Activity-Type based handlers (#551)

* init

* save source id

* fix delete and add improve undo

* test new functions

* add support for threaded comments

* some formatting

* check if URL is no longer available

...and returns either status 410 or 404.

* improve delete handler

* improve update handler

* `object` and `actor` are already required by the inbox endpoint

* fix typo

* simplify queries

* cosmetics

* fix unit tests

* schedule delete comments of deleted actor (#575)

* schedule delete comments of deleted actor

* phpcs

---------

Co-authored-by: Django Doucet <django.doucet@webdevstudios.com>

* move `get_comments_by_actor` to interactions collection

* consistent wording

* implement Tombstone

* fix follow issue

* fix inbox-create

* added missing namespace

* check if field is set

* Fix namespacing issue

* update profile and update interaction

* fields are already validated by inbox

* optimize avatar handling

---------

Co-authored-by: Django <mediaformat.ux@gmail.com>
Co-authored-by: Django Doucet <django.doucet@webdevstudios.com>

activitypub.php

@@ -66,7 +66,7 @@ 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__ . '\Handler', 'init' ) );
 	\add_action( 'init', array( __NAMESPACE__ . '\Admin', 'init' ) );
 	\add_action( 'init', array( __NAMESPACE__ . '\Hashtag', 'init' ) );
 	\add_action( 'init', array( __NAMESPACE__ . '\Mention', 'init' ) );

composer.json

@@ -15,7 +15,8 @@
         "yoast/phpunit-polyfills": "^2.0",
         "dealerdirect/phpcodesniffer-composer-installer": "^1.0.0",
         "sirbrillig/phpcs-variable-analysis": "^2.11",
-        "phpcsstandards/phpcsextra": "^1.1.0"
+        "phpcsstandards/phpcsextra": "^1.1.0",
+        "dms/phpunit-arraysubset-asserts": "^0.4.0"
     },
     "config": {
         "allow-plugins": true

includes/activity/class-activity.php

@@ -194,6 +194,12 @@ class Activity extends Base_Object {
 	 * @return void
 	 */
 	public function set_object( $object ) {
+		// convert array to object
+		if ( is_array( $object ) ) {
+			$object = Base_Object::init_from_array( $object );
+		}
+
+		// set object
 		$this->set( 'object', $object );
 
 		if ( ! is_object( $object ) ) {

includes/activity/class-base-object.php

@@ -585,7 +585,7 @@ class Base_Object {
 
 		foreach ( $array as $key => $value ) {
 			$key = camel_to_snake_case( $key );
-			$object->set( $key, $value );
+			call_user_func( array( $object, 'set_' . $key ), $value );
 		}
 
 		return $object;
@@ -611,7 +611,7 @@ class Base_Object {
 		foreach ( $array as $key => $value ) {
 			if ( $value ) {
 				$key = camel_to_snake_case( $key );
-				$this->set( $key, $value );
+				call_user_func( array( $this, 'set_' . $key ), $value );
 			}
 		}
 	}

includes/class-activitypub.php

@@ -1,8 +1,12 @@
 <?php
 namespace Activitypub;
 
+use Exception;
 use Activitypub\Signature;
 use Activitypub\Collection\Users;
+use Activitypub\Collection\Followers;
+
+use function Activitypub\sanitize_url;
 
 /**
  * ActivityPub Class
@@ -34,6 +38,9 @@ class Activitypub {
 		\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' ) );
+
+		// register several post_types
+		self::register_post_types();
 	}
 
 	/**
@@ -54,7 +61,6 @@ class Activitypub {
 	 */
 	public static function deactivate() {
 		self::flush_rewrite_rules();
-
 		Scheduler::deregister_schedules();
 	}
 
