' => '17a158ceced1355cc8ea');

build/followers/block.json

@@ -0,0 +1,57 @@
+{
+  "$schema": "https://schemas.wp.org/trunk/block.json",
+  "name": "activitypub/followers",
+  "apiVersion": 3,
+  "version": "1.0.0",
+  "title": "Fediverse Followers",
+  "category": "widgets",
+  "description": "Display your followers from the Fediverse on your website.",
+  "textdomain": "activitypub",
+  "icon": "groups",
+  "supports": {
+    "html": false
+  },
+  "attributes": {
+    "title": {
+      "type": "string",
+      "default": "Fediverse Followers"
+    },
+    "selectedUser": {
+      "type": "string",
+      "default": "site"
+    },
+    "per_page": {
+      "type": "number",
+      "default": 10
+    },
+    "order": {
+      "type": "string",
+      "default": "desc",
+      "enum": [
+        "asc",
+        "desc"
+      ]
+    }
+  },
+  "styles": [
+    {
+      "name": "default",
+      "label": "No Lines",
+      "isDefault": true
+    },
+    {
+      "name": "with-lines",
+      "label": "Lines"
+    },
+    {
+      "name": "compact",
+      "label": "Compact"
+    }
+  ],
+  "editorScript": "file:./index.js",
+  "viewScript": "file:./view.js",
+  "style": [
+    "file:./style-view.css",
+    "wp-block-query-pagination"
+  ]
+}

build/followers/index.asset.php

@@ -0,0 +1 @@
+<?php return array('dependencies' => array('react', 'wp-api-fetch', 'wp-block-editor', 'wp-blocks', 'wp-components', 'wp-data', 'wp-element', 'wp-i18n', 'wp-primitives', 'wp-url'), 'version' => '1cbd9cbfcbd7fc813429');

build/followers/index.js

@@ -0,0 +1,3 @@
+(()=>{var e={184:(e,t)=>{var a;!function(){"use strict";var n={}.hasOwnProperty;function l(){for(var e=[],t=0;t<arguments.length;t++){var a=arguments[t];if(a){var r=typeof a;if("string"===r||"number"===r)e.push(a);else if(Array.isArray(a)){if(a.length){var o=l.apply(null,a);o&&e.push(o)}}else if("object"===r){if(a.toString!==Object.prototype.toString&&!a.toString.toString().includes("[native code]")){e.push(a.toString());continue}for(var i in a)n.call(a,i)&&a[i]&&e.push(i)}}}return e.join(" ")}e.exports?(l.default=l,e.exports=l):void 0===(a=function(){return l}.apply(t,[]))||(e.exports=a)}()}},t={};function a(n){var l=t[n];if(void 0!==l)return l.exports;var r=t[n]={exports:{}};return e[n](r,r.exports,a),r.exports}a.n=e=>{var t=e&&e.__esModule?()=>e.default:()=>e;return a.d(t,{a:t}),t},a.d=(e,t)=>{for(var n in t)a.o(t,n)&&!a.o(e,n)&&Object.defineProperty(e,n,{enumerable:!0,get:t[n]})},a.o=(e,t)=>Object.prototype.hasOwnProperty.call(e,t),(()=>{"use strict";const e=window.wp.blocks,t=window.wp.element,n=window.wp.primitives,l=(0,t.createElement)(n.SVG,{xmlns:"http://www.w3.org/2000/svg",viewBox:"0 0 24 24"},(0,t.createElement)(n.Path,{d:"M15.5 9.5a1 1 0 100-2 1 1 0 000 2zm0 1.5a2.5 2.5 0 100-5 2.5 2.5 0 000 5zm-2.25 6v-2a2.75 2.75 0 00-2.75-2.75h-4A2.75 2.75 0 003.75 15v2h1.5v-2c0-.69.56-1.25 1.25-1.25h4c.69 0 1.25.56 1.25 1.25v2h1.5zm7-2v2h-1.5v-2c0-.69-.56-1.25-1.25-1.25H15v-1.5h2.5A2.75 2.75 0 0120.25 15zM9.5 8.5a1 1 0 11-2 0 1 1 0 012 0zm1.5 0a2.5 2.5 0 11-5 0 2.5 2.5 0 015 0z",fillRule:"evenodd"}));function r(){return r=Object.assign?Object.assign.bind():function(e){for(var t=1;t<arguments.length;t++){var a=arguments[t];for(var n in a)Object.prototype.hasOwnProperty.call(a,n)&&(e[n]=a[n])}return e},r.apply(this,arguments)}const o=window.wp.components,i=window.wp.blockEditor,c=window.wp.i18n,s=window.React,p=window.wp.apiFetch;var u=a.n(p);const v=window.wp.url;var m=a(184),b=a.n(m);function w(e){let{active:a,children:n,page:l,pageClick:r,className:o}=e;const i=b()("wp-block activitypub-pager",o,{current:a});return(0,t.createElement)("a",{className:i,onClick:e=>{e.preventDefault(),!a&&r(l)}},n)}const d={outlined:"outlined",minimal:"minimal"};function f(e){let{compact:a,nextLabel:n,page:l,pageClick:r,perPage:o,prevLabel:i,total:c,variant:s=d.outlined}=e;const p=((e,t)=>{let a=[1,e-2,e-1,e,e+1,e+2,t];a.sort(((e,t)=>e-t)),a=a.filter(((e,a,n)=>e>=1&&e<=t&&n.lastIndexOf(e)===a));for(let e=a.length-2;e>=0;e--)a[e]===a[e+1]&&a.splice(e+1,1);return a})(l,Math.ceil(c/o)),u=b()("alignwide wp-block-query-pagination is-content-justification-space-between is-layout-flex wp-block-query-pagination-is-layout-flex",`is-${s}`,{"is-compact":a});return(0,t.createElement)("nav",{className:u},i&&(0,t.createElement)(w,{key:"prev",page:l-1,pageClick:r,active:1===l,"aria-label":i,className:"wp-block-query-pagination-previous block-editor-block-list__block"},i),!a&&(0,t.createElement)("div",{className:"block-editor-block-list__block wp-block wp-block-query-pagination-numbers"},p.map((e=>(0,t.createElement)(w,{key:e,page:e,pageClick:r,active:e===l,className:"page-numbers"},e)))),n&&(0,t.createElement)(w,{key:"next",page:l+1,pageClick:r,active:l===Math.ceil(c/o),"aria-label":n,className:"wp-block-query-pagination-next block-editor-block-list__block"},n))}const{namespace:g}=window._activityPubOptions;function y(e){let{selectedUser:a,per_page:n,order:l,title:o,page:i,setPage:p,className:m="",followLinks:b=!0,followerData:w=!1}=e;const d="site"===a?0:a,[y,k]=(0,s.useState)([]),[E,_]=(0,s.useState)(0),[x,C]=(0,s.useState)(0),[S,O]=function(){const[e,t]=(0,s.useState)(1);return[e,t]}(),N=i||S,P=p||O,L=(0,t.createInterpolateElement)(/* translators: arrow for previous followers link */
+(0,c.__)("<span>←</span> Less","activitypub"),{span:(0,t.createElement)("span",{class:"wp-block-query-pagination-previous-arrow is-arrow-arrow","aria-hidden":"true"})}),j=(0,t.createInterpolateElement)(/* translators: arrow for next followers link */
+(0,c.__)("More <span>→</span>","activitypub"),{span:(0,t.createElement)("span",{class:"wp-block-query-pagination-next-arrow is-arrow-arrow","aria-hidden":"true"})}),M=(e,t)=>{k(e),C(t),_(Math.ceil(t/n))};return(0,s.useEffect)((()=>{if(w&&1===N)return M(w.followers,w.total);const e=function(e,t,a,n){const l=`/${g}/users/${e}/followers`,r={per_page:t,order:a,page:n,context:"full"};return(0,v.addQueryArgs)(l,r)}(d,n,l,N);u()({path:e}).then((e=>M(e.orderedItems,e.totalItems))).catch((()=>{}))}),[d,n,l,N,w]),(0,t.createElement)("div",{className:"activitypub-follower-block "+m},(0,t.createElement)("h3",null,o),(0,t.createElement)("ul",null,y&&y.map((e=>(0,t.createElement)("li",{key:e.url},(0,t.createElement)(h,r({},e,{followLinks:b})))))),E>1&&(0,t.createElement)(f,{page:N,perPage:n,total:x,pageClick:P,nextLabel:j,prevLabel:L,compact:"is-style-compact"===m}))}function h(e){let{name:a,icon:n,url:l,preferredUsername:i,followLinks:c=!0}=e;const s=`@${i}`,p={};return c||(p.onClick=e=>e.preventDefault()),(0,t.createElement)(o.ExternalLink,r({className:"activitypub-link",href:l,title:s},p),(0,t.createElement)("img",{width:"40",height:"40",src:n.url,class:"avatar activitypub-avatar"}),(0,t.createElement)("span",{class:"activitypub-actor"},(0,t.createElement)("strong",{className:"activitypub-name"},a),(0,t.createElement)("span",{class:"sep"},"/"),(0,t.createElement)("span",{class:"activitypub-handle"},s)))}const k=window.wp.data,E=window._activityPubOptions?.enabled;(0,e.registerBlockType)("activitypub/followers",{edit:function(e){let{attributes:a,setAttributes:n}=e;const{order:l,per_page:s,selectedUser:p,title:u}=a,v=(0,i.useBlockProps)(),[m,b]=(0,t.useState)(1),w=[{label:(0,c.__)("New to old","activitypub"),value:"desc"},{label:(0,c.__)("Old to new","activitypub"),value:"asc"}],d=function(){const e=E?.users?(0,k.useSelect)((e=>e("core").getUsers({who:"authors"}))):[];return(0,t.useMemo)((()=>{if(!e)return[];const t=E?.site?[{label:(0,c.__)("Whole Site","activitypub"),value:"site"}]:[];return e.reduce(((e,t)=>(e.push({label:t.name,value:`${t.id}`}),e)),t)}),[e])}(),f=e=>t=>{b(1),n({[e]:t})};return(0,t.useEffect)((()=>{d.length&&(d.find((e=>{let{value:t}=e;return t===p}))||n({selectedUser:d[0].value}))}),[p,d]),(0,t.createElement)("div",v,(0,t.createElement)(i.InspectorControls,{key:"setting"},(0,t.createElement)(o.PanelBody,{title:(0,c.__)("Followers Options","activitypub")},(0,t.createElement)(o.TextControl,{label:(0,c.__)("Title","activitypub"),help:(0,c.__)("Title to display above the list of followers. Blank for none.","activitypub"),value:u,onChange:e=>n({title:e})}),d.length>1&&(0,t.createElement)(o.SelectControl,{label:(0,c.__)("Select User","activitypub"),value:p,options:d,onChange:f("selectedUser")}),(0,t.createElement)(o.SelectControl,{label:(0,c.__)("Sort","activitypub"),value:l,options:w,onChange:f("order")}),(0,t.createElement)(o.RangeControl,{label:(0,c.__)("Number of Followers","activitypub"),value:s,onChange:f("per_page"),min:1,max:10}))),(0,t.createElement)(y,r({},a,{page:m,setPage:b,followLinks:!1})))},save:()=>null,icon:l})})()})();

build/followers/style-view.css

@@ -0,0 +1 @@
+.activitypub-follower-block.is-style-compact .activitypub-handle,.activitypub-follower-block.is-style-compact .sep{display:none}.activitypub-follower-block.is-style-with-lines ul li{border-bottom:.5px solid;margin-bottom:.5rem;padding-bottom:.5rem}.activitypub-follower-block.is-style-with-lines ul li:last-child{border-bottom:none}.activitypub-follower-block.is-style-with-lines .activitypub-handle,.activitypub-follower-block.is-style-with-lines .activitypub-name{text-decoration:none}.activitypub-follower-block.is-style-with-lines .activitypub-handle:hover,.activitypub-follower-block.is-style-with-lines .activitypub-name:hover{text-decoration:underline}.activitypub-follower-block ul{margin:0!important;padding:0!important}.activitypub-follower-block li{display:flex;margin-bottom:1rem}.activitypub-follower-block img{border-radius:50%;height:40px;margin-right:var(--wp--preset--spacing--20,.5rem);width:40px}.activitypub-follower-block .activitypub-link{align-items:center;color:inherit!important;display:flex;flex-flow:row nowrap;max-width:100%;text-decoration:none!important}.activitypub-follower-block .activitypub-handle,.activitypub-follower-block .activitypub-name{text-decoration:underline;text-decoration-thickness:.8px;text-underline-position:under}.activitypub-follower-block .activitypub-handle:hover,.activitypub-follower-block .activitypub-name:hover{text-decoration:none}.activitypub-follower-block .activitypub-name{font-size:var(--wp--preset--font-size--normal,16px)}.activitypub-follower-block .activitypub-actor{font-size:var(--wp--preset--font-size--small,13px);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.activitypub-follower-block .sep{padding:0 .2rem}.activitypub-follower-block .wp-block-query-pagination{margin-top:1.5rem}.activitypub-follower-block .activitypub-pager{cursor:default}.activitypub-follower-block .activitypub-pager.current{opacity:.33}.activitypub-follower-block .page-numbers{padding:0 .2rem}.activitypub-follower-block .page-numbers.current{font-weight:700;opacity:1}

build/followers/view.asset.php

@@ -0,0 +1 @@
+<?php return array('dependencies' => array('react', 'wp-api-fetch', 'wp-components', 'wp-dom-ready', 'wp-element', 'wp-i18n', 'wp-url'), 'version' => 'f0e21057f7ec615290d6');

build/followers/view.js

@@ -0,0 +1,3 @@
+(()=>{var e,t={189:(e,t,a)=>{"use strict";const r=window.wp.element;function n(){return n=Object.assign?Object.assign.bind():function(e){for(var t=1;t<arguments.length;t++){var a=arguments[t];for(var r in a)Object.prototype.hasOwnProperty.call(a,r)&&(e[r]=a[r])}return e},n.apply(this,arguments)}const l=window.React,o=window.wp.apiFetch;var i=a.n(o);const c=window.wp.url,s=window.wp.i18n;var p=a(184),u=a.n(p);function m(e){let{active:t,children:a,page:n,pageClick:l,className:o}=e;const i=u()("wp-block activitypub-pager",o,{current:t});return(0,r.createElement)("a",{className:i,onClick:e=>{e.preventDefault(),!t&&l(n)}},a)}const v={outlined:"outlined",minimal:"minimal"};function f(e){let{compact:t,nextLabel:a,page:n,pageClick:l,perPage:o,prevLabel:i,total:c,variant:s=v.outlined}=e;const p=((e,t)=>{let a=[1,e-2,e-1,e,e+1,e+2,t];a.sort(((e,t)=>e-t)),a=a.filter(((e,a,r)=>e>=1&&e<=t&&r.lastIndexOf(e)===a));for(let e=a.length-2;e>=0;e--)a[e]===a[e+1]&&a.splice(e+1,1);return a})(n,Math.ceil(c/o)),f=u()("alignwide wp-block-query-pagination is-content-justification-space-between is-layout-flex wp-block-query-pagination-is-layout-flex",`is-${s}`,{"is-compact":t});return(0,r.createElement)("nav",{className:f},i&&(0,r.createElement)(m,{key:"prev",page:n-1,pageClick:l,active:1===n,"aria-label":i,className:"wp-block-query-pagination-previous block-editor-block-list__block"},i),!t&&(0,r.createElement)("div",{className:"block-editor-block-list__block wp-block wp-block-query-pagination-numbers"},p.map((e=>(0,r.createElement)(m,{key:e,page:e,pageClick:l,active:e===n,className:"page-numbers"},e)))),a&&(0,r.createElement)(m,{key:"next",page:n+1,pageClick:l,active:n===Math.ceil(c/o),"aria-label":a,className:"wp-block-query-pagination-next block-editor-block-list__block"},a))}const b=window.wp.components,{namespace:d}=window._activityPubOptions;function w(e){let{selectedUser:t,per_page:a,order:o,title:p,page:u,setPage:m,className:v="",followLinks:b=!0,followerData:w=!1}=e;const y="site"===t?0:t,[k,h]=(0,l.useState)([]),[E,O]=(0,l.useState)(0),[x,_]=(0,l.useState)(0),[N,j]=function(){const[e,t]=(0,l.useState)(1);return[e,t]}(),S=u||N,C=m||j,L=(0,r.createInterpolateElement)(/* translators: arrow for previous followers link */
+(0,s.__)("<span>←</span> Less","activitypub"),{span:(0,r.createElement)("span",{class:"wp-block-query-pagination-previous-arrow is-arrow-arrow","aria-hidden":"true"})}),q=(0,r.createInterpolateElement)(/* translators: arrow for next followers link */
+(0,s.__)("More <span>→</span>","activitypub"),{span:(0,r.createElement)("span",{class:"wp-block-query-pagination-next-arrow is-arrow-arrow","aria-hidden":"true"})}),P=(e,t)=>{h(e),_(t),O(Math.ceil(t/a))};return(0,l.useEffect)((()=>{if(w&&1===S)return P(w.followers,w.total);const e=function(e,t,a,r){const n=`/${d}/users/${e}/followers`,l={per_page:t,order:a,page:r,context:"full"};return(0,c.addQueryArgs)(n,l)}(y,a,o,S);i()({path:e}).then((e=>P(e.orderedItems,e.totalItems))).catch((()=>{}))}),[y,a,o,S,w]),(0,r.createElement)("div",{className:"activitypub-follower-block "+v},(0,r.createElement)("h3",null,p),(0,r.createElement)("ul",null,k&&k.map((e=>(0,r.createElement)("li",{key:e.url},(0,r.createElement)(g,n({},e,{followLinks:b})))))),E>1&&(0,r.createElement)(f,{page:S,perPage:a,total:x,pageClick:C,nextLabel:q,prevLabel:L,compact:"is-style-compact"===v}))}function g(e){let{name:t,icon:a,url:l,preferredUsername:o,followLinks:i=!0}=e;const c=`@${o}`,s={};return i||(s.onClick=e=>e.preventDefault()),(0,r.createElement)(b.ExternalLink,n({className:"activitypub-link",href:l,title:c},s),(0,r.createElement)("img",{width:"40",height:"40",src:a.url,class:"avatar activitypub-avatar"}),(0,r.createElement)("span",{class:"activitypub-actor"},(0,r.createElement)("strong",{className:"activitypub-name"},t),(0,r.createElement)("span",{class:"sep"},"/"),(0,r.createElement)("span",{class:"activitypub-handle"},c)))}const y=window.wp.domReady;a.n(y)()((()=>{[].forEach.call(document.querySelectorAll(".activitypub-follower-block"),(e=>{const t=JSON.parse(e.dataset.attrs);(0,r.render)((0,r.createElement)(w,t),e)}))}))},184:(e,t)=>{var a;!function(){"use strict";var r={}.hasOwnProperty;function n(){for(var e=[],t=0;t<arguments.length;t++){var a=arguments[t];if(a){var l=typeof a;if("string"===l||"number"===l)e.push(a);else if(Array.isArray(a)){if(a.length){var o=n.apply(null,a);o&&e.push(o)}}else if("object"===l){if(a.toString!==Object.prototype.toString&&!a.toString.toString().includes("[native code]")){e.push(a.toString());continue}for(var i in a)r.call(a,i)&&a[i]&&e.push(i)}}}return e.join(" ")}e.exports?(n.default=n,e.exports=n):void 0===(a=function(){return n}.apply(t,[]))||(e.exports=a)}()}},a={};function r(e){var n=a[e];if(void 0!==n)return n.exports;var l=a[e]={exports:{}};return t[e](l,l.exports,r),l.exports}r.m=t,e=[],r.O=(t,a,n,l)=>{if(!a){var o=1/0;for(p=0;p<e.length;p++){for(var[a,n,l]=e[p],i=!0,c=0;c<a.length;c++)(!1&l||o>=l)&&Object.keys(r.O).every((e=>r.O[e](a[c])))?a.splice(c--,1):(i=!1,l<o&&(o=l));if(i){e.splice(p--,1);var s=n();void 0!==s&&(t=s)}}return t}l=l||0;for(var p=e.length;p>0&&e[p-1][2]>l;p--)e[p]=e[p-1];e[p]=[a,n,l]},r.n=e=>{var t=e&&e.__esModule?()=>e.default:()=>e;return r.d(t,{a:t}),t},r.d=(e,t)=>{for(var a in t)r.o(t,a)&&!r.o(e,a)&&Object.defineProperty(e,a,{enumerable:!0,get:t[a]})},r.o=(e,t)=>Object.prototype.hasOwnProperty.call(e,t),(()=>{var e={638:0,962:0};r.O.j=t=>0===e[t];var t=(t,a)=>{var n,l,[o,i,c]=a,s=0;if(o.some((t=>0!==e[t]))){for(n in i)r.o(i,n)&&(r.m[n]=i[n]);if(c)var p=c(r)}for(t&&t(a);s<o.length;s++)l=o[s],r.o(e,l)&&e[l]&&e[l][0](),e[l]=0;return r.O(p)},a=globalThis.webpackChunkwordpress_activitypub=globalThis.webpackChunkwordpress_activitypub||[];a.forEach(t.bind(null,0)),a.push=t.bind(null,a.push.bind(a))})();var n=r.O(void 0,[962],(()=>r(189)));n=r.O(n)})();

composer.json

@@ -4,13 +4,24 @@
     "type": "wordpress-plugin",
     "require": {
         "php": ">=5.6.0",
-        "composer/installers": "~1.0"
+        "composer/installers": "^1.0 || ^2.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^5.5",
+        "phpunit/phpunit": "^5.7.21 || ^6.5 || ^7.5 || ^8",
         "phpcompatibility/php-compatibility": "*",
+        "phpcompatibility/phpcompatibility-wp": "*",
         "squizlabs/php_codesniffer": "3.*",
-        "wp-coding-standards/wpcs": "^0.14.1"
+        "wp-coding-standards/wpcs": "dev-develop",
+        "yoast/phpunit-polyfills": "^2.0",
+        "dealerdirect/phpcodesniffer-composer-installer": "^1.0.0",
+        "sirbrillig/phpcs-variable-analysis": "^2.11",
+        "phpcsstandards/phpcsextra": "^1.1.0"
+    },
+    "config": {
+        "allow-plugins": true
+    },
+    "allow-plugins": {
+        "composer/installers": true
     },
     "license": "MIT",
     "authors": [
@@ -25,14 +36,14 @@
     "scripts": {
         "test": [
             "composer install",
-            "bin/install-wp-tests.sh wordpress wordpress wordpress",
+            "bin/install-wp-tests.sh activitypub-test root activitypub-test test-db latest true",
             "vendor/bin/phpunit"
         ],
-        "post-install-cmd": [
-            "\"vendor/bin/phpcs\" --config-set installed_paths vendor/phpcompatibility/php-compatibility,vendor/wp-coding-standards/wpcs"
+        "lint": [
+            "vendor/bin/phpcs -n -q"
         ],
-        "post-update-cmd": [
-            "\"vendor/bin/phpcs\" --config-set installed_paths vendor/phpcompatibility/php-compatibility,vendor/wp-coding-standards/wpcs"
+        "lint:fix": [
+            "vendor/bin/phpcbf"
         ]
     }
 }

docker-compose-test.yml

@@ -0,0 +1,26 @@
+version: '2'
+services:
+  test-db:
+    platform: linux/x86_64
+    image: mysql:5.7
+    environment:
+      MYSQL_DATABASE: activitypub-test
+      MYSQL_ROOT_PASSWORD: activitypub-test
+    healthcheck:
+        test: ["CMD", "curl", "-f", "http://localhost:3306"]
+        interval: 5s
+        timeout: 2s
+        retries: 5
+
+  test-php:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    depends_on:
+      test-db:
+        condition: service_healthy
+    links:
+      - test-db
+    volumes:
+      - .:/app
+    command: ["composer", "run-script", "test"]

docker-compose.yml

@@ -22,5 +22,6 @@ services:
     restart: always
     environment:
       WORDPRESS_DB_HOST: db:3306
+      WORDPRESS_DB_USER: wordpress
       WORDPRESS_DB_PASSWORD: wordpress
       WORDPRESS_DEBUG: 1

includes/activity/class-activity.php

@@ -0,0 +1,223 @@
+<?php
+/**
+ * Inspired by the PHP ActivityPub Library by @Landrok
+ *
+ * @link https://github.com/landrok/activitypub
+ */
+
+namespace Activitypub\Activity;
+
+use Activitypub\Activity\Base_Object;
+
+/**
+ * \Activitypub\Activity\Activity implements the common
+ * attributes of an Activity.
+ *
+ * @see https://www.w3.org/TR/activitystreams-core/#activities
+ * @see https://www.w3.org/TR/activitystreams-core/#intransitiveactivities
+ */
+class Activity extends Base_Object {
+	const CONTEXT = array(
+		'https://www.w3.org/ns/activitystreams',
+		'https://w3id.org/security/v1',
+		array(
+			'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
+			'PropertyValue' => 'schema:PropertyValue',
+			'schema' => 'http://schema.org#',
+			'pt' => 'https://joinpeertube.org/ns#',
+			'toot' => 'http://joinmastodon.org/ns#',
+			'webfinger' => 'https://webfinger.net/#',
+			'litepub' => 'http://litepub.social/ns#',
+			'lemmy' => 'https://join-lemmy.org/ns#',
+			'value' => 'schema:value',
+			'Hashtag' => 'as:Hashtag',
+			'featured' => array(
+				'@id' => 'toot:featured',
+				'@type' => '@id',
+			),
+			'featuredTags' => array(
+				'@id' => 'toot:featuredTags',
+				'@type' => '@id',
+			),
+			'alsoKnownAs' => array(
+				'@id' => 'as:alsoKnownAs',
+				'@type' => '@id',
+			),
+			'moderators' => array(
+				'@id' => 'lemmy:moderators',
+				'@type' => '@id',
+			),
+			'postingRestrictedToMods' => 'lemmy:postingRestrictedToMods',
+			'discoverable' => 'toot:discoverable',
+			'indexable' => 'toot:indexable',
+			'sensitive' => 'as:sensitive',
+			'resource' => 'webfinger:resource',
+		),
+	);
+
+	/**
+	 * The object's unique global identifier
+	 *
+	 * @see https://www.w3.org/TR/activitypub/#obj-id
+	 *
+	 * @var string
+	 */
+	protected $id;
+
+	/**
+	 * @var string
+	 */
+	protected $type = 'Activity';
+
+	/**
+	 * The context within which the object exists or an activity was
+	 * performed.
+	 * The notion of "context" used is intentionally vague.
+	 * The intended function is to serve as a means of grouping objects
+	 * and activities that share a common originating context or
+	 * purpose. An example could be all activities relating to a common
+	 * project or event.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-context
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | null
+	 */
+	protected $context = self::CONTEXT;
+
+	/**
+	 * Describes the direct object of the activity.
+	 * For instance, in the activity "John added a movie to his
+	 * wishlist", the object of the activity is the movie added.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-object-term
+	 *
+	 * @var string
+	 *    | Base_Objectr
+	 *    | Link
+	 *    | null
+	 */
+	protected $object;
+
+	/**
+	 * Describes one or more entities that either performed or are
+	 * expected to perform the activity.
+	 * Any single activity can have multiple actors.
+	 * The actor MAY be specified using an indirect Link.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-actor
+	 *
+	 * @var string
+	 *    | \ActivityPhp\Type\Extended\AbstractActor
+	 *    | array<Actor>
+	 *    | array<Link>
+	 *    | Link
+	 */
+	protected $actor;
+
+	/**
+	 * The indirect object, or target, of the activity.
+	 * The precise meaning of the target is largely dependent on the
+	 * type of action being described but will often be the object of
+	 * the English preposition "to".
+	 * For instance, in the activity "John added a movie to his
+	 * wishlist", the target of the activity is John's wishlist.
+	 * An activity can have more than one target.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-target
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | array<ObjectType>
+	 *    | Link
+	 *    | array<Link>
+	 */
+	protected $target;
+
+	/**
+	 * Describes the result of the activity.
+	 * For instance, if a particular action results in the creation of
+	 * a new resource, the result property can be used to describe
+	 * that new resource.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-result
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | null
+	 */
+	protected $result;
+
+	/**
+	 * An indirect object of the activity from which the
+	 * activity is directed.
+	 * The precise meaning of the origin is the object of the English
+	 * preposition "from".
+	 * For instance, in the activity "John moved an item to List B
+	 * from List A", the origin of the activity is "List A".
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-origin
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | null
+	 */
+	protected $origin;
+
+	/**
+	 * One or more objects used (or to be used) in the completion of an
+	 * Activity.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-instrument
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | null
+	 */
+	protected $instrument;
+
+	/**
+	 * Set the object and copy Object properties to the Activity.
+	 *
+	 * Any to, bto, cc, bcc, and audience properties specified on the object
+	 * MUST be copied over to the new Create activity by the server.
+	 *
+	 * @see https://www.w3.org/TR/activitypub/#object-without-create
+	 *
+	 * @param string|Base_Objectr|Link|null $object
+	 *
+	 * @return void
+	 */
+	public function set_object( $object ) {
+		$this->set( 'object', $object );
+
+		if ( ! is_object( $object ) ) {
+			return;
+		}
+
+		foreach ( array( 'to', 'bto', 'cc', 'bcc', 'audience' ) as $i ) {
+			$this->set( $i, $object->get( $i ) );
+		}
+
+		if ( $object->get_published() && ! $this->get_published() ) {
+			$this->set( 'published', $object->get_published() );
+		}
+
+		if ( $object->get_updated() && ! $this->get_updated() ) {
+			$this->set( 'updated', $object->get_updated() );
+		}
+
+		if ( $object->get_attributed_to() && ! $this->get_actor() ) {
+			$this->set( 'actor', $object->get_attributed_to() );
+		}
+
+		if ( $object->get_id() && ! $this->get_id() ) {
+			$this->set( 'id', $object->get_id() . '#activity' );
+		}
+	}
+}

includes/activity/class-actor.php

@@ -0,0 +1,139 @@
+<?php
+/**
+ * Inspired by the PHP ActivityPub Library by @Landrok
+ *
+ * @link https://github.com/landrok/activitypub
+ */
+
+namespace Activitypub\Activity;
+
+/**
+ * \Activitypub\Activity\Actor is an implementation of
+ * one an Activity Streams Actor.
+ *
+ * Represents an individual actor.
+ *
+ * @see https://www.w3.org/TR/activitystreams-vocabulary/#actor-types
+ */
+class Actor extends Base_Object {
+	/**
+	 * @var string
+	 */
+	protected $type = 'Person';
+
+	/**
+	 * A reference to an ActivityStreams OrderedCollection comprised of
+	 * all the messages received by the actor.
+	 *
+	 * @see https://www.w3.org/TR/activitypub/#inbox
+	 *
+	 * @var string
+	 *    | null
+	 */
+	protected $inbox;
+
+	/**
+	 * A reference to an ActivityStreams OrderedCollection comprised of
+	 * all the messages produced by the actor.
+	 *
+	 * @see https://www.w3.org/TR/activitypub/#outbox
+	 *
+	 * @var string
+	 *    | null
+	 */
+	protected $outbox;
+
+	/**
+	 * A link to an ActivityStreams collection of the actors that this
+	 * actor is following.
+	 *
+	 * @see https://www.w3.org/TR/activitypub/#following
+	 *
+	 * @var string
+	 */
+	protected $following;
+
+	/**
+	 * A link to an ActivityStreams collection of the actors that
+	 * follow this actor.
+	 *
+	 * @see https://www.w3.org/TR/activitypub/#followers
+	 *
+	 * @var string
+	 */
+	protected $followers;
+
+	/**
+	 * A link to an ActivityStreams collection of objects this actor has
+	 * liked.
+	 *
+	 * @see https://www.w3.org/TR/activitypub/#liked
+	 *
+	 * @var string
+	 */
+	protected $liked;
+
+	/**
+	 * A list of supplementary Collections which may be of interest.
+	 *
+	 * @see https://www.w3.org/TR/activitypub/#streams-property
+	 *
+	 * @var array
+	 */
+	protected $streams = array();
+
+	/**
+	 * A short username which may be used to refer to the actor, with no
+	 * uniqueness guarantees.
+	 *
+	 * @see https://www.w3.org/TR/activitypub/#preferredUsername
+	 *
+	 * @var string|null
+	 */
+	protected $preferred_username;
+
+	/**
+	 * A JSON object which maps additional typically server/domain-wide
+	 * endpoints which may be useful either for this actor or someone
+	 * referencing this actor. This mapping may be nested inside the
+	 * actor document as the value or may be a link to a JSON-LD
+	 * document with these properties.
+	 *
+	 * @see https://www.w3.org/TR/activitypub/#endpoints
+	 *
+	 * @var string|array|null
+	 */
+	protected $endpoints;
+
+	/**
+	 * It's not part of the ActivityPub protocol but it's a quite common
+	 * practice to handle an actor public key with a publicKey array:
+	 * [
+	 *     'id' => 'https://my-example.com/actor#main-key'
+	 *     'owner' => 'https://my-example.com/actor',
+	 *     'publicKeyPem' => '-----BEGIN PUBLIC KEY-----
+	 *                       MIIBI [...]
+	 *                       DQIDAQAB
+	 *                       -----END PUBLIC KEY-----'
+	 * ]
+	 *
+	 * @see https://www.w3.org/wiki/SocialCG/ActivityPub/Authentication_Authorization#Signing_requests_using_HTTP_Signatures
+	 *
+	 * @var string|array|null
+	 */
+	protected $public_key;
+
+	/**
+	 * It's not part of the ActivityPub protocol but it's a quite common
+	 * practice to lock an account. If anabled, new followers will not be
+	 * automatically accepted, but will instead require you to manually
+	 * approve them.
+	 *
+	 * WordPress does only support 'false' at the moment.
+	 *
+	 * @see https://docs.joinmastodon.org/spec/activitypub/#as
+	 *
+	 * @var boolean
+	 */
+	protected $manually_approves_followers = false;
+}

includes/activity/class-base-object.php

@@ -0,0 +1,678 @@
+<?php
+/**
+ * Inspired by the PHP ActivityPub Library by @Landrok
+ *
+ * @link https://github.com/landrok/activitypub
+ */
+
+namespace Activitypub\Activity;
+
+use WP_Error;
+use ReflectionClass;
+
+use function Activitypub\camel_to_snake_case;
+use function Activitypub\snake_to_camel_case;
+
+/**
+ * Base_Object is an implementation of one of the
+ * Activity Streams Core Types.
+ *
+ * The Object is the primary base type for the Activity Streams
+ * vocabulary.
+ *
+ * Note: Object is a reserved keyword in PHP. It has been suffixed with
+ * 'Base_' for this reason.
+ *
+ * @see https://www.w3.org/TR/activitystreams-core/#object
+ */
+class Base_Object {
+	/**
+	 * The object's unique global identifier
+	 *
+	 * @see https://www.w3.org/TR/activitypub/#obj-id
+	 *
+	 * @var string
+	 */
+	protected $id;
+
+	/**
+	 * @var string
+	 */
+	protected $type = 'Object';
+
+	/**
+	 * A resource attached or related to an object that potentially
+	 * requires special handling.
+	 * The intent is to provide a model that is at least semantically
+	 * similar to attachments in email.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-attachment
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | array<ObjectType>
+	 *    | array<Link>
+	 *    | null
+	 */
+	protected $attachment;
+
+	/**
+	 * One or more entities to which this object is attributed.
+	 * The attributed entities might not be Actors. For instance, an
+	 * object might be attributed to the completion of another activity.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-attributedto
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | array<ObjectType>
+	 *    | array<Link>
+	 *    | null
+	 */
+	protected $attributed_to;
+
+	/**
+	 * One or more entities that represent the total population of
+	 * entities for which the object can considered to be relevant.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-audience
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | array<ObjectType>
+	 *    | array<Link>
+	 *    | null
+	 */
+	protected $audience;
+
+	/**
+	 * The content or textual representation of the Object encoded as a
+	 * JSON string. By default, the value of content is HTML.
+	 * The mediaType property can be used in the object to indicate a
+	 * different content type.
+	 *
+	 * The content MAY be expressed using multiple language-tagged
+	 * values.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-content
+	 *
+	 * @var string|null
+	 */
+	protected $content;
+
+	/**
+	 * The context within which the object exists or an activity was
+	 * performed.
+	 * The notion of "context" used is intentionally vague.
+	 * The intended function is to serve as a means of grouping objects
+	 * and activities that share a common originating context or
+	 * purpose. An example could be all activities relating to a common
+	 * project or event.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-context
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | null
+	 */
+	protected $context;
+
+	/**
+	 * The content MAY be expressed using multiple language-tagged
+	 * values.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-content
+	 *
+	 * @var array|null
+	 */
+	protected $content_map;
+
+	/**
+	 * A simple, human-readable, plain-text name for the object.
+	 * HTML markup MUST NOT be included.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-name
+	 *
+	 * @var string|null xsd:string
+	 */
+	protected $name;
+
+	/**
+	 * The name MAY be expressed using multiple language-tagged values.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-name
+	 *
+	 * @var array|null rdf:langString
+	 */
+	protected $name_map;
+
+	/**
+	 * The date and time describing the actual or expected ending time
+	 * of the object.
+	 * When used with an Activity object, for instance, the endTime
+	 * property specifies the moment the activity concluded or
+	 * is expected to conclude.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-endtime
+	 *
+	 * @var string|null
+	 */
+	protected $end_time;
+
+	/**
+	 * The entity (e.g. an application) that generated the object.
+	 *
+	 * @var string|null
+	 */
+	protected $generator;
+
+	/**
+	 * An entity that describes an icon for this object.
+	 * The image should have an aspect ratio of one (horizontal)
+	 * to one (vertical) and should be suitable for presentation
+	 * at a small size.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-icon
+	 *
+	 * @var string
+	 *    | Image
+	 *    | Link
+	 *    | array<Image>
+	 *    | array<Link>
+	 *    | null
+	 */
+	protected $icon;
+
+	/**
+	 * An entity that describes an image for this object.
+	 * Unlike the icon property, there are no aspect ratio
+	 * or display size limitations assumed.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-image-term
+	 *
+	 * @var string
+	 *    | Image
+	 *    | Link
+	 *    | array<Image>
+	 *    | array<Link>
+	 *    | null
+	 */
+	protected $image;
+
+	/**
+	 * One or more entities for which this object is considered a
+	 * response.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-inreplyto
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | array<ObjectType>
+	 *    | array<Link>
+	 *    | null
+	 */
+	protected $in_reply_to;
+
+	/**
+	 * One or more physical or logical locations associated with the
+	 * object.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-location
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | array<ObjectType>
+	 *    | array<Link>
+	 *    | null
+	 */
+	protected $location;
+
+	/**
+	 * An entity that provides a preview of this object.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-preview
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | null
+	 */
+	protected $preview;
+
+	/**
+	 * The date and time at which the object was published
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-published
+	 *
+	 * @var string|null xsd:dateTime
+	 */
+	protected $published;
+
+	/**
+	 * A Collection containing objects considered to be responses to
+	 * this object.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-replies
+	 *
+	 * @var string
+	 *    | Collection
+	 *    | Link
+	 *    | null
+	 */
+	protected $replies;
+
+	/**
+	 * The date and time describing the actual or expected starting time
+	 * of the object.
+	 * When used with an Activity object, for instance, the startTime
+	 * property specifies the moment the activity began
+	 * or is scheduled to begin.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-starttime
+	 *
+	 * @var string|null xsd:dateTime
+	 */
+	protected $start_time;
+
+	/**
+	 * A natural language summarization of the object encoded as HTML.
+	 * Multiple language tagged summaries MAY be provided.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-summary
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | null
+	 */
+	protected $summary;
+
+	/**
+	 * The content MAY be expressed using multiple language-tagged
+	 * values.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-summary
+	 *
+	 * @var array<string>|null
+	 */
+	protected $summary_map;
+
+	/**
+	 * One or more "tags" that have been associated with an objects.
+	 * A tag can be any kind of Object.
+	 * The key difference between attachment and tag is that the former
+	 * implies association by inclusion, while the latter implies
+	 * associated by reference.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-tag
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | array<ObjectType>
+	 *    | array<Link>
+	 *    | null
+	 */
+	protected $tag;
+
+	/**
+	 * The date and time at which the object was updated
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-updated
+	 *
+	 * @var string|null xsd:dateTime
+	 */
+	protected $updated;
+
+	/**
+	 * One or more links to representations of the object.
+	 *
+	 * @var string
+	 *    | array<string>
+	 *    | Link
+	 *    | array<Link>
+	 *    | null
+	 */
+	protected $url;
+
+	/**
+	 * An entity considered to be part of the public primary audience
+	 * of an Object
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-to
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | array<ObjectType>
+	 *    | array<Link>
+	 *    | null
+	 */
+	protected $to;
+
+	/**
+	 * An Object that is part of the private primary audience of this
+	 * Object.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-bto
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | array<ObjectType>
+	 *    | array<Link>
+	 *    | null
+	 */
+	protected $bto;
+
+	/**
+	 * An Object that is part of the public secondary audience of this
+	 * Object.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-cc
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | array<ObjectType>
+	 *    | array<Link>
+	 *    | null
+	 */
+	protected $cc;
+
+	/**
+	 * One or more Objects that are part of the private secondary
+	 * audience of this Object.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-bcc
+	 *
+	 * @var string
+	 *    | ObjectType
+	 *    | Link
+	 *    | array<ObjectType>
+	 *    | array<Link>
+	 *    | null
+	 */
+	protected $bcc;
+
+	/**
+	 * The MIME media type of the value of the content property.
+	 * If not specified, the content property is assumed to contain
+	 * text/html content.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-mediatype
+	 *
+	 * @var string|null
+	 */
+	protected $media_type;
+
+	/**
+	 * When the object describes a time-bound resource, such as an audio
+	 * or video, a meeting, etc, the duration property indicates the
+	 * object's approximate duration.
+	 * The value MUST be expressed as an xsd:duration as defined by
+	 * xmlschema11-2, section 3.3.6 (e.g. a period of 5 seconds is
+	 * represented as "PT5S").
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-duration
+	 *
+	 * @var string|null
+	 */
+	protected $duration;
+
+	/**
+	 * Intended to convey some sort of source from which the content
+	 * markup was derived, as a form of provenance, or to support
+	 * future editing by clients.
+	 *
+	 * @see https://www.w3.org/TR/activitypub/#source-property
+	 *
+	 * @var ObjectType
+	 */
+	protected $source;
+
+	/**
+	 * Magic function to implement getter and setter
+	 *
+	 * @param string $method The method name.
+	 * @param string $params The method params.
+	 *
+	 * @return void
+	 */
+	public function __call( $method, $params ) {
+		$var = \strtolower( \substr( $method, 4 ) );
+
+		if ( \strncasecmp( $method, 'get', 3 ) === 0 ) {
+			if ( ! $this->has( $var ) ) {
+				return new WP_Error( 'invalid_key', __( 'Invalid key', 'activitypub' ), array( 'status' => 404 ) );
+			}
+
+			return $this->$var;
+		}
+
+		if ( \strncasecmp( $method, 'set', 3 ) === 0 ) {
+			$this->set( $var, $params[0] );
+		}
+
+		if ( \strncasecmp( $method, 'add', 3 ) === 0 ) {
+			$this->add( $var, $params[0] );
+		}
+	}
+
+	/**
+	 * Magic function, to transform the object to string.
+	 *
+	 * @return string The object id.
+	 */
+	public function __toString() {
+		return $this->to_string();
+	}
+
+	/**
+	 * Function to transform the object to string.
+	 *
+	 * @return string The object id.
+	 */
+	public function to_string() {
+		return $this->get_id();
+	}
+
+	/**
+	 * Generic getter.
+	 *
+	 * @param string $key The key to get.
+	 *
+	 * @return mixed The value.
+	 */
+	public function get( $key ) {
+		if ( ! $this->has( $key ) ) {
+			return new WP_Error( 'invalid_key', __( 'Invalid key', 'activitypub' ), array( 'status' => 404 ) );
+		}
+
+		return call_user_func( array( $this, 'get_' . $key ) );
+	}
+
+	/**
+	 * Check if the object has a key
+	 *
+	 * @param string $key The key to check.
+	 *
+	 * @return boolean True if the object has the key.
+	 */
+	public function has( $key ) {
+		return property_exists( $this, $key );
+	}
+
+	/**
+	 * Generic setter.
+	 *
+	 * @param string $key   The key to set.
+	 * @param string $value The value to set.
+	 *
+	 * @return mixed The value.
+	 */
+	public function set( $key, $value ) {
+		if ( ! $this->has( $key ) ) {
+			return new WP_Error( 'invalid_key', __( 'Invalid key', 'activitypub' ), array( 'status' => 404 ) );
+		}
+
+		$this->$key = $value;
+
+		return $this->$key;
+	}
+
+	/**
+	 * Generic adder.
+	 *
+	 * @param string $key   The key to set.
+	 * @param mixed  $value The value to add.
+	 *
+	 * @return mixed The value.
+	 */
+	public function add( $key, $value ) {
+		if ( ! $this->has( $key ) ) {
+			return new WP_Error( 'invalid_key', __( 'Invalid key', 'activitypub' ), array( 'status' => 404 ) );
+		}
+
+		if ( ! isset( $this->$key ) ) {
+			$this->$key = array();
+		}
+
+		$attributes   = $this->$key;
+		$attributes[] = $value;
+
+		$this->$key = $attributes;
+
+		return $this->$key;
+	}
+
+	/**
+	 * Convert JSON input to an array.
+	 *
+	 * @return string The JSON string.
+	 *
+	 * @return \Activitypub\Activity\Base_Object An Object built from the JSON string.
+	 */
+	public static function init_from_json( $json ) {
+		$array = \json_decode( $json, true );
+
+		if ( ! is_array( $array ) ) {
+			$array = array();
+		}
+
+		return self::init_from_array( $array );
+	}
+
+	/**
+	 * Convert JSON input to an array.
+	 *
+	 * @return string The object array.
+	 *
+	 * @return \Activitypub\Activity\Base_Object An Object built from the JSON string.
+	 */
+	public static function init_from_array( $array ) {
+		if ( ! is_array( $array ) ) {
+			return new WP_Error( 'invalid_array', __( 'Invalid array', 'activitypub' ), array( 'status' => 404 ) );
+		}
+
+		$object = new static();
+
+		foreach ( $array as $key => $value ) {
+			$key = camel_to_snake_case( $key );
+			$object->set( $key, $value );
+		}
+
+		return $object;
+	}
+
+	/**
+	 * Convert JSON input to an array and pre-fill the object.
+	 *
+	 * @param string $json The JSON string.
+	 */
+	public function from_json( $json ) {
+		$array = \json_decode( $json, true );
+
+		$this->from_array( $array );
+	}
+
+	/**
+	 * Convert JSON input to an array and pre-fill the object.
+	 *
+	 * @param array $array The array.
+	 */
+	public function from_array( $array ) {
+		foreach ( $array as $key => $value ) {
+			if ( $value ) {
+				$key = camel_to_snake_case( $key );
+				$this->set( $key, $value );
+			}
+		}
+	}
+
+	/**
+	 * Convert Object to an array.
+	 *
+	 * It tries to get the object attributes if they exist
+	 * and falls back to the getters. Empty values are ignored.
+	 *
+	 * @return array An array built from the Object.
+	 */
+	public function to_array() {
+		$array = array();
+		$vars  = get_object_vars( $this );
+
+		foreach ( $vars as $key => $value ) {
+			// ignotre all _prefixed keys.
+			if ( '_' === substr( $key, 0, 1 ) ) {
+				continue;
+			}
+
+			// if value is empty, try to get it from a getter.
+			if ( ! $value ) {
+				$value = call_user_func( array( $this, 'get_' . $key ) );
+			}
+
+			if ( is_object( $value ) ) {
+				$value = $value->to_array();
+			}
+
+			// if value is still empty, ignore it for the array and continue.
+			if ( isset( $value ) ) {
+				$array[ snake_to_camel_case( $key ) ] = $value;
+			}
+		}
+
+		// replace 'context' key with '@context' and move it to the top.
+		if ( array_key_exists( 'context', $array ) ) {
+			$context = $array['context'];
+			unset( $array['context'] );
+			$array = array_merge( array( '@context' => $context ), $array );
+		}
+
+		$class = new ReflectionClass( $this );
+		$class = strtolower( $class->getShortName() );
+
+		$array = \apply_filters( 'activitypub_activity_object_array', $array, $class, $this->id, $this );
+		$array = \apply_filters( "activitypub_activity_{$class}_object_array", $array, $this->id, $this );
+
+		return $array;
+	}
+
+	/**
+	 * Convert Object to JSON.
+	 *
+	 * @return string The JSON string.
+	 */
+	public function to_json() {
+		$array = $this->to_array();
+
+		return \wp_json_encode( $array, \JSON_HEX_TAG | \JSON_HEX_AMP | \JSON_HEX_QUOT );
+	}
+}

includes/activity/class-event.php

@@ -0,0 +1,23 @@
+<?php
+/**
+ * Inspired by the PHP ActivityPub Library by @Landrok
+ *
+ * @link https://github.com/landrok/activitypub
+ */
+
+namespace Activitypub\Activity;
+
+use Activitypub\Activity\Base_Object;
+
+/**
+ * Event is an implementation of one of the
+ * Activity Streams Event object type
+ *
+ * The Object is the primary base type for the Activity Streams
+ * vocabulary.
+ *
+ * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-event
+ */
+class Note extends Base_Object {
+	protected $type = 'Event';
+}

includes/activity/class-note.php

@@ -0,0 +1,23 @@
+<?php
+/**
+ * Inspired by the PHP ActivityPub Library by @Landrok
+ *
+ * @link https://github.com/landrok/activitypub
+ */
+
+namespace Activitypub\Activity;
+
+use Activitypub\Activity\Base_Object;
+
+/**
+ * Note is an implementation of one of the
+ * Activity Streams Note object type
+ *
+ * The Object is the primary base type for the Activity Streams
+ * vocabulary.
+ *
+ * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-note
+ */
+class Note extends Base_Object {
+	protected $type = 'Note';
+}

includes/class-activity-dispatcher.php

@@ -1,6 +1,16 @@
 <?php
 namespace Activitypub;
 
+use WP_Post;
+use Activitypub\Activity\Activity;
+use Activitypub\Collection\Users;
+use Activitypub\Collection\Followers;
+use Activitypub\Transformer\Transformers_Manager;
+
+use function Activitypub\is_single_user;
+use function Activitypub\is_user_disabled;
+use function Activitypub\safe_remote_post;
+
 /**
  * ActivityPub Activity_Dispatcher Class
  *
@@ -10,74 +20,108 @@ namespace Activitypub;
  */
 class Activity_Dispatcher {
 	/**
-	 * Initialize the class, registering WordPress hooks
+	 * Initialize the class, registering WordPress hooks.
 	 */
 	public static function init() {
-		\add_action( 'activitypub_send_post_activity', array( '\Activitypub\Activity_Dispatcher', 'send_post_activity' ) );
-		\add_action( 'activitypub_send_update_activity', array( '\Activitypub\Activity_Dispatcher', 'send_update_activity' ) );
-		// \add_action( 'activitypub_send_delete_activity', array( '\Activitypub\Activity_Dispatcher', 'send_delete_activity' ) );
+		\add_action( 'activitypub_send_activity', array( self::class, 'send_activity' ), 10, 2 );
+		\add_action( 'activitypub_send_activity', array( self::class, 'send_activity_or_announce' ), 10, 2 );
 	}
 
 	/**
-	 * Send "create" activities
+	 * Send Activities to followers and mentioned users or `Announce` (boost) a blog post.
 	 *
-	 * @param int $post_id
+	 * @param WP_Post $wp_post The ActivityPub Post.
+	 * @param string  $type    The Activity-Type.
+	 *
+	 * @return void
 	 */
-	public static function send_post_activity( $post_id ) {
-		$post = \get_post( $post_id );
-		$user_id = $post->post_author;
+	public static function send_activity_or_announce( WP_Post $wp_post, $type ) {
+		// check if a migration is needed before sending new posts
+		Migration::maybe_migrate();
 
-		$activitypub_post = new \Activitypub\Model\Post( $post );
-		$activitypub_activity = new \Activitypub\Model\Activity( 'Create', \Activitypub\Model\Activity::TYPE_FULL );
-		$activitypub_activity->from_post( $activitypub_post->to_array() );
+		if ( is_user_type_disabled( 'blog' ) ) {
+			return;
+		}
 
-		foreach ( \Activitypub\get_follower_inboxes( $user_id ) as $inbox => $to ) {
-			$activitypub_activity->set_to( $to );
-			$activity = $activitypub_activity->to_json(); // phpcs:ignore
+		$wp_post->post_author = Users::BLOG_USER_ID;
 
-			\Activitypub\safe_remote_post( $inbox, $activity, $user_id );
+		if ( is_single_user() ) {
+			self::send_activity( $wp_post, $type );
+		} else {
+			self::send_announce( $wp_post, $type );
 		}
 	}
 
 	/**
-	 * Send "update" activities
+	 * Send Activities to followers and mentioned users.
 	 *
-	 * @param int $post_id
+	 * @param WP_Post $wp_post The ActivityPub Post.
+	 * @param string  $type    The Activity-Type.
+	 *
+	 * @return void
 	 */
-	public static function send_update_activity( $post_id ) {
-		$post = \get_post( $post_id );
-		$user_id = $post->post_author;
+	public static function send_activity( WP_Post $wp_post, $type ) {
+		if ( is_user_disabled( $wp_post->post_author ) ) {
+			return;
+		}
 
-		$activitypub_post = new \Activitypub\Model\Post( $post );
-		$activitypub_activity = new \Activitypub\Model\Activity( 'Update', \Activitypub\Model\Activity::TYPE_FULL );
-		$activitypub_activity->from_post( $activitypub_post->to_array() );
+		$transformer = Transformers_Manager::instance()->get_transformer( $wp_post );
+		$object = $transformer->to_object();
 
-		foreach ( \Activitypub\get_follower_inboxes( $user_id ) as $inbox => $to ) {
-			$activitypub_activity->set_to( $to );
-			$activity = $activitypub_activity->to_json(); // phpcs:ignore
+		$activity = new Activity();
+		$activity->set_type( $type );
+		$activity->set_object( $object );
 
-			\Activitypub\safe_remote_post( $inbox, $activity, $user_id );
+		$follower_inboxes  = Followers::get_inboxes( $wp_post->post_author );
+		$mentioned_inboxes = Mention::get_inboxes( $activity->get_cc() );
+
+		$inboxes = array_merge( $follower_inboxes, $mentioned_inboxes );
+		$inboxes = array_unique( $inboxes );
+
+		$json = $activity->to_json();
+
+		foreach ( $inboxes as $inbox ) {
+			safe_remote_post( $inbox, $json, $wp_post->post_author );
 		}
 	}
 
 	/**
-	 * Send "delete" activities
+	 * Send Announces to followers and mentioned users.
 	 *
-	 * @param int $post_id
+	 * @param WP_Post $wp_post The ActivityPub Post.
+	 * @param string  $type    The Activity-Type.
+	 *
+	 * @return void
 	 */
-	public static function send_delete_activity( $post_id ) {
-		$post = \get_post( $post_id );
-		$user_id = $post->post_author;
+	public static function send_announce( WP_Post $wp_post, $type ) {
+		if ( ! in_array( $type, array( 'Create', 'Update' ), true ) ) {
+			return;
+		}
 
-		$activitypub_post = new \Activitypub\Model\Post( $post );
-		$activitypub_activity = new \Activitypub\Model\Activity( 'Delete', \Activitypub\Model\Activity::TYPE_FULL );
-		$activitypub_activity->from_post( $activitypub_post->to_array() );
+		if ( is_user_disabled( Users::BLOG_USER_ID ) ) {
+			return;
+		}
 
-		foreach ( \Activitypub\get_follower_inboxes( $user_id ) as $inbox => $to ) {
-			$activitypub_activity->set_to( $to );
-			$activity = $activitypub_activity->to_json(); // phpcs:ignore
+		$transformer = Transformers_Manager::instance()->get_transformer( $wp_post );
+		$object = $transformer->to_object();
 
-			\Activitypub\safe_remote_post( $inbox, $activity, $user_id );
+		$activity = new Activity();
+		$activity->set_type( 'Announce' );
+		// to pre-fill attributes like "published" and "id"
+		$activity->set_object( $object );
+		// send only the id
+		$activity->set_object( $object->get_id() );
+
+		$follower_inboxes  = Followers::get_inboxes( $wp_post->post_author );
+		$mentioned_inboxes = Mention::get_inboxes( $activity->get_cc() );
+
+		$inboxes = array_merge( $follower_inboxes, $mentioned_inboxes );
+		$inboxes = array_unique( $inboxes );
+
+		$json = $activity->to_json();
+
+		foreach ( $inboxes as $inbox ) {
+			safe_remote_post( $inbox, $json, $wp_post->post_author );
 		}
 	}
 }

includes/class-activitypub.php

@@ -1,6 +1,9 @@
 <?php
 namespace Activitypub;
 
+use Activitypub\Signature;
+use Activitypub\Collection\Users;
+
 /**
  * ActivityPub Class
  *
@@ -8,79 +11,106 @@ namespace Activitypub;
  */
 class Activitypub {
 	/**
-	 * Initialize the class, registering WordPress hooks
+	 * Initialize the class, registering WordPress hooks.
 	 */
 	public static function init() {
-		\add_filter( 'template_include', array( '\Activitypub\Activitypub', 'render_json_template' ), 99 );
-		\add_filter( 'query_vars', array( '\Activitypub\Activitypub', 'add_query_vars' ) );
-		\add_action( 'init', array( '\Activitypub\Activitypub', 'add_rewrite_endpoint' ) );
-		\add_filter( 'pre_get_avatar_data', array( '\Activitypub\Activitypub', 'pre_get_avatar_data' ), 11, 2 );
+		\add_filter( 'template_include', array( self::class, 'render_json_template' ), 99 );
+		\add_filter( 'query_vars', array( self::class, 'add_query_vars' ) );
+		\add_filter( 'pre_get_avatar_data', array( self::class, 'pre_get_avatar_data' ), 11, 2 );
+		\add_filter( 'get_comment_link', array( self::class, 'remote_comment_link' ), 11, 3 );
 
 		// Add support for ActivityPub to custom post types
-		$post_types = \get_option( 'activitypub_support_post_types', array( 'post', 'page' ) ) ? \get_option( 'activitypub_support_post_types', array( 'post', 'page' ) ) : array();
+		$transformer_mapping = \get_option( 'activitypub_transformer_mapping', array( 'post' => 'activitypub/default', 'page' => 'activitypub/default' ) ) ? \get_option( 'activitypub_transformer_mapping', array( 'post' => 'activitypub/default', 'page' => 'activitypub/default' ) ) : array();
 
-		foreach ( $post_types as $post_type ) {
+		foreach ( array_keys( $transformer_mapping ) as $post_type ) {
 			\add_post_type_support( $post_type, 'activitypub' );
 		}
 
-		\add_action( 'transition_post_status', array( '\Activitypub\Activitypub', 'schedule_post_activity' ), 10, 3 );
+		\add_action( 'wp_trash_post', array( self::class, 'trash_post' ), 1 );
+		\add_action( 'untrash_post', array( self::class, 'untrash_post' ), 1 );
+
+		\add_action( 'init', array( self::class, 'add_rewrite_rules' ), 11 );
+
+		\add_action( 'after_setup_theme', array( self::class, 'theme_compat' ), 99 );
+
+		\add_action( 'in_plugin_update_message-' . ACTIVITYPUB_PLUGIN_BASENAME, array( self::class, 'plugin_update_message' ) );
 	}
 
 	/**
-	 * Return a AS2 JSON version of an author, post or page
+	 * Activation Hook
 	 *
-	 * @param  string $template the path to the template object
+	 * @return void
+	 */
+	public static function activate() {
+		self::flush_rewrite_rules();
+
+		Scheduler::register_schedules();
+	}
+
+	/**
+	 * Deactivation Hook
 	 *
-	 * @return string the new path to the JSON template
+	 * @return void
+	 */
+	public static function deactivate() {
+		self::flush_rewrite_rules();
+
+		Scheduler::deregister_schedules();
+	}
+
+	/**
+	 * Uninstall Hook
+	 *
+	 * @return void
+	 */
+	public static function uninstall() {
+		Scheduler::deregister_schedules();
+	}
+
+	/**
+	 * Return a AS2 JSON version of an author, post or page.
+	 *
+	 * @param  string $template The path to the template object.
+	 *
+	 * @return string The new path to the JSON template.
 	 */
 	public static function render_json_template( $template ) {
-		if ( ! \is_author() && ! \is_singular() ) {
+		if ( defined( 'REST_REQUEST' ) && REST_REQUEST ) {
+			return $template;
+		}
+
+		if ( ! is_activitypub_request() ) {
+			return $template;
+		}
+
+		$json_template = false;
+
+		// check if user can publish posts
+		if ( \is_author() && is_wp_error( Users::get_by_id( \get_the_author_meta( 'ID' ) ) ) ) {
 			return $template;
 		}
 
 		if ( \is_author() ) {
-			$json_template = \dirname( __FILE__ ) . '/../templates/json-author.php';
+			$json_template = ACTIVITYPUB_PLUGIN_DIR . '/templates/author-json.php';
 		} elseif ( \is_singular() ) {
-			$json_template = \dirname( __FILE__ ) . '/../templates/json-post.php';
+			$json_template = ACTIVITYPUB_PLUGIN_DIR . '/templates/post-json.php';
+		} elseif ( \is_home() ) {
+			$json_template = ACTIVITYPUB_PLUGIN_DIR . '/templates/blog-json.php';
 		}
 
-		global $wp_query;
-
-		if ( isset( $wp_query->query_vars['activitypub'] ) ) {
-			return $json_template;
-		}
-
-		if ( ! isset( $_SERVER['HTTP_ACCEPT'] ) ) {
+		if ( ACTIVITYPUB_AUTHORIZED_FETCH ) {
+			$verification = Signature::verify_http_signature( $_SERVER );
+			if ( \is_wp_error( $verification ) ) {
+				// fallback as template_loader can't return http headers
 				return $template;
 			}
-
-		$accept_header = $_SERVER['HTTP_ACCEPT'];
-
-		if (
-			\stristr( $accept_header, 'application/activity+json' ) ||
-			\stristr( $accept_header, 'application/ld+json' )
-		) {
-			return $json_template;
 		}
 
-		// accept header as an array
-		$accept = \explode( ',', \trim( $accept_header ) );
-
-		if (
-			\in_array( 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"', $accept, true ) ||
-			\in_array( 'application/activity+json', $accept, true ) ||
-			\in_array( 'application/ld+json', $accept, true ) ||
-			\in_array( 'application/json', $accept, true )
-		) {
 		return $json_template;
 	}
 
-		return $template;
-	}
-
 	/**
-	 * Add the 'photos' query variable so WordPress
-	 * won't mangle it.
+	 * Add the 'activitypub' query variable so WordPress won't mangle it.
 	 */
 	public static function add_query_vars( $vars ) {
 		$vars[] = 'activitypub';
@@ -89,43 +119,10 @@ class Activitypub {
 	}
 
 	/**
-	 * Add our rewrite endpoint to permalinks and pages.
-	 */
-	public static function add_rewrite_endpoint() {
-		\add_rewrite_endpoint( 'activitypub', EP_AUTHORS | EP_PERMALINK | EP_PAGES );
-	}
-
-	/**
-	 * Schedule Activities
-	 *
-	 * @param int $post_id
-	 */
-	public static function schedule_post_activity( $new_status, $old_status, $post ) {
-		// do not send activities if post is password protected
-		if ( \post_password_required( $post ) ) {
-			return;
-		}
-
-		// check if post-type supports ActivityPub
-		$post_types = \get_post_types_by_support( 'activitypub' );
-		if ( ! \in_array( $post->post_type, $post_types, true ) ) {
-			return;
-		}
-
-		if ( 'publish' === $new_status && 'publish' !== $old_status ) {
-			\wp_schedule_single_event( \time(), 'activitypub_send_post_activity', array( $post->ID ) );
-		} elseif ( 'publish' === $new_status ) {
-			\wp_schedule_single_event( \time(), 'activitypub_send_update_activity', array( $post->ID ) );
-		} elseif ( 'trash' === $new_status ) {
-			\wp_schedule_single_event( \time(), 'activitypub_send_delete_activity', array( get_permalink( $post ) ) );
-		}
-	}
-
-	/**
-	 * Replaces the default avatar
+	 * Replaces the default avatar.
 	 *
 	 * @param array             $args        Arguments passed to get_avatar_data(), after processing.
-	 * @param int|string|object $id_or_email A user ID, email address, or comment object
+	 * @param int|string|object $id_or_email A user ID, email address, or comment object.
 	 *
 	 * @return array $args
 	 */
@@ -139,13 +136,20 @@ class Activitypub {
 		}
 
 		$allowed_comment_types = \apply_filters( 'get_avatar_comment_types', array( 'comment' ) );
-		if ( ! empty( $id_or_email->comment_type ) && ! \in_array( $id_or_email->comment_type, (array) $allowed_comment_types, true ) ) {
+		if (
+			! empty( $id_or_email->comment_type ) &&
+			! \in_array(
+				$id_or_email->comment_type,
+				(array) $allowed_comment_types,
+				true
+			)
+		) {
 			$args['url'] = false;
 			/** This filter is documented in wp-includes/link-template.php */
 			return \apply_filters( 'get_avatar_data', $args, $id_or_email );
 		}
 
-		// check if comment has an avatar
+		// Check if comment has an avatar.
 		$avatar = self::get_avatar_url( $id_or_email->comment_ID );
 
 		if ( $avatar ) {
@@ -163,8 +167,7 @@ class Activitypub {
 	}
 
 	/**
-	 * Function to retrieve Avatar URL if stored in meta
-	 *
+	 * Function to retrieve Avatar URL if stored in meta.
 	 *
 	 * @param int|WP_Comment $comment
 	 *
@@ -176,4 +179,153 @@ class Activitypub {
 		}
 		return \get_comment_meta( $comment->comment_ID, 'avatar_url', true );
 	}
+
+	/**
+	 * Link remote comments to source url.
+	 *
+	 * @param string $comment_link
+	 * @param object|WP_Comment $comment
+	 *
+	 * @return string $url
+	 */
+	public static function remote_comment_link( $comment_link, $comment ) {
+		$remote_comment_link = get_comment_meta( $comment->comment_ID, 'source_url', true );
+		if ( $remote_comment_link ) {
+			$comment_link = esc_url( $remote_comment_link );
+		}
+		return $comment_link;
+	}
+
+	/**
+	 * Store permalink in meta, to send delete Activity.
+	 *
+	 * @param string $post_id The Post ID.
+	 *
+	 * @return void
+	 */
+	public static function trash_post( $post_id ) {
+		\add_post_meta(
+			$post_id,
+			'activitypub_canonical_url',
+			\get_permalink( $post_id ),
+			true
+		);
+	}
+
+	/**
+	 * Delete permalink from meta
+	 *
+	 * @param string $post_id The Post ID
+	 *
+	 * @return void
+	 */
+	public static function untrash_post( $post_id ) {
+		\delete_post_meta( $post_id, 'activitypub_canonical_url' );
+	}
+
+	/**
+	 * Add rewrite rules
+	 */
+	public static function add_rewrite_rules() {
+		// If another system needs to take precedence over the ActivityPub rewrite rules,
+		// they can define their own and will manually call the appropriate functions as required.
+		if ( ACTIVITYPUB_DISABLE_REWRITES ) {
+			return;
+		}
+
+		if ( ! \class_exists( 'Webfinger' ) ) {
+			\add_rewrite_rule(
+				'^.well-known/webfinger',
+				'index.php?rest_route=/' . ACTIVITYPUB_REST_NAMESPACE . '/webfinger',
+				'top'
+			);
+		}
+
+		if ( ! \class_exists( 'Nodeinfo_Endpoint' ) && true === (bool) \get_option( 'blog_public', 1 ) ) {
+			\add_rewrite_rule(
+				'^.well-known/nodeinfo',
+				'index.php?rest_route=/' . ACTIVITYPUB_REST_NAMESPACE . '/nodeinfo/discovery',
+				'top'
+			);
+			\add_rewrite_rule(
+				'^.well-known/x-nodeinfo2',
+				'index.php?rest_route=/' . ACTIVITYPUB_REST_NAMESPACE . '/nodeinfo2',
+				'top'
+			);
+		}
+
+		\add_rewrite_rule(
+			'^@([\w\-\.]+)',
+			'index.php?rest_route=/' . ACTIVITYPUB_REST_NAMESPACE . '/users/$matches[1]',
+			'top'
+		);
+
+		\add_rewrite_endpoint( 'activitypub', EP_AUTHORS | EP_PERMALINK | EP_PAGES );
+	}
+
+	/**
+	 * Flush rewrite rules;
+	 */
+	public static function flush_rewrite_rules() {
+		self::add_rewrite_rules();
+		\flush_rewrite_rules();
+	}
+
+	/**
+	 * Theme compatibility stuff
+	 *
+	 * @return void
+	 */
+	public static function theme_compat() {
+		$site_icon = get_theme_support( 'custom-logo' );
+
+		if ( ! $site_icon ) {
+			// custom logo support
+			add_theme_support(
+				'custom-logo',
+				array(
+					'height' => 80,
+					'width'  => 80,
+				)
+			);
+		}
+
+		$custom_header = get_theme_support( 'custom-header' );
+
+		if ( ! $custom_header ) {
+			// This theme supports a custom header
+			$custom_header_args = array(
+				'width'       => 1250,
+				'height'      => 600,
+				'header-text' => true,
+			);
+			add_theme_support( 'custom-header', $custom_header_args );
+		}
+	}
+
+	/**
+	 * Display plugin upgrade notice to users
+	 *
+	 * @param array $data The plugin data
+	 *
+	 * @return void
+	 */
+	public static function plugin_update_message( $data ) {
+		if ( ! isset( $data['upgrade_notice'] ) ) {
+			return;
+		}
+
+		printf(
+			'<div class="update-message">%s</div>',
+			wp_kses(
+				wpautop( $data['upgrade_notice '] ),
+				array(
+					'p'      => array(),
+					'a'      => array( 'href', 'title' ),
+					'strong' => array(),
+					'em'     => array(),
+				)
+			)
+		);
+	}
 }

includes/class-admin.php

@@ -1,6 +1,10 @@
 <?php
 namespace Activitypub;
 
+use WP_User_Query;
+use Activitypub\Model\Blog_User;
+use Activitypub\Base\Transformer\Base as Transformer_Base;
+
 /**
  * ActivityPub Admin Class
  *
@@ -11,11 +15,23 @@ class Admin {
 	 * Initialize the class, registering WordPress hooks
 	 */
 	public static function init() {
-		\add_action( 'admin_menu', array( '\Activitypub\Admin', 'admin_menu' ) );
-		\add_action( 'admin_init', array( '\Activitypub\Admin', 'register_settings' ) );
-		\add_action( 'show_user_profile', array( '\Activitypub\Admin', 'add_fediverse_profile' ) );
-		\add_action( 'personal_options_update', array( '\Activitypub\Admin', 'save_profile' ), 11 );
-		\add_action( 'edit_user_profile_update', array( '\Activitypub\Admin', 'save_profile' ), 11 );
+		\add_action( 'admin_menu', array( self::class, 'admin_menu' ) );
+		\add_action( 'admin_init', array( self::class, 'register_settings' ) );
+		\add_action( 'personal_options_update', array( self::class, 'save_user_description' ) );
+		\add_action( 'admin_enqueue_scripts', array( self::class, 'enqueue_scripts' ) );
+
+		if ( ! is_user_disabled( get_current_user_id() ) ) {
+			\add_action( 'show_user_profile', array( self::class, 'add_profile' ) );
+		}
+
+		add_filter(
+			'activitypub/transformers/is_transformer_enabled',
+			function( $should_register, Transformer_Base $transformer_instance ) {
+				return ! Options::is_transformer_disabled( $transformer_instance->get_name() );
+			},
+			10,
+			2
+		);
 	}
 
 	/**
@@ -23,32 +39,61 @@ class Admin {
 	 */
 	public static function admin_menu() {
 		$settings_page = \add_options_page(
-			'ActivityPub',
+			'Welcome',
 			'ActivityPub',
 			'manage_options',
 			'activitypub',
-			array( '\Activitypub\Admin', 'settings_page' )
+			array( self::class, 'settings_page' )
 		);
 
-		\add_action( 'load-' . $settings_page, array( '\Activitypub\Admin', 'add_settings_help_tab' ) );
+		\add_action( 'load-' . $settings_page, array( self::class, 'add_settings_help_tab' ) );
 
-		$followers_list_page = \add_users_page( \__( 'Followers', 'activitypub' ), __( 'Followers (Fediverse)', 'activitypub' ), 'read', 'activitypub-followers-list', array( '\Activitypub\Admin', 'followers_list_page' ) );
+		// user has to be able to publish posts
+		if ( ! is_user_disabled( get_current_user_id() ) ) {
+			$followers_list_page = \add_users_page( \__( 'Followers', 'activitypub' ), \__( 'Followers', 'activitypub' ), 'read', 'activitypub-followers-list', array( self::class, 'followers_list_page' ) );
 
-		\add_action( 'load-' . $followers_list_page, array( '\Activitypub\Admin', 'add_followers_list_help_tab' ) );
+			\add_action( 'load-' . $followers_list_page, array( self::class, 'add_followers_list_help_tab' ) );
+		}
 	}
 
 	/**
 	 * Load settings page
 	 */
 	public static function settings_page() {
-		\load_template( \dirname( __FILE__ ) . '/../templates/settings.php' );
+		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
+		if ( empty( $_GET['tab'] ) ) {
+			$tab = 'welcome';
+		} else {
+			// phpcs:ignore WordPress.Security.NonceVerification.Recommended
+			$tab = sanitize_key( $_GET['tab'] );
+		}
+
+		switch ( $tab ) {
+			case 'settings':
+				\load_template( ACTIVITYPUB_PLUGIN_DIR . 'templates/settings.php' );
+				break;
+			case 'followers':
+				\load_template( ACTIVITYPUB_PLUGIN_DIR . 'templates/blog-user-followers-list.php' );
+				break;
+			case 'welcome':
+			default:
+				wp_enqueue_script( 'plugin-install' );
+				add_thickbox();
+				wp_enqueue_script( 'updates' );
+
+				\load_template( ACTIVITYPUB_PLUGIN_DIR . 'templates/welcome.php' );
+				break;
+		}
 	}
 
 	/**
 	 * Load user settings page
 	 */
 	public static function followers_list_page() {
-		\load_template( \dirname( __FILE__ ) . '/../templates/followers-list.php' );
+		// user has to be able to publish posts
+		if ( ! is_user_disabled( get_current_user_id() ) ) {
+			\load_template( ACTIVITYPUB_PLUGIN_DIR . 'templates/user-followers-list.php' );
+		}
 	}
 
 	/**
@@ -56,122 +101,218 @@ class Admin {
 	 */
 	public static function register_settings() {
 		\register_setting(
-			'activitypub', 'activitypub_post_content_type', array(
+			'activitypub',
+			'activitypub_post_content_type',
+			array(
 				'type' => 'string',
-				'description' => \__( 'Use summary or full content', 'activitypub' ),
+				'description' => \__( 'Use title and link, summary, full or custom content', 'activitypub' ),
 				'show_in_rest' => array(
 					'schema' => array(
-						'enum' => array( 'excerpt', 'content' ),
+						'enum' => array(
+							'title',
+							'excerpt',
+							'content',
+						),
 					),
 				),
 				'default' => 'content',
 			)
 		);
 		\register_setting(
-			'activitypub', 'activitypub_object_type', array(
+			'activitypub',
+			'activitypub_custom_post_content',
+			array(
+				'type' => 'string',
+				'description' => \__( 'Define your own custom post template', 'activitypub' ),
+				'show_in_rest' => true,
+				'default' => ACTIVITYPUB_CUSTOM_POST_CONTENT,
+			)
+		);
+		\register_setting(
+			'activitypub',
+			'activitypub_max_image_attachments',
+			array(
+				'type' => 'integer',
+				'description' => \__( 'Number of images to attach to posts.', 'activitypub' ),
+				'default' => ACTIVITYPUB_MAX_IMAGE_ATTACHMENTS,
+			)
+		);
+		\register_setting(
+			'activitypub',
+			'activitypub_object_type',
+			array(
 				'type' => 'string',
 				'description' => \__( 'The Activity-Object-Type', 'activitypub' ),
 				'show_in_rest' => array(
 					'schema' => array(
-						'enum' => array( 'note', 'article', 'wordpress-post-format' ),
+						'enum' => array(
+							'note',
+							'article',
+							'wordpress-post-format',
+						),
 					),
 				),
 				'default' => 'note',
 			)
 		);
 		\register_setting(
-			'activitypub', 'activitypub_use_shortlink', array(
-				'type' => 'boolean',
-				'description' => \__( 'Use the Shortlink instead of the permalink', 'activitypub' ),
-				'default' => 0,
-			)
-		);
-		\register_setting(
-			'activitypub', 'activitypub_use_hashtags', array(
+			'activitypub',
+			'activitypub_use_hashtags',
+			array(
 				'type' => 'boolean',
 				'description' => \__( 'Add hashtags in the content as native tags and replace the #tag with the tag-link', 'activitypub' ),
-				'default' => 0,
+				'default' => '0',
 			)
 		);
-		\register_setting(
-			'activitypub', 'activitypub_add_tags_as_hashtags', array(
-				'type' => 'boolean',
-				'description' => \__( 'Add all tags as hashtags at the end of each activity', 'activitypub' ),
-				'default' => 0,
-			)
-		);
-		\register_setting(
-			'activitypub', 'activitypub_support_post_types', array(
-				'type'         => 'string',
-				'description'  => \esc_html__( 'Enable ActivityPub support for post types', 'activitypub' ),
-				'show_in_rest' => true,
-				'default'      => array( 'post', 'pages' ),
-			)
-		);
-		\register_setting(
-			'activitypub', 'activitypub_profile_fields', array(
+
+		/**
+		 * Flexible activation of post_types together with mapping ActivityPub transformers.
+		 *
+		 * If a post-type is not mapped to any ActivtiyPub transformer it means it is not activated
+		 * for ActivityPub federation.
+		 *
+		 * @since version_number_transformer_management_placeholder
+		 */
+		register_setting(
+			'activitypub',
+			'activitypub_transformer_mapping',
+			array(
 				'type'         => 'array',
-				'description'  => \esc_html__( 'You can have up to 4 items displayed as a table on your profile.', 'activitypub' ),
+				'default'      => array(
+					'post' => 'note',
+				),
+				'show_in_rest' => array(
+					'schema' => array(
+						'type'  => 'array',
+						'items' => array(
+							'type' => 'string',
+						),
+					),
+				),
+				'sanitize_callback' => function ( $value ) {
+					// Check if $value is an array
+					if ( ! is_array( $value ) ) {
+						return array();
+					}
+					$value_keys = array_keys( $value );
+
+					$all_public_post_types = \get_post_types( array( 'public' => true ), 'names' );
+
+					// Unset the keys that are missing in $keysToCheck
+					foreach ( array_diff( $value_keys, $all_public_post_types ) as $missing_key ) {
+						unset( $value[ $missing_key ] );
+					}
+					// var_dump($value);
+					return $value;
+				},
+			)
+		);
+		\register_setting(
+			'activitypub',
+			'activitypub_blog_user_identifier',
+			array(
+				'type'              => 'string',
+				'description'       => \esc_html__( 'The Identifier of the Blog-User', 'activitypub' ),
 				'show_in_rest'      => true,
-				'default'      => array(),
+				'default'           => Blog_User::get_default_username(),
+				'sanitize_callback' => function( $value ) {
+					// hack to allow dots in the username
+					$parts     = explode( '.', $value );
+					$sanitized = array();
+
+					foreach ( $parts as $part ) {
+						$sanitized[] = \sanitize_title( $part );
+					}
+
+					$sanitized = implode( '.', $sanitized );
+
+					// check for login or nicename.
+					$user = new WP_User_Query(
+						array(
+							'search'         => $sanitized,
+							'search_columns' => array( 'user_login', 'user_nicename' ),
+							'number'         => 1,
+							'hide_empty'     => true,
+							'fields'         => 'ID',
+						)
+					);
+
+					if ( $user->results ) {
+						add_settings_error(
+							'activitypub_blog_user_identifier',
+							'activitypub_blog_user_identifier',
+							\esc_html__( 'You cannot use an existing author\'s name for the blog profile ID.', 'activitypub' ),
+							'error'
+						);
+
+						return Blog_User::get_default_username();
+					}
+
+					return $sanitized;
+				},
+			)
+		);
+		\register_setting(
+			'activitypub',
+			'activitypub_enable_users',
+			array(
+				'type' => 'boolean',
+				'description' => \__( 'Every Author on this Blog (with the publish_posts capability) gets his own ActivityPub enabled Profile.', 'activitypub' ),
+				'default' => '1',
+			)
+		);
+		\register_setting(
+			'activitypub',
+			'activitypub_enable_blog_user',
+			array(
+				'type' => 'boolean',
+				'description' => \__( 'Your Blog becomes an ActivityPub compatible Profile.', 'activitypub' ),
+				'default' => '0',
 			)
 		);
 	}
 
 	public static function add_settings_help_tab() {
-		\get_current_screen()->add_help_tab(
-			array(
-				'id'      => 'overview',
-				'title'   => \__( 'Overview', 'activitypub' ),
-				'content' =>
-					'<p>' . \__( 'ActivityPub is a decentralized social networking protocol based on the ActivityStreams 2.0 data format. ActivityPub is an official W3C recommended standard published by the W3C Social Web Working Group. It provides a client to server API for creating, updating and deleting content, as well as a federated server to server API for delivering notifications and subscribing to content.', 'activitypub' ) . '</p>',
-			)
-		);
-
-		\get_current_screen()->set_help_sidebar(
-			'<p><strong>' . \__( 'For more information:', 'activitypub' ) . '</strong></p>' .
-			'<p>' . \__( '<a href="https://activitypub.rocks/">Test Suite</a>', 'activitypub' ) . '</p>' .
-			'<p>' . \__( '<a href="https://www.w3.org/TR/activitypub/">W3C Spec</a>', 'activitypub' ) . '</p>' .
-			'<p>' . \__( '<a href="https://github.com/pfefferle/wordpress-activitypub/issues">Give us feedback</a>', 'activitypub' ) . '</p>' .
-			'<hr />' .
-			'<p>' . \__( '<a href="https://notiz.blog/donate">Donate</a>', 'activitypub' ) . '</p>'
-		);
+		require_once ACTIVITYPUB_PLUGIN_DIR . 'includes/help.php';
 	}
 
 	public static function add_followers_list_help_tab() {
 		// todo
 	}
 
-	/**
-	 * Undocumented function
-	 *
-	 * @param [type] $user
-	 * @return void
-	 */
-	public static function add_fediverse_profile( $user ) {
-		\load_template( \dirname( __FILE__ ) . '/../templates/user-settings.php' );
+	public static function add_profile( $user ) {
+		$description = get_user_meta( $user->ID, 'activitypub_user_description', true );
+
+		\load_template(
+			ACTIVITYPUB_PLUGIN_DIR . 'templates/user-settings.php',
+			true,
+			array(
+				'description' => $description,
+			)
+		);
 	}
 
-	/**
-	 * Save the ActivityPub specific data.
-	 *
-	 * @param int $user_id
-	 * @return void
-	 */
-	public static function save_profile( $user_id ) {
-		if ( ! current_user_can( 'edit_user', $user_id ) ) {
+	public static function save_user_description( $user_id ) {
+		if ( ! isset( $_REQUEST['_apnonce'] ) ) {
 			return false;
 		}
-
-		$profile_fields = array();
-
-        if ( isset( $_POST['activitypub_profile_fields'] ) ) {
-			foreach ( $_POST['activitypub_profile_fields'] as $key => $value ) {
-
+		$nonce = sanitize_text_field( wp_unslash( $_REQUEST['_apnonce'] ) );
+		if (
+			! wp_verify_nonce( $nonce, 'activitypub-user-description' ) ||
+			! current_user_can( 'edit_user', $user_id )
+		) {
+			return false;
+		}
+		$description = ! empty( $_POST['activitypub-user-description'] ) ? sanitize_text_field( wp_unslash( $_POST['activitypub-user-description'] ) ) : false;
+		if ( $description ) {
+			update_user_meta( $user_id, 'activitypub_user_description', $description );
 		}
 	}
 
-		echo "<pre>";
-		var_dump($_POST);
+	public static function enqueue_scripts( $hook_suffix ) {
+		if ( false !== strpos( $hook_suffix, 'activitypub' ) ) {
+			wp_enqueue_style( 'activitypub-admin-styles', plugins_url( 'assets/css/activitypub-admin.css', ACTIVITYPUB_PLUGIN_FILE ), array(), '1.0.0' );
+			wp_enqueue_script( 'activitypub-admin-styles', plugins_url( 'assets/js/activitypub-admin.js', ACTIVITYPUB_PLUGIN_FILE ), array( 'jquery' ), '1.0.0', false );
+		}
 	}
 }

includes/class-blocks.php

@@ -0,0 +1,151 @@
+<?php
+namespace Activitypub;
+
+use Activitypub\Collection\Followers;
+use Activitypub\Collection\Users as User_Collection;
+use Activitypub\is_user_type_disabled;
+
+class Blocks {
+	public static function init() {
+		// this is already being called on the init hook, so just add it.
+		self::register_blocks();
+		\add_action( 'wp_enqueue_scripts', array( self::class, 'add_data' ) );
+		\add_action( 'enqueue_block_editor_assets', array( self::class, 'add_data' ) );
+	}
+
+	public static function add_data() {
+		$context = is_admin() ? 'editor' : 'view';
+		$followers_handle = 'activitypub-followers-' . $context . '-script';
+		$follow_me_handle = 'activitypub-follow-me-' . $context . '-script';
+		$data = array(
+			'namespace' => ACTIVITYPUB_REST_NAMESPACE,
+			'enabled' => array(
+				'site' => ! is_user_type_disabled( 'blog' ),
+				'users' => ! is_user_type_disabled( 'user' ),
+			),
+		);
+		$js = sprintf( 'var _activityPubOptions = %s;', wp_json_encode( $data ) );
+		\wp_add_inline_script( $followers_handle, $js, 'before' );
+		\wp_add_inline_script( $follow_me_handle, $js, 'before' );
+	}
+
+	public static function register_blocks() {
+		\register_block_type_from_metadata(
+			ACTIVITYPUB_PLUGIN_DIR . '/build/followers',
+			array(
+				'render_callback' => array( self::class, 'render_follower_block' ),
+			)
+		);
+		\register_block_type_from_metadata(
+			ACTIVITYPUB_PLUGIN_DIR . '/build/follow-me',
+			array(
+				'render_callback' => array( self::class, 'render_follow_me_block' ),
+			)
+		);
+	}
+
+	private static function get_user_id( $user_string ) {
+		if ( is_numeric( $user_string ) ) {
+			return absint( $user_string );
+		}
+		// any other non-numeric falls back to 0, including the `site` string used in the UI
+		return 0;
+	}
+
+	/**
+	 * Filter an array by a list of keys.
+	 * @param array $array The array to filter.
+	 * @param array $keys The keys to keep.
+	 * @return array The filtered array.
+	 */
+	protected static function filter_array_by_keys( $array, $keys ) {
+		return array_intersect_key( $array, array_flip( $keys ) );
+	}
+
+	/**
+	 * Render the follow me block.
+	 * @param array $attrs The block attributes.
+	 * @return string The HTML to render.
+	 */
+	public static function render_follow_me_block( $attrs ) {
+		$user_id = self::get_user_id( $attrs['selectedUser'] );
+		$user = User_Collection::get_by_id( $user_id );
+		if ( ! is_wp_error( $user ) ) {
+			$attrs['profileData'] = self::filter_array_by_keys(
+				$user->to_array(),
+				array( 'icon', 'name', 'resource' )
+			);
+		}
+		$wrapper_attributes = get_block_wrapper_attributes(
+			array(
+				'aria-label' => __( 'Follow me on the Fediverse', 'activitypub' ),
+				'class'      => 'activitypub-follow-me-block-wrapper',
+				'data-attrs' => wp_json_encode( $attrs ),
+			)
+		);
+		// todo: render more than an empty div?
+		return '<div ' . $wrapper_attributes . '></div>';
+	}
+
+	public static function render_follower_block( $attrs ) {
+		$followee_user_id = self::get_user_id( $attrs['selectedUser'] );
+		$per_page = absint( $attrs['per_page'] );
+		$follower_data = Followers::get_followers_with_count( $followee_user_id, $per_page );
+
+		$attrs['followerData']['total'] = $follower_data['total'];
+		$attrs['followerData']['followers'] = array_map(
+			function( $follower ) {
+				return self::filter_array_by_keys(
+					$follower->to_array(),
+					array( 'icon', 'name', 'preferredUsername', 'url' )
+				);
+			},
+			$follower_data['followers']
+		);
+		$wrapper_attributes = get_block_wrapper_attributes(
+			array(
+				'aria-label' => __( 'Fediverse Followers', 'activitypub' ),
+				'class'      => 'activitypub-follower-block',
+				'data-attrs' => wp_json_encode( $attrs ),
+			)
+		);
+
+		$html = '<div ' . $wrapper_attributes . '>';
+		if ( $attrs['title'] ) {
+			$html .= '<h3>' . esc_html( $attrs['title'] ) . '</h3>';
+		}
+		$html .= '<ul>';
+		foreach ( $follower_data['followers'] as $follower ) {
+			$html .= '<li>' . self::render_follower( $follower ) . '</li>';
+		}
+		// We are only pagination on the JS side. Could be revisited but we gotta ship!
+		$html .= '</ul></div>';
+		return $html;
+	}
+
+	public static function render_follower( $follower ) {
+		$external_svg = '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24" class="components-external-link__icon css-rvs7bx esh4a730" aria-hidden="true" focusable="false"><path d="M18.2 17c0 .7-.6 1.2-1.2 1.2H7c-.7 0-1.2-.6-1.2-1.2V7c0-.7.6-1.2 1.2-1.2h3.2V4.2H7C5.5 4.2 4.2 5.5 4.2 7v10c0 1.5 1.2 2.8 2.8 2.8h10c1.5 0 2.8-1.2 2.8-2.8v-3.6h-1.5V17zM14.9 3v1.5h3.7l-6.4 6.4 1.1 1.1 6.4-6.4v3.7h1.5V3h-6.3z"></path></svg>';
+		$template =
+			'<a href="%s" title="%s" class="components-external-link activitypub-link" target="_blank" rel="external noreferrer noopener">
+				<img width="40" height="40" src="%s" class="avatar activitypub-avatar" />
+				<span class="activitypub-actor">
+					<strong class="activitypub-name">%s</strong>
+					<span class="sep">/</span>
+					<span class="activitypub-handle">@%s</span>
+				</span>
+				%s
+			</a>';
+
+		$data = $follower->to_array();
+
+		return sprintf(
+			$template,
+			esc_url( $data['url'] ),
+			esc_attr( $data['name'] ),
+			esc_attr( $data['icon']['url'] ),
+			esc_html( $data['name'] ),
+			esc_html( $data['preferredUsername'] ),
+			$external_svg
+		);
+	}
+}

includes/class-debug.php

@@ -1,6 +1,9 @@
 <?php
 namespace Activitypub;
 
+use WP_DEBUG;
+use WP_DEBUG_LOG;
+
 /**
  * ActivityPub Debug Class
  *
@@ -11,19 +14,22 @@ class Debug {
 	 * Initialize the class, registering WordPress hooks
 	 */
 	public static function init() {
-		if ( WP_DEBUG_LOG ) {
-			\add_action( 'activitypub_safe_remote_post_response', array( '\Activitypub\Debug', 'log_remote_post_responses' ), 10, 4 );
+		if ( WP_DEBUG && WP_DEBUG_LOG ) {
+			\add_action( 'activitypub_safe_remote_post_response', array( self::class, 'log_remote_post_responses' ), 10, 4 );
 		}
 	}
 
 	public static function log_remote_post_responses( $response, $url, $body, $user_id ) {
+		// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log, WordPress.PHP.DevelopmentFunctions.error_log_print_r
 		\error_log( "Request to: {$url} with response: " . \print_r( $response, true ) );
 	}
 
 	public static function write_log( $log ) {
 		if ( \is_array( $log ) || \is_object( $log ) ) {
+			// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log, WordPress.PHP.DevelopmentFunctions.error_log_print_r
 			\error_log( \print_r( $log, true ) );
 		} else {
+			// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log
 			\error_log( $log );
 		}
 	}

includes/class-hashtag.php

@@ -12,12 +12,8 @@ class Hashtag {
 	 */
 	public static function init() {
 		if ( '1' === \get_option( 'activitypub_use_hashtags', '1' ) ) {
-			\add_filter( 'wp_insert_post', array( '\Activitypub\Hashtag', 'insert_post' ), 99, 2 );
-			\add_filter( 'the_content', array( '\Activitypub\Hashtag', 'the_content' ), 99, 2 );
-		}
-		if ( '1' === \get_option( 'activitypub_add_tags_as_hashtags', '0' ) ) {
-			\add_filter( 'activitypub_the_summary', array( '\Activitypub\Hashtag', 'add_hashtags_to_content' ), 10, 2 );
-			\add_filter( 'activitypub_the_content', array( '\Activitypub\Hashtag', 'add_hashtags_to_content' ), 10, 2 );
+			\add_filter( 'wp_insert_post', array( self::class, 'insert_post' ), 10, 2 );
+			\add_filter( 'the_content', array( self::class, 'the_content' ), 10, 2 );
 		}
 	}
 
@@ -25,15 +21,15 @@ class Hashtag {
 	 * Filter to save #tags as real WordPress tags
 	 *
 	 * @param int     $id the rev-id
-	 * @param array $data the post-data as array
+	 * @param WP_Post $post the post
 	 *
 	 * @return
 	 */
-	public static function insert_post( $id, $data ) {
-		if ( \preg_match_all( '/' . ACTIVITYPUB_HASHTAGS_REGEXP . '/i', $data->post_content, $match ) ) {
+	public static function insert_post( $id, $post ) {
+		if ( \preg_match_all( '/' . ACTIVITYPUB_HASHTAGS_REGEXP . '/i', $post->post_content, $match ) ) {
 			$tags = \implode( ', ', $match[1] );
 
-			\wp_add_post_tags( $data->post_parent, $tags );
+			\wp_add_post_tags( $post->post_parent, $tags );
 		}
 
 		return $id;
@@ -47,10 +43,61 @@ class Hashtag {
 	 * @return string the filtered post-content
 	 */
 	public static function the_content( $the_content ) {
-		$the_content = \preg_replace_callback( '/' . ACTIVITYPUB_HASHTAGS_REGEXP . '/i', array( '\Activitypub\Hashtag', 'replace_with_links' ), $the_content );
-
+		// small protection against execution timeouts: limit to 1 MB
+		if ( mb_strlen( $the_content ) > MB_IN_BYTES ) {
 			return $the_content;
 		}
+		$tag_stack = array();
+		$protected_tags = array(
+			'pre',
+			'code',
+			'textarea',
+			'style',
+			'a',
+		);
+		$content_with_links = '';
+		$in_protected_tag = false;
+		foreach ( wp_html_split( $the_content ) as $chunk ) {
+			if ( preg_match( '#^<!--[\s\S]*-->$#i', $chunk, $m ) ) {
+				$content_with_links .= $chunk;
+				continue;
+			}
+
+			if ( preg_match( '#^<(/)?([a-z-]+)\b[^>]*>$#i', $chunk, $m ) ) {
+				$tag = strtolower( $m[2] );
+				if ( '/' === $m[1] ) {
+					// Closing tag.
+					$i = array_search( $tag, $tag_stack );
+					// We can only remove the tag from the stack if it is in the stack.
+					if ( false !== $i ) {
+						$tag_stack = array_slice( $tag_stack, 0, $i );
+					}
+				} else {
+					// Opening tag, add it to the stack.
+					$tag_stack[] = $tag;
+				}
+
+				// If we're in a protected tag, the tag_stack contains at least one protected tag string.
+				// The protected tag state can only change when we encounter a start or end tag.
+				$in_protected_tag = array_intersect( $tag_stack, $protected_tags );
+
+				// Never inspect tags.
+				$content_with_links .= $chunk;
+				continue;
+			}
+
+			if ( $in_protected_tag ) {
+				// Don't inspect a chunk inside an inspected tag.
+				$content_with_links .= $chunk;
+				continue;
+			}
+
+			// Only reachable when there is no protected tag in the stack.
+			$content_with_links .= \preg_replace_callback( '/' . ACTIVITYPUB_HASHTAGS_REGEXP . '/i', array( '\Activitypub\Hashtag', 'replace_with_links' ), $chunk );
+		}
+
+		return $content_with_links;
+	}
 
 	/**
 	 * A callback for preg_replace to build the term links
@@ -64,33 +111,9 @@ class Hashtag {
 
 		if ( $tag_object ) {
 			$link = \get_term_link( $tag_object, 'post_tag' );
-			return \sprintf( '<a rel="tag" class="u-tag u-category" href="%s">#%s</a>', $link, $tag );
+			return \sprintf( '<a rel="tag" class="hashtag u-tag u-category" href="%s">#%s</a>', $link, $tag );
 		}
 
 		return '#' . $tag;
 	}
-
-	/**
-	 * Adds all tags as hashtags to the post/summary content
-	 *
-	 * @param string  $content
-	 * @param WP_Post $post
-	 *
-	 * @return string
-	 */
-	public static function add_hashtags_to_content( $content, $post ) {
-		$tags = \get_the_tags( $post->ID );
-
-		if ( ! $tags ) {
-			return $content;
-		}
-
-		$hash_tags = array();
-
-		foreach ( $tags as $tag ) {
-			$hash_tags[] = \sprintf( '<a rel="tag" class="u-tag u-category" href="%s">#%s</a>', \get_tag_link( $tag ), $tag->slug );
-		}
-
-		return $content . '<p>' . \implode( ' ', $hash_tags ) . '</p>';
-	}
 }

includes/class-health-check.php

@@ -1,12 +1,377 @@
 <?php
 namespace Activitypub;
 
+use WP_Error;
+use Activitypub\Webfinger;
+use Activitypub\Collection\Users;
+
+use function Activitypub\get_plugin_version;
+use function Activitypub\is_user_type_disabled;
+use function Activitypub\get_webfinger_resource;
+
 /**
  * ActivityPub Health_Check Class
  *
  * @author Matthias Pfefferle
  */
 class Health_Check {
+
+	/**
+	 * Initialize health checks
+	 *
+	 * @return void
+	 */
 	public static function init() {
+		\add_filter( 'site_status_tests', array( self::class, 'add_tests' ) );
+		\add_filter( 'debug_information', array( self::class, 'debug_information' ) );
+	}
+
+	public static function add_tests( $tests ) {
+		if ( ! is_user_type_disabled( 'user' ) ) {
+			$tests['direct']['activitypub_test_author_url'] = array(
+				'label' => \__( 'Author URL test', 'activitypub' ),
+				'test'  => array( self::class, 'test_author_url' ),
+			);
+		}
+
+		$tests['direct']['activitypub_test_webfinger'] = array(
+			'label' => __( 'WebFinger Test', 'activitypub' ),
+			'test'  => array( self::class, 'test_webfinger' ),
+		);
+
+		$tests['direct']['activitypub_test_system_cron'] = array(
+			'label' => __( 'System Cron Test', 'activitypub' ),
+			'test'  => array( self::class, 'test_system_cron' ),
+		);
+
+		return $tests;
+	}
+
+	/**
+	 * Author URL tests
+	 *
+	 * @return array
+	 */
+	public static function test_author_url() {
+		$result = array(
+			'label'       => \__( 'Author URL accessible', 'activitypub' ),
+			'status'      => 'good',
+			'badge'       => array(
+				'label' => \__( 'ActivityPub', 'activitypub' ),
+				'color' => 'green',
+			),
+			'description' => \sprintf(
+				'<p>%s</p>',
+				\__( 'Your author URL is accessible and supports the required "Accept" header.', 'activitypub' )
+			),
+			'actions'     => '',
+			'test'        => 'test_author_url',
+		);
+
+		$check = self::is_author_url_accessible();
+
+		if ( true === $check ) {
+			return $result;
+		}
+
+		$result['status']         = 'critical';
+		$result['label']          = \__( 'Author URL is not accessible', 'activitypub' );
+		$result['badge']['color'] = 'red';
+		$result['description']    = \sprintf(
+			'<p>%s</p>',
+			$check->get_error_message()
+		);
+
+		return $result;
+	}
+
+	/**
+	 * System Cron tests
+	 *
+	 * @return array
+	 */
+	public static function test_system_cron() {
+		$result = array(
+			'label'       => \__( 'System Task Scheduler configured', 'activitypub' ),
+			'status'      => 'good',
+			'badge'       => array(
+				'label' => \__( 'ActivityPub', 'activitypub' ),
+				'color' => 'green',
+			),
+			'description' => \sprintf(
+				'<p>%s</p>',
+				\esc_html__( 'You seem to use the System Task Scheduler to process WP_Cron tasks.', 'activitypub' )
+			),
+			'actions'     => '',
+			'test'        => 'test_system_cron',
+		);
+
+		if ( defined( 'DISABLE_WP_CRON' ) && DISABLE_WP_CRON ) {
+			return $result;
+		}
+
+		$result['status']         = 'recommended';
+		$result['label']          = \__( 'System Task Scheduler not configured', 'activitypub' );
+		$result['badge']['color'] = 'orange';
+		$result['description']    = \sprintf(
+			'<p>%s</p>',
+			\__( 'Enhance your WordPress site’s performance and mitigate potential heavy loads caused by plugins like ActivityPub by setting up a system cron job to run WP Cron. This ensures scheduled tasks are executed consistently and reduces the reliance on website traffic for trigger events.', 'activitypub' )
+		);
+		$result['actions'] .= sprintf(
+			'<p><a href="%s" target="_blank" rel="noopener">%s<span class="screen-reader-text"> %s</span><span aria-hidden="true" class="dashicons dashicons-external"></span></a></p>',
+			__( 'https://developer.wordpress.org/plugins/cron/hooking-wp-cron-into-the-system-task-scheduler/', 'activitypub' ),
+			__( 'Learn how to hook the WP-Cron into the System Task Scheduler.', 'activitypub' ),
+			/* translators: Hidden accessibility text. */
+			__( '(opens in a new tab)', 'activitypub' )
+		);
+
+		return $result;
+	}
+
+	/**
+	 * WebFinger tests
+	 *
+	 * @return array
+	 */
+	public static function test_webfinger() {
+		$result = array(
+			'label'       => \__( 'WebFinger endpoint', 'activitypub' ),
+			'status'      => 'good',
+			'badge'       => array(
+				'label' => \__( 'ActivityPub', 'activitypub' ),
+				'color' => 'green',
+			),
+			'description' => \sprintf(
+				'<p>%s</p>',
+				\__( 'Your WebFinger endpoint is accessible and returns the correct information.', 'activitypub' )
+			),
+			'actions'     => '',
+			'test'        => 'test_webfinger',
+		);
+
+		$check = self::is_webfinger_endpoint_accessible();
+
+		if ( true === $check ) {
+			return $result;
+		}
+
+		$result['status']         = 'critical';
+		$result['label']          = \__( 'WebFinger endpoint is not accessible', 'activitypub' );
+		$result['badge']['color'] = 'red';
+		$result['description']    = \sprintf(
+			'<p>%s</p>',
+			$check->get_error_message()
+		);
+
+		return $result;
+	}
+
+	/**
+	 * Check if `author_posts_url` is accessible and that request returns correct JSON
+	 *
+	 * @return boolean|WP_Error
+	 */
+	public static function is_author_url_accessible() {
+		$user = \wp_get_current_user();
+		$author_url = \get_author_posts_url( $user->ID );
+		$reference_author_url = self::get_author_posts_url( $user->ID, $user->user_nicename );
+
+		// check for "author" in URL
+		if ( $author_url !== $reference_author_url ) {
+			return new WP_Error(
+				'author_url_not_accessible',
+				\sprintf(
+					// translators: %s: Author URL
+					\__(
+						'Your author URL <code>%s</code> was replaced, this is often done by plugins.',
+						'activitypub'
+					),
+					$author_url
+				)
+			);
+		}
+
+		// try to access author URL
+		$response = \wp_remote_get(
+			$author_url,
+			array(
+				'headers' => array( 'Accept' => 'application/activity+json' ),
+				'redirection' => 0,
+			)
+		);
+
+		if ( \is_wp_error( $response ) ) {
+			return new WP_Error(
+				'author_url_not_accessible',
+				\sprintf(
+					// translators: %s: Author URL
+					\__(
+						'Your author URL <code>%s</code> is not accessible. Please check your WordPress setup or permalink structure. If the setup seems fine, maybe check if a plugin might restrict the access.',
+						'activitypub'
+					),
+					$author_url
+				)
+			);
+		}
+
+		$response_code = \wp_remote_retrieve_response_code( $response );
+
+		// check for redirects
+		if ( \in_array( $response_code, array( 301, 302, 307, 308 ), true ) ) {
+			return new WP_Error(
+				'author_url_not_accessible',
+				\sprintf(
+					// translators: %s: Author URL
+					\__(
+						'Your author URL <code>%s</code> is redirecting to another page, this is often done by SEO plugins like "Yoast SEO".',
+						'activitypub'
+					),
+					$author_url
+				)
+			);
+		}
+
+		// check if response is JSON
+		$body = \wp_remote_retrieve_body( $response );
+
+		if ( ! \is_string( $body ) || ! \is_array( \json_decode( $body, true ) ) ) {
+			return new WP_Error(
+				'author_url_not_accessible',
+				\sprintf(
+					// translators: %s: Author URL
+					\__(
+						'Your author URL <code>%s</code> does not return valid JSON for <code>application/activity+json</code>. Please check if your hosting supports alternate <code>Accept</code> headers.',
+						'activitypub'
+					),
+					$author_url
+				)
+			);
+		}
+
+		return true;
+	}
+
+	/**
+	 * Check if WebFinger endpoint is accessible and profile request returns correct JSON
+	 *
+	 * @return boolean|WP_Error
+	 */
+	public static function is_webfinger_endpoint_accessible() {
+		$user = \wp_get_current_user();
+
+		if ( ! is_user_type_disabled( 'blog' ) ) {
+			$account = get_webfinger_resource( $user->ID );
+		} elseif ( ! is_user_type_disabled( 'user' ) ) {
+			$account = get_webfinger_resource( Users::BLOG_USER_ID );
+		} else {
+			$account = '';
+		}
+
+		$url = Webfinger::resolve( $account );
+		if ( \is_wp_error( $url ) ) {
+			$allowed = array( 'code' => array() );
+			$not_accessible = wp_kses(
+				// translators: %s: Author URL
+				\__(
+					'Your WebFinger endpoint <code>%s</code> is not accessible. Please check your WordPress setup or permalink structure.',
+					'activitypub'
+				),
+				$allowed
+			);
+			$invalid_response = wp_kses(
+				// translators: %s: Author URL
+				\__(
+					'Your WebFinger endpoint <code>%s</code> does not return valid JSON for <code>application/jrd+json</code>.',
+					'activitypub'
+				),
+				$allowed
+			);
+
+			$health_messages = array(
+				'webfinger_url_not_accessible' => \sprintf(
+					$not_accessible,
+					$url->get_error_data()
+				),
+				'webfinger_url_invalid_response' => \sprintf(
+					// translators: %s: Author URL
+					$invalid_response,
+					$url->get_error_data()
+				),
+			);
+			$message = null;
+			if ( isset( $health_messages[ $url->get_error_code() ] ) ) {
+				$message = $health_messages[ $url->get_error_code() ];
+			}
+			return new WP_Error(
+				$url->get_error_code(),
+				$message,
+				$url->get_error_data()
+			);
+		}
+
+		return true;
+	}
+
+	/**
+	 * Retrieve the URL to the author page for the user with the ID provided.
+	 *
+	 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
+	 *
+	 * @param int    $author_id       Author ID.
+	 * @param string $author_nicename Optional. The author's nicename (slug). Default empty.
+	 *
+	 * @return string The URL to the author's page.
+	 */
+	public static function get_author_posts_url( $author_id, $author_nicename = '' ) {
+		global $wp_rewrite;
+		$auth_id = (int) $author_id;
+		$link = $wp_rewrite->get_author_permastruct();
+
+		if ( empty( $link ) ) {
+			$file = home_url( '/' );
+			$link = $file . '?author=' . $auth_id;
+		} else {
+			if ( '' === $author_nicename ) {
+				$user = get_userdata( $author_id );
+				if ( ! empty( $user->user_nicename ) ) {
+					$author_nicename = $user->user_nicename;
+				}
+			}
+			$link = str_replace( '%author%', $author_nicename, $link );
+			$link = home_url( user_trailingslashit( $link ) );
+		}
+
+		return $link;
+	}
+
+	/**
+	 * Static function for generating site debug data when required.
+	 *
+	 * @param array $info The debug information to be added to the core information page.
+	 * @return array The filtered information
+	 */
+	public static function debug_information( $info ) {
+		$info['activitypub'] = array(
+			'label'  => __( 'ActivityPub', 'activitypub' ),
+			'fields' => array(
+				'webfinger' => array(
+					'label'   => __( 'WebFinger Resource', 'activitypub' ),
+					'value'   => Webfinger::get_user_resource( wp_get_current_user()->ID ),
+					'private' => true,
+				),
+				'author_url' => array(
+					'label'   => __( 'Author URL', 'activitypub' ),
+					'value'   => get_author_posts_url( wp_get_current_user()->ID ),
+					'private' => true,
+				),
+				'plugin_version' => array(
+					'label'   => __( 'Plugin Version', 'activitypub' ),
+					'value'   => get_plugin_version(),
+					'private' => true,
+				),
+			),
+		);
+
+		return $info;
 	}
 }

includes/class-http.php

@@ -0,0 +1,111 @@
+<?php
+namespace Activitypub;
+
+use WP_Error;
+use Activitypub\Collection\Users;
+
+/**
+ * ActivityPub HTTP Class
+ *
+ * @author Matthias Pfefferle
+ */
+class Http {
+	/**
+	 * Send a POST Request with the needed HTTP Headers
+	 *
+	 * @param string $url     The URL endpoint
+	 * @param string $body    The Post Body
+	 * @param int    $user_id The WordPress User-ID
+	 *
+	 * @return array|WP_Error The POST Response or an WP_ERROR
+	 */
+	public static function post( $url, $body, $user_id ) {
+		do_action( 'activitypub_pre_http_post', $url, $body, $user_id );
+
+		$date = \gmdate( 'D, d M Y H:i:s T' );
+		$digest = Signature::generate_digest( $body );
+		$signature = Signature::generate_signature( $user_id, 'post', $url, $date, $digest );
+
+		$wp_version = \get_bloginfo( 'version' );
+
+		/**
+		 * Filter the HTTP headers user agent.
+		 *
+		 * @param string $user_agent The user agent string.
+		 */
+		$user_agent = \apply_filters( 'http_headers_useragent', 'WordPress/' . $wp_version . '; ' . \get_bloginfo( 'url' ) );
+		$args = array(
+			'timeout' => 100,
+			'limit_response_size' => 1048576,
+			'redirection' => 3,
+			'user-agent' => "$user_agent; ActivityPub",
+			'headers' => array(
+				'Accept' => 'application/activity+json',
+				'Content-Type' => 'application/activity+json',
+				'Digest' => $digest,
+				'Signature' => $signature,
+				'Date' => $date,
+			),
+			'body' => $body,
+		);
+
+		$response = \wp_safe_remote_post( $url, $args );
+		$code     = \wp_remote_retrieve_response_code( $response );
+
+		if ( $code >= 400 ) {
+			$response = new WP_Error( $code, __( 'Failed HTTP Request', 'activitypub' ), array( 'status' => $code ) );
+		}
+
+		\do_action( 'activitypub_safe_remote_post_response', $response, $url, $body, $user_id );
+
+		return $response;
+	}
+
+	/**
+	 * Send a GET Request with the needed HTTP Headers
+	 *
+	 * @param string $url     The URL endpoint
+	 * @param int    $user_id The WordPress User-ID
+	 *
+	 * @return array|WP_Error The GET Response or an WP_ERROR
+	 */
+	public static function get( $url ) {
+		do_action( 'activitypub_pre_http_get', $url );
+
+		$date = \gmdate( 'D, d M Y H:i:s T' );
+		$signature = Signature::generate_signature( Users::APPLICATION_USER_ID, 'get', $url, $date );
+
+		$wp_version = \get_bloginfo( 'version' );
+
+		/**
+		 * Filter the HTTP headers user agent.
+		 *
+		 * @param string $user_agent The user agent string.
+		 */
+		$user_agent = \apply_filters( 'http_headers_useragent', 'WordPress/' . $wp_version . '; ' . \get_bloginfo( 'url' ) );
+
+		$args = array(
+			'timeout' => apply_filters( 'activitypub_remote_get_timeout', 100 ),
+			'limit_response_size' => 1048576,
+			'redirection' => 3,
+			'user-agent' => "$user_agent; ActivityPub",
+			'headers' => array(
+				'Accept' => 'application/activity+json',
+				'Content-Type' => 'application/activity+json',
+				'Signature' => $signature,
+				'Date' => $date,
+			),
+		);
+
+		$response = \wp_safe_remote_get( $url, $args );
+		$code     = \wp_remote_retrieve_response_code( $response );
+
+		if ( $code >= 400 ) {
+			$response = new WP_Error( $code, __( 'Failed HTTP Request', 'activitypub' ), array( 'status' => $code ) );
+		}
+
+		\do_action( 'activitypub_safe_remote_get_response', $response, $url );
+
+		return $response;
+	}
+}

includes/class-mention.php

@@ -0,0 +1,173 @@
+<?php
+namespace Activitypub;
+
+use WP_Error;
+use Activitypub\Webfinger;
+
+/**
+ * ActivityPub Mention Class
+ *
+ * @author Alex Kirk
+ */
+class Mention {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		\add_filter( 'the_content', array( self::class, 'the_content' ), 99, 2 );
+		\add_filter( 'activitypub_extract_mentions', array( self::class, 'extract_mentions' ), 99, 2 );
+	}
+
+	/**
+	 * Filter to replace the mentions in the content with links
+	 *
+	 * @param string $the_content the post-content
+	 *
+	 * @return string the filtered post-content
+	 */
+	public static function the_content( $the_content ) {
+		// small protection against execution timeouts: limit to 1 MB
+		if ( mb_strlen( $the_content ) > MB_IN_BYTES ) {
+			return $the_content;
+		}
+		$tag_stack = array();
+		$protected_tags = array(
+			'pre',
+			'code',
+			'textarea',
+			'style',
+			'a',
+		);
+		$content_with_links = '';
+		$in_protected_tag = false;
+		foreach ( wp_html_split( $the_content ) as $chunk ) {
+			if ( preg_match( '#^<!--[\s\S]*-->$#i', $chunk, $m ) ) {
+				$content_with_links .= $chunk;
+				continue;
+			}
+
+			if ( preg_match( '#^<(/)?([a-z-]+)\b[^>]*>$#i', $chunk, $m ) ) {
+				$tag = strtolower( $m[2] );
+				if ( '/' === $m[1] ) {
+					// Closing tag.
+					$i = array_search( $tag, $tag_stack );
+					// We can only remove the tag from the stack if it is in the stack.
+					if ( false !== $i ) {
+						$tag_stack = array_slice( $tag_stack, 0, $i );
+					}
+				} else {
+					// Opening tag, add it to the stack.
+					$tag_stack[] = $tag;
+				}
+
+				// If we're in a protected tag, the tag_stack contains at least one protected tag string.
+				// The protected tag state can only change when we encounter a start or end tag.
+				$in_protected_tag = array_intersect( $tag_stack, $protected_tags );
+
+				// Never inspect tags.
+				$content_with_links .= $chunk;
+				continue;
+			}
+
+			if ( $in_protected_tag ) {
+				// Don't inspect a chunk inside an inspected tag.
+				$content_with_links .= $chunk;
+				continue;
+			}
+
+			// Only reachable when there is no protected tag in the stack.
+			$content_with_links .= \preg_replace_callback( '/@' . ACTIVITYPUB_USERNAME_REGEXP . '/', array( self::class, 'replace_with_links' ), $chunk );
+		}
+
+		return $content_with_links;
+	}
+
+	/**
+	 * A callback for preg_replace to build the user links
+	 *
+	 * @param array $result the preg_match results
+	 *
+	 * @return string the final string
+	 */
+	public static function replace_with_links( $result ) {
+		$metadata = get_remote_metadata_by_actor( $result[0] );
+
+		if ( ! empty( $metadata ) && ! is_wp_error( $metadata ) && ! empty( $metadata['url'] ) ) {
+			$username = ltrim( $result[0], '@' );
+			if ( ! empty( $metadata['name'] ) ) {
+				$username = $metadata['name'];
+			}
+			if ( ! empty( $metadata['preferredUsername'] ) ) {
+				$username = $metadata['preferredUsername'];
+			}
+			return \sprintf( '<a rel="mention" class="u-url mention" href="%s">@<span>%s</span></a>', esc_url( $metadata['url'] ), esc_html( $username ) );
+		}
+
+		return $result[0];
+	}
+
+	/**
+	 * Get the Inboxes for the mentioned Actors
+	 *
+	 * @param array $mentioned The list of Actors that were mentioned
+	 *
+	 * @return array The list of Inboxes
+	 */
+	public static function get_inboxes( $mentioned ) {
+		$inboxes = array();
+
+		foreach ( $mentioned as $actor ) {
+			$inbox = self::get_inbox_by_mentioned_actor( $actor );
+
+			if ( ! is_wp_error( $inbox ) && $inbox ) {
+				$inboxes[] = $inbox;
+			}
+		}
+
+		return $inboxes;
+	}
+
+	/**
+	 * Get the inbox from the Remote-Profile of a mentioned Actor
+	 *
+	 * @param string $actor The Actor-URL
+	 *
+	 * @return string The Inbox-URL
+	 */
+	public static function get_inbox_by_mentioned_actor( $actor ) {
+		$metadata = get_remote_metadata_by_actor( $actor );
+
+		if ( \is_wp_error( $metadata ) ) {
+			return $metadata;
+		}
+
+		if ( isset( $metadata['endpoints'] ) && isset( $metadata['endpoints']['sharedInbox'] ) ) {
+			return $metadata['endpoints']['sharedInbox'];
+		}
+
+		if ( \array_key_exists( 'inbox', $metadata ) ) {
+			return $metadata['inbox'];
+		}
+
+		return new WP_Error( 'activitypub_no_inbox', \__( 'No "Inbox" found', 'activitypub' ), $metadata );
+	}
+
+	/**
+	 * Extract the mentions from the post_content.
+	 *
+	 * @param array  $mentions The already found mentions.
+	 * @param string $post_content The post content.
+	 *
+	 * @return mixed The discovered mentions.
+	 */
+	public static function extract_mentions( $mentions, $post_content ) {
+		\preg_match_all( '/@' . ACTIVITYPUB_USERNAME_REGEXP . '/i', $post_content, $matches );
+		foreach ( $matches[0] as $match ) {
+			$link = Webfinger::resolve( $match );
+			if ( ! is_wp_error( $link ) ) {
+				$mentions[ $match ] = $link;
+			}
+		}
+		return $mentions;
+	}
+}

includes/class-migration.php

@@ -0,0 +1,198 @@
+<?php
+namespace Activitypub;
+
+use Activitypub\Activitypub;
+use Activitypub\Model\Blog_User;
+use Activitypub\Collection\Followers;
+use Activitypub\Admin;
+
+/**
+ * ActivityPub Migration Class
+ *
+ * @author Matthias Pfefferle
+ */
+class Migration {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		\add_action( 'activitypub_schedule_migration', array( self::class, 'maybe_migrate' ) );
+	}
+
+	/**
+	 * Get the target version.
+	 *
+	 * This is the version that the database structure will be updated to.
+	 * It is the same as the plugin version.
+	 *
+	 * @return string The target version.
+	 */
+	public static function get_target_version() {
+		return get_plugin_version();
+	}
+
+	/**
+	 * The current version of the database structure.
+	 *
+	 * @return string The current version.
+	 */
+	public static function get_version() {
+		return get_option( 'activitypub_db_version', 0 );
+	}
+
+	/**
+	 * Locks the database migration process to prevent simultaneous migrations.
+	 *
+	 * @return void
+	 */
+	public static function lock() {
+		\update_option( 'activitypub_migration_lock', \time() );
+	}
+
+	/**
+	 * Unlocks the database migration process.
+	 *
+	 * @return void
+	 */
+	public static function unlock() {
+		\delete_option( 'activitypub_migration_lock' );
+	}
+
+	/**
+	 * Whether the database migration process is locked.
+	 *
+	 * @return boolean
+	 */
+	public static function is_locked() {
+		$lock = \get_option( 'activitypub_migration_lock' );
+
+		if ( ! $lock ) {
+			return false;
+		}
+
+		$lock = (int) $lock;
+
+		if ( $lock < \time() - 1800 ) {
+			self::unlock();
+			return false;
+		}
+
+		return true;
+	}
+
+	/**
+	 * Whether the database structure is up to date.
+	 *
+	 * @return bool True if the database structure is up to date, false otherwise.
+	 */
+	public static function is_latest_version() {
+		return (bool) version_compare(
+			self::get_version(),
+			self::get_target_version(),
+			'=='
+		);
+	}
+
+	/**
+	 * Updates the database structure if necessary.
+	 */
+	public static function maybe_migrate() {
+		if ( self::is_latest_version() ) {
+			return;
+		}
+
+		if ( self::is_locked() ) {
+			return;
+		}
+
+		self::lock();
+
+		$version_from_db = self::get_version();
+
+		if ( version_compare( $version_from_db, '0.17.0', '<' ) ) {
+			self::migrate_from_0_16();
+		}
+		if ( version_compare( $version_from_db, '1.0.0', '<' ) ) {
+			self::migrate_from_0_17();
+		}
+		if ( version_compare( $version_from_db, 'version_number_transformer_management_placeholder', '<' ) ) {
+			self::migrate_from_version_number_transformer_management_placeholder();
+		}
+
+		update_option( 'activitypub_db_version', self::get_target_version() );
+
+		self::unlock();
+	}
+
+	/**
+	 * Updates the supported post type settings to the mapped transformer setting.
+	 * TODO: Test this
+	 * @return void
+	 */
+	private static function migrate_from_version_number_transformer_management_placeholder() {
+		$supported_post_types = \get_option( 'activitypub_support_post_types', array( 'post', 'page' ) );
+		Admin::register_settings();
+		$transformer_mapping = array();
+		foreach ( $supported_post_types as $supported_post_type ) {
+			$transformer_mapping[ $supported_post_type ] = ACTIVITYPUB_DEFAULT_TRANSFORMER;
+		}
+		update_option( 'activitypub_transformer_mapping', $transformer_mapping );
+	}
+
+	/**
+	 * Updates the DB-schema of the followers-list
+	 *
+	 * @return void
+	 */
+	private static function migrate_from_0_17() {
+		// migrate followers
+		foreach ( get_users( array( 'fields' => 'ID' ) ) as $user_id ) {
+			$followers = get_user_meta( $user_id, 'activitypub_followers', true );
+
+			if ( $followers ) {
+				foreach ( $followers as $actor ) {
+					Followers::add_follower( $user_id, $actor );
+				}
+			}
+		}
+
+		Activitypub::flush_rewrite_rules();
+	}
+
+	/**
+	 * Updates the custom template to use shortcodes instead of the deprecated templates.
+	 *
+	 * @return void
+	 */
+	private static function migrate_from_0_16() {
+		// Get the custom template.
+		$old_content = \get_option( 'activitypub_custom_post_content', ACTIVITYPUB_CUSTOM_POST_CONTENT );
+
+		// If the old content exists but is a blank string, we're going to need a flag to updated it even
+		// after setting it to the default contents.
+		$need_update = false;
+
+		// If the old contents is blank, use the defaults.
+		if ( '' === $old_content ) {
+			$old_content = ACTIVITYPUB_CUSTOM_POST_CONTENT;
+			$need_update = true;
+		}
+
+		// Set the new content to be the old content.
+		$content = $old_content;
+
+		// Convert old templates to shortcodes.
+		$content = \str_replace( '%title%', '[ap_title]', $content );
+		$content = \str_replace( '%excerpt%', '[ap_excerpt]', $content );
+		$content = \str_replace( '%content%', '[ap_content]', $content );
+		$content = \str_replace( '%permalink%', '[ap_permalink type="html"]', $content );
+		$content = \str_replace( '%shortlink%', '[ap_shortlink type="html"]', $content );
+		$content = \str_replace( '%hashtags%', '[ap_hashtags]', $content );
+		$content = \str_replace( '%tags%', '[ap_hashtags]', $content );
+
+		// Store the new template if required.
+		if ( $content !== $old_content || $need_update ) {
+			\update_option( 'activitypub_custom_post_content', $content );
+		}
+	}
+}

includes/class-scheduler.php

@@ -0,0 +1,168 @@
+<?php
+
+namespace Activitypub;
+
+use Activitypub\Collection\Users;
+use Activitypub\Collection\Followers;
+
+/**
+ * ActivityPub Scheduler Class
+ *
+ * @author Matthias Pfefferle
+ */
+class Scheduler {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		\add_action( 'transition_post_status', array( self::class, 'schedule_post_activity' ), 33, 3 );
+
+		\add_action( 'activitypub_update_followers', array( self::class, 'update_followers' ) );
+		\add_action( 'activitypub_cleanup_followers', array( self::class, 'cleanup_followers' ) );
+
+		\add_action( 'admin_init', array( self::class, 'schedule_migration' ) );
+	}
+
+	/**
+	 * Schedule all ActivityPub schedules.
+	 *
+	 * @return void
+	 */
+	public static function register_schedules() {
+		if ( ! \wp_next_scheduled( 'activitypub_update_followers' ) ) {
+			\wp_schedule_event( time(), 'hourly', 'activitypub_update_followers' );
+		}
+
+		if ( ! \wp_next_scheduled( 'activitypub_cleanup_followers' ) ) {
+			\wp_schedule_event( time(), 'daily', 'activitypub_cleanup_followers' );
+		}
+	}
+
+	/**
+	 * Unscedule all ActivityPub schedules.
+	 *
+	 * @return void
+	 */
+	public static function deregister_schedules() {
+		wp_unschedule_hook( 'activitypub_update_followers' );
+		wp_unschedule_hook( 'activitypub_cleanup_followers' );
+	}
+
+
+	/**
+	 * Schedule Activities.
+	 *
+	 * @param string  $new_status New post status.
+	 * @param string  $old_status Old post status.
+	 * @param WP_Post $post       Post object.
+	 */
+	public static function schedule_post_activity( $new_status, $old_status, $post ) {
+		// Do not send activities if post is password protected.
+		if ( \post_password_required( $post ) ) {
+			return;
+		}
+
+		// Check if post-type supports ActivityPub.
+		$post_types = \get_post_types_by_support( 'activitypub' );
+		if ( ! \in_array( $post->post_type, $post_types, true ) ) {
+			return;
+		}
+
+		$type = false;
+
+		if ( 'publish' === $new_status && 'publish' !== $old_status ) {
+			$type = 'Create';
+		} elseif ( 'publish' === $new_status ) {
+			$type = 'Update';
+		} elseif ( 'trash' === $new_status ) {
+			$type = 'Delete';
+		}
+
+		if ( ! $type ) {
+			return;
+		}
+
+		\wp_schedule_single_event(
+			\time(),
+			'activitypub_send_activity',
+			array( $post, $type )
+		);
+
+		\wp_schedule_single_event(
+			\time(),
+			sprintf(
+				'activitypub_send_%s_activity',
+				\strtolower( $type )
+			),
+			array( $post )
+		);
+	}
+
+	/**
+	 * Update followers
+	 *
+	 * @return void
+	 */
+	public static function update_followers() {
+		$number = 5;
+
+		if ( defined( 'DISABLE_WP_CRON' ) && DISABLE_WP_CRON ) {
+			$number = 50;
+		}
+
+		$followers = Followers::get_outdated_followers( $number );
+
+		foreach ( $followers as $follower ) {
+			$meta = get_remote_metadata_by_actor( $follower->get_url(), false );
+
+			if ( empty( $meta ) || ! is_array( $meta ) || is_wp_error( $meta ) ) {
+				Followers::add_error( $follower->get__id(), $meta );
+			} else {
+				$follower->from_array( $meta );
+				$follower->update();
+			}
+		}
+	}
+
+	/**
+	 * Cleanup followers
+	 *
+	 * @return void
+	 */
+	public static function cleanup_followers() {
+		$number = 5;
+
+		if ( defined( 'DISABLE_WP_CRON' ) && DISABLE_WP_CRON ) {
+			$number = 50;
+		}
+
+		$followers = Followers::get_faulty_followers( $number );
+
+		foreach ( $followers as $follower ) {
+			$meta = get_remote_metadata_by_actor( $follower->get_url(), false );
+
+			if ( is_tombstone( $meta ) ) {
+				$follower->delete();
+			} elseif ( empty( $meta ) || ! is_array( $meta ) || is_wp_error( $meta ) ) {
+				if ( $follower->count_errors() >= 5 ) {
+					$follower->delete();
+				} else {
+					Followers::add_error( $follower->get__id(), $meta );
+				}
+			} else {
+				$follower->reset_errors();
+			}
+		}
+	}
+
+	/**
+	 * Schedule migration if DB-Version is not up to date.
+	 *
+	 * @return void
+	 */
+	public static function schedule_migration() {
+		if ( ! \wp_next_scheduled( 'activitypub_schedule_migration' ) && ! Migration::is_latest_version() ) {
+			\wp_schedule_single_event( \time(), 'activitypub_schedule_migration' );
+		}
+	}
+}

includes/class-shortcodes.php

@@ -0,0 +1,584 @@
+<?php
+namespace Activitypub;
+
+use function Activitypub\esc_hashtag;
+
+class Shortcodes {
+	/**
+	 * Register the shortcodes
+	 */
+	public static function register() {
+		foreach ( get_class_methods( self::class ) as $shortcode ) {
+			if ( 'init' !== $shortcode ) {
+				add_shortcode( 'ap_' . $shortcode, array( self::class, $shortcode ) );
+			}
+		}
+	}
+
+	/**
+	 * Unregister the shortcodes
+	 */
+	public static function unregister() {
+		foreach ( get_class_methods( self::class ) as $shortcode ) {
+			if ( 'init' !== $shortcode ) {
+				remove_shortcode( 'ap_' . $shortcode );
+			}
+		}
+	}
+
+	/**
+	 * Generates output for the 'ap_hashtags' shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The post tags as hashtags.
+	 */
+	public static function hashtags( $atts, $content, $tag ) {
+		$item = self::get_item();
+
+		if ( ! $item ) {
+			return '';
+		}
+
+		$tags = \get_the_tags( $item->ID );
+
+		if ( ! $tags ) {
+			return '';
+		}
+
+		$hash_tags = array();
+
+		foreach ( $tags as $tag ) {
+			$hash_tags[] = \sprintf(
+				'<a rel="tag" class="hashtag u-tag u-category" href="%s">%s</a>',
+				\esc_url( \get_tag_link( $tag ) ),
+				esc_hashtag( $tag->name )
+			);
+		}
+
+		return \implode( ' ', $hash_tags );
+	}
+
+	/**
+	 * Generates output for the 'ap_title' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The post title.
+	 */
+	public static function title( $atts, $content, $tag ) {
+		$item = self::get_item();
+
+		if ( ! $item ) {
+			return '';
+		}
+
+		return \wp_strip_all_tags( \get_the_title( $item->ID ), true );
+	}
+
+	/**
+	 * Generates output for the 'ap_excerpt' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The post excerpt.
+	 */
+	public static function excerpt( $atts, $content, $tag ) {
+		$item = self::get_item();
+
+		if ( ! $item ) {
+			return '';
+		}
+
+		$atts = shortcode_atts(
+			array( 'length' => ACTIVITYPUB_EXCERPT_LENGTH ),
+			$atts,
+			$tag
+		);
+
+		$excerpt_length = intval( $atts['length'] );
+
+		if ( 0 === $excerpt_length ) {
+			$excerpt_length = ACTIVITYPUB_EXCERPT_LENGTH;
+		}
+
+		$excerpt = \get_post_field( 'post_excerpt', $item );
+
+		if ( '' === $excerpt ) {
+
+			$content = \get_post_field( 'post_content', $item );
+
+			// An empty string will make wp_trim_excerpt do stuff we do not want.
+			if ( '' !== $content ) {
+				$excerpt = \strip_shortcodes( $content );
+
+				/** This filter is documented in wp-includes/post-template.php */
+				$excerpt = \apply_filters( 'the_content', $excerpt );
+				$excerpt = \str_replace( ']]>', ']]&gt;', $excerpt );
+			}
+		}
+
+		// Strip out any remaining tags.
+		$excerpt = \wp_strip_all_tags( $excerpt );
+
+		/** This filter is documented in wp-includes/formatting.php */
+		$excerpt_more = \apply_filters( 'excerpt_more', ' [...]' );
+		$excerpt_more_len = strlen( $excerpt_more );
+
+		// We now have a excerpt, but we need to check it's length, it may be longer than we want for two reasons:
+		//
+		//   * The user has entered a manual excerpt which is longer that what we want.
+		//   * No manual excerpt exists so we've used the content which might be longer than we want.
+		//
+		// Either way, let's trim it up if we need too.  Also, don't forget to take into account the more indicator
+		// as part of the total length.
+		//
+
+		// Setup a variable to hold the current excerpts length.
+		$current_excerpt_length = strlen( $excerpt );
+
+		// Setup a variable to keep track of our target length.
+		$target_excerpt_length = $excerpt_length - $excerpt_more_len;
+
+		// Setup a variable to keep track of the current max length.
+		$current_excerpt_max = $target_excerpt_length;
+
+		// This is a loop since we can't calculate word break the string after 'the_excpert' filter has run (we would break
+		// all kinds of html tags), so we have to cut the excerpt down a bit at a time until we hit our target length.
+		while ( $current_excerpt_length > $target_excerpt_length && $current_excerpt_max > 0 ) {
+			// Trim the excerpt based on wordwrap() positioning.
+			// Note: we're using <br> as the linebreak just in case there are any newlines existing in the excerpt from the user.
+			//       There won't be any <br> left after we've run wp_strip_all_tags() in the code above, so they're
+			//       safe to use here.  It won't be included in the final excerpt as the substr() will trim it off.
+			$excerpt = substr( $excerpt, 0, strpos( wordwrap( $excerpt, $current_excerpt_max, '<br>' ), '<br>' ) );
+
+			// If something went wrong, or we're in a language that wordwrap() doesn't understand,
+			// just chop it off and don't worry about breaking in the middle of a word.
+			if ( strlen( $excerpt ) > $excerpt_length - $excerpt_more_len ) {
+				$excerpt = substr( $excerpt, 0, $current_excerpt_max );
+			}
+
+			// Add in the more indicator.
+			$excerpt = $excerpt . $excerpt_more;
+
+			// Run it through the excerpt filter which will add some html tags back in.
+			$excerpt_filtered = apply_filters( 'the_excerpt', $excerpt );
+
+			// Now set the current excerpt length to this new filtered length.
+			$current_excerpt_length = strlen( $excerpt_filtered );
+
+			// Check to see if we're over the target length.
+			if ( $current_excerpt_length > $target_excerpt_length ) {
+				// If so, remove 20 characters from the current max and run the loop again.
+				$current_excerpt_max = $current_excerpt_max - 20;
+			}
+		}
+
+		return \apply_filters( 'the_excerpt', $excerpt );
+	}
+
+	/**
+	 * Generates output for the 'ap_content' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The post content.
+	 */
+	public static function content( $atts, $content, $tag ) {
+		$item = self::get_item();
+
+		if ( ! $item ) {
+			return '';
+		}
+
+		// prevent inception
+		remove_shortcode( 'ap_content' );
+
+		$atts = shortcode_atts(
+			array( 'apply_filters' => 'yes' ),
+			$atts,
+			$tag
+		);
+
+		$content = \get_post_field( 'post_content', $item );
+
+		if ( 'yes' === $atts['apply_filters'] ) {
+			$content = \apply_filters( 'the_content', $content );
+		} else {
+			$content = do_blocks( $content );
+			$content = wptexturize( $content );
+			$content = wp_filter_content_tags( $content );
+		}
+
+		// replace script and style elements
+		$content = \preg_replace( '@<(script|style)[^>]*?>.*?</\\1>@si', '', $content );
+		$content = strip_shortcodes( $content );
+		$content = \trim( \preg_replace( '/[\n\r\t]/', '', $content ) );
+
+		add_shortcode( 'ap_content', array( 'Activitypub\Shortcodes', 'content' ) );
+
+		return $content;
+	}
+
+	/**
+	 * Generates output for the 'ap_permalink' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The post permalink.
+	 */
+	public static function permalink( $atts, $content, $tag ) {
+		$item = self::get_item();
+
+		if ( ! $item ) {
+			return '';
+		}
+
+		$atts = shortcode_atts(
+			array(
+				'type' => 'url',
+			),
+			$atts,
+			$tag
+		);
+
+		if ( 'url' === $atts['type'] ) {
+			return \esc_url( \get_permalink( $item->ID ) );
+		}
+
+		return \sprintf(
+			'<a href="%1$s">%1$s</a>',
+			\esc_url( \get_permalink( $item->ID ) )
+		);
+	}
+
+	/**
+	 * Generates output for the 'ap_shortlink' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The post shortlink.
+	 */
+	public static function shortlink( $atts, $content, $tag ) {
+		$item = self::get_item();
+
+		if ( ! $item ) {
+			return '';
+		}
+
+		$atts = shortcode_atts(
+			array(
+				'type' => 'url',
+			),
+			$atts,
+			$tag
+		);
+
+		if ( 'url' === $atts['type'] ) {
+			return \esc_url( \wp_get_shortlink( $item->ID ) );
+		}
+
+		return \sprintf(
+			'<a href="%1$s">%1$s</a>',
+			\esc_url( \wp_get_shortlink( $item->ID ) )
+		);
+	}
+
+	/**
+	 * Generates output for the 'ap_image' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string
+	 */
+	public static function image( $atts, $content, $tag ) {
+		$item = self::get_item();
+
+		if ( ! $item ) {
+			return '';
+		}
+
+		$atts = shortcode_atts(
+			array(
+				'type' => 'full',
+			),
+			$atts,
+			$tag
+		);
+
+		$size = 'full';
+
+		if ( in_array(
+			$atts['type'],
+			array( 'thumbnail', 'medium', 'large', 'full' ),
+			true
+		) ) {
+			$size = $atts['type'];
+		}
+
+		$image = \get_the_post_thumbnail_url( $item->ID, $size );
+
+		if ( ! $image ) {
+			return '';
+		}
+
+		return \esc_url( $image );
+	}
+
+	/**
+	 * Generates output for the 'ap_hashcats' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The post categories as hashtags.
+	 */
+	public static function hashcats( $atts, $content, $tag ) {
+		$item = self::get_item();
+
+		if ( ! $item ) {
+			return '';
+		}
+
+		$categories = \get_the_category( $item->ID );
+
+		if ( ! $categories ) {
+			return '';
+		}
+
+		$hash_tags = array();
+
+		foreach ( $categories as $category ) {
+			$hash_tags[] = \sprintf(
+				'<a rel="tag" class="hashtag u-tag u-category" href="%s">%s</a>',
+				\esc_url( \get_category_link( $category ) ),
+				esc_hashtag( $category->name )
+			);
+		}
+
+		return \implode( ' ', $hash_tags );
+	}
+
+	/**
+	 * Generates output for the 'ap_author' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The author name.
+	 */
+	public static function author( $atts, $content, $tag ) {
+		$item = self::get_item();
+
+		if ( ! $item ) {
+			return '';
+		}
+
+		$author_id = \get_post_field( 'post_author', $item->ID );
+		$name = \get_the_author_meta( 'display_name', $author_id );
+
+		if ( ! $name ) {
+			return '';
+		}
+
+		return wp_strip_all_tags( $name );
+	}
+
+	/**
+	 * Generates output for the 'ap_authorurl' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The author URL.
+	 */
+	public static function authorurl( $atts, $content, $tag ) {
+		$item = self::get_item();
+
+		if ( ! $item ) {
+			return '';
+		}
+
+		$author_id = \get_post_field( 'post_author', $item->ID );
+		$url = \get_the_author_meta( 'user_url', $author_id );
+
+		if ( ! $url ) {
+			return '';
+		}
+
+		return \esc_url( $url );
+	}
+
+	/**
+	 * Generates output for the 'ap_blogurl' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The site URL.
+	 */
+	public static function blogurl( $atts, $content, $tag ) {
+		return \esc_url( \get_bloginfo( 'url' ) );
+	}
+
+	/**
+	 * Generates output for the 'ap_blogname' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string
+	 */
+	public static function blogname( $atts, $content, $tag ) {
+		return \wp_strip_all_tags( \get_bloginfo( 'name' ) );
+	}
+
+	/**
+	 * Generates output for the 'ap_blogdesc' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The site description.
+	 */
+	public static function blogdesc( $atts, $content, $tag ) {
+		return \wp_strip_all_tags( \get_bloginfo( 'description' ) );
+	}
+
+	/**
+	 * Generates output for the 'ap_date' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The post date.
+	 */
+	public static function date( $atts, $content, $tag ) {
+		$item = self::get_item();
+
+		if ( ! $item ) {
+			return '';
+		}
+
+		$datetime = \get_post_datetime( $item );
+		$dateformat = \get_option( 'date_format' );
+		$timeformat = \get_option( 'time_format' );
+
+		$date = $datetime->format( $dateformat );
+
+		if ( ! $date ) {
+			return '';
+		}
+
+		return $date;
+	}
+
+	/**
+	 * Generates output for the 'ap_time' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The post time.
+	 */
+	public static function time( $atts, $content, $tag ) {
+		$item = self::get_item();
+
+		if ( ! $item ) {
+			return '';
+		}
+
+		$datetime = \get_post_datetime( $item );
+		$dateformat = \get_option( 'date_format' );
+		$timeformat = \get_option( 'time_format' );
+
+		$date = $datetime->format( $timeformat );
+
+		if ( ! $date ) {
+			return '';
+		}
+
+		return $date;
+	}
+
+	/**
+	 * Generates output for the 'ap_datetime' Shortcode
+	 *
+	 * @param array  $atts    The Shortcode attributes.
+	 * @param string $content The ActivityPub post-content.
+	 * @param string $tag     The tag/name of the Shortcode.
+	 *
+	 * @return string The post date/time.
+	 */
+	public static function datetime( $atts, $content, $tag ) {
+		$item = self::get_item();
+
+		if ( ! $item ) {
+			return '';
+		}
+
+		$datetime = \get_post_datetime( $item );
+		$dateformat = \get_option( 'date_format' );
+		$timeformat = \get_option( 'time_format' );
+
+		$date = $datetime->format( $dateformat . ' @ ' . $timeformat );
+
+		if ( ! $date ) {
+			return '';
+		}
+
+		return $date;
+	}
+
+	/**
+	 * Get a WordPress item to federate.
+	 *
+	 * Checks if item (WP_Post) is "public", a supported post type
+	 * and not password protected.
+	 *
+	 * @return null|WP_Post The WordPress item.
+	 */
+	protected static function get_item() {
+		$post = \get_post();
+
+		if ( ! $post ) {
+			return null;
+		}
+
+		if ( 'publish' !== \get_post_status( $post ) ) {
+			return null;
+		}
+
+		if ( \post_password_required( $post ) ) {
+			return null;
+		}
+
+		if ( ! \in_array( \get_post_type( $post ), \get_post_types_by_support( 'activitypub' ), true ) ) {
+			return null;
+		}
+
+		return $post;
+	}
+}

includes/class-signature.php

@@ -1,59 +1,95 @@
 <?php
 namespace Activitypub;
 
+use WP_Error;
+use DateTime;
+use DateTimeZone;
+use WP_REST_Request;
+use Activitypub\Collection\Users;
+
 /**
  * ActivityPub Signature Class
  *
  * @author Matthias Pfefferle
+ * @author Django Doucet
  */
 class Signature {
 
 	/**
-	 * @param int $user_id
+	 * Return the public key for a given user.
 	 *
-	 * @return mixed
+	 * @param int  $user_id The WordPress User ID.
+	 * @param bool $force   Force the generation of a new key pair.
+	 *
+	 * @return mixed The public key.
 	 */
-	public static function get_public_key( $user_id, $force = false ) {
-		$key = \get_user_meta( $user_id, 'magic_sig_public_key' );
-
-		if ( $key && ! $force ) {
-			return $key[0];
+	public static function get_public_key_for( $user_id, $force = false ) {
+		if ( $force ) {
+			self::generate_key_pair_for( $user_id );
 		}
 
-		self::generate_key_pair( $user_id );
-		$key = \get_user_meta( $user_id, 'magic_sig_public_key' );
+		$key_pair = self::get_keypair_for( $user_id );
 
-		return $key[0];
+		return $key_pair['public_key'];
 	}
 
 	/**
-	 * @param int $user_id
+	 * Return the private key for a given user.
 	 *
-	 * @return mixed
+	 * @param int  $user_id The WordPress User ID.
+	 * @param bool $force   Force the generation of a new key pair.
+	 *
+	 * @return mixed The private key.
 	 */
-	public static function get_private_key( $user_id, $force = false ) {
-		$key = \get_user_meta( $user_id, 'magic_sig_private_key' );
-
-		if ( $key && ! $force ) {
-			return $key[0];
+	public static function get_private_key_for( $user_id, $force = false ) {
+		if ( $force ) {
+			self::generate_key_pair_for( $user_id );
 		}
 
-		self::generate_key_pair( $user_id );
-		$key = \get_user_meta( $user_id, 'magic_sig_private_key' );
+		$key_pair = self::get_keypair_for( $user_id );
 
-		return $key[0];
+		return $key_pair['private_key'];
+	}
+
+	/**
+	 * Return the key pair for a given user.
+	 *
+	 * @param int $user_id The WordPress User ID.
+	 *
+	 * @return array The key pair.
+	 */
+	public static function get_keypair_for( $user_id ) {
+		$option_key = self::get_signature_options_key_for( $user_id );
+		$key_pair = \get_option( $option_key );
+
+		if ( ! $key_pair ) {
+			$key_pair = self::generate_key_pair_for( $user_id );
+		}
+
+		return $key_pair;
 	}
 
 	/**
 	 * Generates the pair keys
 	 *
-	 * @param int $user_id
+	 * @param int $user_id The WordPress User ID.
+	 *
+	 * @return array The key pair.
 	 */
-	public static function generate_key_pair( $user_id ) {
+	protected static function generate_key_pair_for( $user_id ) {
+		$option_key = self::get_signature_options_key_for( $user_id );
+		$key_pair = self::check_legacy_key_pair_for( $user_id );
+
+		if ( $key_pair ) {
+			\add_option( $option_key, $key_pair );
+
+			return $key_pair;
+		}
+
 		$config = array(
 			'digest_alg' => 'sha512',
 			'private_key_bits' => 2048,
-			'private_key_type' => OPENSSL_KEYTYPE_RSA,
+			'private_key_type' => \OPENSSL_KEYTYPE_RSA,
 		);
 
 		$key = \openssl_pkey_new( $config );
@@ -61,17 +97,96 @@ class Signature {
 
 		\openssl_pkey_export( $key, $priv_key );
 
-		// private key
-		\update_user_meta( $user_id, 'magic_sig_private_key', $priv_key );
-
 		$detail = \openssl_pkey_get_details( $key );
 
-		// public key
-		\update_user_meta( $user_id, 'magic_sig_public_key', $detail['key'] );
+		// check if keys are valid
+		if (
+			empty( $priv_key ) || ! is_string( $priv_key ) ||
+			! isset( $detail['key'] ) || ! is_string( $detail['key'] )
+		) {
+			return array(
+				'private_key' => null,
+				'public_key'  => null,
+			);
 		}
 
-	public static function generate_signature( $user_id, $url, $date ) {
-		$key = self::get_private_key( $user_id );
+		$key_pair = array(
+			'private_key' => $priv_key,
+			'public_key'  => $detail['key'],
+		);
+
+		// persist keys
+		\add_option( $option_key, $key_pair );
+
+		return $key_pair;
+	}
+
+	/**
+	 * Return the option key for a given user.
+	 *
+	 * @param int $user_id The WordPress User ID.
+	 *
+	 * @return string The option key.
+	 */
+	protected static function get_signature_options_key_for( $user_id ) {
+		$id = $user_id;
+
+		if ( $user_id > 0 ) {
+			$user = \get_userdata( $user_id );
+			// sanatize username because it could include spaces and special chars
+			$id = sanitize_title( $user->user_login );
+		}
+
+		return 'activitypub_keypair_for_' . $id;
+	}
+
+	/**
+	 * Check if there is a legacy key pair
+	 *
+	 * @param int $user_id The WordPress User ID.
+	 *
+	 * @return array|bool The key pair or false.
+	 */
+	protected static function check_legacy_key_pair_for( $user_id ) {
+		switch ( $user_id ) {
+			case 0:
+				$public_key = \get_option( 'activitypub_blog_user_public_key' );
+				$private_key = \get_option( 'activitypub_blog_user_private_key' );
+				break;
+			case -1:
+				$public_key = \get_option( 'activitypub_application_user_public_key' );
+				$private_key = \get_option( 'activitypub_application_user_private_key' );
+				break;
+			default:
+				$public_key = \get_user_meta( $user_id, 'magic_sig_public_key', true );
+				$private_key = \get_user_meta( $user_id, 'magic_sig_private_key', true );
+				break;
+		}
+
+		if ( ! empty( $public_key ) && is_string( $public_key ) && ! empty( $private_key ) && is_string( $private_key ) ) {
+			return array(
+				'private_key' => $private_key,
+				'public_key'  => $public_key,
+			);
+		}
+
+		return false;
+	}
+
+	/**
+	 * Generates the Signature for a HTTP Request
+	 *
+	 * @param int    $user_id     The WordPress User ID.
+	 * @param string $http_method The HTTP method.
+	 * @param string $url         The URL to send the request to.
+	 * @param string $date        The date the request is sent.
+	 * @param string $digest      The digest of the request body.
+	 *
+	 * @return string The signature.
+	 */
+	public static function generate_signature( $user_id, $http_method, $url, $date, $digest = null ) {
+		$user = Users::get_by_id( $user_id );
+		$key  = self::get_private_key_for( $user->get__id() );
 
 		$url_parts = \wp_parse_url( $url );
 
@@ -88,18 +203,297 @@ class Signature {
 			$path .= '?' . $url_parts['query'];
 		}
 
-		$signed_string = "(request-target): post $path\nhost: $host\ndate: $date";
+		$http_method = \strtolower( $http_method );
+
+		if ( ! empty( $digest ) ) {
+			$signed_string = "(request-target): $http_method $path\nhost: $host\ndate: $date\ndigest: $digest";
+		} else {
+			$signed_string = "(request-target): $http_method $path\nhost: $host\ndate: $date";
+		}
 
 		$signature = null;
-		\openssl_sign( $signed_string, $signature, $key, OPENSSL_ALGO_SHA256 );
+		\openssl_sign( $signed_string, $signature, $key, \OPENSSL_ALGO_SHA256 );
 		$signature = \base64_encode( $signature ); // phpcs:ignore
 
-		$key_id = \get_author_posts_url( $user_id ) . '#main-key';
+		$key_id = $user->get_url() . '#main-key';
 
+		if ( ! empty( $digest ) ) {
+			return \sprintf( 'keyId="%s",algorithm="rsa-sha256",headers="(request-target) host date digest",signature="%s"', $key_id, $signature );
+		} else {
 			return \sprintf( 'keyId="%s",algorithm="rsa-sha256",headers="(request-target) host date",signature="%s"', $key_id, $signature );
 		}
+	}
 
-	public static function verify_signature( $headers, $signature ) {
+	/**
+	 * Verifies the http signatures
+	 *
+	 * @param WP_REST_Request|array $request The request object or $_SERVER array.
+	 *
+	 * @return mixed A boolean or WP_Error.
+	 */
+	public static function verify_http_signature( $request ) {
+		if ( is_object( $request ) ) { // REST Request object
+			// check if route starts with "index.php"
+			if ( str_starts_with( $request->get_route(), '/index.php' ) || ! rest_get_url_prefix() ) {
+				$route = $request->get_route();
+			} else {
+				$route = '/' . rest_get_url_prefix() . '/' . ltrim( $request->get_route(), '/' );
+			}
 
+			// fix route for subdirectory installs
+			$path = \wp_parse_url( \get_home_url(), PHP_URL_PATH );
+
+			if ( \is_string( $path ) ) {
+				$path = trim( $path, '/' );
+			}
+
+			if ( $path ) {
+				$route = '/' . $path . $route;
+			}
+
+			$headers = $request->get_headers();
+			$headers['(request-target)'][0] = strtolower( $request->get_method() ) . ' ' . $route;
+		} else {
+			$request = self::format_server_request( $request );
+			$headers = $request['headers']; // $_SERVER array
+			$headers['(request-target)'][0] = strtolower( $headers['request_method'][0] ) . ' ' . $headers['request_uri'][0];
+		}
+
+		if ( ! isset( $headers['signature'] ) ) {
+			return new WP_Error( 'activitypub_signature', __( 'Request not signed', 'activitypub' ), array( 'status' => 401 ) );
+		}
+
+		if ( array_key_exists( 'signature', $headers ) ) {
+			$signature_block = self::parse_signature_header( $headers['signature'][0] );
+		} elseif ( array_key_exists( 'authorization', $headers ) ) {
+			$signature_block = self::parse_signature_header( $headers['authorization'][0] );
+		}
+
+		if ( ! isset( $signature_block ) || ! $signature_block ) {
+			return new WP_Error( 'activitypub_signature', __( 'Incompatible request signature. keyId and signature are required', 'activitypub' ), array( 'status' => 401 ) );
+		}
+
+		$signed_headers = $signature_block['headers'];
+		if ( ! $signed_headers ) {
+			$signed_headers = array( 'date' );
+		}
+
+		$signed_data = self::get_signed_data( $signed_headers, $signature_block, $headers );
+		if ( ! $signed_data ) {
+			return new WP_Error( 'activitypub_signature', __( 'Signed request date outside acceptable time window', 'activitypub' ), array( 'status' => 401 ) );
+		}
+
+		$algorithm = self::get_signature_algorithm( $signature_block );
+		if ( ! $algorithm ) {
+			return new WP_Error( 'activitypub_signature', __( 'Unsupported signature algorithm (only rsa-sha256 and hs2019 are supported)', 'activitypub' ), array( 'status' => 401 ) );
+		}
+
+		if ( \in_array( 'digest', $signed_headers, true ) && isset( $body ) ) {
+			if ( is_array( $headers['digest'] ) ) {
+				$headers['digest'] = $headers['digest'][0];
+			}
+			$digest = explode( '=', $headers['digest'], 2 );
+			if ( 'SHA-256' === $digest[0] ) {
+				$hashalg = 'sha256';
+			}
+			if ( 'SHA-512' === $digest[0] ) {
+				$hashalg = 'sha512';
+			}
+
+			if ( \base64_encode( \hash( $hashalg, $body, true ) ) !== $digest[1] ) { // phpcs:ignore
+				return new WP_Error( 'activitypub_signature', __( 'Invalid Digest header', 'activitypub' ), array( 'status' => 401 ) );
+			}
+		}
+
+		$public_key = self::get_remote_key( $signature_block['keyId'] );
+
+		if ( \is_wp_error( $public_key ) ) {
+			return $public_key;
+		}
+
+		$verified = \openssl_verify( $signed_data, $signature_block['signature'], $public_key, $algorithm ) > 0;
+
+		if ( ! $verified ) {
+			return new WP_Error( 'activitypub_signature', __( 'Invalid signature', 'activitypub' ), array( 'status' => 401 ) );
+		}
+		return $verified;
+	}
+
+	/**
+	 * Get public key from key_id
+	 *
+	 * @param string $key_id The URL to the public key.
+	 *
+	 * @return WP_Error|string The public key or WP_Error.
+	 */
+	public static function get_remote_key( $key_id ) { // phpcs:ignore
+		$actor = get_remote_metadata_by_actor( strip_fragment_from_url( $key_id ) ); // phpcs:ignore
+		if ( \is_wp_error( $actor ) ) {
+			return new WP_Error(
+				'activitypub_no_remote_profile_found',
+				__( 'No Profile found or Profile not accessible', 'activitypub' ),
+				array( 'status' => 401 )
+			);
+		}
+		if ( isset( $actor['publicKey']['publicKeyPem'] ) ) {
+			return \rtrim( $actor['publicKey']['publicKeyPem'] ); // phpcs:ignore
+		}
+		return new WP_Error(
+			'activitypub_no_remote_key_found',
+			__( 'No Public-Key found', 'activitypub' ),
+			array( 'status' => 401 )
+		);
+	}
+
+	/**
+	 * Gets the signature algorithm from the signature header
+	 *
+	 * @param array $signature_block
+	 *
+	 * @return string The signature algorithm.
+	 */
+	public static function get_signature_algorithm( $signature_block ) {
+		if ( $signature_block['algorithm'] ) {
+			switch ( $signature_block['algorithm'] ) {
+				case 'rsa-sha-512':
+					return 'sha512'; //hs2019 https://datatracker.ietf.org/doc/html/draft-cavage-http-signatures-12
+				default:
+					return 'sha256';
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * Parses the Signature header
+	 *
+	 * @param string $signature The signature header.
+	 *
+	 * @return array signature parts
+	 */
+	public static function parse_signature_header( $signature ) {
+		$parsed_header  = array();
+		$matches        = array();
+
+		if ( \preg_match( '/keyId="(.*?)"/ism', $signature, $matches ) ) {
+			$parsed_header['keyId'] = trim( $matches[1] );
+		}
+		if ( \preg_match( '/created=([0-9]*)/ism', $signature, $matches ) ) {
+			$parsed_header['(created)'] = trim( $matches[1] );
+		}
+		if ( \preg_match( '/expires=([0-9]*)/ism', $signature, $matches ) ) {
+			$parsed_header['(expires)'] = trim( $matches[1] );
+		}
+		if ( \preg_match( '/algorithm="(.*?)"/ism', $signature, $matches ) ) {
+			$parsed_header['algorithm'] = trim( $matches[1] );
+		}
+		if ( \preg_match( '/headers="(.*?)"/ism', $signature, $matches ) ) {
+			$parsed_header['headers'] = \explode( ' ', trim( $matches[1] ) );
+		}
+		if ( \preg_match( '/signature="(.*?)"/ism', $signature, $matches ) ) {
+			$parsed_header['signature'] = \base64_decode( preg_replace( '/\s+/', '', trim( $matches[1] ) ) ); // phpcs:ignore
+		}
+
+		if ( ( $parsed_header['signature'] ) && ( $parsed_header['algorithm'] ) && ( ! $parsed_header['headers'] ) ) {
+			$parsed_header['headers'] = array( 'date' );
+		}
+
+		return $parsed_header;
+	}
+
+	/**
+	 * Gets the header data from the included pseudo headers
+	 *
+	 * @param array $signed_headers  The signed headers.
+	 * @param array $signature_block (pseudo-headers)
+	 * @param array $headers         (http headers)
+	 *
+	 * @return string signed headers for comparison
+	 */
+	public static function get_signed_data( $signed_headers, $signature_block, $headers ) {
+		$signed_data = '';
+		// This also verifies time-based values by returning false if any of these are out of range.
+		foreach ( $signed_headers as $header ) {
+			if ( 'host' === $header ) {
+				if ( isset( $headers['x_original_host'] ) ) {
+					$signed_data .= $header . ': ' . $headers['x_original_host'][0] . "\n";
+					continue;
+				}
+			}
+			if ( '(request-target)' === $header ) {
+				$signed_data .= $header . ': ' . $headers[ $header ][0] . "\n";
+				continue;
+			}
+			if ( str_contains( $header, '-' ) ) {
+				$signed_data .= $header . ': ' . $headers[ str_replace( '-', '_', $header ) ][0] . "\n";
+				continue;
+			}
+			if ( '(created)' === $header ) {
+				if ( ! empty( $signature_block['(created)'] ) && \intval( $signature_block['(created)'] ) > \time() ) {
+					// created in future
+					return false;
+				}
+			}
+			if ( '(expires)' === $header ) {
+				if ( ! empty( $signature_block['(expires)'] ) && \intval( $signature_block['(expires)'] ) < \time() ) {
+					// expired in past
+					return false;
+				}
+			}
+			if ( 'date' === $header ) {
+				// allow a bit of leeway for misconfigured clocks.
+				$d = new DateTime( $headers[ $header ][0] );
+				$d->setTimeZone( new DateTimeZone( 'UTC' ) );
+				$c = $d->format( 'U' );
+
+				$dplus = time() + ( 3 * HOUR_IN_SECONDS );
+				$dminus = time() - ( 3 * HOUR_IN_SECONDS );
+
+				if ( $c > $dplus || $c < $dminus ) {
+					// time out of range
+					return false;
+				}
+			}
+			$signed_data .= $header . ': ' . $headers[ $header ][0] . "\n";
+		}
+		return \rtrim( $signed_data, "\n" );
+	}
+
+	/**
+	 * Generates the digest for a HTTP Request
+	 *
+	 * @param string $body The body of the request.
+	 *
+	 * @return string The digest.
+	 */
+	public static function generate_digest( $body ) {
+		$digest = \base64_encode( \hash( 'sha256', $body, true ) ); // phpcs:ignore
+		return "SHA-256=$digest";
+	}
+
+	/**
+	 * Formats the $_SERVER to resemble the WP_REST_REQUEST array,
+	 * for use with verify_http_signature()
+	 *
+	 * @param array $_SERVER The $_SERVER array.
+	 *
+	 * @return array $request The formatted request array.
+	 */
+	public static function format_server_request( $server ) {
+		$request = array();
+		foreach ( $server as $param_key => $param_val ) {
+			$req_param = strtolower( $param_key );
+			if ( 'REQUEST_URI' === $req_param ) {
+				$request['headers']['route'][] = $param_val;
+			} else {
+				$header_key = str_replace(
+					'http_',
+					'',
+					$req_param
+				);
+				$request['headers'][ $header_key ][] = \wp_unslash( $param_val );
+			}
+		}
+		return $request;
 	}
 }

includes/class-webfinger.php

@@ -0,0 +1,208 @@
+<?php
+namespace Activitypub;
+
+use WP_Error;
+use Activitypub\Collection\Users;
+
+/**
+ * ActivityPub WebFinger Class
+ *
+ * @author Matthias Pfefferle
+ *
+ * @see https://webfinger.net/
+ */
+class Webfinger {
+	/**
+	 * Returns a users WebFinger "resource"
+	 *
+	 * @param int $user_id
+	 *
+	 * @return string The user-resource
+	 */
+	public static function get_user_resource( $user_id ) {
+		// use WebFinger plugin if installed
+		if ( \function_exists( '\get_webfinger_resource' ) ) {
+			return \get_webfinger_resource( $user_id, false );
+		}
+
+		$user = Users::get_by_id( $user_id );
+		if ( ! $user || is_wp_error( $user ) ) {
+			return '';
+		}
+
+		return $user->get_resource();
+	}
+
+	/**
+	 * Resolve a WebFinger resource
+	 *
+	 * @param string $resource The WebFinger resource
+	 *
+	 * @return string|WP_Error The URL or WP_Error
+	 */
+	public static function resolve( $resource ) {
+		if ( ! $resource ) {
+			return null;
+		}
+
+		if ( ! preg_match( '/^@?' . ACTIVITYPUB_USERNAME_REGEXP . '$/i', $resource, $m ) ) {
+			return null;
+		}
+
+		$transient_key = 'activitypub_resolve_' . ltrim( $resource, '@' );
+
+		$link = \get_transient( $transient_key );
+		if ( $link ) {
+			return $link;
+		}
+
+		$url = \add_query_arg( 'resource', 'acct:' . ltrim( $resource, '@' ), 'https://' . $m[2] . '/.well-known/webfinger' );
+		if ( ! \wp_http_validate_url( $url ) ) {
+			$response = new WP_Error( 'invalid_webfinger_url', null, $url );
+			\set_transient( $transient_key, $response, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
+			return $response;
+		}
+
+		// try to access author URL
+		$response = \wp_remote_get(
+			$url,
+			array(
+				'headers' => array( 'Accept' => 'application/jrd+json' ),
+				'redirection' => 2,
+				'timeout' => 2,
+			)
+		);
+
+		if ( \is_wp_error( $response ) ) {
+			$link = new WP_Error( 'webfinger_url_not_accessible', null, $url );
+			\set_transient( $transient_key, $link, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
+			return $link;
+		}
+
+		$body = \wp_remote_retrieve_body( $response );
+		$body = \json_decode( $body, true );
+
+		if ( empty( $body['links'] ) ) {
+			$link = new WP_Error( 'webfinger_url_invalid_response', null, $url );
+			\set_transient( $transient_key, $link, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
+			return $link;
+		}
+
+		foreach ( $body['links'] as $link ) {
+			if ( 'self' === $link['rel'] && 'application/activity+json' === $link['type'] ) {
+				\set_transient( $transient_key, $link['href'], WEEK_IN_SECONDS );
+				return $link['href'];
+			}
+		}
+
+		$link = new WP_Error( 'webfinger_url_no_activitypub', null, $body );
+		\set_transient( $transient_key, $link, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
+		return $link;
+	}
+
+	/**
+	 * Convert a URI string to an identifier and its host.
+	 * Automatically adds acct: if it's missing.
+	 *
+	 * @param string $url The URI (acct:, mailto:, http:, https:)
+	 *
+	 * @return WP_Error|array Error reaction or array with
+	 *                        identifier and host as values
+	 */
+	public static function get_identifier_and_host( $url ) {
+		// remove leading @
+		$url = ltrim( $url, '@' );
+
+		if ( ! preg_match( '/^([a-zA-Z+]+):/', $url, $match ) ) {
+			$identifier = 'acct:' . $url;
+			$scheme = 'acct';
+		} else {
+			$identifier = $url;
+			$scheme = $match[1];
+		}
+
+		$host = null;
+
+		switch ( $scheme ) {
+			case 'acct':
+			case 'mailto':
+			case 'xmpp':
+				if ( strpos( $identifier, '@' ) !== false ) {
+					$host = substr( $identifier, strpos( $identifier, '@' ) + 1 );
+				}
+				break;
+			default:
+				$host = wp_parse_url( $identifier, PHP_URL_HOST );
+				break;
+		}
+
+		if ( empty( $host ) ) {
+			return new WP_Error( 'invalid_identifier', __( 'Invalid Identifier', 'activitypub' ) );
+		}
+
+		return array( $identifier, $host );
+	}
+
+	/**
+	 * Get the WebFinger data for a given URI
+	 *
+	 * @param string $identifier The Identifier: <identifier>@<host>
+	 * @param string $host       The Host: <identifier>@<host>
+	 *
+	 * @return WP_Error|array Error reaction or array with
+	 *                        identifier and host as values
+	 */
+	public static function get_data( $identifier, $host ) {
+		$webfinger_url = 'https://' . $host . '/.well-known/webfinger?resource=' . rawurlencode( $identifier );
+
+		$response = wp_safe_remote_get(
+			$webfinger_url,
+			array(
+				'headers' => array( 'Accept' => 'application/jrd+json' ),
+				'redirection' => 0,
+				'timeout' => 2,
+			)
+		);
+
+		if ( is_wp_error( $response ) ) {
+			return new WP_Error( 'webfinger_url_not_accessible', null, $webfinger_url );
+		}
+
+		$body = wp_remote_retrieve_body( $response );
+
+		return json_decode( $body, true );
+	}
+
+	/**
+	 * Undocumented function
+	 *
+	 * @return void
+	 */
+	public static function get_remote_follow_endpoint( $uri ) {
+		$identifier_and_host = self::get_identifier_and_host( $uri );
+
+		if ( is_wp_error( $identifier_and_host ) ) {
+			return $identifier_and_host;
+		}
+
+		list( $identifier, $host ) = $identifier_and_host;
+
+		$data = self::get_data( $identifier, $host );
+
+		if ( is_wp_error( $data ) ) {
+			return $data;
+		}
+
+		if ( empty( $data['links'] ) ) {
+			return new WP_Error( 'webfinger_url_invalid_response', null, $data );
+		}
+
+		foreach ( $data['links'] as $link ) {
+			if ( 'http://ostatus.org/schema/1.0/subscribe' === $link['rel'] ) {
+				return $link['template'];
+			}
+		}
+
+		return new WP_Error( 'webfinger_remote_follow_endpoint_invalid', $data, array( 'status' => 417 ) );
+	}
+}

includes/collection/class-followers.php

@@ -0,0 +1,585 @@
+<?php
+namespace Activitypub\Collection;
+
+use WP_Error;
+use Exception;
+use WP_Query;
+use Activitypub\Http;
+use Activitypub\Webfinger;
+use Activitypub\Model\Follower;
+use Activitypub\Collection\Users;
+use Activitypub\Activity\Activity;
+use Activitypub\Activity\Base_Object;
+
+use function Activitypub\is_tombstone;
+use function Activitypub\get_remote_metadata_by_actor;
+
+/**
+ * ActivityPub Followers Collection
+ *
+ * @author Matt Wiebe
+ * @author Matthias Pfefferle
+ */
+class Followers {
+	const POST_TYPE = 'ap_follower';
+	const CACHE_KEY_INBOXES = 'follower_inboxes_%s';
+
+	/**
+	 * Register WordPress hooks/actions and register Taxonomy
+	 *
+	 * @return void
+	 */
+	public static function init() {
+		// register "followers" post_type
+		self::register_post_type();
+
+		\add_action( 'activitypub_inbox_follow', array( self::class, 'handle_follow_request' ), 10, 2 );
+		\add_action( 'activitypub_inbox_undo', array( self::class, 'handle_undo_request' ), 10, 2 );
+
+		\add_action( 'activitypub_followers_post_follow', array( self::class, 'send_follow_response' ), 10, 4 );
+	}
+
+	/**
+	 * Register the "Followers" Taxonomy
+	 *
+	 * @return void
+	 */
+	private static function register_post_type() {
+		register_post_type(
+			self::POST_TYPE,
+			array(
+				'labels'           => array(
+					'name'          => _x( 'Followers', 'post_type plural name', 'activitypub' ),
+					'singular_name' => _x( 'Follower', 'post_type single name', 'activitypub' ),
+				),
+				'public'           => false,
+				'hierarchical'     => false,
+				'rewrite'          => false,
+				'query_var'        => false,
+				'delete_with_user' => false,
+				'can_export'       => true,
+				'supports'         => array(),
+			)
+		);
+
+		register_post_meta(
+			self::POST_TYPE,
+			'activitypub_inbox',
+			array(
+				'type'              => 'string',
+				'single'            => true,
+				'sanitize_callback' => array( self::class, 'sanitize_url' ),
+			)
+		);
+
+		register_post_meta(
+			self::POST_TYPE,
+			'activitypub_errors',
+			array(
+				'type'              => 'string',
+				'single'            => false,
+				'sanitize_callback' => function( $value ) {
+					if ( ! is_string( $value ) ) {
+						throw new Exception( 'Error message is no valid string' );
+					}
+
+					return esc_sql( $value );
+				},
+			)
+		);
+
+		register_post_meta(
+			self::POST_TYPE,
+			'activitypub_user_id',
+			array(
+				'type'              => 'string',
+				'single'            => false,
+				'sanitize_callback' => function( $value ) {
+					return esc_sql( $value );
+				},
+			)
+		);
+
+		register_post_meta(
+			self::POST_TYPE,
+			'activitypub_actor_json',
+			array(
+				'type'              => 'string',
+				'single'            => true,
+				'sanitize_callback' => function( $value ) {
+					return sanitize_text_field( $value );
+				},
+			)
+		);
+
+		do_action( 'activitypub_after_register_post_type' );
+	}
+
+	public static function sanitize_url( $value ) {
+		if ( filter_var( $value, FILTER_VALIDATE_URL ) === false ) {
+			return null;
+		}
+
+		return esc_url_raw( $value );
+	}
+
+	/**
+	 * Handle the "Follow" Request
+	 *
+	 * @param array $object    The JSON "Follow" Activity
+	 * @param int   $user_id The ID of the ID of the WordPress User
+	 *
+	 * @return void
+	 */
+	public static function handle_follow_request( $object, $user_id ) {
+		// save follower
+		$follower = self::add_follower( $user_id, $object['actor'] );
+
+		do_action( 'activitypub_followers_post_follow', $object['actor'], $object, $user_id, $follower );
+	}
+
+	/**
+	 * Handle "Unfollow" requests
+	 *
+	 * @param array $object  The JSON "Undo" Activity
+	 * @param int   $user_id The ID of the ID of the WordPress User
+	 */
+	public static function handle_undo_request( $object, $user_id ) {
+		if (
+			isset( $object['object'] ) &&
+			isset( $object['object']['type'] ) &&
+			'Follow' === $object['object']['type']
+		) {
+			self::remove_follower( $user_id, $object['actor'] );
+		}
+	}
+
+	/**
+	 * Add new Follower
+	 *
+	 * @param int    $user_id The ID of the WordPress User
+	 * @param string $actor   The Actor URL
+	 *
+	 * @return array|WP_Error The Follower (WP_Post array) or an WP_Error
+	 */
+	public static function add_follower( $user_id, $actor ) {
+		$meta = get_remote_metadata_by_actor( $actor );
+
+		if ( is_tombstone( $meta ) ) {
+			return $meta;
+		}
+
+		if ( empty( $meta ) || ! is_array( $meta ) || is_wp_error( $meta ) ) {
+			return new WP_Error( 'activitypub_invalid_follower', __( 'Invalid Follower', 'activitypub' ), array( 'status' => 400 ) );
+		}
+
+		$follower = new Follower();
+		$follower->from_array( $meta );
+
+		$id = $follower->upsert();
+
+		if ( is_wp_error( $id ) ) {
+			return $id;
+		}
+
+		$post_meta = get_post_meta( $id, 'activitypub_user_id' );
+
+		// phpcs:ignore WordPress.PHP.StrictInArray.MissingTrueStrict
+		if ( is_array( $post_meta ) && ! in_array( $user_id, $post_meta ) ) {
+			add_post_meta( $id, 'activitypub_user_id', $user_id );
+			wp_cache_delete( sprintf( self::CACHE_KEY_INBOXES, $user_id ), 'activitypub' );
+		}
+
+		return $follower;
+	}
+
+	/**
+	 * Remove a Follower
+	 *
+	 * @param int    $user_id The ID of the WordPress User
+	 * @param string $actor   The Actor URL
+	 *
+	 * @return bool|WP_Error True on success, false or WP_Error on failure.
+	 */
+	public static function remove_follower( $user_id, $actor ) {
+		wp_cache_delete( sprintf( self::CACHE_KEY_INBOXES, $user_id ), 'activitypub' );
+
+		$follower = self::get_follower( $user_id, $actor );
+
+		if ( ! $follower ) {
+			return false;
+		}
+
+		return delete_post_meta( $follower->get__id(), 'activitypub_user_id', $user_id );
+	}
+
+	/**
+	 * Get a Follower
+	 *
+	 * @param int    $user_id The ID of the WordPress User
+	 * @param string $actor   The Actor URL
+	 *
+	 * @return \Activitypub\Model\Follower The Follower object
+	 */
+	public static function get_follower( $user_id, $actor ) {
+		global $wpdb;
+
+		$post_id = $wpdb->get_var(
+			$wpdb->prepare(
+				"SELECT DISTINCT p.ID FROM $wpdb->posts p INNER JOIN $wpdb->postmeta pm ON p.ID = pm.post_id WHERE p.post_type = %s AND pm.meta_key = 'activitypub_user_id' AND pm.meta_value = %d AND p.guid = %s",
+				array(
+					esc_sql( self::POST_TYPE ),
+					esc_sql( $user_id ),
+					esc_sql( $actor ),
+				)
+			)
+		);
+
+		if ( $post_id ) {
+			$post = get_post( $post_id );
+			return Follower::init_from_cpt( $post );
+		}
+
+		return null;
+	}
+
+	/**
+	 * Send Accept response
+	 *
+	 * @param string                     $actor    The Actor URL
+	 * @param array                      $object   The Activity object
+	 * @param int                        $user_id  The ID of the WordPress User
+	 * @param Activitypub\Model\Follower $follower The Follower object
+	 *
+	 * @return void
+	 */
+	public static function send_follow_response( $actor, $object, $user_id, $follower ) {
+		if ( is_wp_error( $follower ) ) {
+			// it is not even possible to send a "Reject" because
+			// we can not get the Remote-Inbox
+			return;
+		}
+
+		// only send minimal data
+		$object = array_intersect_key(
+			$object,
+			array_flip(
+				array(
+					'id',
+					'type',
+					'actor',
+					'object',
+				)
+			)
+		);
+
+		$user = Users::get_by_id( $user_id );
+
+		// get inbox
+		$inbox = $follower->get_shared_inbox();
+
+		// send "Accept" activity
+		$activity = new Activity();
+		$activity->set_type( 'Accept' );
+		$activity->set_object( $object );
+		$activity->set_actor( $user->get_id() );
+		$activity->set_to( $actor );
+		$activity->set_id( $user->get_id() . '#follow-' . \preg_replace( '~^https?://~', '', $actor ) . '-' . \time() );
+
+		$activity = $activity->to_json();
+
+		Http::post( $inbox, $activity, $user_id );
+	}
+
+	/**
+	 * Get the Followers of a given user
+	 *
+	 * @param int    $user_id The ID of the WordPress User.
+	 * @param int    $number  Maximum number of results to return.
+	 * @param int    $page    Page number.
+	 * @param array  $args    The WP_Query arguments.
+	 * @return array List of `Follower` objects.
+	 */
+	public static function get_followers( $user_id, $number = -1, $page = null, $args = array() ) {
+		$data = self::get_followers_with_count( $user_id, $number, $page, $args );
+		return $data['followers'];
+	}
+
+	/**
+	 * Get the Followers of a given user, along with a total count for pagination purposes.
+	 *
+	 * @param int    $user_id The ID of the WordPress User.
+	 * @param int    $number  Maximum number of results to return.
+	 * @param int    $page    Page number.
+	 * @param array  $args    The WP_Query arguments.
+	 *
+	 * @return array
+	 *               followers List of `Follower` objects.
+	 *               total     Total number of followers.
+	 */
+	public static function get_followers_with_count( $user_id, $number = -1, $page = null, $args = array() ) {
+		$defaults = array(
+			'post_type'      => self::POST_TYPE,
+			'posts_per_page' => $number,
+			'paged'          => $page,
+			'orderby'        => 'ID',
+			'order'          => 'DESC',
+			// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
+			'meta_query'     => array(
+				array(
+					'key'   => 'activitypub_user_id',
+					'value' => $user_id,
+				),
+			),
+		);
+
+		$args = wp_parse_args( $args, $defaults );
+		$query = new WP_Query( $args );
+		$total = $query->found_posts;
+		$followers = array_map(
+			function( $post ) {
+				return Follower::init_from_cpt( $post );
+			},
+			$query->get_posts()
+		);
+		return compact( 'followers', 'total' );
+	}
+
+	/**
+	 * Get all Followers
+	 *
+	 * @param array $args The WP_Query arguments.
+	 *
+	 * @return array The Term list of Followers.
+	 */
+	public static function get_all_followers() {
+		$args = array(
+			// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
+			'meta_query' => array(
+				'relation' => 'AND',
+				array(
+					'key'     => 'activitypub_inbox',
+					'compare' => 'EXISTS',
+				),
+				array(
+					'key'     => 'activitypub_actor_json',
+					'compare' => 'EXISTS',
+				),
+			),
+		);
+		return self::get_followers( null, null, null, $args );
+	}
+
+	/**
+	 * Count the total number of followers
+	 *
+	 * @param int $user_id The ID of the WordPress User
+	 *
+	 * @return int The number of Followers
+	 */
+	public static function count_followers( $user_id ) {
+		$query = new WP_Query(
+			array(
+				'post_type'  => self::POST_TYPE,
+				'fields'     => 'ids',
+				// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
+				'meta_query' => array(
+					'relation' => 'AND',
+					array(
+						'key'   => 'activitypub_user_id',
+						'value' => $user_id,
+					),
+					array(
+						'key'     => 'activitypub_inbox',
+						'compare' => 'EXISTS',
+					),
+					array(
+						'key'     => 'activitypub_actor_json',
+						'compare' => 'EXISTS',
+					),
+				),
+			)
+		);
+
+		return $query->found_posts;
+	}
+
+	/**
+	 * Returns all Inboxes fo a Users Followers
+	 *
+	 * @param int $user_id The ID of the WordPress User
+	 *
+	 * @return array The list of Inboxes
+	 */
+	public static function get_inboxes( $user_id ) {
+		$cache_key = sprintf( self::CACHE_KEY_INBOXES, $user_id );
+		$inboxes = wp_cache_get( $cache_key, 'activitypub' );
+
+		if ( $inboxes ) {
+			return $inboxes;
+		}
+
+		// get all Followers of a ID of the WordPress User
+		$posts = new WP_Query(
+			array(
+				'post_type'  => self::POST_TYPE,
+				'fields'     => 'ids',
+				// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
+				'meta_query' => array(
+					'relation' => 'AND',
+					array(
+						'key'     => 'activitypub_inbox',
+						'compare' => 'EXISTS',
+					),
+					array(
+						'key'   => 'activitypub_user_id',
+						'value' => $user_id,
+					),
+					array(
+						'key'     => 'activitypub_inbox',
+						'value'   => '',
+						'compare' => '!=',
+					),
+				),
+			)
+		);
+
+		$posts = $posts->get_posts();
+
+		if ( ! $posts ) {
+			return array();
+		}
+
+		global $wpdb;
+		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery
+		$results = $wpdb->get_col(
+			$wpdb->prepare(
+				"SELECT DISTINCT meta_value FROM {$wpdb->postmeta}
+				WHERE post_id IN (" . implode( ', ', array_fill( 0, count( $posts ), '%d' ) ) . ")
+				AND meta_key = 'activitypub_inbox'
+				AND meta_value IS NOT NULL",
+				$posts
+			)
+		);
+
+		$inboxes = array_filter( $results );
+		wp_cache_set( $cache_key, $inboxes, 'activitypub' );
+
+		return $inboxes;
+	}
+
+	/**
+	 * Get all Followers that have not been updated for a given time
+	 *
+	 * @param enum $output     The output format, supported ARRAY_N, OBJECT and ACTIVITYPUB_OBJECT.
+	 * @param int  $number     Limits the result.
+	 * @param int  $older_than The time in seconds.
+	 *
+	 * @return mixed The Term list of Followers, the format depends on $output.
+	 */
+	public static function get_outdated_followers( $number = 50, $older_than = 86400 ) {
+		$args = array(
+			'post_type'      => self::POST_TYPE,
+			'posts_per_page' => $number,
+			'orderby'        => 'modified',
+			'order'          => 'ASC',
+			'post_status'    => 'any', // 'any' includes 'trash
+			'date_query'     => array(
+				array(
+					'column' => 'post_modified_gmt',
+					'before' => gmdate( 'Y-m-d', \time() - $older_than ),
+				),
+			),
+		);
+
+		$posts = new WP_Query( $args );
+		$items = array();
+
+		foreach ( $posts->get_posts() as $follower ) {
+			$items[] = Follower::init_from_cpt( $follower ); // phpcs:ignore
+		}
+
+		return $items;
+	}
+
+	/**
+	 * Get all Followers that had errors
+	 *
+	 * @param enum    $output The output format, supported ARRAY_N, OBJECT and ACTIVITYPUB_OBJECT
+	 * @param integer $number The number of Followers to return.
+	 *
+	 * @return mixed The Term list of Followers, the format depends on $output.
+	 */
+	public static function get_faulty_followers( $number = 20 ) {
+		$args = array(
+			'post_type'      => self::POST_TYPE,
+			'posts_per_page' => $number,
+			// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
+			'meta_query'     => array(
+				'relation' => 'OR',
+				array(
+					'key'     => 'activitypub_errors',
+					'compare' => 'EXISTS',
+				),
+				array(
+					'key'     => 'activitypub_inbox',
+					'compare' => 'NOT EXISTS',
+				),
+				array(
+					'key'     => 'activitypub_actor_json',
+					'compare' => 'NOT EXISTS',
+				),
+				array(
+					'key'     => 'activitypub_inbox',
+					'value'   => '',
+					'compare' => '=',
+				),
+				array(
+					'key'     => 'activitypub_actor_json',
+					'value'   => '',
+					'compare' => '=',
+				),
+			),
+		);
+
+		$posts = new WP_Query( $args );
+		$items = array();
+
+		foreach ( $posts->get_posts() as $follower ) {
+			$items[] = Follower::init_from_cpt( $follower ); // phpcs:ignore
+		}
+
+		return $items;
+	}
+
+	/**
+	 * This function is used to store errors that occur when
+	 * sending an ActivityPub message to a Follower.
+	 *
+	 * The error will be stored in the
+	 * post meta.
+	 *
+	 * @param int   $post_id The ID of the WordPress Custom-Post-Type.
+	 * @param mixed $error   The error message. Can be a string or a WP_Error.
+	 *
+	 * @return int|false The meta ID on success, false on failure.
+	 */
+	public static function add_error( $post_id, $error ) {
+		if ( is_string( $error ) ) {
+			$error_message = $error;
+		} elseif ( is_wp_error( $error ) ) {
+			$error_message = $error->get_error_message();
+		} else {
+			$error_message = __(
+				'Unknown Error or misconfigured Error-Message',
+				'activitypub'
+			);
+		}
+
+		return add_post_meta(
+			$post_id,
+			'activitypub_errors',
+			$error_message
+		);
+	}
+}

includes/collection/class-users.php

@@ -0,0 +1,209 @@
+<?php
+namespace Activitypub\Collection;
+
+use WP_Error;
+use WP_User_Query;
+use Activitypub\Model\User;
+use Activitypub\Model\Blog_User;
+use Activitypub\Model\Application_User;
+
+use function Activitypub\is_user_disabled;
+
+class Users {
+	/**
+	 * The ID of the Blog User
+	 *
+	 * @var int
+	 */
+	const BLOG_USER_ID = 0;
+
+	/**
+	 * The ID of the Application User
+	 *
+	 * @var int
+	 */
+	const APPLICATION_USER_ID = -1;
+
+	/**
+	 * Get the User by ID
+	 *
+	 * @param int $user_id The User-ID.
+	 *
+	 * @return \Acitvitypub\Model\User The User.
+	 */
+	public static function get_by_id( $user_id ) {
+		if ( is_string( $user_id ) || is_numeric( $user_id ) ) {
+			$user_id = (int) $user_id;
+		}
+
+		if ( is_user_disabled( $user_id ) ) {
+			return new WP_Error(
+				'activitypub_user_not_found',
+				\__( 'User not found', 'activitypub' ),
+				array( 'status' => 404 )
+			);
+		}
+
+		if ( self::BLOG_USER_ID === $user_id ) {
+			return Blog_User::from_wp_user( $user_id );
+		} elseif ( self::APPLICATION_USER_ID === $user_id ) {
+			return Application_User::from_wp_user( $user_id );
+		} elseif ( $user_id > 0 ) {
+			return User::from_wp_user( $user_id );
+		}
+
+		return new WP_Error(
+			'activitypub_user_not_found',
+			\__( 'User not found', 'activitypub' ),
+			array( 'status' => 404 )
+		);
+	}
+
+	/**
+	 * Get the User by username.
+	 *
+	 * @param string $username The User-Name.
+	 *
+	 * @return \Acitvitypub\Model\User The User.
+	 */
+	public static function get_by_username( $username ) {
+		// check for blog user.
+		if ( Blog_User::get_default_username() === $username ) {
+			return self::get_by_id( self::BLOG_USER_ID );
+		}
+
+		if ( get_option( 'activitypub_blog_user_identifier' ) === $username ) {
+			return self::get_by_id( self::BLOG_USER_ID );
+		}
+
+		// check for application user.
+		if ( 'application' === $username ) {
+			return self::get_by_id( self::APPLICATION_USER_ID );
+		}
+
+		// check for 'activitypub_username' meta
+		$user = new WP_User_Query(
+			array(
+				'number'         => 1,
+				'hide_empty'     => true,
+				'fields'         => 'ID',
+				// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
+				'meta_query' => array(
+					'relation' => 'OR',
+					array(
+						'key'     => 'activitypub_user_identifier',
+						'value'   => $username,
+						'compare' => 'LIKE',
+					),
+				),
+			)
+		);
+
+		if ( $user->results ) {
+			return self::get_by_id( $user->results[0] );
+		}
+
+		// check for login or nicename.
+		$user = new WP_User_Query(
+			array(
+				'search'         => $username,
+				'search_columns' => array( 'user_login', 'user_nicename' ),
+				'number'         => 1,
+				'hide_empty'     => true,
+				'fields'         => 'ID',
+			)
+		);
+
+		if ( $user->results ) {
+			return self::get_by_id( $user->results[0] );
+		}
+
+		return new WP_Error(
+			'activitypub_user_not_found',
+			\__( 'User not found', 'activitypub' ),
+			array( 'status' => 404 )
+		);
+	}
+
+	/**
+	 * Get the User by resource.
+	 *
+	 * @param string $resource The User-Resource.
+	 *
+	 * @return \Acitvitypub\Model\User The User.
+	 */
+	public static function get_by_resource( $resource ) {
+		if ( \strpos( $resource, '@' ) === false ) {
+			return new WP_Error(
+				'activitypub_unsupported_resource',
+				\__( 'Resource is invalid', 'activitypub' ),
+				array( 'status' => 400 )
+			);
+		}
+
+		$resource = \str_replace( 'acct:', '', $resource );
+
+		$resource_identifier = \substr( $resource, 0, \strrpos( $resource, '@' ) );
+		$resource_host = self::normalize_host( \substr( \strrchr( $resource, '@' ), 1 ) );
+		$blog_host = self::normalize_host( \wp_parse_url( \home_url( '/' ), \PHP_URL_HOST ) );
+
+		if ( $blog_host !== $resource_host ) {
+			return new WP_Error(
+				'activitypub_wrong_host',
+				\__( 'Resource host does not match blog host', 'activitypub' ),
+				array( 'status' => 404 )
+			);
+		}
+
+		return self::get_by_username( $resource_identifier );
+	}
+
+	/**
+	 * Get the User by resource.
+	 *
+	 * @param string $resource The User-Resource.
+	 *
+	 * @return \Acitvitypub\Model\User The User.
+	 */
+	public static function get_by_various( $id ) {
+		if ( is_numeric( $id ) ) {
+			return self::get_by_id( $id );
+		} elseif ( filter_var( $id, FILTER_VALIDATE_URL ) ) {
+			return self::get_by_resource( $id );
+		} else {
+			return self::get_by_username( $id );
+		}
+	}
+
+	/**
+	 * Normalize the host.
+	 *
+	 * @param string $host The host.
+	 *
+	 * @return string The normalized host.
+	 */
+	public static function normalize_host( $host ) {
+		return \str_replace( 'www.', '', $host );
+	}
+
+	/**
+	 * Get the User collection.
+	 *
+	 * @return array The User collection.
+	 */
+	public static function get_collection() {
+		$users = \get_users(
+			array(
+				'capability__in' => array( 'publish_posts' ),
+			)
+		);
+
+		$return = array();
+
+		foreach ( $users as $user ) {
+			$return[] = User::from_wp_user( $user->ID );
+		}
+
+		return $return;
+	}
+}

includes/compat.php

@@ -0,0 +1,49 @@
+<?php
+/**
+ * ActivityPub implementation for WordPress/PHP functions either missing from older WordPress/PHP versions or not included by default.
+ */
+
+if ( ! function_exists( 'str_starts_with' ) ) {
+	/**
+	 * Polyfill for `str_starts_with()` function added in PHP 8.0.
+	 *
+	 * Performs a case-sensitive check indicating if
+	 * the haystack begins with needle.
+	 *
+	 * @param string $haystack The string to search in.
+	 * @param string $needle   The substring to search for in the `$haystack`.
+	 * @return bool True if `$haystack` starts with `$needle`, otherwise false.
+	 */
+	function str_starts_with( $haystack, $needle ) {
+		if ( '' === $needle ) {
+			return true;
+		}
+
+		return 0 === strpos( $haystack, $needle );
+	}
+}
+
+if ( ! function_exists( 'get_self_link' ) ) {
+	/**
+	 * Returns the link for the currently displayed feed.
+	 *
+	 * @return string Correct link for the atom:self element.
+	 */
+	function get_self_link() {
+		$host = wp_parse_url( home_url() );
+		$path = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
+		return esc_url( apply_filters( 'self_link', set_url_scheme( 'http://' . $host['host'] . $path ) ) );
+	}
+}
+
+if ( ! function_exists( 'is_countable' ) ) {
+	/**
+	 * Polyfill for `is_countable()` function added in PHP 7.3.
+	 *
+	 * @param mixed $value The value to check.
+	 * @return bool True if `$value` is countable, otherwise false.
+	 */
+	function is_countable( $value ) {
+			return is_array( $value ) || $value instanceof \Countable;
+	}
+}

includes/debug.php

@@ -0,0 +1,17 @@
+<?php
+namespace Activitypub;
+
+/**
+ * Allow localhost URLs if WP_DEBUG is true.
+ *
+ * @param array  $r   Array of HTTP request args.
+ * @param string $url The request URL.
+ *
+ * @return array Array or string of HTTP request arguments.
+ */
+function allow_localhost( $r, $url ) {
+	$r['reject_unsafe_urls'] = false;
+
+	return $r;
+}
+add_filter( 'http_request_args', '\Activitypub\allow_localhost', 10, 2 );

includes/functions.php

@@ -1,115 +1,84 @@
 <?php
 namespace Activitypub;
 
+use WP_Error;
+use Activitypub\Http;
+use Activitypub\Activity\Activity;
+use Activitypub\Collection\Followers;
+use Activitypub\Collection\Users;
+
 /**
  * Returns the ActivityPub default JSON-context
  *
  * @return array the activitypub context
  */
 function get_context() {
-	$context = array(
-		'https://www.w3.org/ns/activitystreams',
-		'https://w3id.org/security/v1',
-		array(
-			'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
-			'PropertyValue' => 'schema:PropertyValue',
-			'schema' => 'http://schema.org#',
-			'value' => 'schema:value',
-		),
-	);
+	$context = Activity::CONTEXT;
 
 	return \apply_filters( 'activitypub_json_context', $context );
 }
 
 function safe_remote_post( $url, $body, $user_id ) {
-	$date = \gmdate( 'D, d M Y H:i:s T' );
-	$signature = \Activitypub\Signature::generate_signature( $user_id, $url, $date );
+	return Http::post( $url, $body, $user_id );
+}
 
-	$wp_version = \get_bloginfo( 'version' );
-	$user_agent = \apply_filters( 'http_headers_useragent', 'WordPress/' . $wp_version . '; ' . \get_bloginfo( 'url' ) );
-	$args = array(
-		'timeout' => 100,
-		'limit_response_size' => 1048576,
-		'redirection' => 3,
-		'user-agent' => "$user_agent; ActivityPub",
-		'headers' => array(
-			'Accept' => 'application/activity+json',
-			'Content-Type' => 'application/activity+json',
-			'Signature' => $signature,
-			'Date' => $date,
-		),
-		'body' => $body,
-	);
-
-	$response = \wp_safe_remote_post( $url, $args );
-
-	\do_action( 'activitypub_safe_remote_post_response', $response, $url, $body, $user_id );
-
-	return $response;
+function safe_remote_get( $url ) {
+	return Http::get( $url );
 }
 
 /**
  * Returns a users WebFinger "resource"
  *
- * @param int $user_id
+ * @param int $user_id The User-ID.
  *
- * @return string The user-resource
+ * @return string The User-Resource.
  */
 function get_webfinger_resource( $user_id ) {
-	// use WebFinger plugin if installed
-	if ( \function_exists( '\get_webfinger_resource' ) ) {
-		return \get_webfinger_resource( $user_id, false );
-	}
-
-	$user = \get_user_by( 'id', $user_id );
-
-	return $user->user_login . '@' . \wp_parse_url( \home_url(), PHP_URL_HOST );
+	return Webfinger::get_user_resource( $user_id );
 }
 
 /**
- * [get_metadata_by_actor description]
+ * Requests the Meta-Data from the Actors profile
  *
- * @param sting $actor
+ * @param string $actor  The Actor URL.
+ * @param bool   $cached If the result should be cached.
  *
- * @return array
+ * @return array|WP_Error The Actor profile as array or WP_Error on failure.
  */
-function get_remote_metadata_by_actor( $actor ) {
-	$metadata = \get_transient( 'activitypub_' . $actor );
+function get_remote_metadata_by_actor( $actor, $cached = true ) {
+	$pre = apply_filters( 'pre_get_remote_metadata_by_actor', false, $actor );
+	if ( $pre ) {
+		return $pre;
+	}
+	if ( preg_match( '/^@?' . ACTIVITYPUB_USERNAME_REGEXP . '$/i', $actor ) ) {
+		$actor = Webfinger::resolve( $actor );
+	}
+
+	if ( ! $actor ) {
+		return new WP_Error( 'activitypub_no_valid_actor_identifier', \__( 'The "actor" identifier is not valid', 'activitypub' ), array( 'status' => 404, 'actor' => $actor ) );
+	}
+
+	if ( is_wp_error( $actor ) ) {
+		return $actor;
+	}
+
+	$transient_key = 'activitypub_' . $actor;
+
+	// only check the cache if needed.
+	if ( $cached ) {
+		$metadata = \get_transient( $transient_key );
 
 		if ( $metadata ) {
 			return $metadata;
 		}
-
-	if ( ! \wp_http_validate_url( $actor ) ) {
-		return new \WP_Error( 'activitypub_no_valid_actor_url', \__( 'The "actor" is no valid URL', 'activitypub' ), $actor );
 	}
 
-	// we just need any user to generate a request signature
-	$user_id = \reset( \get_users( array (
-		'number' => 1,
-		'who'    => 'authors',
-		'fields' => 'ID'
-	) ) );
+	if ( ! \wp_http_validate_url( $actor ) ) {
+		$metadata = new WP_Error( 'activitypub_no_valid_actor_url', \__( 'The "actor" is no valid URL', 'activitypub' ), array( 'status' => 400, 'actor' => $actor ) );
+		return $metadata;
+	}
 
-	$date = \gmdate( 'D, d M Y H:i:s T' );
-	$signature = \Activitypub\Signature::generate_signature( $user_id, $url, $date );
-
-	$wp_version = \get_bloginfo( 'version' );
-
-	$user_agent = \apply_filters( 'http_headers_useragent', 'WordPress/' . $wp_version . '; ' . \get_bloginfo( 'url' ) );
-	$args       = array(
-		'timeout'             => 100,
-		'limit_response_size' => 1048576,
-		'redirection'         => 3,
-		'user-agent'          => "$user_agent; ActivityPub",
-		'headers'             => array(
-			'accept' => 'application/activity+json, application/ld+json, application/ld+json; profile="https://www.w3.org/ns/activitystreams"',
-			'Signature' => $signature,
-			'Date' => $date,
-		),
-	);
-
-	$response = \wp_safe_remote_get( $actor, $args );
+	$response = Http::get( $actor );
 
 	if ( \is_wp_error( $response ) ) {
 		return $response;
@@ -119,115 +88,35 @@ function get_remote_metadata_by_actor( $actor ) {
 	$metadata = \json_decode( $metadata, true );
 
 	if ( ! $metadata ) {
-		return new \WP_Error( 'activitypub_invalid_json', \__( 'No valid JSON data', 'activitypub' ), $actor );
+		$metadata = new WP_Error( 'activitypub_invalid_json', \__( 'No valid JSON data', 'activitypub' ), array( 'status' => 400, 'actor' => $actor ) );
+		return $metadata;
 	}
 
-	\set_transient( 'activitypub_' . $actor, $metadata, WEEK_IN_SECONDS );
+	\set_transient( $transient_key, $metadata, WEEK_IN_SECONDS );
 
 	return $metadata;
 }
 
 /**
- * [get_inbox_by_actor description]
- * @param  [type] $actor [description]
- * @return [type]        [description]
+ * Returns the followers of a given user.
+ *
+ * @param int $user_id The User-ID.
+ *
+ * @return array The followers.
  */
-function get_inbox_by_actor( $actor ) {
-	$metadata = \Activitypub\get_remote_metadata_by_actor( $actor );
-
-	if ( \is_wp_error( $metadata ) ) {
-		return $metadata;
-	}
-
-	if ( isset( $metadata['endpoints'] ) && isset( $metadata['endpoints']['sharedInbox'] ) ) {
-		return $metadata['endpoints']['sharedInbox'];
-	}
-
-	if ( \array_key_exists( 'inbox', $metadata ) ) {
-		return $metadata['inbox'];
-	}
-
-	return new \WP_Error( 'activitypub_no_inbox', __( 'No "Inbox" found', 'activitypub' ), $metadata );
-}
-
-/**
- * [get_inbox_by_actor description]
- * @param  [type] $actor [description]
- * @return [type]        [description]
- */
-function get_publickey_by_actor( $actor, $key_id ) {
-	$metadata = \Activitypub\get_remote_metadata_by_actor( $actor );
-
-	if ( \is_wp_error( $metadata ) ) {
-		return $metadata;
-	}
-
-	if (
-		isset( $metadata['publicKey'] ) &&
-		isset( $metadata['publicKey']['id'] ) &&
-		isset( $metadata['publicKey']['owner'] ) &&
-		isset( $metadata['publicKey']['publicKeyPem'] ) &&
-		$key_id === $metadata['publicKey']['id'] &&
-		$actor === $metadata['publicKey']['owner']
-	) {
-		return $metadata['publicKey']['publicKeyPem'];
-	}
-
-	return new \WP_Error( 'activitypub_no_public_key', \__( 'No "Public-Key" found', 'activitypub' ), $metadata );
-}
-
-function get_follower_inboxes( $user_id ) {
-	$followers = \Activitypub\Peer\Followers::get_followers( $user_id );
-	$inboxes = array();
-
-	foreach ( $followers as $follower ) {
-		$inbox = \Activitypub\get_inbox_by_actor( $follower );
-		if ( ! $inbox || \is_wp_error( $inbox ) ) {
-			continue;
-		}
-		// init array if empty
-		if ( ! isset( $inboxes[ $inbox ] ) ) {
-			$inboxes[ $inbox ] = array();
-		}
-		$inboxes[ $inbox ][] = $follower;
-	}
-
-	return $inboxes;
-}
-
-function get_identifier_settings( $user_id ) {
-	?>
-<table class="form-table">
-	<tbody>
-		<tr>
-			<th scope="row">
-				<label><?php \esc_html_e( 'Profile identifier', 'activitypub' ); ?></label>
-			</th>
-			<td>
-				<p><code><?php echo \esc_html( \Activitypub\get_webfinger_resource( $user_id ) ); ?></code> or <code><?php echo \esc_url( \get_author_posts_url( $user_id ) ); ?></code></p>
-				<?php // translators: the webfinger resource ?>
-				<p class="description"><?php \printf( \esc_html__( 'Try to follow "@%s" in the Mastodon/Friendica search field.', 'activitypub' ), \esc_html( \Activitypub\get_webfinger_resource( $user_id ) ) ); ?></p>
-			</td>
-		</tr>
-	</tbody>
-</table>
-	<?php
-}
-
 function get_followers( $user_id ) {
-	$followers = \Activitypub\Peer\Followers::get_followers( $user_id );
-
-	if ( ! $followers ) {
-		return array();
-	}
-
-	return $followers;
+	return Followers::get_followers( $user_id );
 }
 
+/**
+ * Count the number of followers for a given user.
+ *
+ * @param int $user_id The User-ID.
+ *
+ * @return int The number of followers.
+ */
 function count_followers( $user_id ) {
-	$followers = \Activitypub\get_followers( $user_id );
-
-	return \count( $followers );
+	return Followers::count_followers( $user_id );
 }
 
 /**
@@ -243,13 +132,13 @@ function url_to_authorid( $url ) {
 	global $wp_rewrite;
 
 	// check if url hase the same host
-	if ( wp_parse_url( site_url(), PHP_URL_HOST ) !== wp_parse_url( $url, PHP_URL_HOST ) ) {
+	if ( \wp_parse_url( \site_url(), \PHP_URL_HOST ) !== \wp_parse_url( $url, \PHP_URL_HOST ) ) {
 		return 0;
 	}
 
 	// first, check to see if there is a 'author=N' to match against
 	if ( \preg_match( '/[?&]author=(\d+)/i', $url, $values ) ) {
-		$id = absint( $values[1] );
+		$id = \absint( $values[1] );
 		if ( $id ) {
 			return $id;
 		}
@@ -269,7 +158,7 @@ function url_to_authorid( $url ) {
 
 	// match the rewrite rule with the passed url
 	if ( \preg_match( '/https?:\/\/(.+)' . \preg_quote( $author_regexp, '/' ) . '([^\/]+)/i', $url, $match ) ) {
-		$user = get_user_by( 'slug', $match[2] );
+		$user = \get_user_by( 'slug', $match[2] );
 		if ( $user ) {
 			return $user->ID;
 		}
@@ -277,3 +166,394 @@ function url_to_authorid( $url ) {
 
 	return 0;
 }
+
+/**
+ * Check for Tombstone Objects
+ *
+ * @see https://www.w3.org/TR/activitypub/#delete-activity-outbox
+ *
+ * @param WP_Error $wp_error A WP_Error-Response of an HTTP-Request
+ *
+ * @return boolean true if HTTP-Code is 410 or 404
+ */
+function is_tombstone( $wp_error ) {
+	if ( ! is_wp_error( $wp_error ) ) {
+		return false;
+	}
+
+	if ( in_array( (int) $wp_error->get_error_code(), array( 404, 410 ), true ) ) {
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * Get the REST URL relative to this plugin's namespace.
+ *
+ * @param string $path Optional. REST route path. Otherwise this plugin's namespaced root.
+ *
+ * @return string REST URL relative to this plugin's namespace.
+ */
+function get_rest_url_by_path( $path = '' ) {
+	// we'll handle the leading slash.
+	$path = ltrim( $path, '/' );
+	$namespaced_path = sprintf( '/%s/%s', ACTIVITYPUB_REST_NAMESPACE, $path );
+	return \get_rest_url( null, $namespaced_path );
+}
+
+/**
+ * Convert a string from camelCase to snake_case.
+ *
+ * @param string $string The string to convert.
+ *
+ * @return string The converted string.
+ */
+// phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound
+function camel_to_snake_case( $string ) {
+	return strtolower( preg_replace( '/(?<!^)[A-Z]/', '_$0', $string ) );
+}
+
+/**
+ * Convert a string from snake_case to camelCase.
+ *
+ * @param string $string The string to convert.
+ *
+ * @return string The converted string.
+ */
+// phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound
+function snake_to_camel_case( $string ) {
+	return lcfirst( str_replace( '_', '', ucwords( $string, '_' ) ) );
+}
+
+/**
+ * Escapes a Tag, to be used as a hashtag.
+ *
+ * @param string $string The string to escape.
+ *
+ * @return string The escaped hastag.
+ */
+function esc_hashtag( $string ) {
+
+	$hashtag = \wp_specialchars_decode( $string, ENT_QUOTES );
+	// Remove all characters that are not letters, numbers, or underscores.
+	$hashtag = \preg_replace( '/emoji-regex(*SKIP)(?!)|[^\p{L}\p{Nd}_]+/u', '_', $hashtag );
+
+	// Capitalize every letter that is preceded by an underscore.
+	$hashtag = preg_replace_callback(
+		'/_(.)/',
+		function ( $matches ) {
+			return '' . strtoupper( $matches[1] );
+		},
+		$hashtag
+	);
+
+	// Add a hashtag to the beginning of the string.
+	$hashtag = ltrim( $hashtag, '#' );
+	$hashtag = '#' . $hashtag;
+
+	/**
+	 * Allow defining your own custom hashtag generation rules.
+	 *
+	 * @param string $hashtag The hashtag to be returned.
+	 * @param string $string  The original string.
+	 */
+	$hashtag = apply_filters( 'activitypub_esc_hashtag', $hashtag, $string );
+
+	return esc_html( $hashtag );
+}
+
+/**
+ * Check if a request is for an ActivityPub request.
+ *
+ * @return bool False by default.
+ */
+function is_activitypub_request() {
+	global $wp_query;
+
+	/*
+	 * ActivityPub requests are currently only made for
+	 * author archives, singular posts, and the homepage.
+	 */
+	if ( ! \is_author() && ! \is_singular() && ! \is_home() && ! defined( '\REST_REQUEST' ) ) {
+		return false;
+	}
+
+	// Check if the current post type supports ActivityPub.
+	if ( \is_singular() ) {
+		$queried_object = \get_queried_object();
+		$post_type      = \get_post_type( $queried_object );
+
+		if ( ! \post_type_supports( $post_type, 'activitypub' ) ) {
+			return false;
+		}
+	}
+
+	// One can trigger an ActivityPub request by adding ?activitypub to the URL.
+	// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.VariableRedeclaration
+	global $wp_query;
+	if ( isset( $wp_query->query_vars['activitypub'] ) ) {
+		return true;
+	}
+
+	/*
+	 * The other (more common) option to make an ActivityPub request
+	 * is to send an Accept header.
+	 */
+	if ( isset( $_SERVER['HTTP_ACCEPT'] ) ) {
+		$accept = sanitize_text_field( wp_unslash( $_SERVER['HTTP_ACCEPT'] ) );
+
+		/*
+		 * $accept can be a single value, or a comma separated list of values.
+		 * We want to support both scenarios,
+		 * and return true when the header includes at least one of the following:
+		 * - application/activity+json
+		 * - application/ld+json
+		 * - application/json
+		 */
+		if ( preg_match( '/(application\/(ld\+json|activity\+json|json))/i', $accept ) ) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/**
+ * This function checks if a user is disabled for ActivityPub.
+ *
+ * @param int $user_id The User-ID.
+ *
+ * @return boolean True if the user is disabled, false otherwise.
+ */
+function is_user_disabled( $user_id ) {
+	$return = false;
+
+	switch ( $user_id ) {
+		// if the user is the application user, it's always enabled.
+		case \Activitypub\Collection\Users::APPLICATION_USER_ID:
+			$return = false;
+			break;
+		// if the user is the blog user, it's only enabled in single-user mode.
+		case \Activitypub\Collection\Users::BLOG_USER_ID:
+			if ( is_user_type_disabled( 'blog' ) ) {
+				$return = true;
+				break;
+			}
+
+			$return = false;
+			break;
+		// if the user is any other user, it's enabled if it can publish posts.
+		default:
+			if ( ! \get_user_by( 'id', $user_id ) ) {
+				$return = true;
+				break;
+			}
+
+			if ( is_user_type_disabled( 'user' ) ) {
+				$return = true;
+				break;
+			}
+
+			if ( ! \user_can( $user_id, 'publish_posts' ) ) {
+				$return = true;
+				break;
+			}
+
+			$return = false;
+			break;
+	}
+
+	return apply_filters( 'activitypub_is_user_disabled', $return, $user_id );
+}
+
+/**
+ * Checks if a User-Type is disabled for ActivityPub.
+ *
+ * This function is used to check if the 'blog' or 'user'
+ * type is disabled for ActivityPub.
+ *
+ * @param enum $type Can be 'blog' or 'user'.
+ *
+ * @return boolean True if the user type is disabled, false otherwise.
+ */
+function is_user_type_disabled( $type ) {
+	switch ( $type ) {
+		case 'blog':
+			if ( \defined( 'ACTIVITYPUB_SINGLE_USER_MODE' ) ) {
+				if ( ACTIVITYPUB_SINGLE_USER_MODE ) {
+					$return = false;
+					break;
+				}
+			}
+
+			if ( \defined( 'ACTIVITYPUB_DISABLE_BLOG_USER' ) ) {
+				$return = ACTIVITYPUB_DISABLE_BLOG_USER;
+				break;
+			}
+
+			if ( '1' !== \get_option( 'activitypub_enable_blog_user', '0' ) ) {
+				$return = true;
+				break;
+			}
+
+			$return = false;
+			break;
+		case 'user':
+			if ( \defined( 'ACTIVITYPUB_SINGLE_USER_MODE' ) ) {
+				if ( ACTIVITYPUB_SINGLE_USER_MODE ) {
+					$return = true;
+					break;
+				}
+			}
+
+			if ( \defined( 'ACTIVITYPUB_DISABLE_USER' ) ) {
+				$return = ACTIVITYPUB_DISABLE_USER;
+				break;
+			}
+
+			if ( '1' !== \get_option( 'activitypub_enable_users', '1' ) ) {
+				$return = true;
+				break;
+			}
+
+			$return = false;
+			break;
+		default:
+			$return = new WP_Error( 'activitypub_wrong_user_type', __( 'Wrong user type', 'activitypub' ), array( 'status' => 400 ) );
+			break;
+	}
+
+	return apply_filters( 'activitypub_is_user_type_disabled', $return, $type );
+}
+
+/**
+ * Check if the blog is in single-user mode.
+ *
+ * @return boolean True if the blog is in single-user mode, false otherwise.
+ */
+function is_single_user() {
+	if (
+		false === is_user_type_disabled( 'blog' ) &&
+		true === is_user_type_disabled( 'user' )
+	) {
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * Check if a site supports the block editor.
+ *
+ * @return boolean True if the site supports the block editor, false otherwise.
+ */
+function site_supports_blocks() {
+	if ( \version_compare( \get_bloginfo( 'version' ), '5.9', '<' ) ) {
+		return false;
+	}
+
+	if ( ! \function_exists( 'register_block_type_from_metadata' ) ) {
+		return false;
+	}
+
+	/**
+	 * Allow plugins to disable block editor support,
+	 * thus disabling blocks registered by the ActivityPub plugin.
+	 *
+	 * @param boolean $supports_blocks True if the site supports the block editor, false otherwise.
+	 */
+	return apply_filters( 'activitypub_site_supports_blocks', true );
+}
+
+/**
+ * Check if data is valid JSON.
+ *
+ * @param string $data The data to check.
+ *
+ * @return boolean True if the data is JSON, false otherwise.
+ */
+function is_json( $data ) {
+	return \is_array( \json_decode( $data, true ) ) ? true : false;
+}
+
+/**
+ * Check if a blog is public based on the `blog_public` option
+ *
+ * @return bollean True if public, false if not
+ */
+function is_blog_public() {
+	return (bool) apply_filters( 'activitypub_is_blog_public', \get_option( 'blog_public', 1 ) );
+}
+
+/**
+ * Get active users based on a given duration
+ *
+ * @param int $duration The duration to check in month(s)
+ *
+ * @return int The number of active users
+ */
+function get_active_users( $duration = 1 ) {
+
+	$duration = intval( $duration );
+	$transient_key = sprintf( 'monthly_active_users_%d', $duration );
+	$count = get_transient( $transient_key );
+
+	if ( false === $count ) {
+		global $wpdb;
+		$query = "SELECT COUNT( DISTINCT post_author ) FROM {$wpdb->posts} WHERE post_type = 'post' AND post_status = 'publish' AND post_date <= DATE_SUB( NOW(), INTERVAL %d MONTH )";
+		$query = $wpdb->prepare( $query, $duration );
+		$count = $wpdb->get_var( $query ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery
+
+		set_transient( $transient_key, $count, DAY_IN_SECONDS );
+	}
+
+	// if 0 authors where active
+	if ( 0 === $count ) {
+		return 0;
+	}
+
+	// if single user mode
+	if ( is_single_user() ) {
+		return 1;
+	}
+
+	// if blog user is disabled
+	if ( is_user_disabled( Users::BLOG_USER_ID ) ) {
+		return $count;
+	}
+
+	// also count blog user
+	return $count + 1;
+}
+
+/**
+ * Get the total number of users
+ *
+ * @return int The total number of users
+ */
+function get_total_users() {
+	// if single user mode
+	if ( is_single_user() ) {
+		return 1;
+	}
+
+	$users = \get_users(
+		array(
+			'capability__in' => array( 'publish_posts' ),
+		)
+	);
+
+	if ( is_array( $users ) ) {
+		$users = count( $users );
+	} else {
+		$users = 1;
+	}
+
+	// if blog user is disabled
+	if ( is_user_disabled( Users::BLOG_USER_ID ) ) {
+		return $users;
+	}
+
+	return $users + 1;
+}

includes/help.php

@@ -0,0 +1,75 @@
+<?php
+
+\get_current_screen()->add_help_tab(
+	array(
+		'id'      => 'template-tags',
+		'title'   => \__( 'Template Tags', 'activitypub' ),
+		'content' =>
+			'<p>' . __( 'The following Template Tags are available:', 'activitypub' ) . '</p>' .
+			'<dl>' .
+				'<dt><code>[ap_title]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The post\'s title.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_content apply_filters="yes"]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The post\'s content. With <code>apply_filters</code> you can decide if filters (<code>apply_filters( \'the_content\', $content )</code>) should be applied or not (default is <code>yes</code>). The values can be <code>yes</code> or <code>no</code>. <code>apply_filters</code> attribute is optional.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_excerpt length="400"]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The post\'s excerpt (default 400 chars). <code>length</code> attribute is optional.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_permalink type="url"]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The post\'s permalink. <code>type</code> can be either: <code>url</code> or <code>html</code> (an &lt;a /&gt; tag). <code>type</code> attribute is optional.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_shortlink type="url"]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The post\'s shortlink. <code>type</code> can be either <code>url</code> or <code>html</code> (an &lt;a /&gt; tag). I can recommend <a href="https://wordpress.org/plugins/hum/" target="_blank">Hum</a>, to prettify the Shortlinks. <code>type</code> attribute is optional.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_hashtags]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The post\'s tags as hashtags.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_hashcats]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The post\'s categories as hashtags.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_image type=full]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The URL for the post\'s featured image, defaults to full size. The type attribute can be any of the following: <code>thumbnail</code>, <code>medium</code>, <code>large</code>, <code>full</code>. <code>type</code> attribute is optional.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_author]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The author\'s name.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_authorurl]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The URL to the author\'s profile page.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_date]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The post\'s date.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_time]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The post\'s time.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_datetime]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The post\'s date/time formated as "date @ time".', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_blogurl]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The URL to the site.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_blogname]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The name of the site.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+				'<dt><code>[ap_blogdesc]</code></dt>' .
+				'<dd>' . \wp_kses( __( 'The description of the site.', 'activitypub' ), array( 'code' => array() ) ) . '</dd>' .
+			'</dl>' .
+			'<p>' . __( 'You may also use any Shortcode normally available to you on your site, however be aware that Shortcodes may significantly increase the size of your content depending on what they do.', 'activitypub' ) . '</p>' .
+			'<p>' . __( 'Note: the old Template Tags are now deprecated and automatically converted to the new ones.', 'activitypub' ) . '</p>' .
+			'<p>' . \wp_kses( \__( '<a href="https://github.com/pfefferle/wordpress-activitypub/issues/new" target="_blank">Let me know</a> if you miss a Template Tag.', 'activitypub' ), 'activitypub' ) . '</p>',
+	)
+);
+
+\get_current_screen()->add_help_tab(
+	array(
+		'id'      => 'glossary',
+		'title'   => \__( 'Glossary', 'activitypub' ),
+		'content' =>
+			'<p><h2>' . \__( 'Fediverse', 'activitypub' ) . '</h2></p>' .
+			'<p>' . \__( 'The Fediverse is a new word made of two words: "federation" + "universe"', 'activitypub' ) . '</p>' .
+			'<p>' . \__( 'It is a federated social network running on free open software on a myriad of computers across the globe. Many independent servers are interconnected and allow people to interact with one another. There\'s no one central site: you choose a server to register. This ensures some decentralization and sovereignty of data. Fediverse (also called Fedi) has no built-in advertisements, no tricky algorithms, no one big corporation dictating the rules. Instead we have small cozy communities of like-minded people. Welcome!', 'activitypub' ) . '</p>' .
+			'<p>' . \__( 'For more informations please visit <a href="https://fediverse.party/" target="_blank">fediverse.party</a>', 'activitypub' ) . '</p>' .
+			'<p><h2>' . \__( 'ActivityPub', 'activitypub' ) . '</h2></p>' .
+			'<p>' . \__( 'ActivityPub is a decentralized social networking protocol based on the ActivityStreams 2.0 data format. ActivityPub is an official W3C recommended standard published by the W3C Social Web Working Group. It provides a client to server API for creating, updating and deleting content, as well as a federated server to server API for delivering notifications and subscribing to content.', 'activitypub' ) . '</p>' .
+			'<p><h2>' . \__( 'WebFinger', 'activitypub' ) . '</h2></p>' .
+			'<p>' . \__( 'WebFinger is used to discover information about people or other entities on the Internet that are identified by a URI using standard Hypertext Transfer Protocol (HTTP) methods over a secure transport. A WebFinger resource returns a JavaScript Object Notation (JSON) object describing the entity that is queried. The JSON object is referred to as the JSON Resource Descriptor (JRD).', 'activitypub' ) . '</p>' .
+			'<p>' . \__( 'For a person, the type of information that might be discoverable via WebFinger includes a personal profile address, identity service, telephone number, or preferred avatar. For other entities on the Internet, a WebFinger resource might return JRDs containing link relations that enable a client to discover, for example, that a printer can print in color on A4 paper, the physical location of a server, or other static information.', 'activitypub' ) . '</p>' .
+			'<p>' . \__( 'On Mastodon [and other Plattforms], user profiles can be hosted either locally on the same website as yours, or remotely on a completely different website. The same username may be used on a different domain. Therefore, a Mastodon user\'s full mention consists of both the username and the domain, in the form <code>@username@domain</code>. In practical terms, <code>@user@example.com</code> is not the same as <code>@user@example.org</code>. If the domain is not included, Mastodon will try to find a local user named <code>@username</code>. However, in order to deliver to someone over ActivityPub, the <code>@username@domain</code> mention is not enough – mentions must be translated to an HTTPS URI first, so that the remote actor\'s inbox and outbox can be found. (This paragraph is copied from the <a href="https://docs.joinmastodon.org/spec/webfinger/" target="_blank">Mastodon Documentation</a>)', 'activitypub' ) . '</p>' .
+			'<p>' . \__( 'For more informations please visit <a href="https://webfinger.net/" target="_blank">webfinger.net</a>', 'activitypub' ) . '</p>' .
+			'<p><h2>' . \__( 'NodeInfo', 'activitypub' ) . '</h2></p>' .
+			'<p>' . \__( 'NodeInfo is an effort to create a standardized way of exposing metadata about a server running one of the distributed social networks. The two key goals are being able to get better insights into the user base of distributed social networking and the ability to build tools that allow users to choose the best fitting software and server for their needs.', 'activitypub' ) . '</p>' .
+			'<p>' . \__( 'For more informations please visit <a href="http://nodeinfo.diaspora.software/" target="_blank">nodeinfo.diaspora.software</a>', 'activitypub' ) . '</p>',
+	)
+);
+
+\get_current_screen()->set_help_sidebar(
+	'<p><strong>' . \__( 'For more information:', 'activitypub' ) . '</strong></p>' .
+	'<p>' . \__( '<a href="https://wordpress.org/support/plugin/activitypub/">Get support</a>', 'activitypub' ) . '</p>' .
+	'<p>' . \__( '<a href="https://github.com/automattic/wordpress-activitypub/issues">Report an issue</a>', 'activitypub' ) . '</p>'
+);

includes/model/class-activity.php

@@ -1,95 +0,0 @@
-<?php
-namespace Activitypub\Model;
-
-/**
- * ActivityPub Post Class
- *
- * @author Matthias Pfefferle
- *
- * @see https://www.w3.org/TR/activitypub/
- */
-class Activity {
-	private $context = array( 'https://www.w3.org/ns/activitystreams' );
-	private $published = '';
-	private $id = '';
-	private $type = 'Create';
-	private $actor = '';
-	private $to = array( 'https://www.w3.org/ns/activitystreams#Public' );
-	private $cc = array( 'https://www.w3.org/ns/activitystreams#Public' );
-	private $object = null;
-
-	const TYPE_SIMPLE = 'simple';
-	const TYPE_FULL = 'full';
-	const TYPE_NONE = 'none';
-
-	public function __construct( $type = 'Create', $context = self::TYPE_SIMPLE ) {
-		if ( 'none' === $context ) {
-			$this->context = null;
-		} elseif ( 'full' === $context ) {
-			$this->context = \Activitypub\get_context();
-		}
-
-		$this->type = \ucfirst( $type );
-		$this->published = \date( 'Y-m-d\TH:i:s\Z', \strtotime( 'now' ) );
-	}
-
-	public function __call( $method, $params ) {
-		$var = \strtolower( \substr( $method, 4 ) );
-
-		if ( \strncasecmp( $method, 'get', 3 ) === 0 ) {
-			return $this->$var;
-		}
-
-		if ( \strncasecmp( $method, 'set', 3 ) === 0 ) {
-			$this->$var = $params[0];
-		}
-	}
-
-	public function from_post( $object ) {
-		$this->object = $object;
-		$this->published = $object['published'];
-		$this->actor = $object['attributedTo'];
-		$this->id = $object['id'];
-	}
-
-	public function from_comment( $object ) {
-
-	}
-
-	public function to_array() {
-		$array = \get_object_vars( $this );
-
-		if ( $this->context ) {
-			$array = array( '@context' => $this->context ) + $array;
-		}
-
-		unset( $array['context'] );
-
-		return $array;
-	}
-
-	public function to_json() {
-		return \wp_json_encode( $this->to_array(), JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_QUOT );
-	}
-
-	public function to_simple_array() {
-		$activity = array(
-			'@context' => $this->context,
-			'type' => $this->type,
-			'actor' => $this->actor,
-			'object' => $this->object,
-			'to' => $this->to,
-			'cc' => $this->cc,
-		);
-
-		if ( $this->id ) {
-			$activity['id'] = $this->id;
-		}
-
-		return $activity;
-	}
-
-	public function to_simple_json() {
-		return \wp_json_encode( $this->to_simple_array(), JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_QUOT );
-	}
-}

includes/model/class-application-user.php

@@ -0,0 +1,72 @@
+<?php
+namespace Activitypub\Model;
+
+use WP_Query;
+use Activitypub\Signature;
+use Activitypub\Collection\Users;
+
+use function Activitypub\get_rest_url_by_path;
+
+class Application_User extends Blog_User {
+	/**
+	 * The User-ID
+	 *
+	 * @var int
+	 */
+	protected $_id = Users::APPLICATION_USER_ID; // phpcs:ignore PSR2.Classes.PropertyDeclaration.Underscore
+
+	/**
+	 * The User-Type
+	 *
+	 * @var string
+	 */
+	protected $type = 'Application';
+
+	/**
+	 * If the User is discoverable.
+	 *
+	 * @var boolean
+	 */
+	protected $discoverable = false;
+
+	/**
+	 * Get the User-Url.
+	 *
+	 * @return string The User-Url.
+	 */
+	public function get_url() {
+		return get_rest_url_by_path( 'application' );
+	}
+
+	public function get_name() {
+		return 'application';
+	}
+
+	public function get_preferred_username() {
+		return $this::get_name();
+	}
+
+	public function get_followers() {
+		return null;
+	}
+
+	public function get_following() {
+		return null;
+	}
+
+	public function get_attachment() {
+		return null;
+	}
+
+	public function get_featured() {
+		return null;
+	}
+
+	public function get_moderators() {
+		return null;
+	}
+
+	public function get_indexable() {
+		return false;
+	}
+}

includes/model/class-blog-user.php

@@ -0,0 +1,243 @@
+<?php
+namespace Activitypub\Model;
+
+use WP_Query;
+use Activitypub\Signature;
+use Activitypub\Collection\Users;
+
+use function Activitypub\is_single_user;
+use function Activitypub\is_user_disabled;
+use function Activitypub\get_rest_url_by_path;
+
+class Blog_User extends User {
+	/**
+	 * The User-ID
+	 *
+	 * @var int
+	 */
+	protected $_id = Users::BLOG_USER_ID; // phpcs:ignore PSR2.Classes.PropertyDeclaration.Underscore
+
+	/**
+	 * The User-Type
+	 *
+	 * @var string
+	 */
+	protected $type = null;
+
+	/**
+	 * Is Account discoverable?
+	 *
+	 * @var boolean
+	 */
+	protected $discoverable = true;
+
+	public static function from_wp_user( $user_id ) {
+		if ( is_user_disabled( $user_id ) ) {
+			return new WP_Error(
+				'activitypub_user_not_found',
+				\__( 'User not found', 'activitypub' ),
+				array( 'status' => 404 )
+			);
+		}
+
+		$object = new static();
+		$object->_id = $user_id;
+
+		return $object;
+	}
+
+	/**
+	 * Get the type of the object.
+	 *
+	 * If the Blog is in "single user" mode, return "Person" insted of "Group".
+	 *
+	 * @return string The type of the object.
+	 */
+	public function get_type() {
+		if ( is_single_user() ) {
+			return 'Person';
+		} else {
+			return 'Group';
+		}
+	}
+
+	/**
+	 * Get the User-Name.
+	 *
+	 * @return string The User-Name.
+	 */
+	public function get_name() {
+		return \wp_strip_all_tags(
+			\html_entity_decode(
+				\get_bloginfo( 'name' ),
+				\ENT_QUOTES,
+				'UTF-8'
+			)
+		);
+	}
+
+	/**
+	 * Get the User-Description.
+	 *
+	 * @return string The User-Description.
+	 */
+	public function get_summary() {
+		return \wpautop(
+			\wp_kses(
+				\get_bloginfo( 'description' ),
+				'default'
+			)
+		);
+	}
+
+	/**
+	 * Get the User-Url.
+	 *
+	 * @return string The User-Url.
+	 */
+	public function get_url() {
+		return \esc_url( \trailingslashit( get_home_url() ) . '@' . $this->get_preferred_username() );
+	}
+
+	/**
+	 * Returns the User-URL with @-Prefix for the username.
+	 *
+	 * @return string The User-URL with @-Prefix for the username.
+	 */
+	public function get_at_url() {
+		return \esc_url( \trailingslashit( get_home_url() ) . '@' . $this->get_preferred_username() );
+	}
+
+	/**
+	 * Generate a default Username.
+	 *
+	 * @return string The auto-generated Username.
+	 */
+	public static function get_default_username() {
+		// check if domain host has a subdomain
+		$host = \wp_parse_url( \get_home_url(), \PHP_URL_HOST );
+		$host = \preg_replace( '/^www\./i', '', $host );
+
+		/**
+		 * Filter the default blog username.
+		 *
+		 * @param string $host The default username.
+		 */
+		return apply_filters( 'activitypub_default_blog_username', $host );
+	}
+
+	/**
+	 * Get the preferred User-Name.
+	 *
+	 * @return string The User-Name.
+	 */
+	public function get_preferred_username() {
+		$username = \get_option( 'activitypub_blog_user_identifier' );
+
+		if ( $username ) {
+			return $username;
+		}
+
+		return self::get_default_username();
+	}
+
+	/**
+	 * Get the User-Icon.
+	 *
+	 * @return array The User-Icon.
+	 */
+	public function get_icon() {
+		// try site icon first
+		$icon_id = get_option( 'site_icon' );
+
+		// try custom logo second
+		if ( ! $icon_id ) {
+			$icon_id = get_theme_mod( 'custom_logo' );
+		}
+
+		$icon_url = false;
+
+		if ( $icon_id ) {
+			$icon = wp_get_attachment_image_src( $icon_id, 'full' );
+			if ( $icon ) {
+				$icon_url = $icon[0];
+			}
+		}
+
+		if ( ! $icon_url ) {
+			// fallback to default icon
+			$icon_url = plugins_url( '/assets/img/wp-logo.png', ACTIVITYPUB_PLUGIN_FILE );
+		}
+
+		return array(
+			'type' => 'Image',
+			'url'  => esc_url( $icon_url ),
+		);
+	}
+
+	/**
+	 * Get the User-Header-Image.
+	 *
+	 * @return array|null The User-Header-Image.
+	 */
+	public function get_header_image() {
+		if ( \has_header_image() ) {
+			return array(
+				'type' => 'Image',
+				'url'  => esc_url( \get_header_image() ),
+			);
+		}
+
+		return null;
+	}
+
+	public function get_published() {
+		$first_post = new WP_Query(
+			array(
+				'orderby' => 'date',
+				'order'   => 'ASC',
+				'number'  => 1,
+			)
+		);
+
+		if ( ! empty( $first_post->posts[0] ) ) {
+			$time = \strtotime( $first_post->posts[0]->post_date_gmt );
+		} else {
+			$time = \time();
+		}
+
+		return \gmdate( 'Y-m-d\TH:i:s\Z', $time );
+	}
+
+	public function get_attachment() {
+		return array();
+	}
+
+	public function get_canonical_url() {
+		return \home_url();
+	}
+
+	public function get_moderators() {
+		if ( is_single_user() || 'Group' !== $this->get_type() ) {
+			return null;
+		}
+
+		return get_rest_url_by_path( 'collections/moderators' );
+	}
+
+	public function get_attributed_to() {
+		if ( is_single_user() || 'Group' !== $this->get_type() ) {
+			return null;
+		}
+
+		return get_rest_url_by_path( 'collections/moderators' );
+	}
+
+	public function get_posting_restricted_to_mods() {
+		if ( 'Group' === $this->get_type() ) {
+			return true;
+		}
+
+		return null;
+	}
+}

includes/model/class-follower.php

@@ -0,0 +1,366 @@
+<?php
+namespace Activitypub\Model;
+
+use WP_Error;
+use WP_Query;
+use Activitypub\Activity\Actor;
+use Activitypub\Collection\Followers;
+
+/**
+ * ActivityPub Follower Class
+ *
+ * This Object represents a single Follower.
+ * There is no direct reference to a WordPress User here.
+ *
+ * @author Matt Wiebe
+ * @author Matthias Pfefferle
+ *
+ * @see https://www.w3.org/TR/activitypub/#follow-activity-inbox
+ */
+class Follower extends Actor {
+	/**
+	 * The complete Remote-Profile of the Follower
+	 *
+	 * @var array
+	 */
+	protected $_id; // phpcs:ignore PSR2.Classes.PropertyDeclaration.Underscore
+
+	/**
+	 * Get the errors.
+	 *
+	 * @return mixed
+	 */
+	public function get_errors() {
+		return get_post_meta( $this->_id, 'activitypub_errors' );
+	}
+
+	/**
+	 * Get the Summary.
+	 *
+	 * @return int The Summary.
+	 */
+	public function get_summary() {
+		if ( isset( $this->summary ) ) {
+			return $this->summary;
+		}
+
+		return '';
+	}
+
+	/**
+	 * Getter for URL attribute.
+	 *
+	 * Falls back to ID, if no URL is set. This is relevant for
+	 * Plattforms like Lemmy, where the ID is the URL.
+	 *
+	 * @return string The URL.
+	 */
+	public function get_url() {
+		if ( $this->url ) {
+			return $this->url;
+		}
+
+		return $this->id;
+	}
+
+	/**
+	 * Reset (delete) all errors.
+	 *
+	 * @return void
+	 */
+	public function reset_errors() {
+		delete_post_meta( $this->_id, 'activitypub_errors' );
+	}
+
+	/**
+	 * Count the errors.
+	 *
+	 * @return int The number of errors.
+	 */
+	public function count_errors() {
+		$errors = $this->get_errors();
+
+		if ( is_array( $errors ) && ! empty( $errors ) ) {
+			return count( $errors );
+		}
+
+		return 0;
+	}
+
+	/**
+	 * Return the latest error message.
+	 *
+	 * @return string The error message.
+	 */
+	public function get_latest_error_message() {
+		$errors = $this->get_errors();
+
+		if ( is_array( $errors ) && ! empty( $errors ) ) {
+			return reset( $errors );
+		}
+
+		return '';
+	}
+
+	/**
+	 * Update the current Follower-Object.
+	 *
+	 * @return void
+	 */
+	public function update() {
+		$this->save();
+	}
+
+	/**
+	 * Validate the current Follower-Object.
+	 *
+	 * @return boolean True if the verification was successful.
+	 */
+	public function is_valid() {
+		// the minimum required attributes
+		$required_attributes = array(
+			'id',
+			'preferredUsername',
+			'inbox',
+			'publicKey',
+			'publicKeyPem',
+		);
+
+		foreach ( $required_attributes as $attribute ) {
+			if ( ! $this->get( $attribute ) ) {
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	 * Save the current Follower-Object.
+	 *
+	 * @return int|WP_Error The Post-ID or an WP_Error.
+	 */
+	public function save() {
+		if ( ! $this->is_valid() ) {
+			return new WP_Error( 'activitypub_invalid_follower', __( 'Invalid Follower', 'activitypub' ), array( 'status' => 400 ) );
+		}
+
+		if ( ! $this->get__id() ) {
+			global $wpdb;
+
+			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
+			$post_id = $wpdb->get_var(
+				$wpdb->prepare(
+					"SELECT ID FROM $wpdb->posts WHERE guid=%s",
+					esc_sql( $this->get_id() )
+				)
+			);
+
+			if ( $post_id ) {
+				$post = get_post( $post_id );
+				$this->set__id( $post->ID );
+			}
+		}
+
+		$args = array(
+			'ID'           => $this->get__id(),
+			'guid'         => esc_url_raw( $this->get_id() ),
+			'post_title'   => wp_strip_all_tags( sanitize_text_field( $this->get_name() ) ),
+			'post_author'  => 0,
+			'post_type'    => Followers::POST_TYPE,
+			'post_name'    => esc_url_raw( $this->get_id() ),
+			'post_excerpt' => sanitize_text_field( wp_kses( $this->get_summary(), 'user_description' ) ),
+			'post_status'  => 'publish',
+			'meta_input'   => $this->get_post_meta_input(),
+		);
+
+		$post_id = wp_insert_post( $args );
+		$this->_id = $post_id;
+
+		return $post_id;
+	}
+
+	/**
+	 * Upsert the current Follower-Object.
+	 *
+	 * @return int|WP_Error The Post-ID or an WP_Error.
+	 */
+	public function upsert() {
+		return $this->save();
+	}
+
+	/**
+	 * Delete the current Follower-Object.
+	 *
+	 * Beware that this os deleting a Follower for ALL users!!!
+	 *
+	 * To delete only the User connection (unfollow)
+	 * @see \Activitypub\Rest\Followers::remove_follower()
+	 *
+	 * @return void
+	 */
+	public function delete() {
+		wp_delete_post( $this->_id );
+	}
+
+	/**
+	 * Update the post meta.
+	 *
+	 * @return void
+	 */
+	protected function get_post_meta_input() {
+		$meta_input = array();
+		$meta_input['activitypub_inbox'] = $this->get_shared_inbox();
+		$meta_input['activitypub_actor_json'] = $this->to_json();
+
+		return $meta_input;
+	}
+
+	/**
+	 * Get the icon.
+	 *
+	 * Sets a fallback to better handle API and HTML outputs.
+	 *
+	 * @return array The icon.
+	 */
+	public function get_icon() {
+		if ( isset( $this->icon['url'] ) ) {
+			return $this->icon;
+		}
+
+		return array(
+			'type' => 'Image',
+			'mediaType' => 'image/jpeg',
+			'url'  => ACTIVITYPUB_PLUGIN_URL . 'assets/img/mp.jpg',
+		);
+	}
+
+	/**
+	 * Get Name.
+	 *
+	 * Tries to extract a name from the URL or ID if not set.
+	 *
+	 * @return string The name.
+	 */
+	public function get_name() {
+		if ( $this->name ) {
+			return $this->name;
+		} elseif ( $this->preferred_username ) {
+			return $this->preferred_username;
+		}
+
+		return $this->extract_name_from_uri();
+	}
+
+	/**
+	 * The preferred Username.
+	 *
+	 * Tries to extract a name from the URL or ID if not set.
+	 *
+	 * @return string The preferred Username.
+	 */
+	public function get_preferred_username() {
+		if ( $this->preferred_username ) {
+			return $this->preferred_username;
+		}
+
+		return $this->extract_name_from_uri();
+	}
+
+	/**
+	 * Get the Icon URL (Avatar)
+	 *
+	 * @return string The URL to the Avatar.
+	 */
+	public function get_icon_url() {
+		$icon = $this->get_icon();
+
+		if ( ! $icon ) {
+			return '';
+		}
+
+		if ( is_array( $icon ) ) {
+			return $icon['url'];
+		}
+
+		return $icon;
+	}
+
+	/**
+	 * Get the shared inbox, with a fallback to the inbox.
+	 *
+	 * @return string|null The URL to the shared inbox, the inbox or null.
+	 */
+	public function get_shared_inbox() {
+		if ( ! empty( $this->get_endpoints()['sharedInbox'] ) ) {
+			return $this->get_endpoints()['sharedInbox'];
+		} elseif ( ! empty( $this->get_inbox() ) ) {
+			return $this->get_inbox();
+		}
+
+		return null;
+	}
+
+	/**
+	 * Convert a Custom-Post-Type input to an Activitypub\Model\Follower.
+	 *
+	 * @return string The JSON string.
+	 *
+	 * @return array Activitypub\Model\Follower
+	 */
+	public static function init_from_cpt( $post ) {
+		$actor_json = get_post_meta( $post->ID, 'activitypub_actor_json', true );
+		$object = self::init_from_json( $actor_json );
+		$object->set__id( $post->ID );
+		$object->set_id( $post->guid );
+		$object->set_name( $post->post_title );
+		$object->set_summary( $post->post_excerpt );
+		$object->set_published( gmdate( 'Y-m-d H:i:s', strtotime( $post->post_date ) ) );
+		$object->set_updated( gmdate( 'Y-m-d H:i:s', strtotime( $post->post_modified ) ) );
+
+		return $object;
+	}
+
+	/**
+	 * Infer a shortname from the Actor ID or URL. Used only for fallbacks,
+	 * we will try to use what's supplied.
+	 *
+	 * @return string Hopefully the name of the Follower.
+	 */
+	protected function extract_name_from_uri() {
+		// prefer the URL, but fall back to the ID.
+		if ( $this->url ) {
+			$name = $this->url;
+		} else {
+			$name = $this->id;
+		}
+
+		if ( \filter_var( $name, FILTER_VALIDATE_URL ) ) {
+			$name = \rtrim( $name, '/' );
+			$path = \wp_parse_url( $name, PHP_URL_PATH );
+
+			if ( $path ) {
+				if ( \strpos( $name, '@' ) !== false ) {
+					// expected: https://example.com/@user (default URL pattern)
+					$name = \preg_replace( '|^/@?|', '', $path );
+				} else {
+					// expected: https://example.com/users/user (default ID pattern)
+					$parts = \explode( '/', $path );
+					$name  = \array_pop( $parts );
+				}
+			}
+		} elseif (
+			\is_email( $name ) ||
+			\strpos( $name, 'acct' ) === 0 ||
+			\strpos( $name, '@' ) === 0
+		) {
+			// expected: user@example.com or acct:user@example (WebFinger)
+			$name  = \ltrim( $name, '@' );
+			$name  = \ltrim( $name, 'acct:' );
+			$parts = \explode( '@', $name );
+			$name  = $parts[0];
+		}
+
+		return $name;
+	}
+}

includes/model/class-post.php

@@ -1,316 +1,132 @@
 <?php
 namespace Activitypub\Model;
 
+use Activitypub\Transformer\Post as Transformer_Post;
+
 /**
  * ActivityPub Post Class
  *
  * @author Matthias Pfefferle
  */
 class Post {
+	/**
+	 * The \Activitypub\Activity\Base_Object object.
+	 *
+	 * @var \Activitypub\Activity\Base_Object
+	 */
+	protected $object;
+
+	/**
+	 * The WordPress Post Object.
+	 *
+	 * @var WP_Post
+	 */
 	private $post;
 
 	/**
-	 * Initialize the class, registering WordPress hooks
+	 * Constructor
+	 *
+	 * @param WP_Post $post
+	 * @param int     $post_author
 	 */
-	public static function init() {
-		\add_filter( 'activitypub_the_summary', array( '\Activitypub\Model\Post', 'add_backlink_to_content' ), 15, 2 );
-		\add_filter( 'activitypub_the_content', array( '\Activitypub\Model\Post', 'add_backlink_to_content' ), 15, 2 );
+	// phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.FoundAfterLastUsed, VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+	public function __construct( $post, $post_author = null ) {
+		_deprecated_function( __CLASS__, '1.0.0', '\Activitypub\Transformer\Post' );
+
+		$this->post = $post;
+		$transformer = new Transformer_Post();
+		$this->object = $transformer->set_wp_post( $post )->to_object();
 	}
 
-	public function __construct( $post = null ) {
-		$this->post = \get_post( $post );
-	}
-
-	public function get_post() {
-		return $this->post;
-	}
-
-	public function get_post_author() {
-		return $this->post->post_author;
+	/**
+	 * Returns the User ID.
+	 *
+	 * @return int the User ID.
+	 */
+	public function get_user_id() {
+		return apply_filters( 'activitypub_post_user_id', $this->post->post_author, $this->post );
 	}
 
+	/**
+	 * Converts this Object into an Array.
+	 *
+	 * @return array the array representation of a Post.
+	 */
 	public function to_array() {
-		$post = $this->post;
-
-		$array = array(
-			'id' => \get_permalink( $post ),
-			'type' => $this->get_object_type(),
-			'published' => \date( 'Y-m-d\TH:i:s\Z', \strtotime( $post->post_date ) ),
-			'attributedTo' => \get_author_posts_url( $post->post_author ),
-			'summary' => $this->get_the_title(),
-			'inReplyTo' => null,
-			'content' => $this->get_the_content(),
-			'contentMap' => array(
-				\strstr( \get_locale(), '_', true ) => $this->get_the_content(),
-			),
-			'to' => array( 'https://www.w3.org/ns/activitystreams#Public' ),
-			'cc' => array( 'https://www.w3.org/ns/activitystreams#Public' ),
-			'attachment' => $this->get_attachments(),
-			'tag' => $this->get_tags(),
-		);
-
-		return \apply_filters( 'activitypub_post', $array );
+		return \apply_filters( 'activitypub_post', $this->object->to_array(), $this->post );
 	}
 
+	/**
+	 * Returns the Actor of this Object.
+	 *
+	 * @return string The URL of the Actor.
+	 */
+	public function get_actor() {
+		$user = User_Factory::get_by_id( $this->get_user_id() );
+
+		return $user->get_url();
+	}
+
+	/**
+	 * Converts this Object into a JSON String
+	 *
+	 * @return string
+	 */
 	public function to_json() {
-		return \wp_json_encode( $this->to_array(), JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_QUOT );
+		return \wp_json_encode( $this->to_array(), \JSON_HEX_TAG | \JSON_HEX_AMP | \JSON_HEX_QUOT );
 	}
 
+	/**
+	 * Returns the URL of an Activity Object
+	 *
+	 * @return string
+	 */
+	public function get_url() {
+		return $this->object->get_url();
+	}
+
+	/**
+	 * Returns the ID of an Activity Object
+	 *
+	 * @return string
+	 */
+	public function get_id() {
+		return $this->object->get_id();
+	}
+
+	/**
+	 * Returns a list of Image Attachments
+	 *
+	 * @return array
+	 */
 	public function get_attachments() {
-		$max_images = \apply_filters( 'activitypub_max_images', 3 );
-
-		$images = array();
-
-		// max images can't be negative or zero
-		if ( $max_images <= 0 ) {
-			$max_images = 1;
-		}
-
-		$id = $this->post->ID;
-
-		$image_ids = array();
-		// list post thumbnail first if this post has one
-		if ( \function_exists( 'has_post_thumbnail' ) && \has_post_thumbnail( $id ) ) {
-			$image_ids[] = \get_post_thumbnail_id( $id );
-			$max_images--;
-		}
-		// then list any image attachments
-		$query = new \WP_Query(
-			array(
-				'post_parent' => $id,
-				'post_status' => 'inherit',
-				'post_type' => 'attachment',
-				'post_mime_type' => 'image',
-				'order' => 'ASC',
-				'orderby' => 'menu_order ID',
-				'posts_per_page' => $max_images,
-			)
-		);
-		foreach ( $query->get_posts() as $attachment ) {
-			if ( ! \in_array( $attachment->ID, $image_ids, true ) ) {
-				$image_ids[] = $attachment->ID;
-			}
-		}
-
-		$image_ids = \array_unique( $image_ids );
-
-		// get URLs for each image
-		foreach ( $image_ids as $id ) {
-			$alt = \get_post_meta( $id, '_wp_attachment_image_alt', true );
-			$thumbnail = \wp_get_attachment_image_src( $id, 'full' );
-			$mimetype = \get_post_mime_type( $id );
-
-			if ( $thumbnail ) {
-				$image = array(
-					'type' => 'Image',
-					'url' => $thumbnail[0],
-					'mediaType' => $mimetype
-				);
-				if ( $alt ) {
-					$image['name'] = $alt;
-				}
-				$images[] = $image;
-			}
-		}
-
-		return $images;
+		return $this->object->get_attachment();
 	}
 
+	/**
+	 * Returns a list of Tags, used in the Post
+	 *
+	 * @return array
+	 */
 	public function get_tags() {
-		$tags = array();
-
-		$post_tags = \get_the_tags( $this->post->ID );
-		if ( $post_tags ) {
-			foreach ( $post_tags as $post_tag ) {
-				$tag = array(
-					'type' => 'Hashtag',
-					'href' => \get_tag_link( $post_tag->term_id ),
-					'name' => '#' . $post_tag->slug,
-				);
-				$tags[] = $tag;
-			}
-		}
-
-		return $tags;
+		return $this->object->get_tag();
 	}
 
 	/**
 	 * Returns the as2 object-type for a given post
 	 *
-	 * @param string $type the object-type
-	 * @param Object $post the post-object
-	 *
 	 * @return string the object-type
 	 */
 	public function get_object_type() {
-		if ( 'wordpress-post-format' !== \get_option( 'activitypub_object_type', 'note' ) ) {
-			return \ucfirst( \get_option( 'activitypub_object_type', 'note' ) );
-		}
-
-		$post_type = \get_post_type( $this->post );
-		switch ( $post_type ) {
-			case 'post':
-				$post_format = \get_post_format( $this->post );
-				switch ( $post_format ) {
-					case 'aside':
-					case 'status':
-					case 'quote':
-					case 'note':
-						$object_type = 'Note';
-						break;
-					case 'gallery':
-					case 'image':
-						$object_type = 'Image';
-						break;
-					case 'video':
-						$object_type = 'Video';
-						break;
-					case 'audio':
-						$object_type = 'Audio';
-						break;
-					default:
-						$object_type = 'Article';
-						break;
-				}
-				break;
-			case 'page':
-				$object_type = 'Page';
-				break;
-			case 'attachment':
-				$mime_type = \get_post_mime_type();
-				$media_type = \preg_replace( '/(\/[a-zA-Z]+)/i', '', $mime_type );
-				switch ( $media_type ) {
-					case 'audio':
-						$object_type = 'Audio';
-						break;
-					case 'video':
-						$object_type = 'Video';
-						break;
-					case 'image':
-						$object_type = 'Image';
-						break;
-				}
-				break;
-			default:
-				$object_type = 'Article';
-				break;
-		}
-
-		return $object_type;
-	}
-
-	public function get_the_content() {
-		if ( 'excerpt' === \get_option( 'activitypub_post_content_type', 'content' ) ) {
-			return $this->get_the_post_summary();
-		}
-
-		return $this->get_the_post_content();
-	}
-
-	public function get_the_title() {
-		if ( 'Article' === $this->get_object_type() ) {
-			$title = \get_the_title( $this->post );
-
-			return \html_entity_decode( $title, ENT_QUOTES, 'UTF-8' );
-		}
-
-		return null;
+		return $this->object->get_type();
 	}
 
 	/**
-	 * Get the excerpt for a post for use outside of the loop.
+	 * Returns the content for the ActivityPub Item.
 	 *
-	 * @param int     Optional excerpt length.
-	 *
-	 * @return string The excerpt.
+	 * @return string the content
 	 */
-	public function get_the_post_excerpt( $excerpt_length = 400 ) {
-		$post = $this->post;
-
-		$excerpt = \get_post_field( 'post_excerpt', $post );
-
-		if ( '' === $excerpt ) {
-
-			$content = \get_post_field( 'post_content', $post );
-
-			// An empty string will make wp_trim_excerpt do stuff we do not want.
-			if ( '' !== $content ) {
-
-				$excerpt = \strip_shortcodes( $content );
-
-				/** This filter is documented in wp-includes/post-template.php */
-				$excerpt = \apply_filters( 'the_content', $excerpt );
-				$excerpt = \str_replace( ']]>', ']]>', $excerpt );
-
-				$excerpt_length = \apply_filters( 'excerpt_length', $excerpt_length );
-
-				/** This filter is documented in wp-includes/formatting.php */
-				$excerpt_more = \apply_filters( 'excerpt_more', ' [...]' );
-
-				$excerpt = \wp_trim_words( $excerpt, $excerpt_length, $excerpt_more );
-			}
-		}
-
-		return $excerpt;
-	}
-
-	/**
-	 * Get the content for a post for use outside of the loop.
-	 *
-	 * @return string The content.
-	 */
-	public function get_the_post_content() {
-		$post = $this->post;
-
-		$content = \get_post_field( 'post_content', $post );
-
-		$filtered_content = \apply_filters( 'the_content', $content );
-		$filtered_content = \apply_filters( 'activitypub_the_content', $filtered_content, $this->post );
-
-		$decoded_content = \html_entity_decode( $filtered_content, ENT_QUOTES, 'UTF-8' );
-
-		$allowed_html = \apply_filters( 'activitypub_allowed_html', '<a><p><ul><ol><li><code><blockquote><pre>' );
-
-		return \trim( \preg_replace( '/[\r\n]{2,}/', '', \strip_tags( $decoded_content, $allowed_html ) ) );
-	}
-
-	/**
-	 * Get the excerpt for a post for use outside of the loop.
-	 *
-	 * @param int     Optional excerpt length.
-	 *
-	 * @return string The excerpt.
-	 */
-	public function get_the_post_summary( $summary_length = 400 ) {
-		$summary = $this->get_the_post_excerpt( $summary_length );
-
-		$filtered_summary = \apply_filters( 'the_excerpt', $summary );
-		$filtered_summary = \apply_filters( 'activitypub_the_summary', $filtered_summary, $this->post );
-
-		$decoded_summary = \html_entity_decode( $filtered_summary, ENT_QUOTES, 'UTF-8' );
-
-		$allowed_html = \apply_filters( 'activitypub_allowed_html', '<a><p>' );
-
-		return \trim( \preg_replace( '/[\r\n]{2,}/', '', \strip_tags( $decoded_summary, $allowed_html ) ) );
-	}
-
-	/**
-	 * Adds a backlink to the post/summary content
-	 *
-	 * @param string  $content
-	 * @param WP_Post $post
-	 *
-	 * @return string
-	 */
-	public static function add_backlink_to_content( $content, $post ) {
-		$link = '';
-
-		if ( \get_option( 'activitypub_use_shortlink', 0 ) ) {
-			$link = \esc_url( \wp_get_shortlink( $post->ID ) );
-		} else {
-			$link = \esc_url( \get_permalink( $post->ID ) );
-		}
-
-		return $content . '<p><a href="' . $link . '">' . $link . '</a></p>';
+	public function get_content() {
+		return $this->object->get_content();
 	}
 }

includes/model/class-user.php

@@ -0,0 +1,300 @@
+<?php
+namespace Activitypub\Model;
+
+use WP_Query;
+use WP_Error;
+use Activitypub\Signature;
+use Activitypub\Collection\Users;
+use Activitypub\Activity\Actor;
+
+use function Activitypub\is_user_disabled;
+use function Activitypub\get_rest_url_by_path;
+
+class User extends Actor {
+	/**
+	 * The local User-ID (WP_User).
+	 *
+	 * @var int
+	 */
+	protected $_id; // phpcs:ignore PSR2.Classes.PropertyDeclaration.Underscore
+
+	/**
+	 * The Featured-Posts.
+	 *
+	 * @see https://docs.joinmastodon.org/spec/activitypub/#featured
+	 *
+	 * @var string
+	 */
+	protected $featured;
+
+	/**
+	 * Moderators endpoint.
+	 *
+	 * @see https://join-lemmy.org/docs/contributors/05-federation.html
+	 *
+	 * @var string
+	 */
+	protected $moderators;
+
+	/**
+	 * The User-Type
+	 *
+	 * @var string
+	 */
+	protected $type = 'Person';
+
+	/**
+	 * If the User is discoverable.
+	 *
+	 * @see https://docs.joinmastodon.org/spec/activitypub/#discoverable
+	 *
+	 * @var boolean
+	 */
+	protected $discoverable = true;
+
+	/**
+	 * If the User is indexable.
+	 *
+	 * @var boolean
+	 */
+	protected $indexable;
+
+	/**
+	 * The WebFinger Resource.
+	 *
+	 * @var string<url>
+	 */
+	protected $resource;
+
+	/**
+	 * Restrict posting to mods
+	 *
+	 * @see https://join-lemmy.org/docs/contributors/05-federation.html
+	 *
+	 * @var boolean
+	 */
+	protected $posting_restricted_to_mods = null;
+
+	public static function from_wp_user( $user_id ) {
+		if ( is_user_disabled( $user_id ) ) {
+			return new WP_Error(
+				'activitypub_user_not_found',
+				\__( 'User not found', 'activitypub' ),
+				array( 'status' => 404 )
+			);
+		}
+
+		$object = new static();
+		$object->_id = $user_id;
+
+		return $object;
+	}
+
+	/**
+	 * Get the User-ID.
+	 *
+	 * @return string The User-ID.
+	 */
+	public function get_id() {
+		return $this->get_url();
+	}
+
+	/**
+	 * Get the User-Name.
+	 *
+	 * @return string The User-Name.
+	 */
+	public function get_name() {
+		return \esc_attr( \get_the_author_meta( 'display_name', $this->_id ) );
+	}
+
+	/**
+	 * Get the User-Description.
+	 *
+	 * @return string The User-Description.
+	 */
+	public function get_summary() {
+		$description = get_user_meta( $this->_id, 'activitypub_user_description', true );
+		if ( empty( $description ) ) {
+			$description = get_user_meta( $this->_id, 'description', true );
+		}
+		return \wpautop( \wp_kses( $description, 'default' ) );
+	}
+
+	/**
+	 * Get the User-Url.
+	 *
+	 * @return string The User-Url.
+	 */
+	public function get_url() {
+		return \esc_url( \get_author_posts_url( $this->_id ) );
+	}
+
+	/**
+	 * Returns the User-URL with @-Prefix for the username.
+	 *
+	 * @return string The User-URL with @-Prefix for the username.
+	 */
+	public function get_at_url() {
+		return \esc_url( \trailingslashit( get_home_url() ) . '@' . $this->get_username() );
+	}
+
+	public function get_preferred_username() {
+		return \esc_attr( \get_the_author_meta( 'login', $this->_id ) );
+	}
+
+	public function get_icon() {
+		$icon = \esc_url(
+			\get_avatar_url(
+				$this->_id,
+				array( 'size' => 120 )
+			)
+		);
+
+		return array(
+			'type' => 'Image',
+			'url'  => $icon,
+		);
+	}
+
+	public function get_image() {
+		if ( \has_header_image() ) {
+			$image = \esc_url( \get_header_image() );
+			return array(
+				'type' => 'Image',
+				'url'  => $image,
+			);
+		}
+
+		return null;
+	}
+
+	public function get_published() {
+		return \gmdate( 'Y-m-d\TH:i:s\Z', \strtotime( \get_the_author_meta( 'registered', $this->_id ) ) );
+	}
+
+	public function get_public_key() {
+		return array(
+			'id'       => $this->get_id() . '#main-key',
+			'owner'    => $this->get_id(),
+			'publicKeyPem' => Signature::get_public_key_for( $this->get__id() ),
+		);
+	}
+
+	/**
+	 * Returns the Inbox-API-Endpoint.
+	 *
+	 * @return string The Inbox-Endpoint.
+	 */
+	public function get_inbox() {
+		return get_rest_url_by_path( sprintf( 'users/%d/inbox', $this->get__id() ) );
+	}
+
+	/**
+	 * Returns the Outbox-API-Endpoint.
+	 *
+	 * @return string The Outbox-Endpoint.
+	 */
+	public function get_outbox() {
+		return get_rest_url_by_path( sprintf( 'users/%d/outbox', $this->get__id() ) );
+	}
+
+	/**
+	 * Returns the Followers-API-Endpoint.
+	 *
+	 * @return string The Followers-Endpoint.
+	 */
+	public function get_followers() {
+		return get_rest_url_by_path( sprintf( 'users/%d/followers', $this->get__id() ) );
+	}
+
+	/**
+	 * Returns the Following-API-Endpoint.
+	 *
+	 * @return string The Following-Endpoint.
+	 */
+	public function get_following() {
+		return get_rest_url_by_path( sprintf( 'users/%d/following', $this->get__id() ) );
+	}
+
+	/**
+	 * Returns the Featured-API-Endpoint.
+	 *
+	 * @return string The Featured-Endpoint.
+	 */
+	public function get_featured() {
+		return get_rest_url_by_path( sprintf( 'users/%d/collections/featured', $this->get__id() ) );
+	}
+
+	/**
+	 * Extend the User-Output with Attachments.
+	 *
+	 * @return array The extended User-Output.
+	 */
+	public function get_attachment() {
+		$array = array();
+
+		$array[] = array(
+			'type' => 'PropertyValue',
+			'name' => \__( 'Blog', 'activitypub' ),
+			'value' => \html_entity_decode(
+				'<a rel="me" title="' . \esc_attr( \home_url( '/' ) ) . '" target="_blank" href="' . \home_url( '/' ) . '">' . \wp_parse_url( \home_url( '/' ), \PHP_URL_HOST ) . '</a>',
+				\ENT_QUOTES,
+				'UTF-8'
+			),
+		);
+
+		$array[] = array(
+			'type' => 'PropertyValue',
+			'name' => \__( 'Profile', 'activitypub' ),
+			'value' => \html_entity_decode(
+				'<a rel="me" title="' . \esc_attr( \get_author_posts_url( $this->get__id() ) ) . '" target="_blank" href="' . \get_author_posts_url( $this->get__id() ) . '">' . \wp_parse_url( \get_author_posts_url( $this->get__id() ), \PHP_URL_HOST ) . '</a>',
+				\ENT_QUOTES,
+				'UTF-8'
+			),
+		);
+
+		if ( \get_the_author_meta( 'user_url', $this->get__id() ) ) {
+			$array[] = array(
+				'type' => 'PropertyValue',
+				'name' => \__( 'Website', 'activitypub' ),
+				'value' => \html_entity_decode(
+					'<a rel="me" title="' . \esc_attr( \get_the_author_meta( 'user_url', $this->get__id() ) ) . '" target="_blank" href="' . \get_the_author_meta( 'user_url', $this->get__id() ) . '">' . \wp_parse_url( \get_the_author_meta( 'user_url', $this->get__id() ), \PHP_URL_HOST ) . '</a>',
+					\ENT_QUOTES,
+					'UTF-8'
+				),
+			);
+		}
+
+		return $array;
+	}
+
+	/**
+	 * Returns a user@domain type of identifier for the user.
+	 *
+	 * @return string The Webfinger-Identifier.
+	 */
+	public function get_resource() {
+		return $this->get_preferred_username() . '@' . \wp_parse_url( \home_url(), \PHP_URL_HOST );
+	}
+
+	public function get_canonical_url() {
+		return $this->get_url();
+	}
+
+	public function get_streams() {
+		return null;
+	}
+
+	public function get_tag() {
+		return array();
+	}
+
+	public function get_indexable() {
+		if ( \get_option( 'blog_public', 1 ) ) {
+			return true;
+		} else {
+			return false;
+		}
+	}
+}

includes/peer/class-followers.php

@@ -9,72 +9,26 @@ namespace Activitypub\Peer;
 class Followers {
 
 	public static function get_followers( $author_id ) {
-		$followers = \get_user_option( 'activitypub_followers', $author_id );
+		_deprecated_function( __METHOD__, '1.0.0', '\Activitypub\Collection\Followers::get_followers' );
 
-		if ( ! $followers ) {
-			return array();
-		}
-
-		foreach ( $followers as $key => $follower ) {
-			if (
-				\is_array( $follower ) &&
-				isset( $follower['type'] ) &&
-				'Person' === $follower['type'] &&
-				isset( $follower['id'] ) &&
-				false !== \filter_var( $follower['id'], FILTER_VALIDATE_URL )
-			) {
-				$followers[ $key ] = $follower['id'];
-			}
-		}
-
-		return $followers;
+		return \Activitypub\Collection\Followers::get_followers( $author_id );
 	}
 
 	public static function count_followers( $author_id ) {
-		$followers = self::get_followers( $author_id );
+		_deprecated_function( __METHOD__, '1.0.0', '\Activitypub\Collection\Followers::count_followers' );
 
-		return \count( $followers );
+		return \Activitypub\Collection\Followers::count_followers( $author_id );
 	}
 
 	public static function add_follower( $actor, $author_id ) {
-		$followers = \get_user_option( 'activitypub_followers', $author_id );
+		_deprecated_function( __METHOD__, '1.0.0', '\Activitypub\Collection\Followers::add_follower' );
 
-		if ( ! \is_string( $actor ) ) {
-			if (
-				\is_array( $actor ) &&
-				isset( $actor['type'] ) &&
-				'Person' === $actor['type'] &&
-				isset( $actor['id'] ) &&
-				false !== \filter_var( $actor['id'], FILTER_VALIDATE_URL )
-			) {
-				$actor = $actor['id'];
-			}
-
-			return new \WP_Error( 'invalid_actor_object', \__( 'Unknown Actor schema', 'activitypub' ), array(
-				'status' => 404,
-			) );
-		}
-
-		if ( ! \is_array( $followers ) ) {
-			$followers = array( $actor );
-		} else {
-			$followers[] = $actor;
-		}
-
-		$followers = \array_unique( $followers );
-
-		\update_user_meta( $author_id, 'activitypub_followers', $followers );
+		return \Activitypub\Collection\Followers::add_follower( $author_id, $actor );
 	}
 
 	public static function remove_follower( $actor, $author_id ) {
-		$followers = \get_user_option( 'activitypub_followers', $author_id );
+		_deprecated_function( __METHOD__, '1.0.0', '\Activitypub\Collection\Followers::remove_follower' );
 
-		foreach ( $followers as $key => $value ) {
-			if ( $value === $actor ) {
-				unset( $followers[ $key ] );
-			}
-		}
-
-		\update_user_meta( $author_id, 'activitypub_followers', $followers );
+		return \Activitypub\Collection\Followers::remove_follower( $author_id, $actor );
 	}
 }

includes/rest/class-collection.php

@@ -0,0 +1,222 @@
+<?php
+namespace Activitypub\Rest;
+
+use WP_Error;
+use WP_REST_Server;
+use WP_REST_Response;
+use Activitypub\Transformer\Transformers_Manager;
+use Activitypub\Activity\Activity;
+use Activitypub\Collection\Users as User_Collection;
+
+use function Activitypub\esc_hashtag;
+use function Activitypub\is_single_user;
+use function Activitypub\get_rest_url_by_path;
+
+/**
+ * ActivityPub Collections REST-Class
+ *
+ * @author Matthias Pfefferle
+ *
+ * @see https://docs.joinmastodon.org/spec/activitypub/#featured
+ * @see https://docs.joinmastodon.org/spec/activitypub/#featuredTags
+ */
+class Collection {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		self::register_routes();
+	}
+
+	/**
+	 * Register routes
+	 */
+	public static function register_routes() {
+		\register_rest_route(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/users/(?P<user_id>[\w\-\.]+)/collections/tags',
+			array(
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( self::class, 'tags_get' ),
+					'args'                => self::request_parameters(),
+					'permission_callback' => '__return_true',
+				),
+			)
+		);
+
+		\register_rest_route(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/users/(?P<user_id>[\w\-\.]+)/collections/featured',
+			array(
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( self::class, 'featured_get' ),
+					'args'                => self::request_parameters(),
+					'permission_callback' => '__return_true',
+				),
+			)
+		);
+
+		\register_rest_route(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/collections/moderators',
+			array(
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( self::class, 'moderators_get' ),
+					'permission_callback' => '__return_true',
+				),
+			)
+		);
+	}
+
+	/**
+	 * The Featured Tags endpoint
+	 *
+	 * @param WP_REST_Request $request The request object.
+	 *
+	 * @return WP_REST_Response The response object.
+	 */
+	public static function tags_get( $request ) {
+		$user_id = $request->get_param( 'user_id' );
+		$user    = User_Collection::get_by_various( $user_id );
+
+		if ( is_wp_error( $user ) ) {
+			return $user;
+		}
+
+		$number = 4;
+
+		$tags = \get_terms(
+			array(
+				'taxonomy' => 'post_tag',
+				'orderby'  => 'count',
+				'order'    => 'DESC',
+				'number'   => $number,
+			)
+		);
+
+		if ( is_wp_error( $tags ) ) {
+			$tags = array();
+		}
+
+		$response = array(
+			'@context'   => Activity::CONTEXT,
+			'id'         => get_rest_url_by_path( sprintf( 'users/%d/collections/tags', $user->get__id() ) ),
+			'type'       => 'Collection',
+			'totalItems' => is_countable( $tags ) ? count( $tags ) : 0,
+			'items'      => array(),
+		);
+
+		foreach ( $tags as $tag ) {
+			$response['items'][] = array(
+				'type' => 'Hashtag',
+				'href' => \esc_url( \get_tag_link( $tag ) ),
+				'name' => esc_hashtag( $tag->name ),
+			);
+		}
+
+		$rest_response = new WP_REST_Response( $response, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
+
+		return $rest_response;
+	}
+
+	/**
+	 * Featured posts endpoint
+	 *
+	 * @param WP_REST_Request $request The request object.
+	 *
+	 * @return WP_REST_Response The response object.
+	 */
+	public static function featured_get( $request ) {
+		$user_id = $request->get_param( 'user_id' );
+		$user    = User_Collection::get_by_various( $user_id );
+
+		if ( is_wp_error( $user ) ) {
+			return $user;
+		}
+
+		$sticky_posts = \get_option( 'sticky_posts' );
+
+		if ( ! is_single_user() && User_Collection::BLOG_USER_ID === $user->get__id() ) {
+			$posts = array();
+		} elseif ( $sticky_posts ) {
+			$args = array(
+				'post__in'            => $sticky_posts,
+				'ignore_sticky_posts' => 1,
+				'orderby'             => 'date',
+				'order'               => 'DESC',
+			);
+
+			if ( $user->get__id() > 0 ) {
+				$args['author'] = $user->get__id();
+			}
+
+			$posts = \get_posts( $args );
+		} else {
+			$posts = array();
+		}
+
+		$response = array(
+			'@context'     => Activity::CONTEXT,
+			'id'           => get_rest_url_by_path( sprintf( 'users/%d/collections/featured', $user_id ) ),
+			'type'         => 'OrderedCollection',
+			'totalItems'   => is_countable( $posts ) ? count( $posts ) : 0,
+			'orderedItems' => array(),
+		);
+
+		foreach ( $posts as $post ) {
+			$response['orderedItems'][] = Transformers_Manager::instance()->get_transformer( $post )->to_object()->to_array();
+		}
+
+		$rest_response = new WP_REST_Response( $response, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
+
+		return $rest_response;
+	}
+
+	/**
+	 * Moderators endpoint
+	 *
+	 * @param WP_REST_Request $request The request object.
+	 *
+	 * @return WP_REST_Response The response object.
+	 */
+	public static function moderators_get( $request ) {
+		$response = array(
+			'@context'     => Activity::CONTEXT,
+			'id'           => get_rest_url_by_path( 'collections/moderators' ),
+			'type'         => 'OrderedCollection',
+			'orderedItems' => array(),
+		);
+
+		$users = User_Collection::get_collection();
+
+		foreach ( $users as $user ) {
+			$response['orderedItems'][] = $user->get_url();
+		}
+
+		$rest_response = new WP_REST_Response( $response, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
+
+		return $rest_response;
+	}
+
+	/**
+	 * The supported parameters
+	 *
+	 * @return array list of parameters
+	 */
+	public static function request_parameters() {
+		$params = array();
+
+		$params['user_id'] = array(
+			'required' => true,
+			'type' => 'string',
+		);
+
+		return $params;
+	}
+}

includes/rest/class-followers.php

@@ -1,6 +1,15 @@
 <?php
 namespace Activitypub\Rest;
 
+use WP_Error;
+use stdClass;
+use WP_REST_Server;
+use WP_REST_Response;
+use Activitypub\Collection\Users as User_Collection;
+use Activitypub\Collection\Followers as Follower_Collection;
+
+use function Activitypub\get_rest_url_by_path;
+
 /**
  * ActivityPub Followers REST-Class
  *
@@ -13,7 +22,7 @@ class Followers {
 	 * Initialize the class, registering WordPress hooks
 	 */
 	public static function init() {
-		\add_action( 'rest_api_init', array( '\Activitypub\Rest\Followers', 'register_routes' ) );
+		self::register_routes();
 	}
 
 	/**
@@ -21,11 +30,14 @@ class Followers {
 	 */
 	public static function register_routes() {
 		\register_rest_route(
-			'activitypub/1.0', '/users/(?P<id>\d+)/followers', array(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/users/(?P<user_id>[\w\-\.]+)/followers',
 			array(
-					'methods'  => \WP_REST_Server::READABLE,
-					'callback' => array( '\Activitypub\Rest\Followers', 'get' ),
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( self::class, 'get' ),
 					'args'                => self::request_parameters(),
+					'permission_callback' => '__return_true',
 				),
 			)
 		);
@@ -39,39 +51,62 @@ class Followers {
 	 * @return WP_REST_Response
 	 */
 	public static function get( $request ) {
-		$user_id = $request->get_param( 'id' );
-		$user    = \get_user_by( 'ID', $user_id );
+		$user_id = $request->get_param( 'user_id' );
+		$user    = User_Collection::get_by_various( $user_id );
 
-		if ( ! $user ) {
-			return new \WP_Error( 'rest_invalid_param', \__( 'User not found', 'activitypub' ), array(
-				'status' => 404,
-				'params' => array(
-					'user_id' => \__( 'User not found', 'activitypub' ),
-				),
-			) );
+		if ( is_wp_error( $user ) ) {
+			return $user;
 		}
 
+		$order    = $request->get_param( 'order' );
+		$per_page = (int) $request->get_param( 'per_page' );
+		$page     = (int) $request->get_param( 'page' );
+		$context  = $request->get_param( 'context' );
+
 		/*
 		 * Action triggerd prior to the ActivityPub profile being created and sent to the client
 		 */
-		\do_action( 'activitypub_outbox_pre' );
+		\do_action( 'activitypub_rest_followers_pre' );
 
-		$json = new \stdClass();
+		$data = Follower_Collection::get_followers_with_count( $user_id, $per_page, $page, array( 'order' => ucwords( $order ) ) );
+		$json = new stdClass();
 
 		$json->{'@context'} = \Activitypub\get_context();
 
-		$json->partOf = \get_rest_url( null, "/activitypub/1.0/users/$user_id/followers" ); // phpcs:ignore
-		$json->totalItems = \Activitypub\count_followers( $user_id ); // phpcs:ignore
-		$json->orderedItems = \Activitypub\Peer\Followers::get_followers( $user_id ); // phpcs:ignore
+		$json->id = get_rest_url_by_path( sprintf( 'users/%d/followers', $user->get__id() ) );
+		$json->generator = 'http://wordpress.org/?v=' . \get_bloginfo_rss( 'version' );
+		$json->actor = $user->get_id();
+		$json->type = 'OrderedCollectionPage';
 
-		$json->first = $json->partOf; // phpcs:ignore
+		$json->totalItems = $data['total']; // phpcs:ignore
+		$json->partOf = get_rest_url_by_path( sprintf( 'users/%d/followers', $user->get__id() ) ); // phpcs:ignore
 
-		$json->first = \get_rest_url( null, "/activitypub/1.0/users/$user_id/followers" );
+		$json->first = \add_query_arg( 'page', 1, $json->partOf ); // phpcs:ignore
+		$json->last  = \add_query_arg( 'page', \ceil ( $json->totalItems / $per_page ), $json->partOf ); // phpcs:ignore
 
-		$response = new \WP_REST_Response( $json, 200 );
-		$response->header( 'Content-Type', 'application/activity+json' );
+		if ( $page && ( ( \ceil ( $json->totalItems / $per_page ) ) > $page ) ) { // phpcs:ignore
+			$json->next  = \add_query_arg( 'page', $page + 1, $json->partOf ); // phpcs:ignore
+		}
 
-		return $response;
+		if ( $page && ( $page > 1 ) ) { // phpcs:ignore
+			$json->prev  = \add_query_arg( 'page', $page - 1, $json->partOf ); // phpcs:ignore
+		}
+
+		// phpcs:ignore
+		$json->orderedItems = array_map(
+			function( $item ) use ( $context ) {
+				if ( 'full' === $context ) {
+					return $item->to_array();
+				}
+				return $item->get_url();
+			},
+			$data['followers']
+		);
+
+		$rest_response = new WP_REST_Response( $json, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
+
+		return $rest_response;
 	}
 
 	/**
@@ -84,11 +119,29 @@ class Followers {
 
 		$params['page'] = array(
 			'type' => 'integer',
+			'default' => 1,
 		);
 
-		$params['id'] = array(
-			'required' => true,
+		$params['per_page'] = array(
 			'type' => 'integer',
+			'default' => 20,
+		);
+
+		$params['order'] = array(
+			'type'    => 'string',
+			'default' => 'desc',
+			'enum'    => array( 'asc', 'desc' ),
+		);
+
+		$params['user_id'] = array(
+			'required' => true,
+			'type' => 'string',
+		);
+
+		$params['context'] = array(
+			'type' => 'string',
+			'default' => 'simple',
+			'enum' => array( 'simple', 'full' ),
 		);
 
 		return $params;

includes/rest/class-following.php

@@ -1,6 +1,12 @@
 <?php
 namespace Activitypub\Rest;
 
+use WP_REST_Response;
+use Activitypub\Collection\Users as User_Collection;
+
+use function Activitypub\is_single_user;
+use function Activitypub\get_rest_url_by_path;
+
 /**
  * ActivityPub Following REST-Class
  *
@@ -13,7 +19,9 @@ class Following {
 	 * Initialize the class, registering WordPress hooks
 	 */
 	public static function init() {
-		\add_action( 'rest_api_init', array( '\Activitypub\Rest\Following', 'register_routes' ) );
+		self::register_routes();
+
+		\add_filter( 'activitypub_rest_following', array( self::class, 'default_following' ), 10, 2 );
 	}
 
 	/**
@@ -21,11 +29,14 @@ class Following {
 	 */
 	public static function register_routes() {
 		\register_rest_route(
-			'activitypub/1.0', '/users/(?P<id>\d+)/following', array(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/users/(?P<user_id>[\w\-\.]+)/following',
+			array(
 				array(
 					'methods'             => \WP_REST_Server::READABLE,
-					'callback' => array( '\Activitypub\Rest\Following', 'get' ),
+					'callback'            => array( self::class, 'get' ),
 					'args'                => self::request_parameters(),
+					'permission_callback' => '__return_true',
 				),
 			)
 		);
@@ -39,39 +50,40 @@ class Following {
 	 * @return WP_REST_Response
 	 */
 	public static function get( $request ) {
-		$user_id = $request->get_param( 'id' );
-		$user    = \get_user_by( 'ID', $user_id );
+		$user_id = $request->get_param( 'user_id' );
+		$user    = User_Collection::get_by_various( $user_id );
 
-		if ( ! $user ) {
-			return new \WP_Error( 'rest_invalid_param', \__( 'User not found', 'activitypub' ), array(
-				'status' => 404,
-				'params' => array(
-					'user_id' => \__( 'User not found', 'activitypub' ),
-				),
-			) );
+		if ( is_wp_error( $user ) ) {
+			return $user;
 		}
 
 		/*
 		 * Action triggerd prior to the ActivityPub profile being created and sent to the client
 		 */
-		\do_action( 'activitypub_outbox_pre' );
+		\do_action( 'activitypub_rest_following_pre' );
 
 		$json = new \stdClass();
 
 		$json->{'@context'} = \Activitypub\get_context();
 
-		$json->partOf = \get_rest_url( null, "/activitypub/1.0/users/$user_id/following" ); // phpcs:ignore
-		$json->totalItems = 0; // phpcs:ignore
-		$json->orderedItems = array(); // phpcs:ignore
+		$json->id = get_rest_url_by_path( sprintf( 'users/%d/following', $user->get__id() ) );
+		$json->generator = 'http://wordpress.org/?v=' . \get_bloginfo_rss( 'version' );
+		$json->actor = $user->get_id();
+		$json->type = 'OrderedCollectionPage';
+
+		$json->partOf = get_rest_url_by_path( sprintf( 'users/%d/following', $user->get__id() ) ); // phpcs:ignore
+
+		$items = apply_filters( 'activitypub_rest_following', array(), $user ); // phpcs:ignore
+
+		$json->totalItems = is_countable( $items ) ? count( $items ) : 0; // phpcs:ignore
+		$json->orderedItems = $items; // phpcs:ignore
 
 		$json->first = $json->partOf; // phpcs:ignore
 
-		$json->first = \get_rest_url( null, "/activitypub/1.0/users/$user_id/following" );
+		$rest_response = new WP_REST_Response( $json, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
 
-		$response = new \WP_REST_Response( $json, 200 );
-		$response->header( 'Content-Type', 'application/activity+json' );
-
-		return $response;
+		return $rest_response;
 	}
 
 	/**
@@ -86,11 +98,34 @@ class Following {
 			'type' => 'integer',
 		);
 
-		$params['id'] = array(
+		$params['user_id'] = array(
 			'required' => true,
-			'type' => 'integer',
+			'type' => 'string',
 		);
 
 		return $params;
 	}
+
+	/**
+	 * Add the Blog Authors to the following list of the Blog Actor
+	 * if Blog not in single mode.
+	 *
+	 * @param array $array The array of following urls.
+	 * @param User  $user  The user object.
+	 *
+	 * @return array The array of following urls.
+	 */
+	public static function default_following( $array, $user ) {
+		if ( 0 !== $user->get__id() || is_single_user() ) {
+			return $array;
+		}
+
+		$users = User_Collection::get_collection();
+
+		foreach ( $users as $user ) {
+			$array[] = $user->get_url();
+		}
+
+		return $array;
+	}
 }

includes/rest/class-inbox.php

@@ -1,6 +1,17 @@
 <?php
 namespace Activitypub\Rest;
 
+use WP_Error;
+use WP_REST_Server;
+use WP_REST_Response;
+use Activitypub\Activity\Activity;
+use Activitypub\Collection\Users as User_Collection;
+
+use function Activitypub\get_context;
+use function Activitypub\url_to_authorid;
+use function Activitypub\get_rest_url_by_path;
+use function Activitypub\get_remote_metadata_by_actor;
+
 /**
  * ActivityPub Inbox REST-Class
  *
@@ -13,13 +24,9 @@ class Inbox {
 	 * Initialize the class, registering WordPress hooks
 	 */
 	public static function init() {
-		\add_action( 'rest_api_init', array( '\Activitypub\Rest\Inbox', 'register_routes' ) );
-		//\add_filter( 'rest_pre_serve_request', array( '\Activitypub\Rest\Inbox', 'serve_request' ), 11, 4 );
-		\add_action( 'activitypub_inbox_follow', array( '\Activitypub\Rest\Inbox', 'handle_follow' ), 10, 2 );
-		\add_action( 'activitypub_inbox_unfollow', array( '\Activitypub\Rest\Inbox', 'handle_unfollow' ), 10, 2 );
-		//\add_action( 'activitypub_inbox_like', array( '\Activitypub\Rest\Inbox', 'handle_reaction' ), 10, 2 );
-		//\add_action( 'activitypub_inbox_announce', array( '\Activitypub\Rest\Inbox', 'handle_reaction' ), 10, 2 );
-		\add_action( 'activitypub_inbox_create', array( '\Activitypub\Rest\Inbox', 'handle_create' ), 10, 2 );
+		self::register_routes();
+
+		\add_action( 'activitypub_inbox_create', array( self::class, 'handle_create' ), 10, 2 );
 	}
 
 	/**
@@ -27,147 +34,161 @@ class Inbox {
 	 */
 	public static function register_routes() {
 		\register_rest_route(
-			'activitypub/1.0', '/inbox', array(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/inbox',
 			array(
-					'methods'  => \WP_REST_Server::EDITABLE,
-					'callback' => array( '\Activitypub\Rest\Inbox', 'shared_inbox' ),
+				array(
+					'methods'             => WP_REST_Server::CREATABLE,
+					'callback'            => array( self::class, 'shared_inbox_post' ),
+					'args'                => self::shared_inbox_post_parameters(),
+					'permission_callback' => '__return_true',
 				),
 			)
 		);
 
 		\register_rest_route(
-			'activitypub/1.0', '/users/(?P<id>\d+)/inbox', array(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/users/(?P<user_id>[\w\-\.]+)/inbox',
 			array(
-					'methods'  => \WP_REST_Server::EDITABLE,
-					'callback' => array( '\Activitypub\Rest\Inbox', 'user_inbox' ),
-					'args'     => self::request_parameters(),
+				array(
+					'methods'             => WP_REST_Server::CREATABLE,
+					'callback'            => array( self::class, 'user_inbox_post' ),
+					'args'                => self::user_inbox_post_parameters(),
+					'permission_callback' => '__return_true',
+				),
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( self::class, 'user_inbox_get' ),
+					'args'                => self::user_inbox_get_parameters(),
+					'permission_callback' => '__return_true',
 				),
 			)
 		);
 	}
 
-	/**
-	 * Hooks into the REST API request to verify the signature.
-	 *
-	 * @param bool                      $served  Whether the request has already been served.
-	 * @param WP_HTTP_ResponseInterface $result  Result to send to the client. Usually a WP_REST_Response.
-	 * @param WP_REST_Request           $request Request used to generate the response.
-	 * @param WP_REST_Server            $server  Server instance.
-	 *
-	 * @return true
-	 */
-	public static function serve_request( $served, $result, $request, $server ) {
-		if ( '/activitypub' !== \substr( $request->get_route(), 0, 12 ) ) {
-			return $served;
-		}
-
-		if ( 'POST' !== $request->get_method() ) {
-			return $served;
-		}
-
-		$signature = $request->get_header( 'signature' );
-
-		if ( ! $signature ) {
-			return $served;
-		}
-
-		$headers = $request->get_headers();
-
-		//\Activitypub\Signature::verify_signature( $headers, $key );
-
-		return $served;
-	}
-
 	/**
 	 * Renders the user-inbox
 	 *
 	 * @param  WP_REST_Request   $request
+	 * @return WP_REST_Response
+	 */
+	public static function user_inbox_get( $request ) {
+		$user_id = $request->get_param( 'user_id' );
+		$user    = User_Collection::get_by_various( $user_id );
+
+		if ( is_wp_error( $user ) ) {
+			return $user;
+		}
+
+		$page = $request->get_param( 'page', 0 );
+
+		/*
+		 * Action triggerd prior to the ActivityPub profile being created and sent to the client
+		 */
+		\do_action( 'activitypub_rest_inbox_pre' );
+
+		$json = new \stdClass();
+
+		$json->{'@context'} = get_context();
+		$json->id = get_rest_url_by_path( sprintf( 'users/%d/inbox', $user->get__id() ) );
+		$json->generator = 'http://wordpress.org/?v=' . \get_bloginfo_rss( 'version' );
+		$json->type = 'OrderedCollectionPage';
+		$json->partOf = get_rest_url_by_path( sprintf( 'users/%d/inbox', $user->get__id() ) ); // phpcs:ignore
+
+		$json->totalItems = 0; // phpcs:ignore
+
+		$json->orderedItems = array(); // phpcs:ignore
+
+		$json->first = $json->partOf; // phpcs:ignore
+
+		// filter output
+		$json = \apply_filters( 'activitypub_rest_inbox_array', $json );
+
+		/*
+		 * Action triggerd after the ActivityPub profile has been created and sent to the client
+		 */
+		\do_action( 'activitypub_inbox_post' );
+
+		$rest_response = new WP_REST_Response( $json, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
+
+		return $rest_response;
+	}
+
+	/**
+	 * Handles user-inbox requests
+	 *
+	 * @param  WP_REST_Request   $request
 	 *
 	 * @return WP_REST_Response
 	 */
-	public static function user_inbox( $request ) {
-		$author_id = $request->get_param( 'id' );
+	public static function user_inbox_post( $request ) {
+		$user_id = $request->get_param( 'user_id' );
+		$user    = User_Collection::get_by_various( $user_id );
 
-		$data = \json_decode( $request->get_body(), true );
-
-		if ( ! \is_array( $data ) || ! \array_key_exists( 'type', $data ) ) {
-			return new \WP_Error( 'rest_invalid_data', \__( 'Invalid payload', 'activitypub' ), array( 'status' => 422 ) );
+		if ( is_wp_error( $user ) ) {
+			return $user;
 		}
 
-		$type = 'create';
-		if ( ! empty( $data['type'] ) ) {
-			$type = \strtolower( $data['type'] );
-		}
+		$data = $request->get_json_params();
+		$type = $request->get_param( 'type' );
+		$type = \strtolower( $type );
 
-		\do_action( 'activitypub_inbox', $data, $author_id, $type );
-		\do_action( "activitypub_inbox_{$type}", $data, $author_id );
+		\do_action( 'activitypub_inbox', $data, $user->get__id(), $type );
+		\do_action( "activitypub_inbox_{$type}", $data, $user->get__id() );
 
-		return new \WP_REST_Response( array(), 202 );
+		$rest_response = new WP_REST_Response( array(), 202 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
+
+		return $rest_response;
 	}
 
 	/**
 	 * The shared inbox
 	 *
-	 * @param  [type] $request [description]
+	 * @param  WP_REST_Request   $request
 	 *
-	 * @return WP_Error not yet implemented
+	 * @return WP_REST_Response
 	 */
-	public static function shared_inbox( $request ) {
-		$data = \json_decode( $request->get_body(), true );
+	public static function shared_inbox_post( $request ) {
+		$data = $request->get_json_params();
+		$type = $request->get_param( 'type' );
+		$users = self::extract_recipients( $data );
 
-		if ( empty( $data['to'] ) ) {
-			return new \WP_Error( 'rest_invalid_data', \__( 'No receiving actor set', 'activitypub' ), array( 'status' => 422 ) );
+		if ( ! $users ) {
+			return new WP_Error(
+				'rest_invalid_param',
+				\__( 'No recipients found', 'activitypub' ),
+				array(
+					'status' => 400,
+					'params' => array(
+						'to' => \__( 'Please check/validate "to" field', 'activitypub' ),
+						'bto' => \__( 'Please check/validate "bto" field', 'activitypub' ),
+						'cc' => \__( 'Please check/validate "cc" field', 'activitypub' ),
+						'bcc' => \__( 'Please check/validate "bcc" field', 'activitypub' ),
+						'audience' => \__( 'Please check/validate "audience" field', 'activitypub' ),
+					),
+				)
+			);
 		}
 
-		if ( \filter_var( $data['to'], \FILTER_VALIDATE_URL ) ) {
-			$author_id = \Activitypub\url_to_authorid( $data['to'] );
+		foreach ( $users as $user ) {
+			$user = User_Collection::get_by_various( $user );
 
-			if ( ! $author_id ) {
-				return new \WP_Error( 'rest_invalid_data', \__( 'No matching user', 'activitypub' ), array( 'status' => 422 ) );
-			}
-		} else {
-			// get the identifier at the left of the '@'
-			$parts = \explode( '@', $data['to'] );
-
-			if ( 3 === \count( $parts ) ) {
-				$username = $parts[1];
-				$host = $parts[2];
-			} elseif ( 2 === \count( $parts ) ) {
-				$username = $parts[0];
-				$host = $parts[1];
+			if ( is_wp_error( $user ) ) {
+				continue;
 			}
 
-			if ( ! $username || ! $host ) {
-				return new \WP_Error( 'rest_invalid_data', \__( 'Invalid actor identifier', 'activitypub' ), array( 'status' => 422 ) );
+			$type = \strtolower( $type );
+
+			\do_action( 'activitypub_inbox', $data, $user->ID, $type );
+			\do_action( "activitypub_inbox_{$type}", $data, $user->ID );
 		}
 
-			// check domain
-			if ( ! \wp_parse_url( \home_url(), \PHP_URL_HOST ) !== $host ) {
-				return new \WP_Error( 'rest_invalid_data', \__( 'Invalid host', 'activitypub' ), array( 'status' => 422 ) );
-			}
+		$rest_response = new WP_REST_Response( array(), 202 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
 
-			$author = \get_user_by( 'login', $username );
-
-			if ( ! $author ) {
-				return new \WP_Error( 'rest_invalid_data', \__( 'No matching user', 'activitypub' ), array( 'status' => 422 ) );
-			}
-
-			$author_id = $author->ID;
-		}
-
-		if ( ! \is_array( $data ) || ! \array_key_exists( 'type', $data ) ) {
-			return new \WP_Error( 'rest_invalid_data', \__( 'Invalid payload', 'activitypub' ), array( 'status' => 422 ) );
-		}
-
-		$type = 'create';
-		if ( ! empty( $data['type'] ) ) {
-			$type = \strtolower( $data['type'] );
-		}
-
-		\do_action( 'activitypub_inbox', $data, $author_id, $type );
-		\do_action( "activitypub_inbox_{$type}", $data, $author_id );
-
-		return new \WP_REST_Response( array(), 202 );
+		return $rest_response;
 	}
 
 	/**
@@ -175,7 +196,79 @@ class Inbox {
 	 *
 	 * @return array list of parameters
 	 */
-	public static function request_parameters() {
+	public static function user_inbox_get_parameters() {
+		$params = array();
+
+		$params['page'] = array(
+			'type' => 'integer',
+		);
+
+		$params['user_id'] = array(
+			'required' => true,
+			'type' => 'string',
+		);
+
+		return $params;
+	}
+
+	/**
+	 * The supported parameters
+	 *
+	 * @return array list of parameters
+	 */
+	public static function user_inbox_post_parameters() {
+		$params = array();
+
+		$params['page'] = array(
+			'type' => 'integer',
+		);
+
+		$params['user_id'] = array(
+			'required' => true,
+			'type' => 'string',
+		);
+
+		$params['id'] = array(
+			'required' => true,
+			'sanitize_callback' => 'esc_url_raw',
+		);
+
+		$params['actor'] = array(
+			'required' => true,
+			'sanitize_callback' => function( $param, $request, $key ) {
+				if ( \is_array( $param ) ) {
+					if ( isset( $param['id'] ) ) {
+						$param = $param['id'];
+					} else {
+						$param = $param['url'];
+					}
+				}
+				return \esc_url_raw( $param );
+			},
+		);
+
+		$params['type'] = array(
+			'required' => true,
+			//'type' => 'enum',
+			//'enum' => array( 'Create' ),
+			//'sanitize_callback' => function( $param, $request, $key ) {
+			//  return \strtolower( $param );
+			//},
+		);
+
+		$params['object'] = array(
+			'required' => true,
+		);
+
+		return $params;
+	}
+
+	/**
+	 * The supported parameters
+	 *
+	 * @return array list of parameters
+	 */
+	public static function shared_inbox_post_parameters() {
 		$params = array();
 
 		$params['page'] = array(
@@ -184,92 +277,69 @@ class Inbox {
 
 		$params['id'] = array(
 			'required' => true,
-			'type' => 'integer',
+			'type' => 'string',
+			'sanitize_callback' => 'esc_url_raw',
+		);
+
+		$params['actor'] = array(
+			'required' => true,
+			//'type' => array( 'object', 'string' ),
+			'sanitize_callback' => function( $param, $request, $key ) {
+				if ( ! \is_string( $param ) ) {
+					$param = $param['id'];
+				}
+				return \esc_url_raw( $param );
+			},
+		);
+
+		$params['type'] = array(
+			'required' => true,
+			//'type' => 'enum',
+			//'enum' => array( 'Create' ),
+			//'sanitize_callback' => function( $param, $request, $key ) {
+			//  return \strtolower( $param );
+			//},
+		);
+
+		$params['object'] = array(
+			'required' => true,
+			//'type' => 'object',
+		);
+
+		$params['to'] = array(
+			'required' => false,
+			'sanitize_callback' => function( $param, $request, $key ) {
+				if ( \is_string( $param ) ) {
+					$param = array( $param );
+				}
+
+				return $param;
+			},
+		);
+
+		$params['cc'] = array(
+			'sanitize_callback' => function( $param, $request, $key ) {
+				if ( \is_string( $param ) ) {
+					$param = array( $param );
+				}
+
+				return $param;
+			},
+		);
+
+		$params['bcc'] = array(
+			'sanitize_callback' => function( $param, $request, $key ) {
+				if ( \is_string( $param ) ) {
+					$param = array( $param );
+				}
+
+				return $param;
+			},
 		);
 
 		return $params;
 	}
 
-	/**
-	 * Handles "Follow" requests
-	 *
-	 * @param  array $object  The activity-object
-	 * @param  int   $user_id The id of the local blog-user
-	 */
-	public static function handle_follow( $object, $user_id ) {
-		if ( ! \array_key_exists( 'actor', $object ) ) {
-			return new \WP_Error( 'activitypub_no_actor', __( 'No "Actor" found', 'activitypub' ) );
-		}
-
-		// save follower
-		\Activitypub\Peer\Followers::add_follower( $object['actor'], $user_id );
-
-		// get inbox
-		$inbox = \Activitypub\get_inbox_by_actor( $object['actor'] );
-
-		// send "Accept" activity
-		$activity = new \Activitypub\Model\Activity( 'Accept', \Activitypub\Model\Activity::TYPE_SIMPLE );
-		$activity->set_object( $object );
-		$activity->set_actor( \get_author_posts_url( $user_id ) );
-		$activity->set_to( $object['actor'] );
-		$activity->set_id( \get_author_posts_url( $user_id ) . '#follow' . \preg_replace( '~^https?://~', '', $object['actor'] ) );
-
-		$activity = $activity->to_simple_json();
-
-		$response = \Activitypub\safe_remote_post( $inbox, $activity, $user_id );
-	}
-
-	/**
-	 * Handles "Unfollow" requests
-	 *
-	 * @param  array $object  The activity-object
-	 * @param  int   $user_id The id of the local blog-user
-	 */
-	public static function handle_unfollow( $object, $user_id ) {
-		if ( ! \array_key_exists( 'actor', $object ) ) {
-			return new \WP_Error( 'activitypub_no_actor', \__( 'No "Actor" found', 'activitypub' ) );
-		}
-
-		\Activitypub\Peer\Followers::remove_follower( $object['actor'], $user_id );
-	}
-
-	/**
-	 * Handles "Reaction" requests
-	 *
-	 * @param  array $object  The activity-object
-	 * @param  int   $user_id The id of the local blog-user
-	 */
-	public static function handle_reaction( $object, $user_id ) {
-		if ( ! \array_key_exists( 'actor', $object ) ) {
-			return new \WP_Error( 'activitypub_no_actor', \__( 'No "Actor" found', 'activitypub' ) );
-		}
-
-		$meta = \Activitypub\get_remote_metadata_by_actor( $object['actor'] );
-
-		$commentdata = array(
-			'comment_post_ID' => \url_to_postid( $object['object'] ),
-			'comment_author' => \esc_attr( $meta['name'] ),
-			'comment_author_email' => '',
-			'comment_author_url' => \esc_url_raw( $object['actor'] ),
-			'comment_content' => \esc_url_raw( $object['actor'] ),
-			'comment_type' => \esc_attr( \strtolower( $object['type'] ) ),
-			'comment_parent' => 0,
-			'comment_meta' => array(
-				'source_url' => \esc_url_raw( $object['id'] ),
-				'avatar_url' => \esc_url_raw( $meta['icon']['url'] ),
-				'protocol' => 'activitypub',
-			),
-		);
-
-		// disable flood control
-		\remove_action( 'check_comment_flood', 'check_comment_flood_db', 10 );
-
-		$state = \wp_new_comment( $commentdata, true );
-
-		// re-add flood control
-		\add_action( 'check_comment_flood', 'check_comment_flood_db', 10, 4 );
-	}
-
 	/**
 	 * Handles "Create" requests
 	 *
@@ -277,18 +347,31 @@ class Inbox {
 	 * @param  int   $user_id The id of the local blog-user
 	 */
 	public static function handle_create( $object, $user_id ) {
-		if ( ! \array_key_exists( 'actor', $object ) ) {
-			return new \WP_Error( 'activitypub_no_actor', __( 'No "Actor" found', 'activitypub' ) );
+		$meta = get_remote_metadata_by_actor( $object['actor'] );
+
+		if ( ! isset( $object['object']['inReplyTo'] ) ) {
+			return;
 		}
 
-		$meta = \Activitypub\get_remote_metadata_by_actor( $object['actor'] );
+		// check if Activity is public or not
+		if ( ! self::is_activity_public( $object ) ) {
+			// @todo maybe send email
+			return;
+		}
+
+		$comment_post_id = \url_to_postid( $object['object']['inReplyTo'] );
+
+		// save only replys and reactions
+		if ( ! $comment_post_id ) {
+			return false;
+		}
 
 		$commentdata = array(
-			'comment_post_ID' => \url_to_postid( $object['object']['inReplyTo'] ),
+			'comment_post_ID' => $comment_post_id,
 			'comment_author' => \esc_attr( $meta['name'] ),
 			'comment_author_url' => \esc_url_raw( $object['actor'] ),
-			'comment_content' => \wp_filter_kses( $object['object']['content'] ),
-			'comment_type' => '',
+			'comment_content' => addslashes( \wp_kses( $object['object']['content'], 'pre_comment_content' ) ),
+			'comment_type' => 'comment',
 			'comment_author_email' => '',
 			'comment_parent' => 0,
 			'comment_meta' => array(
@@ -301,9 +384,135 @@ class Inbox {
 		// disable flood control
 		\remove_action( 'check_comment_flood', 'check_comment_flood_db', 10 );
 
+		// do not require email for AP entries
+		\add_filter( 'pre_option_require_name_email', '__return_false' );
+
+		// No nonce possible for this submission route
+		\add_filter(
+			'akismet_comment_nonce',
+			function() {
+				return 'inactive';
+			}
+		);
+
+		\add_filter( 'wp_kses_allowed_html', array( self::class, 'allowed_comment_html' ), 10, 2 );
+
 		$state = \wp_new_comment( $commentdata, true );
 
+		\remove_filter( 'wp_kses_allowed_html', array( self::class, 'allowed_comment_html' ) );
+		\remove_filter( 'pre_option_require_name_email', '__return_false' );
+
 		// re-add flood control
 		\add_action( 'check_comment_flood', 'check_comment_flood_db', 10, 4 );
+
+		do_action( 'activitypub_handled_create', $object, $user_id, $state, $commentdata );
+	}
+
+	/**
+	 * Extract recipient URLs from Activity object
+	 *
+	 * @param  array $data
+	 *
+	 * @return array The list of user URLs
+	 */
+	public static function extract_recipients( $data ) {
+		$recipient_items = array();
+
+		foreach ( array( 'to', 'bto', 'cc', 'bcc', 'audience' ) as $i ) {
+			if ( array_key_exists( $i, $data ) ) {
+				if ( is_array( $data[ $i ] ) ) {
+					$recipient = $data[ $i ];
+				} else {
+					$recipient = array( $data[ $i ] );
+				}
+				$recipient_items = array_merge( $recipient_items, $recipient );
+			}
+
+			if ( is_array( $data['object'] ) && array_key_exists( $i, $data['object'] ) ) {
+				if ( is_array( $data['object'][ $i ] ) ) {
+					$recipient = $data['object'][ $i ];
+				} else {
+					$recipient = array( $data['object'][ $i ] );
+				}
+				$recipient_items = array_merge( $recipient_items, $recipient );
+			}
+		}
+
+		$recipients = array();
+
+		// flatten array
+		foreach ( $recipient_items as $recipient ) {
+			if ( is_array( $recipient ) ) {
+				// check if recipient is an object
+				if ( array_key_exists( 'id', $recipient ) ) {
+					$recipients[] = $recipient['id'];
+				}
+			} else {
+				$recipients[] = $recipient;
+			}
+		}
+
+		return array_unique( $recipients );
+	}
+
+	/**
+	 * Get local user recipients
+	 *
+	 * @param  array $data
+	 *
+	 * @return array The list of local users
+	 */
+	public static function get_recipients( $data ) {
+		$recipients = self::extract_recipients( $data );
+		$users = array();
+
+		foreach ( $recipients as $recipient ) {
+			$user_id = url_to_authorid( $recipient );
+
+			$user = get_user_by( 'id', $user_id );
+
+			if ( $user ) {
+				$users[] = $user;
+			}
+		}
+
+		return $users;
+	}
+
+	/**
+	 * Check if passed Activity is Public
+	 *
+	 * @param array $data
+	 * @return boolean
+	 */
+	public static function is_activity_public( $data ) {
+		$recipients = self::extract_recipients( $data );
+
+		return in_array( 'https://www.w3.org/ns/activitystreams#Public', $recipients, true );
+	}
+
+	/**
+	 * Adds line breaks to the list of allowed comment tags.
+	 *
+	 * @param  array  $allowedtags Allowed HTML tags.
+	 * @param  string $context     Context.
+	 * @return array               Filtered tag list.
+	 */
+	public static function allowed_comment_html( $allowedtags, $context = '' ) {
+		if ( 'pre_comment_content' !== $context ) {
+			// Do nothing.
+			return $allowedtags;
+		}
+
+		// Add `p` and `br` to the list of allowed tags.
+		if ( ! array_key_exists( 'br', $allowedtags ) ) {
+			$allowedtags['br'] = array();
+		}
+
+		if ( ! array_key_exists( 'p', $allowedtags ) ) {
+			$allowedtags['p'] = array();
+		}
+
+		return $allowedtags;
 	}
 }

includes/rest/class-nodeinfo.php

@@ -1,6 +1,12 @@
 <?php
 namespace Activitypub\Rest;
 
+use WP_REST_Response;
+
+use function Activitypub\get_total_users;
+use function Activitypub\get_active_users;
+use function Activitypub\get_rest_url_by_path;
+
 /**
  * ActivityPub NodeInfo REST-Class
  *
@@ -13,9 +19,7 @@ class Nodeinfo {
 	 * Initialize the class, registering WordPress hooks
 	 */
 	public static function init() {
-		\add_action( 'rest_api_init', array( '\Activitypub\Rest\Nodeinfo', 'register_routes' ) );
-		\add_filter( 'nodeinfo_data', array( '\Activitypub\Rest\Nodeinfo', 'add_nodeinfo_discovery' ), 10, 2 );
-		\add_filter( 'nodeinfo2_data', array( '\Activitypub\Rest\Nodeinfo', 'add_nodeinfo2_discovery' ), 10 );
+		self::register_routes();
 	}
 
 	/**
@@ -23,28 +27,37 @@ class Nodeinfo {
 	 */
 	public static function register_routes() {
 		\register_rest_route(
-			'activitypub/1.0', '/nodeinfo/discovery', array(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/nodeinfo/discovery',
+			array(
 				array(
 					'methods'             => \WP_REST_Server::READABLE,
-					'callback' => array( '\Activitypub\Rest\Nodeinfo', 'discovery' ),
+					'callback'            => array( self::class, 'discovery' ),
+					'permission_callback' => '__return_true',
 				),
 			)
 		);
 
 		\register_rest_route(
-			'activitypub/1.0', '/nodeinfo', array(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/nodeinfo',
+			array(
 				array(
 					'methods'             => \WP_REST_Server::READABLE,
-					'callback' => array( '\Activitypub\Rest\Nodeinfo', 'nodeinfo' ),
+					'callback'            => array( self::class, 'nodeinfo' ),
+					'permission_callback' => '__return_true',
 				),
 			)
 		);
 
 		\register_rest_route(
-			'activitypub/1.0', '/nodeinfo2', array(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/nodeinfo2',
+			array(
 				array(
 					'methods'             => \WP_REST_Server::READABLE,
-					'callback' => array( '\Activitypub\Rest\Nodeinfo', 'nodeinfo2' ),
+					'callback'            => array( self::class, 'nodeinfo2' ),
+					'permission_callback' => '__return_true',
 				),
 			)
 		);
@@ -58,6 +71,11 @@ class Nodeinfo {
 	 * @return WP_REST_Response
 	 */
 	public static function nodeinfo( $request ) {
+		/*
+		 * Action triggerd prior to the ActivityPub profile being created and sent to the client
+		 */
+		\do_action( 'activitypub_rest_nodeinfo_pre' );
+
 		$nodeinfo = array();
 
 		$nodeinfo['version'] = '2.0';
@@ -66,13 +84,14 @@ class Nodeinfo {
 			'version' => \get_bloginfo( 'version' ),
 		);
 
-		$users = \count_users();
 		$posts = \wp_count_posts();
 		$comments = \wp_count_comments();
 
 		$nodeinfo['usage'] = array(
 			'users' => array(
-				'total' => (int) $users['total_users'],
+				'total'          => get_total_users(),
+				'activeMonth'    => get_active_users( '1 month ago' ),
+				'activeHalfyear' => get_active_users( '6 month ago' ),
 			),
 			'localPosts' => (int) $posts->publish,
 			'localComments' => (int) $comments->approved,
@@ -86,11 +105,7 @@ class Nodeinfo {
 			'outbound' => array(),
 		);
 
-		$nodeinfo['metadata'] = array(
-			'email' => \get_option( 'admin_email' ),
-		);
-
-		return new \WP_REST_Response( $nodeinfo, 200 );
+		return new WP_REST_Response( $nodeinfo, 200 );
 	}
 
 	/**
@@ -101,23 +116,29 @@ class Nodeinfo {
 	 * @return WP_REST_Response
 	 */
 	public static function nodeinfo2( $request ) {
+		/*
+		 * Action triggerd prior to the ActivityPub profile being created and sent to the client
+		 */
+		\do_action( 'activitypub_rest_nodeinfo2_pre' );
+
 		$nodeinfo = array();
 
 		$nodeinfo['version'] = '1.0';
 		$nodeinfo['server'] = array(
-			'baseUrl' => home_url( '/' ),
+			'baseUrl' => \home_url( '/' ),
 			'name' => \get_bloginfo( 'name' ),
 			'software' => 'wordpress',
 			'version' => \get_bloginfo( 'version' ),
 		);
 
-		$users = \count_users();
 		$posts = \wp_count_posts();
 		$comments = \wp_count_comments();
 
 		$nodeinfo['usage'] = array(
 			'users' => array(
-				'total' => (int) $users['total_users'],
+				'total'          => get_total_users(),
+				'activeMonth'    => get_active_users( 1 ),
+				'activeHalfyear' => get_active_users( 6 ),
 			),
 			'localPosts' => (int) $posts->publish,
 			'localComments' => (int) $comments->approved,
@@ -131,11 +152,7 @@ class Nodeinfo {
 			'outbound' => array(),
 		);
 
-		$nodeinfo['metadata'] = array(
-			'email' => \get_option( 'admin_email' ),
-		);
-
-		return new \WP_REST_Response( $nodeinfo, 200 );
+		return new WP_REST_Response( $nodeinfo, 200 );
 	}
 
 	/**
@@ -150,42 +167,10 @@ class Nodeinfo {
 		$discovery['links'] = array(
 			array(
 				'rel' => 'http://nodeinfo.diaspora.software/ns/schema/2.0',
-				'href' => \get_rest_url( null, 'activitypub/1.0/nodeinfo' ),
+				'href' => get_rest_url_by_path( 'nodeinfo' ),
 			),
 		);
 
 		return new \WP_REST_Response( $discovery, 200 );
 	}
-
-	/**
-	 * Extend NodeInfo data
-	 *
-	 * @param array  $nodeinfo NodeInfo data
-	 * @param string           The NodeInfo Version
-	 *
-	 * @return array           The extended array
-	 */
-	public static function add_nodeinfo_discovery( $nodeinfo, $version ) {
-		if ( '2.0' === $version ) {
-			$nodeinfo['protocols'][] = 'activitypub';
-		} else {
-			$nodeinfo['protocols']['inbound'][]  = 'activitypub';
-			$nodeinfo['protocols']['outbound'][] = 'activitypub';
-		}
-
-		return $nodeinfo;
-	}
-
-	/**
-	 * Extend NodeInfo2 data
-	 *
-	 * @param  array $nodeinfo NodeInfo2 data
-	 *
-	 * @return array           The extended array
-	 */
-	public static function add_nodeinfo2_discovery( $nodeinfo ) {
-		$nodeinfo['protocols'][] = 'activitypub';
-
-		return $nodeinfo;
-	}
 }

includes/rest/class-ostatus.php

@@ -1,30 +0,0 @@
-<?php
-namespace Activitypub\Rest;
-
-/**
- * ActivityPub OStatus REST-Class
- *
- * @author Matthias Pfefferle
- *
- * @see https://www.w3.org/community/ostatus/
- */
-class Ostatus {
-	/**
-	 * Register routes
-	 */
-	public static function register_routes() {
-		\register_rest_route(
-			'activitypub/1.0', '/ostatus/remote-follow', array(
-				array(
-					'methods'  => \WP_REST_Server::READABLE,
-					'callback' => array( '\Activitypub\Rest\Ostatus', 'get' ),
-					// 'args'     => self::request_parameters(),
-				),
-			)
-		);
-	}
-
-	public static function get() {
-		// @todo implement
-	}
-}

includes/rest/class-outbox.php

@@ -1,6 +1,17 @@
 <?php
 namespace Activitypub\Rest;
 
+use stdClass;
+use WP_Error;
+use WP_REST_Server;
+use WP_REST_Response;
+use Activitypub\Transformer\Transformers_Manager;
+use Activitypub\Activity\Activity;
+use Activitypub\Collection\Users as User_Collection;
+
+use function Activitypub\get_context;
+use function Activitypub\get_rest_url_by_path;
+
 /**
  * ActivityPub Outbox REST-Class
  *
@@ -13,7 +24,7 @@ class Outbox {
 	 * Initialize the class, registering WordPress hooks
 	 */
 	public static function init() {
-		\add_action( 'rest_api_init', array( '\Activitypub\Rest\Outbox', 'register_routes' ) );
+		self::register_routes();
 	}
 
 	/**
@@ -21,11 +32,14 @@ class Outbox {
 	 */
 	public static function register_routes() {
 		\register_rest_route(
-			'activitypub/1.0', '/users/(?P<id>\d+)/outbox', array(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/users/(?P<user_id>[\w\-\.]+)/outbox',
 			array(
-					'methods'  => \WP_REST_Server::READABLE,
-					'callback' => array( '\Activitypub\Rest\Outbox', 'user_outbox' ),
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( self::class, 'user_outbox_get' ),
 					'args'                => self::request_parameters(),
+					'permission_callback' => '__return_true',
 				),
 			)
 		);
@@ -37,71 +51,83 @@ class Outbox {
 	 * @param  WP_REST_Request   $request
 	 * @return WP_REST_Response
 	 */
-	public static function user_outbox( $request ) {
-		$user_id = $request->get_param( 'id' );
-		$author  = \get_user_by( 'ID', $user_id );
+	public static function user_outbox_get( $request ) {
+		$user_id = $request->get_param( 'user_id' );
+		$user    = User_Collection::get_by_various( $user_id );
 
-		if ( ! $author ) {
-			return new \WP_Error( 'rest_invalid_param', __( 'User not found', 'activitypub' ), array(
-				'status' => 404,
-				'params' => array(
-					'user_id' => \__( 'User not found', 'activitypub' ),
-				),
-			) );
+		if ( is_wp_error( $user ) ) {
+			return $user;
 		}
 
-		$page = $request->get_param( 'page', 0 );
+		$post_types = array_keys( \get_option( 'activitypub_transformer_mapping', array( 'post' => 'activitypub/default', 'page' => 'activitypub/default' ) ) );
+
+		$page = $request->get_param( 'page', 1 );
 
 		/*
 		 * Action triggerd prior to the ActivityPub profile being created and sent to the client
 		 */
-		\do_action( 'activitypub_outbox_pre' );
+		\do_action( 'activitypub_rest_outbox_pre' );
 
-		$json = new \stdClass();
+		$json = new stdClass();
 
-		$json->{'@context'} = \Activitypub\get_context();
-		$json->id = \home_url( \add_query_arg( null, null ) );
+		$json->{'@context'} = get_context();
+		$json->id = get_rest_url_by_path( sprintf( 'users/%d/outbox', $user_id ) );
 		$json->generator = 'http://wordpress.org/?v=' . \get_bloginfo_rss( 'version' );
-		$json->actor = \get_author_posts_url( $user_id );
+		$json->actor = $user->get_id();
 		$json->type = 'OrderedCollectionPage';
-		$json->partOf = \get_rest_url( null, "/activitypub/1.0/users/$user_id/outbox" ); // phpcs:ignore
+		$json->partOf = get_rest_url_by_path( sprintf( 'users/%d/outbox', $user_id ) ); // phpcs:ignore
+		$json->totalItems = 0; // phpcs:ignore
 
-		$count_posts = \wp_count_posts();
-		$json->totalItems = \intval( $count_posts->publish ); // phpcs:ignore
-
-		$posts = \get_posts( array(
-			'posts_per_page' => 10,
-			'author' => $user_id,
-			'offset' => $page * 10,
-		) );
-
-		$json->first = \add_query_arg( 'page', 0, $json->partOf ); // phpcs:ignore
-		$json->last  = \add_query_arg( 'page', ( \ceil ( $json->totalItems / 10 ) ) - 1, $json->partOf ); // phpcs:ignore
-
-		if ( ( \ceil ( $json->totalItems / 10 ) ) - 1 > $page ) { // phpcs:ignore
-			$json->next  = \add_query_arg( 'page', ++$page, $json->partOf ); // phpcs:ignore
+		foreach ( $post_types as $post_type ) {
+			$count_posts = \wp_count_posts( $post_type );
+			$json->totalItems += \intval( $count_posts->publish ); // phpcs:ignore
 		}
 
+		$json->first = \add_query_arg( 'page', 1, $json->partOf ); // phpcs:ignore
+		$json->last  = \add_query_arg( 'page', \ceil ( $json->totalItems / 10 ), $json->partOf ); // phpcs:ignore
+
+		if ( $page && ( ( \ceil ( $json->totalItems / 10 ) ) > $page ) ) { // phpcs:ignore
+			$json->next  = \add_query_arg( 'page', $page + 1, $json->partOf ); // phpcs:ignore
+		}
+
+		if ( $page && ( $page > 1 ) ) { // phpcs:ignore
+			$json->prev  = \add_query_arg( 'page', $page - 1, $json->partOf ); // phpcs:ignore
+		}
+
+		if ( $page ) {
+			$posts = \get_posts(
+				array(
+					'posts_per_page' => 10,
+					'author'         => $user_id,
+					'paged'          => $page,
+					'post_type'      => $post_types,
+				)
+			);
+
 			foreach ( $posts as $post ) {
-			$activitypub_post = new \Activitypub\Model\Post( $post );
-			$activitypub_activity = new \Activitypub\Model\Activity( 'Create', \Activitypub\Model\Activity::TYPE_NONE );
-			$activitypub_activity->from_post( $activitypub_post->to_array() );
-			$json->orderedItems[] = $activitypub_activity->to_array(); // phpcs:ignore
+				$transformer = \Activitypub\Transformer\Transformers_Manager::instance()->get_transformer( $post );
+				$post = $transformer->to_object();
+				$activity = new Activity();
+				$activity->set_type( 'Create' );
+				$activity->set_context( null );
+				$activity->set_object( $post );
+
+				$json->orderedItems[] = $activity->to_array(); // phpcs:ignore
+			}
 		}
 
 		// filter output
-		$json = \apply_filters( 'activitypub_outbox_array', $json );
+		$json = \apply_filters( 'activitypub_rest_outbox_array', $json );
 
 		/*
 		 * Action triggerd after the ActivityPub profile has been created and sent to the client
 		 */
 		\do_action( 'activitypub_outbox_post' );
 
-		$response = new \WP_REST_Response( $json, 200 );
+		$rest_response = new WP_REST_Response( $json, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
 
-		$response->header( 'Content-Type', 'application/activity+json' );
-
-		return $response;
+		return $rest_response;
 	}
 
 	/**
@@ -114,11 +140,12 @@ class Outbox {
 
 		$params['page'] = array(
 			'type' => 'integer',
+			'default' => 1,
 		);
 
-		$params['id'] = array(
+		$params['user_id'] = array(
 			'required' => true,
-			'type' => 'integer',
+			'type' => 'string',
 		);
 
 		return $params;

includes/rest/class-server.php

@@ -0,0 +1,126 @@
+<?php
+namespace Activitypub\Rest;
+
+use stdClass;
+use WP_Error;
+use WP_REST_Response;
+use Activitypub\Signature;
+use Activitypub\Model\Application_User;
+
+/**
+ * ActivityPub Server REST-Class
+ *
+ * @author Django Doucet
+ *
+ * @see https://www.w3.org/TR/activitypub/#security-verification
+ */
+class Server {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		self::register_routes();
+
+		\add_filter( 'rest_request_before_callbacks', array( self::class, 'authorize_activitypub_requests' ), 10, 3 );
+	}
+
+	/**
+	 * Register routes
+	 */
+	public static function register_routes() {
+		\register_rest_route(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/application',
+			array(
+				array(
+					'methods'             => \WP_REST_Server::READABLE,
+					'callback'            => array( self::class, 'application_actor' ),
+					'permission_callback' => '__return_true',
+				),
+			)
+		);
+	}
+
+	/**
+	 * Render Application actor profile
+	 *
+	 * @return WP_REST_Response The JSON profile of the Application Actor.
+	 */
+	public static function application_actor() {
+		$user = new Application_User();
+
+		$user->set_context(
+			\Activitypub\Activity\Activity::CONTEXT
+		);
+
+		$json = $user->to_array();
+
+		$rest_response = new WP_REST_Response( $json, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
+
+		return $rest_response;
+	}
+
+	/**
+	 * Callback function to authorize each api requests
+	 *
+	 * @see WP_REST_Request
+	 *
+	 * @param WP_REST_Response|WP_HTTP_Response|WP_Error|mixed $response Result to send to the client.
+	 *                                                                   Usually a WP_REST_Response or WP_Error.
+	 * @param array                                            $handler  Route handler used for the request.
+	 * @param WP_REST_Request                                  $request  Request used to generate the response.
+	 *
+	 * @return mixed|WP_Error The response, error, or modified response.
+	 */
+	public static function authorize_activitypub_requests( $response, $handler, $request ) {
+		if ( 'HEAD' === $request->get_method() ) {
+			return $response;
+		}
+
+		$route = $request->get_route();
+
+		// check if it is an activitypub request and exclude webfinger and nodeinfo endpoints
+		if (
+			! \str_starts_with( $route, '/' . ACTIVITYPUB_REST_NAMESPACE ) ||
+			\str_starts_with( $route, '/' . \trailingslashit( ACTIVITYPUB_REST_NAMESPACE ) . 'webfinger' ) ||
+			\str_starts_with( $route, '/' . \trailingslashit( ACTIVITYPUB_REST_NAMESPACE ) . 'nodeinfo' )
+		) {
+			return $response;
+		}
+
+		/**
+		 * Filter to defer signature verification
+		 *
+		 * Skip signature verification for debugging purposes or to reduce load for
+		 * certain Activity-Types, like "Delete".
+		 *
+		 * @param bool            $defer   Whether to defer signature verification.
+		 * @param WP_REST_Request $request The request used to generate the response.
+		 *
+		 * @return bool Whether to defer signature verification.
+		 */
+		$defer = \apply_filters( 'activitypub_defer_signature_verification', false, $request );
+
+		if ( $defer ) {
+			return $response;
+		}
+
+		// POST-Requets are always signed
+		if ( 'GET' !== $request->get_method() ) {
+			$verified_request = Signature::verify_http_signature( $request );
+			if ( \is_wp_error( $verified_request ) ) {
+				return new WP_Error( 'activitypub_signature_verification', $verified_request->get_error_message(), array( 'status' => 401 ) );
+			}
+		} elseif ( 'GET' === $request->get_method() ) { // GET-Requests are only signed in secure mode
+			if ( ACTIVITYPUB_AUTHORIZED_FETCH ) {
+				$verified_request = Signature::verify_http_signature( $request );
+				if ( \is_wp_error( $verified_request ) ) {
+					return new WP_Error( 'activitypub_signature_verification', $verified_request->get_error_message(), array( 'status' => 401 ) );
+				}
+			}
+		}
+
+		return $response;
+	}
+}

includes/rest/class-users.php

@@ -0,0 +1,155 @@
+<?php
+namespace Activitypub\Rest;
+
+use WP_Error;
+use WP_REST_Server;
+use WP_REST_Request;
+use WP_REST_Response;
+use Activitypub\Webfinger;
+use Activitypub\Activity\Activity;
+use Activitypub\Collection\Users as User_Collection;
+
+use function Activitypub\is_activitypub_request;
+
+/**
+ * ActivityPub Followers REST-Class
+ *
+ * @author Matthias Pfefferle
+ *
+ * @see https://www.w3.org/TR/activitypub/#followers
+ */
+class Users {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		self::register_routes();
+	}
+
+	/**
+	 * Register routes
+	 */
+	public static function register_routes() {
+		\register_rest_route(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/users/(?P<user_id>[\w\-\.]+)',
+			array(
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( self::class, 'get' ),
+					'args'                => self::request_parameters(),
+					'permission_callback' => '__return_true',
+				),
+			)
+		);
+
+		\register_rest_route(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/users/(?P<user_id>[\w\-\.]+)/remote-follow',
+			array(
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( self::class, 'remote_follow_get' ),
+
+					'args'                => array(
+						'resource' => array(
+							'required'          => true,
+							'sanitize_callback' => 'sanitize_text_field',
+						),
+					),
+					'permission_callback' => '__return_true',
+				),
+			)
+		);
+	}
+
+	/**
+	 * Handle GET request
+	 *
+	 * @param  WP_REST_Request   $request
+	 *
+	 * @return WP_REST_Response
+	 */
+	public static function get( $request ) {
+		$user_id = $request->get_param( 'user_id' );
+		$user    = User_Collection::get_by_various( $user_id );
+
+		if ( is_wp_error( $user ) ) {
+			return $user;
+		}
+
+		// redirect to canonical URL if it is not an ActivityPub request
+		if ( ! is_activitypub_request() ) {
+			header( 'Location: ' . $user->get_canonical_url(), true, 301 );
+			exit;
+		}
+
+		/*
+		 * Action triggerd prior to the ActivityPub profile being created and sent to the client
+		 */
+		\do_action( 'activitypub_rest_users_pre' );
+
+		$user->set_context(
+			Activity::CONTEXT
+		);
+
+		$json = $user->to_array();
+
+		$rest_response = new WP_REST_Response( $json, 200 );
+		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
+
+		return $rest_response;
+	}
+
+
+	/**
+	 * Endpoint for remote follow UI/Block
+	 *
+	 * @param WP_REST_Request $request The request object.
+	 *
+	 * @return void|string The URL to the remote follow page
+	 */
+	public static function remote_follow_get( WP_REST_Request $request ) {
+		$resource = $request->get_param( 'resource' );
+		$user_id  = $request->get_param( 'user_id' );
+		$user     = User_Collection::get_by_various( $user_id );
+
+		if ( is_wp_error( $user ) ) {
+			return $user;
+		}
+
+		$template = Webfinger::get_remote_follow_endpoint( $resource );
+
+		if ( is_wp_error( $template ) ) {
+			return $template;
+		}
+
+		$resource = $user->get_resource();
+		$url      = str_replace( '{uri}', $resource, $template );
+
+		return new WP_REST_Response(
+			array( 'url' => $url ),
+			200
+		);
+	}
+
+	/**
+	 * The supported parameters
+	 *
+	 * @return array list of parameters
+	 */
+	public static function request_parameters() {
+		$params = array();
+
+		$params['page'] = array(
+			'type' => 'string',
+		);
+
+		$params['user_id'] = array(
+			'required' => true,
+			'type'     => 'string',
+		);
+
+		return $params;
+	}
+}

includes/rest/class-webfinger.php

@@ -1,6 +1,10 @@
 <?php
 namespace Activitypub\Rest;
 
+use WP_Error;
+use WP_REST_Response;
+use Activitypub\Collection\Users as User_Collection;
+
 /**
  * ActivityPub WebFinger REST-Class
  *
@@ -10,77 +14,51 @@ namespace Activitypub\Rest;
  */
 class Webfinger {
 	/**
-	 * Initialize the class, registering WordPress hooks
+	 * Initialize the class, registering WordPress hooks.
+	 *
+	 * @return void
 	 */
 	public static function init() {
-		\add_action( 'rest_api_init', array( '\Activitypub\Rest\Webfinger', 'register_routes' ) );
-		\add_action( 'webfinger_user_data', array( '\Activitypub\Rest\Webfinger', 'add_webfinger_discovery' ), 10, 3 );
+		self::register_routes();
 	}
 
 	/**
-	 * Register routes
+	 * Register routes.
+	 *
+	 * @return void
 	 */
 	public static function register_routes() {
 		\register_rest_route(
-			'activitypub/1.0', '/webfinger', array(
+			ACTIVITYPUB_REST_NAMESPACE,
+			'/webfinger',
+			array(
 				array(
 					'methods'             => \WP_REST_Server::READABLE,
-					'callback' => array( '\Activitypub\Rest\Webfinger', 'webfinger' ),
+					'callback'            => array( self::class, 'webfinger' ),
 					'args'                => self::request_parameters(),
+					'permission_callback' => '__return_true',
 				),
 			)
 		);
 	}
 
 	/**
-	 * Render JRD file
+	 * WebFinger endpoint.
 	 *
-	 * @param  WP_REST_Request   $request
-	 * @return WP_REST_Response
+	 * @param WP_REST_Request $request The request object.
+	 *
+	 * @return WP_REST_Response The response object.
 	 */
 	public static function webfinger( $request ) {
+		/*
+		 * Action triggerd prior to the ActivityPub profile being created and sent to the client
+		 */
+		\do_action( 'activitypub_rest_webfinger_pre' );
+
 		$resource = $request->get_param( 'resource' );
+		$response = self::get_profile( $resource );
 
-		$matches = array();
-		$matched = \preg_match( '/^acct:([^@]+)@(.+)$/', $resource, $matches );
-
-		if ( ! $matched ) {
-			return new \WP_Error( 'activitypub_unsupported_resource', \__( 'Resource is invalid', 'activitypub' ), array( 'status' => 400 ) );
-		}
-
-		$resource_identifier = $matches[1];
-		$resource_host = $matches[2];
-
-		if ( \wp_parse_url( \home_url( '/' ), PHP_URL_HOST ) !== $resource_host ) {
-			return new \WP_Error( 'activitypub_wrong_host', \__( 'Resource host does not match blog host', 'activitypub' ), array( 'status' => 404 ) );
-		}
-
-		$user = \get_user_by( 'login', \esc_sql( $resource_identifier ) );
-
-		if ( ! $user ) {
-			return new \WP_Error( 'activitypub_user_not_found', \__( 'User not found', 'activitypub' ), array( 'status' => 404 ) );
-		}
-
-		$json = array(
-			'subject' => $resource,
-			'aliases' => array(
-				\get_author_posts_url( $user->ID ),
-			),
-			'links' => array(
-				array(
-					'rel'  => 'self',
-					'type' => 'application/activity+json',
-					'href' => \get_author_posts_url( $user->ID ),
-				),
-				array(
-					'rel'  => 'http://webfinger.net/rel/profile-page',
-					'type' => 'text/html',
-					'href' => \get_author_posts_url( $user->ID ),
-				),
-			),
-		);
-
-		return new \WP_REST_Response( $json, 200 );
+		return new WP_REST_Response( $response, 200 );
 	}
 
 	/**
@@ -94,26 +72,47 @@ class Webfinger {
 		$params['resource'] = array(
 			'required' => true,
 			'type' => 'string',
-			'pattern' => '^acct:([^@]+)@(.+)$',
+			'pattern' => '^acct:(.+)@(.+)$',
 		);
 
 		return $params;
 	}
 
 	/**
-	 * Add WebFinger discovery links
+	 * Get the WebFinger profile.
 	 *
-	 * @param array   $array    the jrd array
-	 * @param string  $resource the WebFinger resource
-	 * @param WP_User $user     the WordPress user
+	 * @param string $resource the WebFinger resource.
+	 *
+	 * @return array the WebFinger profile.
 	 */
-	public static function add_webfinger_discovery( $array, $resource, $user ) {
-		$array['links'][] = array(
-			'rel'  => 'self',
-			'type' => 'application/activity+json',
-			'href' => \get_author_posts_url( $user->ID ),
+	public static function get_profile( $resource ) {
+		$user = User_Collection::get_by_resource( $resource );
+
+		if ( is_wp_error( $user ) ) {
+			return $user;
+		}
+
+		$aliases = array(
+			$user->get_url(),
 		);
 
-		return $array;
+		$profile = array(
+			'subject' => $resource,
+			'aliases' => array_values( array_unique( $aliases ) ),
+			'links'   => array(
+				array(
+					'rel'  => 'self',
+					'type' => 'application/activity+json',
+					'href' => $user->get_url(),
+				),
+				array(
+					'rel'  => 'http://webfinger.net/rel/profile-page',
+					'type' => 'text/html',
+					'href' => $user->get_url(),
+				),
+			),
+		);
+
+		return $profile;
 	}
 }

includes/table/class-followers.php

@@ -0,0 +1,176 @@
+<?php
+namespace Activitypub\Table;
+
+use WP_List_Table;
+use Activitypub\Collection\Users;
+use Activitypub\Collection\Followers as FollowerCollection;
+
+if ( ! \class_exists( '\WP_List_Table' ) ) {
+		require_once ABSPATH . 'wp-admin/includes/class-wp-list-table.php';
+}
+
+class Followers extends WP_List_Table {
+	private $user_id;
+
+	public function __construct() {
+		if ( get_current_screen()->id === 'settings_page_activitypub' ) {
+			$this->user_id = Users::BLOG_USER_ID;
+		} else {
+			$this->user_id = \get_current_user_id();
+		}
+
+		parent::__construct(
+			array(
+				'singular' => \__( 'Follower', 'activitypub' ),
+				'plural'   => \__( 'Followers', 'activitypub' ),
+				'ajax'     => false,
+			)
+		);
+	}
+
+	public function get_columns() {
+		return array(
+			'cb'         => '<input type="checkbox" />',
+			'avatar'     => \__( 'Avatar', 'activitypub' ),
+			'post_title' => \__( 'Name', 'activitypub' ),
+			'username'   => \__( 'Username', 'activitypub' ),
+			'url'        => \__( 'URL', 'activitypub' ),
+			'published'  => \__( 'Followed', 'activitypub' ),
+			'modified'   => \__( 'Last updated', 'activitypub' ),
+		);
+	}
+
+	public function get_sortable_columns() {
+		$sortable_columns = array(
+			'post_title' => array( 'post_title', true ),
+			'modified'   => array( 'modified', false ),
+			'published'  => array( 'published', false ),
+		);
+
+		return $sortable_columns;
+	}
+
+	public function prepare_items() {
+		$columns = $this->get_columns();
+		$hidden  = array();
+
+		$this->process_action();
+		$this->_column_headers = array( $columns, $hidden, $this->get_sortable_columns() );
+
+		$page_num = $this->get_pagenum();
+		$per_page = 20;
+
+		$args = array();
+
+		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
+		if ( isset( $_GET['orderby'] ) ) {
+			// phpcs:ignore WordPress.Security.NonceVerification.Recommended
+			$args['orderby'] = sanitize_text_field( wp_unslash( $_GET['orderby'] ) );
+		}
+
+		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
+		if ( isset( $_GET['order'] ) ) {
+			// phpcs:ignore WordPress.Security.NonceVerification.Recommended
+			$args['order'] = sanitize_text_field( wp_unslash( $_GET['order'] ) );
+		}
+
+		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
+		if ( isset( $_GET['s'] ) && isset( $_REQUEST['_wpnonce'] ) ) {
+			$nonce = sanitize_text_field( wp_unslash( $_REQUEST['_wpnonce'] ) );
+			if ( wp_verify_nonce( $nonce, 'bulk-' . $this->_args['plural'] ) ) {
+				// phpcs:ignore WordPress.Security.NonceVerification.Recommended
+				$args['s'] = sanitize_text_field( wp_unslash( $_GET['s'] ) );
+			}
+		}
+
+		$followers_with_count = FollowerCollection::get_followers_with_count( $this->user_id, $per_page, $page_num, $args );
+		$followers            = $followers_with_count['followers'];
+		$counter              = $followers_with_count['total'];
+
+		$this->items = array();
+		$this->set_pagination_args(
+			array(
+				'total_items' => $counter,
+				'total_pages' => ceil( $counter / $per_page ),
+				'per_page'    => $per_page,
+			)
+		);
+
+		foreach ( $followers as $follower ) {
+			$item = array(
+				'icon'       => esc_attr( $follower->get_icon_url() ),
+				'post_title' => esc_attr( $follower->get_name() ),
+				'username'   => esc_attr( $follower->get_preferred_username() ),
+				'url'        => esc_attr( $follower->get_url() ),
+				'identifier' => esc_attr( $follower->get_id() ),
+				'published'  => esc_attr( $follower->get_published() ),
+				'modified'   => esc_attr( $follower->get_updated() ),
+			);
+
+			$this->items[] = $item;
+		}
+	}
+
+	public function get_bulk_actions() {
+		return array(
+			'delete' => __( 'Delete', 'activitypub' ),
+		);
+	}
+
+	public function column_default( $item, $column_name ) {
+		if ( ! array_key_exists( $column_name, $item ) ) {
+			return __( 'None', 'activitypub' );
+		}
+		return $item[ $column_name ];
+	}
+
+	public function column_avatar( $item ) {
+		return sprintf(
+			'<img src="%s" width="25px;" />',
+			$item['icon']
+		);
+	}
+
+	public function column_url( $item ) {
+		return sprintf(
+			'<a href="%s" target="_blank">%s</a>',
+			$item['url'],
+			$item['url']
+		);
+	}
+
+	public function column_cb( $item ) {
+		return sprintf( '<input type="checkbox" name="followers[]" value="%s" />', esc_attr( $item['identifier'] ) );
+	}
+
+	public function process_action() {
+		if ( ! isset( $_REQUEST['followers'] ) || ! isset( $_REQUEST['_wpnonce'] ) ) {
+			return false;
+		}
+		$nonce = sanitize_text_field( wp_unslash( $_REQUEST['_wpnonce'] ) );
+		if ( ! wp_verify_nonce( $nonce, 'bulk-' . $this->_args['plural'] ) ) {
+			return false;
+		}
+
+		if ( ! current_user_can( 'edit_user', $this->user_id ) ) {
+			return false;
+		}
+
+		$followers = $_REQUEST['followers']; // phpcs:ignore
+
+		switch ( $this->current_action() ) {
+			case 'delete':
+				if ( ! is_array( $followers ) ) {
+					$followers = array( $followers );
+				}
+				foreach ( $followers as $follower ) {
+					FollowerCollection::remove_follower( $this->user_id, $follower );
+				}
+				break;
+		}
+	}
+
+	public function get_user_count() {
+		return FollowerCollection::count_followers( $this->user_id );
+	}
+}

includes/table/followers-list.php

@@ -1,36 +0,0 @@
-<?php
-namespace Activitypub\Table;
-
-if ( ! \class_exists( '\WP_List_Table' ) ) {
-		require_once ABSPATH . 'wp-admin/includes/class-wp-list-table.php';
-}
-
-class Followers_List extends \WP_List_Table {
-	public function get_columns() {
-		return array(
-			'identifier' => \__( 'Identifier', 'activitypub' ),
-		);
-	}
-
-	public function get_sortable_columns() {
-		return array();
-	}
-
-	public function prepare_items() {
-		$columns = $this->get_columns();
-		$hidden  = array();
-
-		$this->process_action();
-		$this->_column_headers = array( $columns, $hidden, $this->get_sortable_columns() );
-
-		$this->items = array();
-
-		foreach ( \Activitypub\Peer\Followers::get_followers( \get_current_user_id() ) as $follower ) {
-			$this->items[]['identifier'] = \esc_attr( $follower );
-		}
-	}
-
-	public function column_default( $item, $column_name ) {
-		return $item[ $column_name ];
-	}
-}

includes/transformer/class-base.php

@@ -0,0 +1,619 @@
+<?php
+/**
+ * Inspired by the PHP ActivityPub Library by @Landrok
+ *
+ * @link https://github.com/landrok/activitypub
+ */
+namespace Activitypub\Transformer;
+
+use WP_Post;
+use Activitypub\Collection\Users;
+use Activitypub\Model\Blog_User;
+use Activitypub\Activity\Base_Object;
+use Activitypub\Shortcodes;
+
+use function Activitypub\esc_hashtag;
+use function Activitypub\is_single_user;
+use function Activitypub\get_rest_url_by_path;
+use function Activitypub\site_supports_blocks;
+
+/**
+ * Base class to implement WordPress to ActivityPub transformers.
+ */
+abstract class Base {
+	/**
+	 * The WP_Post object.
+	 *
+	 * @var WP_Post
+	 */
+	protected $wp_post;
+
+	/**
+	 * Assign WP_Post Object to a specific transformer instance.
+	 *
+	 * This helps to chain the output of the Transformer.
+	 *
+	 * @param WP_Post $wp_post The WP_Post object.
+	 * @return void
+	 */
+	public function set_wp_post( WP_Post $wp_post ) {
+		$post_type = get_post_type( $wp_post );
+		if ( ! $this->supports_post_type( $post_type ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				/* translators: %s: Block name. */
+				sprintf( 'The Transformer "%s" does not support the post type "%s".', esc_html( $this->get_label() ), esc_html( $post_type ) ),
+				'version_number_transformer_management_placeholder'
+			);
+		}
+		$this->wp_post = $wp_post;
+	}
+
+	/**
+	 * Get the supported WP post types that the transformer can use as an input.
+	 *
+	 * By default all post types are supported.
+	 * You may very likely wish to override this function.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @return string[] An array containing all the supported post types.
+	 */
+	public function get_supported_post_types() {
+		return \get_post_types( array( 'public' => true ), 'names' );
+	}
+
+	/**
+	 * Get the name of the plugin that registered the transformer.
+	 *
+	 * @see Forked from the WordPress elementor plugin.
+	 * @since version_number_transformer_management_placeholder
+	 * @return string Plugin name
+	 */
+	private function get_plugin_name_from_transformer_instance( $transformer ) {
+		$class_reflection = new \ReflectionClass( $transformer );
+
+		$plugin_basename = plugin_basename( $class_reflection->getFileName() );
+
+		$plugin_directory = strtok( $plugin_basename, '/' );
+
+		$plugins_data = get_plugins( '/' . $plugin_directory );
+		$plugin_data  = array_shift( $plugins_data );
+
+		if ( isset( $plugin_data['Name'] ) ) {
+			return $plugin_data['Name'];
+		} else {
+			return esc_html__( 'Unknown', 'activitypub' );
+		}
+	}
+
+	/**
+	 * Return whether the transformer supports a post type.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @return string post_type Post type name.
+	 */
+	final public function supports_post_type( $post_type ) {
+		return in_array( $post_type, $this->get_supported_post_types(), true );
+	}
+
+	/**
+	 * Get the name used for registering the transformer with the ActivityPub plugin.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @return string name
+	 */
+	abstract public function get_name();
+
+	/**
+	 * Get the display name for the ActivityPub transformer.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @return string display name
+	 */
+	abstract public function get_label();
+
+	/**
+	 * Returns the ActivityStreams 2.0 Object-Type for a Post.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#activity-types
+	 *
+	 * @return string The Object-Type.
+	 */
+	abstract protected function get_object_type();
+
+	/**
+	 * Returns the content for the ActivityPub Item.
+	 *
+	 * The content will be generated based on the user settings.
+	 *
+	 * @return string The content.
+	 */
+	protected function get_content() {
+		global $post;
+
+		/**
+		 * Provides an action hook so plugins can add their own hooks/filters before AP content is generated.
+		 *
+		 * Example: if a plugin adds a filter to `the_content` to add a button to the end of posts, it can also remove that filter here.
+		 *
+		 * @param WP_Post $post The post object.
+		 */
+		do_action( 'activitypub_before_get_content', $post );
+
+		// phpcs:ignore WordPress.WP.GlobalVariablesOverride.Prohibited
+		$post    = $this->wp_post;
+		$content = $this->get_post_content_template();
+
+		// Register our shortcodes just in time.
+		Shortcodes::register();
+		// Fill in the shortcodes.
+		setup_postdata( $post );
+		$content = do_shortcode( $content );
+		wp_reset_postdata();
+
+		$content = \wpautop( $content );
+		$content = \preg_replace( '/[\n\r\t]/', '', $content );
+		$content = \trim( $content );
+
+		$content = \apply_filters( 'activitypub_the_content', $content, $post );
+
+		// Don't need these any more, should never appear in a post.
+		Shortcodes::unregister();
+
+		return $content;
+	}
+
+	/**
+	 * Gets the template to use to generate the content of the activitypub item.
+	 *
+	 * @return string The Template.
+	 */
+	protected function get_post_content_template() {
+		if ( 'excerpt' === \get_option( 'activitypub_post_content_type', 'content' ) ) {
+			return "[ap_excerpt]\n\n[ap_permalink type=\"html\"]";
+		}
+
+		if ( 'title' === \get_option( 'activitypub_post_content_type', 'content' ) ) {
+			return "[ap_title]\n\n[ap_permalink type=\"html\"]";
+		}
+
+		if ( 'content' === \get_option( 'activitypub_post_content_type', 'content' ) ) {
+			return "[ap_content]\n\n[ap_permalink type=\"html\"]\n\n[ap_hashtags]";
+		}
+
+		return \get_option( 'activitypub_custom_post_content', ACTIVITYPUB_CUSTOM_POST_CONTENT );
+	}
+
+	/**
+	 * Returns the ID of the Post.
+	 *
+	 * @return string The Posts ID.
+	 */
+	public function get_id() {
+		return $this->get_url();
+	}
+
+	/**
+	 * Returns the URL of the Post.
+	 *
+	 * @return string The Posts URL.
+	 */
+	public function get_url() {
+		$post = $this->wp_post;
+
+		if ( 'trash' === get_post_status( $post ) ) {
+			$permalink = \get_post_meta( $post->ID, 'activitypub_canonical_url', true );
+		} else {
+			$permalink = \get_permalink( $post );
+		}
+
+		return \esc_url( $permalink );
+	}
+
+	/**
+	 * Returns the User-URL of the Author of the Post.
+	 *
+	 * If `single_user` mode is enabled, the URL of the Blog-User is returned.
+	 *
+	 * @return string The User-URL.
+	 */
+	protected function get_attributed_to() {
+		if ( is_single_user() ) {
+			$user = new Blog_User();
+			return $user->get_url();
+		}
+
+		return Users::get_by_id( $this->wp_post->post_author )->get_url();
+	}
+
+	/**
+	 * Generates all Media Attachments for a Post.
+	 *
+	 * @return array The Attachments.
+	 */
+	protected function get_attachments() {
+		// Once upon a time we only supported images, but we now support audio/video as well.
+		// We maintain the image-centric naming for backwards compatibility.
+		$max_media = intval( \apply_filters( 'activitypub_max_image_attachments', \get_option( 'activitypub_max_image_attachments', ACTIVITYPUB_MAX_IMAGE_ATTACHMENTS ) ) );
+
+		if ( site_supports_blocks() && \has_blocks( $this->wp_post->post_content ) ) {
+			return $this->get_block_attachments( $max_media );
+		}
+
+		return $this->get_classic_editor_images( $max_media );
+	}
+
+	/**
+	 * Get media attachments from blocks. They will be formatted as ActivityPub attachments, not as WP attachments.
+	 *
+	 * @param int $max_media The maximum number of attachments to return.
+	 *
+	 * @return array The attachments.
+	 */
+	protected function get_block_attachments( $max_media ) {
+		// max media can't be negative or zero
+		if ( $max_media <= 0 ) {
+			return array();
+		}
+
+		$id = $this->wp_post->ID;
+
+		$media_ids = array();
+
+		// list post thumbnail first if this post has one
+		if ( \function_exists( 'has_post_thumbnail' ) && \has_post_thumbnail( $id ) ) {
+			$media_ids[] = \get_post_thumbnail_id( $id );
+		}
+
+		if ( $max_media > 0 ) {
+			$blocks    = \parse_blocks( $this->wp_post->post_content );
+			$media_ids = self::get_media_ids_from_blocks( $blocks, $media_ids, $max_media );
+		}
+
+		return \array_filter( \array_map( array( self::class, 'wp_attachment_to_activity_attachment' ), $media_ids ) );
+	}
+
+	/**
+	 * Get image attachments from the classic editor.
+	 * Note that audio/video attachments are only supported in the block editor.
+	 *
+	 * @param int $max_images The maximum number of images to return.
+	 *
+	 * @return array The attachments.
+	 */
+	protected function get_classic_editor_images( $max_images ) {
+		// max images can't be negative or zero
+		if ( $max_images <= 0 ) {
+			return array();
+		}
+
+		$id = $this->wp_post->ID;
+
+		$image_ids = array();
+
+		// list post thumbnail first if this post has one
+		if ( \function_exists( 'has_post_thumbnail' ) && \has_post_thumbnail( $id ) ) {
+			$image_ids[] = \get_post_thumbnail_id( $id );
+			--$max_images;
+		}
+
+		if ( $max_images > 0 ) {
+			$query = new \WP_Query(
+				array(
+					'post_parent'    => $id,
+					'post_status'    => 'inherit',
+					'post_type'      => 'attachment',
+					'post_mime_type' => 'image',
+					'order'          => 'ASC',
+					'orderby'        => 'menu_order ID',
+					'posts_per_page' => $max_images,
+				)
+			);
+			foreach ( $query->get_posts() as $attachment ) {
+				if ( ! \in_array( $attachment->ID, $image_ids, true ) ) {
+					$image_ids[] = $attachment->ID;
+				}
+			}
+		}
+		$image_ids = \array_unique( $image_ids );
+
+		return \array_filter( \array_map( array( self::class, 'wp_attachment_to_activity_attachment' ), $image_ids ) );
+	}
+
+	/**
+	 * Recursively get media IDs from blocks.
+	 *
+	 * @param array $blocks The blocks to search for media IDs
+	 * @param array $media_ids The media IDs to append new IDs to
+	 * @param int   $max_media The maximum number of media to return.
+	 *
+	 * @return array The image IDs.
+	 */
+	protected static function get_media_ids_from_blocks( $blocks, $media_ids, $max_media ) {
+
+		foreach ( $blocks as $block ) {
+			// recurse into inner blocks
+			if ( ! empty( $block['innerBlocks'] ) ) {
+				$media_ids = self::get_media_ids_from_blocks( $block['innerBlocks'], $media_ids, $max_media );
+			}
+
+			switch ( $block['blockName'] ) {
+				case 'core/image':
+				case 'core/cover':
+				case 'core/audio':
+				case 'core/video':
+				case 'videopress/video':
+					if ( ! empty( $block['attrs']['id'] ) ) {
+						$media_ids[] = $block['attrs']['id'];
+					}
+					break;
+				case 'jetpack/slideshow':
+				case 'jetpack/tiled-gallery':
+					if ( ! empty( $block['attrs']['ids'] ) ) {
+						$media_ids = array_merge( $media_ids, $block['attrs']['ids'] );
+					}
+					break;
+				case 'jetpack/image-compare':
+					if ( ! empty( $block['attrs']['beforeImageId'] ) ) {
+						$media_ids[] = $block['attrs']['beforeImageId'];
+					}
+					if ( ! empty( $block['attrs']['afterImageId'] ) ) {
+						$media_ids[] = $block['attrs']['afterImageId'];
+					}
+					break;
+			}
+
+			// depupe
+			$media_ids = \array_unique( $media_ids );
+
+			// stop doing unneeded work
+			if ( count( $media_ids ) >= $max_media ) {
+				break;
+			}
+		}
+
+		// still need to slice it because one gallery could knock us over the limit
+		return array_slice( $media_ids, 0, $max_media );
+	}
+
+	/**
+	 * Converts a WordPress Attachment to an ActivityPub Attachment.
+	 *
+	 * @param int $id The Attachment ID.
+	 *
+	 * @return array The ActivityPub Attachment.
+	 */
+	public static function wp_attachment_to_activity_attachment( $id ) {
+		$attachment      = array();
+		$mime_type       = \get_post_mime_type( $id );
+		$mime_type_parts = \explode( '/', $mime_type );
+		// switching on image/audio/video
+		switch ( $mime_type_parts[0] ) {
+			case 'image':
+				$image_size = 'full';
+
+				/**
+				 * Filter the image URL returned for each post.
+				 *
+				 * @param array|false $thumbnail The image URL, or false if no image is available.
+				 * @param int         $id        The attachment ID.
+				 * @param string      $image_size The image size to retrieve. Set to 'full' by default.
+				 */
+				$thumbnail = apply_filters(
+					'activitypub_get_image',
+					self::get_image( $id, $image_size ),
+					$id,
+					$image_size
+				);
+
+				if ( $thumbnail ) {
+					$alt   = \get_post_meta( $id, '_wp_attachment_image_alt', true );
+					$image = array(
+						'type'      => 'Image',
+						'url'       => $thumbnail[0],
+						'mediaType' => $mime_type,
+					);
+
+					if ( $alt ) {
+						$image['name'] = $alt;
+					}
+					$attachment = $image;
+				}
+				break;
+
+			case 'audio':
+			case 'video':
+				$attachment = array(
+					'type'      => 'Document',
+					'mediaType' => $mime_type,
+					'url'       => \wp_get_attachment_url( $id ),
+					'name'      => \get_the_title( $id ),
+				);
+				$meta       = wp_get_attachment_metadata( $id );
+				// height and width for videos
+				if ( isset( $meta['width'] ) && isset( $meta['height'] ) ) {
+					$attachment['width']  = $meta['width'];
+					$attachment['height'] = $meta['height'];
+				}
+				// @todo: add `icon` support for audio/video attachments. Maybe use post thumbnail?
+				break;
+		}
+
+		return \apply_filters( 'activitypub_attachment', $attachment, $id );
+	}
+
+	/**
+	 * Return details about an image attachment.
+	 *
+	 * @param int    $id         The attachment ID.
+	 * @param string $image_size The image size to retrieve. Set to 'full' by default.
+	 *
+	 * @return array|false Array of image data, or boolean false if no image is available.
+	 */
+	protected static function get_image( $id, $image_size = 'full' ) {
+		/**
+		 * Hook into the image retrieval process. Before image retrieval.
+		 *
+		 * @param int    $id         The attachment ID.
+		 * @param string $image_size The image size to retrieve. Set to 'full' by default.
+		 */
+		do_action( 'activitypub_get_image_pre', $id, $image_size );
+
+		$image = \wp_get_attachment_image_src( $id, $image_size );
+
+		/**
+		 * Hook into the image retrieval process. After image retrieval.
+		 *
+		 * @param int    $id         The attachment ID.
+		 * @param string $image_size The image size to retrieve. Set to 'full' by default.
+		 */
+		do_action( 'activitypub_get_image_post', $id, $image_size );
+
+		return $image;
+	}
+
+
+	/**
+	 * Helper function to get the @-Mentions from the post content.
+	 *
+	 * @return array The list of @-Mentions.
+	 */
+	protected function get_mentions() {
+		return apply_filters( 'activitypub_extract_mentions', array(), $this->wp_post->post_content, $this->wp_post );
+	}
+
+		/**
+		 * Returns a list of Mentions, used in the Post.
+		 *
+		 * @see https://docs.joinmastodon.org/spec/activitypub/#Mention
+		 *
+		 * @return array The list of Mentions.
+		 */
+	protected function get_cc() {
+		$cc = array();
+
+		$mentions = $this->get_mentions();
+		if ( $mentions ) {
+			foreach ( $mentions as $url ) {
+				$cc[] = $url;
+			}
+		}
+
+		return $cc;
+	}
+
+	/**
+	 * Returns a list of Tags, used in the Post.
+	 *
+	 * This includes Hash-Tags and Mentions.
+	 *
+	 * @return array The list of Tags.
+	 */
+	protected function get_tags() {
+		$tags = array();
+
+		$post_tags = \get_the_tags( $this->wp_post->ID );
+		if ( $post_tags ) {
+			foreach ( $post_tags as $post_tag ) {
+				$tag    = array(
+					'type' => 'Hashtag',
+					'href' => \esc_url( \get_tag_link( $post_tag->term_id ) ),
+					'name' => esc_hashtag( $post_tag->name ),
+				);
+				$tags[] = $tag;
+			}
+		}
+
+		$mentions = $this->get_mentions();
+		if ( $mentions ) {
+			foreach ( $mentions as $mention => $url ) {
+				$tag    = array(
+					'type' => 'Mention',
+					'href' => \esc_url( $url ),
+					'name' => \esc_html( $mention ),
+				);
+				$tags[] = $tag;
+			}
+		}
+
+		return $tags;
+	}
+
+
+	/**
+	 * Returns the locale of the post.
+	 *
+	 * @return string The locale of the post.
+	 */
+	public function get_locale() {
+		$post_id = $this->wp_post->ID;
+		$lang    = \strtolower( \strtok( \get_locale(), '_-' ) );
+
+		/**
+		 * Filter the locale of the post.
+		 *
+		 * @param string  $lang    The locale of the post.
+		 * @param int     $post_id The post ID.
+		 * @param WP_Post $post    The post object.
+		 *
+		 * @return string The filtered locale of the post.
+		 */
+		return apply_filters( 'activitypub_post_locale', $lang, $post_id, $this->wp_post );
+	}
+
+	/**
+	 * Gets the contentMap
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#dfn-contentmap
+	 *
+	 * @return array the contenmap
+	 */
+	protected function get_content_map() {
+		return array(
+			$this->get_locale() => $this->get_content(),
+		);
+	}
+
+	/**
+	 * Transforms the WP_Post object to an ActivityPub Object
+	 *
+	 * @see \Activitypub\Activity\Base_Object
+	 *
+	 * @return \Activitypub\Activity\Base_Object The ActivityPub Object
+	 */
+	public function to_object() {
+		$wp_post = $this->wp_post;
+		$object  = new Base_Object();
+
+		$object->set_id( $this->get_id() );
+		$object->set_url( $this->get_url() );
+		$object->set_type( $this->get_object_type() );
+
+		$published = \strtotime( $wp_post->post_date_gmt );
+
+		$object->set_published( \gmdate( 'Y-m-d\TH:i:s\Z', $published ) );
+
+		$updated = \strtotime( $wp_post->post_modified_gmt );
+
+		if ( $updated > $published ) {
+			$object->set_updated( \gmdate( 'Y-m-d\TH:i:s\Z', $updated ) );
+		}
+
+		$object->set_attributed_to( $this->get_attributed_to() );
+		$object->set_content( $this->get_content() );
+		$object->set_content_map( $this->get_content_map );
+		$path = sprintf( 'users/%d/followers', intval( $wp_post->post_author ) );
+
+		$object->set_to(
+			array(
+				'https://www.w3.org/ns/activitystreams#Public',
+				get_rest_url_by_path( $path ),
+			)
+		);
+		$object->set_cc( $this->get_cc() );
+		$object->set_attachment( $this->get_attachments() );
+		$object->set_tag( $this->get_tags() );
+
+		return $object;
+	}
+}

includes/transformer/class-post.php

@@ -0,0 +1,109 @@
+<?php
+namespace Activitypub\Transformer;
+
+use WP_Post;
+use Activitypub\Collection\Users;
+use Activitypub\Model\Blog_User;
+use Activitypub\Activity\Base_Object;
+use Activitypub\Shortcodes;
+use Activitypub\Transformer\Base;
+
+use function Activitypub\esc_hashtag;
+use function Activitypub\is_single_user;
+use function Activitypub\get_rest_url_by_path;
+use function Activitypub\site_supports_blocks;
+
+/**
+ * WordPress Post Transformer
+ * The Post Transformer is responsible for transforming a WP_Post object into different othe
+ * Object-Types.
+ *
+ * Currently supported are:
+ * - Activitypub\Activity\Base_Object
+ */
+class Post extends Base {
+	/**
+	 * Getter function for the name of the transformer.
+	 *
+	 * @return string name
+	 */
+	public function get_name() {
+		return 'activitypub/default';
+	}
+
+	/**
+	 * Getter function for the display name (label/title) of the transformer.
+	 *
+	 * @return string name
+	 */
+	public function get_label() {
+		return 'Built-In';
+	}
+
+	/**
+	 * Returns the ActivityStreams 2.0 Object-Type for a Post based on the
+	 * settings and the Post-Type.
+	 *
+	 * @see https://www.w3.org/TR/activitystreams-vocabulary/#activity-types
+	 *
+	 * @return string The Object-Type.
+	 */
+	protected function get_object_type() {
+		if ( 'wordpress-post-format' !== \get_option( 'activitypub_object_type', 'note' ) ) {
+			return \ucfirst( \get_option( 'activitypub_object_type', 'note' ) );
+		}
+
+		// Default to Article.
+		$object_type = 'Article';
+		$post_type   = \get_post_type( $this->wp_post );
+		switch ( $post_type ) {
+			case 'post':
+				$post_format = \get_post_format( $this->wp_post );
+				switch ( $post_format ) {
+					case 'aside':
+					case 'status':
+					case 'quote':
+					case 'note':
+						$object_type = 'Note';
+						break;
+					case 'gallery':
+					case 'image':
+						$object_type = 'Image';
+						break;
+					case 'video':
+						$object_type = 'Video';
+						break;
+					case 'audio':
+						$object_type = 'Audio';
+						break;
+					default:
+						$object_type = 'Article';
+						break;
+				}
+				break;
+			case 'page':
+				$object_type = 'Page';
+				break;
+			case 'attachment':
+				$mime_type  = \get_post_mime_type();
+				$media_type = \preg_replace( '/(\/[a-zA-Z]+)/i', '', $mime_type );
+				switch ( $media_type ) {
+					case 'audio':
+						$object_type = 'Audio';
+						break;
+					case 'video':
+						$object_type = 'Video';
+						break;
+					case 'image':
+						$object_type = 'Image';
+						break;
+				}
+				break;
+			default:
+				$object_type = 'Article';
+				break;
+		}
+
+		return $object_type;
+	}
+}

includes/transformer/class-transformers-manager.php

@@ -0,0 +1,292 @@
+<?php
+/**
+ * Inspired by the way elementor handles addons.
+ *
+ * @link https://github.com/elementor/elementor/
+ * @package Activitypub
+ */
+
+namespace Activitypub\Transformer;
+
+use WP_Post;
+use WP_Comment;
+
+use function Activitypub\camel_to_snake_case;
+use function Activitypub\snake_to_camel_case;
+
+if ( ! defined( 'ABSPATH' ) ) {
+	exit; // Exit if accessed directly.
+}
+
+/**
+ * ActivityPub transformers manager.
+ *
+ * ActivityPub transformers manager handler class is responsible for registering and
+ * initializing all the supported WP-Pobject to ActivityPub transformers.
+ *
+ * @since version_number_transformer_management_placeholder
+ */
+class Transformers_Manager {
+	const DEFAULT_TRANSFORMER_MAPPING = array(
+		'post' => ACTIVITYPUB_DEFAULT_TRANSFORMER,
+		'page' => ACTIVITYPUB_DEFAULT_TRANSFORMER,
+	);
+
+	/**
+	 * Transformers.
+	 *
+	 * Holds the list of all the ActivityPub transformers. Default is `null`.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @access private
+	 *
+	 * @var \ActivityPub\Transformer\Base[]
+	 */
+	private $transformers = null;
+
+	/**
+	 * Transformer_Manager instance.
+	 *
+	 * Holds the transformer instance.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @access protected
+	 *
+	 * @var Transformer_Manager
+	 */
+	protected static $_instances = [];
+
+
+	/**
+	 * Instance.
+	 *
+	 * Ensures only one instance of the transformer manager class is loaded or can be loaded.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @access public
+	 * @static
+	 *
+	 * @return Transformer_Manager An instance of the class.
+	 */
+	public static function instance() {
+		$class_name = static::class_name();
+
+		if ( empty( static::$_instances[ $class_name ] ) ) {
+			static::$_instances[ $class_name ] = new static();
+		}
+
+		return static::$_instances[ $class_name ];
+	}
+
+	/**
+	 * Class name.
+	 *
+	 * Retrieve the name of the class.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @access public
+	 * @static
+	 */
+	public static function class_name() {
+		return get_called_class();
+	}
+
+	/**
+	 * Transformers manager constructor.
+	 *
+	 * Initializing ActivityPub transformers manager.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @access public
+	 */
+	public function __construct() {
+		$this->require_files();
+	}
+
+	/**
+	 * Require files.
+	 *
+	 * Require ActivityPub transformer base class.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @access private
+	 */
+	private function require_files() {
+		require ACTIVITYPUB_PLUGIN_DIR . 'includes/transformer/class-base.php';
+	}
+
+	/**
+	 * Checks if a transformer is registered.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 *
+	 * @param string $name Transformer name including namespace.
+	 * @return bool True if the block type is registered, false otherwise.
+	 */
+	public function is_registered( $name ) {
+		return isset( $this->transformers[ $name ] );
+	}
+
+	/**
+	 * Register a transformer.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @access public
+	 *
+	 * @param \ActivityPub\Transformer\Base $transformer_instance ActivityPub Transformer.
+	 *
+	 * @return bool True if the ActivityPub transformer was registered.
+	 */
+	public function register( \ActivityPub\Transformer\Base $transformer_instance ) {
+
+		if ( ! $transformer_instance instanceof \ActivityPub\Transformer\Base ) {
+			_doing_it_wrong(
+				__METHOD__,
+				\esc_html__( 'ActivityPub transformer instance must be a of \ActivityPub\Transformer_Base class.' ),
+				'version_number_transformer_management_placeholder'
+			);
+			return false;
+		}
+
+		$transformer_name = $transformer_instance->get_name();
+		if ( preg_match( '/[A-Z]+/', $transformer_name ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				\esc_html__( 'ActivityPub transformer names must not contain uppercase characters.' ),
+				'version_number_transformer_management_placeholder'
+			);
+			return false;
+		}
+
+		$name_matcher = '/^[a-z0-9-]+\/[a-z0-9-]+$/';
+		if ( ! preg_match( $name_matcher, $transformer_name ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				\esc_html__( 'ActivityPub transformer names must contain a namespace prefix. Example: my-plugin/my-custom-transformer' ),
+				'version_number_transformer_management_placeholder'
+			);
+			return false;
+		}
+
+		if ( $this->is_registered( $transformer_name ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				/* translators: %s: Block name. */
+				sprintf( 'ActivityPub transformer with name "%s" is already registered.', esc_html( $transformer_name ) ),
+				'version_number_transformer_management_placeholder'
+			);
+			return false;
+		}
+
+		/**
+		 * Should the ActivityPub transformer be registered.
+		 *
+		 * @since version_number_transformer_management_placeholder
+		 *
+		 * @param bool $should_register Should the ActivityPub transformer be registered. Default is `true`.
+		 * @param \ActivityPub\Transformer\Base $transformer_instance Widget instance.
+		 */
+		// TODO: does not implementing this slow down the website? -> compare with gutenberg block registration.
+		// $should_register = apply_filters( 'activitypub/transformers/is_transformer_enabled', true, $transformer_instance );
+
+		// if ( ! $should_register ) {
+		//  return false;
+		// }
+
+		$this->transformers[ $transformer_name ] = $transformer_instance;
+
+		return true;
+	}
+
+	/**
+	 * Init transformers.
+	 *
+	 * Initialize ActivityPub transformer manager.
+	 * Include the builtin transformers by default and add third party ones.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @access private
+	 */
+	private function init_transformers() {
+		$builtin_transformers = [
+			'post',
+		];
+
+		$this->transformers = [];
+
+		foreach ( $builtin_transformers as $transformer_name ) {
+			include ACTIVITYPUB_PLUGIN_DIR . 'includes/transformer/class-' . $transformer_name . '.php';
+
+			$class_name = ucfirst( $transformer_name );
+
+			$class_name = '\Activitypub\Transformer\\' . $class_name;
+
+			$this->register( new $class_name() );
+		}
+
+		/**
+		 * Let other transformers register.
+		 *
+		 * Fires after the built-in Activitypub transformers are registered.
+		 *
+		 * @since version_number_transformer_management_placeholder
+		 *
+		 * @param Transformers_Manager $this The widgets manager.
+		 */
+		do_action( 'activitypub_transformers_register', $this );
+	}
+
+	/**
+	 * Get available ActivityPub transformers.
+	 *
+	 * Retrieve the registered transformers list. If given a transformer name
+	 * it returns the given transformer if it is registered.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @access public
+	 *
+	 * @param string $transformer_name Optional. Transformer name. Default is null.
+	 *
+	 * @return Base|Base[]|null Registered transformers.
+	 */
+	public function get_transformers( $transformer_name = null ) {
+		if ( is_null( $this->transformers ) ) {
+			$this->init_transformers();
+		}
+
+		if ( null !== $transformer_name ) {
+			return isset( $this->transformers[ $transformer_name ] ) ? $this->transformers[ $transformer_name ] : null;
+		}
+
+		return $this->transformers;
+	}
+
+	/**
+	 * Get the mapped ActivityPub transformer.
+	 *
+	 * Returns a new instance of the needed WordPress to ActivityPub transformer.
+	 *
+	 * @since version_number_transformer_management_placeholder
+	 * @access public
+	 *
+	 * @param WP_Post|WP_Comment $object The WordPress Post/Comment.
+	 *
+	 * @return \ActivityPub\Transformer\Base|null Registered transformers.
+	 */
+	public function get_transformer( $object ) {
+		switch ( get_class( $object ) ) {
+			case 'WP_Post':
+				$post_type = get_post_type( $object );
+				$transformer_mapping = \get_option( 'activitypub_transformer_mapping', self::DEFAULT_TRANSFORMER_MAPPING );
+				$transformer_name = $transformer_mapping[ $post_type ];
+				$transformer_class = $this->get_transformers( $transformer_name );
+				$transformer_instance = new $transformer_class();
+				$transformer_instance->set_wp_post( $object );
+				return $transformer_instance;
+			case 'WP_Comment':
+				return new Comment( $object );
+			default:
+				return apply_filters( 'activitypub_transformer', null, $object, get_class( $object ) );
+		}
+	}
+}

integration/class-buddypress.php

@@ -0,0 +1,66 @@
+<?php
+namespace Activitypub\Integration;
+
+/**
+ * Compatibility with the BuddyPress plugin
+ *
+ * @see https://buddypress.org/
+ */
+class Buddypress {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		\add_filter( 'activitypub_json_author_array', array( self::class, 'add_user_metadata' ), 11, 2 );
+	}
+
+	public static function add_user_metadata( $object, $author_id ) {
+		$object->url = bp_core_get_user_domain( $author_id ); //add BP member profile URL as user URL
+
+		// add BuddyPress' cover_image instead of WordPress' header_image
+		$cover_image_url = bp_attachments_get_attachment( 'url', array( 'item_id' => $author_id ) );
+
+		if ( $cover_image_url ) {
+			$object->image = array(
+				'type' => 'Image',
+				'url'  => $cover_image_url,
+			);
+		}
+
+		// change profile URL to BuddyPress' profile URL
+		$object->attachment['profile_url'] = array(
+			'type' => 'PropertyValue',
+			'name' => \__( 'Profile', 'activitypub' ),
+			'value' => \html_entity_decode(
+				'<a rel="me" title="' . \esc_attr( bp_core_get_user_domain( $author_id ) ) . '" target="_blank" href="' . \bp_core_get_user_domain( $author_id ) . '">' . \wp_parse_url( \bp_core_get_user_domain( $author_id ), \PHP_URL_HOST ) . '</a>',
+				\ENT_QUOTES,
+				'UTF-8'
+			),
+		);
+
+		// replace blog URL on multisite
+		if ( is_multisite() ) {
+			$user_blogs = get_blogs_of_user( $author_id ); //get sites of user to send as AP metadata
+
+			if ( ! empty( $user_blogs ) ) {
+				unset( $object->attachment['blog_url'] );
+
+				foreach ( $user_blogs as $blog ) {
+					if ( 1 !== $blog->userblog_id ) {
+						$object->attachment[] = array(
+							'type' => 'PropertyValue',
+							'name' => $blog->blogname,
+							'value' => \html_entity_decode(
+								'<a rel="me" title="' . \esc_attr( $blog->siteurl ) . '" target="_blank" href="' . $blog->siteurl . '">' . \wp_parse_url( $blog->siteurl, \PHP_URL_HOST ) . '</a>',
+								\ENT_QUOTES,
+								'UTF-8'
+							),
+						);
+					}
+				}
+			}
+		}
+
+		return $object;
+	}
+}

integration/class-nodeinfo.php

@@ -0,0 +1,64 @@
+<?php
+namespace Activitypub\Integration;
+
+use function Activitypub\get_total_users;
+use function Activitypub\get_active_users;
+
+/**
+ * Compatibility with the NodeInfo plugin
+ *
+ * @see https://wordpress.org/plugins/nodeinfo/
+ */
+class Nodeinfo {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		\add_filter( 'nodeinfo_data', array( self::class, 'add_nodeinfo_discovery' ), 10, 2 );
+		\add_filter( 'nodeinfo2_data', array( self::class, 'add_nodeinfo2_discovery' ), 10 );
+	}
+
+	/**
+	 * Extend NodeInfo data
+	 *
+	 * @param array  $nodeinfo NodeInfo data
+	 * @param string           The NodeInfo Version
+	 *
+	 * @return array The extended array
+	 */
+	public static function add_nodeinfo_discovery( $nodeinfo, $version ) {
+		if ( $version >= '2.0' ) {
+			$nodeinfo['protocols'][] = 'activitypub';
+		} else {
+			$nodeinfo['protocols']['inbound'][]  = 'activitypub';
+			$nodeinfo['protocols']['outbound'][] = 'activitypub';
+		}
+
+		$nodeinfo['usage']['users'] = array(
+			'total'          => get_total_users(),
+			'activeMonth'    => get_active_users( '1 month ago' ),
+			'activeHalfyear' => get_active_users( '6 month ago' ),
+		);
+
+		return $nodeinfo;
+	}
+
+	/**
+	 * Extend NodeInfo2 data
+	 *
+	 * @param  array $nodeinfo NodeInfo2 data
+	 *
+	 * @return array The extended array
+	 */
+	public static function add_nodeinfo2_discovery( $nodeinfo ) {
+		$nodeinfo['protocols'][] = 'activitypub';
+
+		$nodeinfo['usage']['users'] = array(
+			'total'          => get_total_users(),
+			'activeMonth'    => get_active_users( '1 month ago' ),
+			'activeHalfyear' => get_active_users( '6 month ago' ),
+		);
+
+		return $nodeinfo;
+	}
+}

integration/class-webfinger.php

@@ -0,0 +1,62 @@
+<?php
+namespace Activitypub\Integration;
+
+use Activitypub\Rest\Webfinger as Webfinger_Rest;
+use Activitypub\Collection\Users as User_Collection;
+
+/**
+ * Compatibility with the WebFinger plugin
+ *
+ * @see https://wordpress.org/plugins/webfinger/
+ */
+class Webfinger {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		\add_filter( 'webfinger_user_data', array( self::class, 'add_user_discovery' ), 10, 3 );
+		\add_filter( 'webfinger_data', array( self::class, 'add_pseudo_user_discovery' ), 99, 2 );
+	}
+
+	/**
+	 * Add WebFinger discovery links
+	 *
+	 * @param array   $array    the jrd array
+	 * @param string  $resource the WebFinger resource
+	 * @param WP_User $user     the WordPress user
+	 *
+	 * @return array the jrd array
+	 */
+	public static function add_user_discovery( $array, $resource, $user ) {
+		$user = User_Collection::get_by_id( $user->ID );
+
+		if ( ! $user || is_wp_error( $user ) ) {
+			return $array;
+		}
+
+		$array['links'][] = array(
+			'rel'  => 'self',
+			'type' => 'application/activity+json',
+			'href' => $user->get_url(),
+		);
+
+		return $array;
+	}
+
+	/**
+	 * Add WebFinger discovery links
+	 *
+	 * @param array   $array    the jrd array
+	 * @param string  $resource the WebFinger resource
+	 * @param WP_User $user     the WordPress user
+	 *
+	 * @return array the jrd array
+	 */
+	public static function add_pseudo_user_discovery( $array, $resource ) {
+		if ( $array ) {
+			return $array;
+		}
+
+		return Webfinger_Rest::get_profile( $resource );
+	}
+}

languages/activitypub.pot

@@ -1,301 +0,0 @@
-# Copyright (C) 2019 Matthias Pfefferle
-# This file is distributed under the MIT.
-msgid ""
-msgstr ""
-"Project-Id-Version: ActivityPub 0.9.1\n"
-"Report-Msgid-Bugs-To: "
-"https://wordpress.org/support/plugin/wordpress-activitypub\n"
-"POT-Creation-Date: 2019-11-27 08:14:18+00:00\n"
-"MIME-Version: 1.0\n"
-"Content-Type: text/plain; charset=utf-8\n"
-"Content-Transfer-Encoding: 8bit\n"
-"PO-Revision-Date: 2019-MO-DA HO:MI+ZONE\n"
-"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
-"Language-Team: LANGUAGE <LL@li.org>\n"
-"X-Generator: grunt-wp-i18n 1.0.3\n"
-
-#: includes/class-admin.php:33
-msgid "Followers"
-msgstr ""
-
-#: includes/class-admin.php:33 templates/followers-list.php:2
-msgid "Followers (Fediverse)"
-msgstr ""
-
-#: includes/class-admin.php:59
-msgid "Use summary or full content"
-msgstr ""
-
-#: includes/class-admin.php:71
-msgid "The Activity-Object-Type"
-msgstr ""
-
-#: includes/class-admin.php:83 templates/settings.php:33
-msgid "Use the Shortlink instead of the permalink"
-msgstr ""
-
-#: includes/class-admin.php:90
-msgid ""
-"Add hashtags in the content as native tags and replace the #tag with the "
-"tag-link"
-msgstr ""
-
-#: includes/class-admin.php:97
-msgid "Add all tags as hashtags at the end of each activity"
-msgstr ""
-
-#: includes/class-admin.php:104
-msgid "Enable ActivityPub support for post types"
-msgstr ""
-
-#: includes/class-admin.php:115
-msgid "Overview"
-msgstr ""
-
-#: includes/class-admin.php:117
-msgid ""
-"ActivityPub is a decentralized social networking protocol based on the "
-"ActivityStreams 2.0 data format. ActivityPub is an official W3C recommended "
-"standard published by the W3C Social Web Working Group. It provides a "
-"client to server API for creating, updating and deleting content, as well "
-"as a federated server to server API for delivering notifications and "
-"subscribing to content."
-msgstr ""
-
-#: includes/class-admin.php:122
-msgid "For more information:"
-msgstr ""
-
-#: includes/class-admin.php:123
-msgid "<a href=\"https://activitypub.rocks/\">Test Suite</a>"
-msgstr ""
-
-#: includes/class-admin.php:124
-msgid "<a href=\"https://www.w3.org/TR/activitypub/\">W3C Spec</a>"
-msgstr ""
-
-#: includes/class-admin.php:125
-msgid ""
-"<a href=\"https://github.com/pfefferle/wordpress-activitypub/issues\">Give "
-"us feedback</a>"
-msgstr ""
-
-#: includes/class-admin.php:127
-msgid "<a href=\"https://notiz.blog/donate\">Donate</a>"
-msgstr ""
-
-#: includes/class-admin.php:137
-msgid "Fediverse"
-msgstr ""
-
-#: includes/functions.php:84
-msgid "The \"actor\" is no valid URL"
-msgstr ""
-
-#: includes/functions.php:110
-msgid "No valid JSON data"
-msgstr ""
-
-#: includes/functions.php:138
-msgid "No \"Inbox\" found"
-msgstr ""
-
-#: includes/functions.php:164
-msgid "No \"Public-Key\" found"
-msgstr ""
-
-#: includes/functions.php:192
-msgid "Profile identifier"
-msgstr ""
-
-#: includes/functions.php:197
-#. translators: the webfinger resource
-msgid "Try to follow \"@%s\" in the Mastodon/Friendica search field."
-msgstr ""
-
-#: includes/peer/class-followers.php:53
-msgid "Unknown Actor schema"
-msgstr ""
-
-#: includes/rest/class-followers.php:46 includes/rest/class-followers.php:49
-#: includes/rest/class-following.php:46 includes/rest/class-following.php:49
-#: includes/rest/class-outbox.php:45 includes/rest/class-outbox.php:48
-#: includes/rest/class-webfinger.php:61
-msgid "User not found"
-msgstr ""
-
-#: includes/rest/class-inbox.php:94 includes/rest/class-inbox.php:159
-msgid "Invalid payload"
-msgstr ""
-
-#: includes/rest/class-inbox.php:119
-msgid "No receiving actor set"
-msgstr ""
-
-#: includes/rest/class-inbox.php:126 includes/rest/class-inbox.php:152
-msgid "No matching user"
-msgstr ""
-
-#: includes/rest/class-inbox.php:141
-msgid "Invalid actor identifier"
-msgstr ""
-
-#: includes/rest/class-inbox.php:146
-msgid "Invalid host"
-msgstr ""
-
-#: includes/rest/class-inbox.php:201 includes/rest/class-inbox.php:230
-#: includes/rest/class-inbox.php:244 includes/rest/class-inbox.php:281
-msgid "No \"Actor\" found"
-msgstr ""
-
-#: includes/rest/class-webfinger.php:48
-msgid "Resource is invalid"
-msgstr ""
-
-#: includes/rest/class-webfinger.php:55
-msgid "Resource host does not match blog host"
-msgstr ""
-
-#: includes/table/followers-list.php:11
-msgid "Identifier"
-msgstr ""
-
-#: templates/followers-list.php:4
-msgid "You currently have %s followers."
-msgstr ""
-
-#: templates/json-author.php:48
-msgid "Blog"
-msgstr ""
-
-#: templates/json-author.php:58
-msgid "Profile"
-msgstr ""
-
-#: templates/json-author.php:69
-msgid "Website"
-msgstr ""
-
-#: templates/settings.php:2
-msgid "ActivityPub Settings"
-msgstr ""
-
-#: templates/settings.php:4
-msgid ""
-"ActivityPub turns your blog into a federated social network. This means you "
-"can share and talk to everyone using the ActivityPub protocol, including "
-"users of Friendica, Pleroma and Mastodon."
-msgstr ""
-
-#: templates/settings.php:9
-msgid "Activities"
-msgstr ""
-
-#: templates/settings.php:11
-msgid "All activity related settings."
-msgstr ""
-
-#: templates/settings.php:17
-msgid "Post-Content"
-msgstr ""
-
-#: templates/settings.php:21
-msgid "Excerpt"
-msgstr ""
-
-#: templates/settings.php:21
-msgid "A content summary, shortened to 400 characters and without markup."
-msgstr ""
-
-#: templates/settings.php:24
-msgid "Content (default)"
-msgstr ""
-
-#: templates/settings.php:24
-msgid "The full content."
-msgstr ""
-
-#: templates/settings.php:30
-msgid "Backlink"
-msgstr ""
-
-#: templates/settings.php:39
-msgid "Activity-Object-Type"
-msgstr ""
-
-#: templates/settings.php:43
-msgid "Note (default)"
-msgstr ""
-
-#: templates/settings.php:43
-msgid "Should work with most platforms."
-msgstr ""
-
-#: templates/settings.php:46
-msgid "Article"
-msgstr ""
-
-#: templates/settings.php:46
-msgid ""
-"The presentation of the \"Article\" might change on different platforms. "
-"Mastodon for example shows the \"Article\" type as a simple link."
-msgstr ""
-
-#: templates/settings.php:49
-msgid "WordPress Post-Format"
-msgstr ""
-
-#: templates/settings.php:49
-msgid "Maps the WordPress Post-Format to the ActivityPub Object Type."
-msgstr ""
-
-#: templates/settings.php:54
-msgid "Supported post types"
-msgstr ""
-
-#: templates/settings.php:57
-msgid "Enable ActivityPub support for the following post types:"
-msgstr ""
-
-#: templates/settings.php:74
-msgid "Hashtags"
-msgstr ""
-
-#: templates/settings.php:78
-msgid ""
-"Add hashtags in the content as native tags and replace the "
-"<code>#tag</code> with the tag-link."
-msgstr ""
-
-#: templates/settings.php:81
-msgid "Add all tags as hashtags to the end of each activity."
-msgstr ""
-
-#: templates/settings.php:96
-msgid ""
-"If you like this plugin, what about a small <a "
-"href=\"https://notiz.blog/donate\">donation</a>?"
-msgstr ""
-
-#. Plugin Name of the plugin/theme
-msgid "ActivityPub"
-msgstr ""
-
-#. Plugin URI of the plugin/theme
-msgid "https://github.com/pfefferle/wordpress-activitypub/"
-msgstr ""
-
-#. Description of the plugin/theme
-msgid ""
-"The ActivityPub protocol is a decentralized social networking protocol "
-"based upon the ActivityStreams 2.0 data format."
-msgstr ""
-
-#. Author of the plugin/theme
-msgid "Matthias Pfefferle"
-msgstr ""
-
-#. Author URI of the plugin/theme
-msgid "https://notiz.blog/"
-msgstr ""

package.json

@@ -1,5 +1,5 @@
 {
-  "name": "activitypub",
+  "name": "wordpress-activitypub",
   "description": "The ActivityPub protocol is a decentralized social networking protocol based upon the ActivityStreams 2.0 data format.",
   "repository": {
     "type": "git",
@@ -9,15 +9,27 @@
     "name": "Matthias Pfefferle",
     "web": "https://notiz.blog"
   },
+  "scripts": {
+    "dev": "wp-scripts start",
+    "build": "wp-scripts build",
+    "readme": "grunt wp_readme_to_markdown"
+  },
   "license": "MIT",
   "bugs": {
     "url": "https://github.com/pfefferle/wordpress-activitypub/issues"
   },
   "homepage": "https://github.com/pfefferle/wordpress-activitypub#readme",
   "devDependencies": {
-    "grunt": "^1.0.3",
+    "@wordpress/blocks": "^12.11.0",
+    "@wordpress/components": "^25.0.0",
+    "@wordpress/data": "^9.4.0",
+    "@wordpress/dom-ready": "^3.36.0",
+    "@wordpress/element": "^5.11.0",
+    "@wordpress/scripts": "^26.5.0",
+    "classnames": "^2.3.2",
+    "grunt": "^1.1.0",
     "grunt-checktextdomain": "^1.0.1",
-    "grunt-wp-i18n": "^1.0.2",
+    "grunt-wp-i18n": "^1.0.3",
     "grunt-wp-readme-to-markdown": "^2.0.1"
   }
 }

phpcs.xml

@@ -3,17 +3,17 @@
 	<description>WordPress ActivityPub Standards</description>
 	<file>./activitypub.php</file>
 	<file>./includes/</file>
-	<config name="minimum_supported_wp_version" value="4.7"/>
-	<config name="installed_paths" value="vendor/phpcompatibility/php-compatibility" />
-	<config name="installed_paths" value="vendor/wp-coding-standards/wpcs" />
 	<exclude-pattern>*\.(inc|css|js|svg)</exclude-pattern>
 	<exclude-pattern>*/vendor/*</exclude-pattern>
 	<exclude-pattern>*/node_modules/*</exclude-pattern>
 	<rule ref="PHPCompatibility"/>
 	<config name="testVersion" value="5.6-"/>
+	<rule ref="PHPCompatibilityWP"/>
+	<config name="minimum_supported_wp_version" value="4.7"/>
 	<rule ref="WordPress-Core">
 		<exclude name="Generic.Formatting.MultipleStatementAlignment.NotSameWarning" />
 		<exclude name="WordPress.Arrays.MultipleStatementAlignment.DoubleArrowNotAligned" />
+		<exclude name="Squiz.Functions.MultiLineFunctionDeclaration.SpaceAfterFunction" />
 	</rule>
 	<rule ref="WordPress.Files.FileName">
 		<properties>
@@ -24,4 +24,50 @@
 	<rule ref="WordPress-Extra" />
 	<rule ref="WordPress.WP.I18n"/>
 	<config name="text_domain" value="activitypub,default"/>
+	<arg value="ps"/>
+	<arg name="parallel" value="20"/>
+	<rule ref="VariableAnalysis"/>
+	<rule ref="VariableAnalysis.CodeAnalysis.VariableAnalysis.UndefinedVariable">
+		<type>error</type>
+	</rule>
+	<rule ref="VariableAnalysis.CodeAnalysis.VariableAnalysis">
+		<properties>
+			<property name="allowUnusedCaughtExceptions" value="true"/>
+		</properties>
+	</rule>
+	<rule ref="WordPress"/>
+	<rule ref="WordPress.WP.I18n.NoHtmlWrappedStrings">
+		<type>error</type>
+	</rule>
+	<rule ref="Generic.CodeAnalysis.UnusedFunctionParameter"/>
+	<rule ref="Generic.Arrays.DisallowShortArraySyntax">
+	  <severity>0</severity>
+	</rule>
+	<rule ref="Universal.Arrays.DisallowShortArraySyntax">
+	  <severity>0</severity>
+	</rule>
+	<rule ref="Squiz.Commenting">
+		<severity>0</severity>
+	</rule>
+	<rule ref="Generic.Commenting">
+		<severity>0</severity>
+	</rule>
+	<rule ref="WordPress.Files.FileName">
+		<severity>0</severity>
+	</rule>
+	<rule ref="WordPress.DB.PreparedSQL.NotPrepared">
+		<severity>0</severity>
+	</rule>
+	<rule ref="WordPress.WP.CapitalPDangit">
+		<severity>0</severity>
+	</rule>
+	<rule ref="WordPress.Arrays.ArrayDeclarationSpacing.AssociativeArrayFound">
+		<severity>0</severity>
+	</rule>
+	<rule ref="WordPress.PHP.YodaConditions.NotYoda">
+		<type>warning</type>
+	</rule>
+	<rule ref="WordPress.Arrays.ArrayDeclarationSpacing">
+		<exclude-pattern>**/*.asset.php</exclude-pattern>
+	</rule>
 </ruleset>