@@ -328,4 +334,80 @@ class Activitypub {
 			)
 		);
 	}
+
+	/**
+	 * Register the "Followers" Taxonomy
+	 *
+	 * @return void
+	 */
+	private static function register_post_types() {
+		register_post_type(
+			Followers::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(
+			Followers::POST_TYPE,
+			'activitypub_inbox',
+			array(
+				'type'              => 'string',
+				'single'            => true,
+				'sanitize_callback' => 'sanitize_url',
+			)
+		);
+
+		register_post_meta(
+			Followers::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(
+			Followers::POST_TYPE,
+			'activitypub_user_id',
+			array(
+				'type'              => 'string',
+				'single'            => false,
+				'sanitize_callback' => function( $value ) {
+					return esc_sql( $value );
+				},
+			)
+		);
+
+		register_post_meta(
+			Followers::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' );
+	}
 }

includes/class-handler.php

@@ -0,0 +1,33 @@
+<?php
+namespace Activitypub;
+
+use Activitypub\Handler\Create;
+use Activitypub\Handler\Delete;
+use Activitypub\Handler\Follow;
+use Activitypub\Handler\Undo;
+use Activitypub\Handler\Update;
+
+/**
+ * Handler class.
+ */
+class Handler {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		self::register_handlers();
+	}
+
+	/**
+	 * Register handlers.
+	 */
+	public static function register_handlers() {
+		Create::init();
+		Delete::init();
+		Follow::init();
+		Undo::init();
+		Update::init();
+
+		do_action( 'activitypub_register_handlers' );
+	}
+}

includes/class-http.php

@@ -20,7 +20,7 @@ class Http {
 	 * @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 );
+		\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 );
@@ -70,7 +70,7 @@ class Http {
 	 * @return array|WP_Error The GET Response or an WP_ERROR
 	 */
 	public static function get( $url ) {
-		do_action( 'activitypub_pre_http_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 );
@@ -108,4 +108,24 @@ class Http {
 
 		return $response;
 	}
+
+	/**
+	 * Check for URL for Tombstone.
+	 *
+	 * @param string $url The URL to check.
+	 *
+	 * @return bool True if the URL is a tombstone.
+	 */
+	public static function is_tombstone( $url ) {
+		\do_action( 'activitypub_pre_http_is_tombstone', $url );
+
+		$response = \wp_safe_remote_get( $url );
+		$code     = \wp_remote_retrieve_response_code( $response );
+
+		if ( in_array( (int) $code, array( 404, 410 ), true ) ) {
+			return true;
+		}
+
+		return false;
+	}
 }

includes/collection/class-followers.php

@@ -2,14 +2,10 @@
 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;
@@ -24,136 +20,6 @@ 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
 	 *
@@ -214,16 +80,17 @@ class Followers {
 	}
 
 	/**
-	 * Get a Follower
+	 * 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
+	 * @return \Activitypub\Model\Follower|null The Follower object or null
 	 */
 	public static function get_follower( $user_id, $actor ) {
 		global $wpdb;
 
+		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
 		$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",
@@ -244,51 +111,29 @@ class Followers {
 	}
 
 	/**
-	 * Send Accept response
+	 * Get a Follower by Actor indepenent from the User.
 	 *
-	 * @param string                     $actor    The Actor URL
+	 * @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
+	 * @return \Activitypub\Model\Follower|null The Follower object or null
 	 */
-	public static function send_follow_response( $actor, $object, $user_id, $follower ) {
+	public static function get_follower_by_actor( $actor ) {
-		if ( is_wp_error( $follower ) ) {
+		global $wpdb;
-			// it is not even possible to send a "Reject" because
-			// we can not get the Remote-Inbox
-			return;
-		}
 
-		// only send minimal data
+		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
-		$object = array_intersect_key(
+		$post_id = $wpdb->get_var(
-			$object,
+			$wpdb->prepare(
-			array_flip(
+				"SELECT ID FROM $wpdb->posts WHERE guid=%s",
-				array(
+				esc_sql( $actor )
-					'id',
-					'type',
-					'actor',
-					'object',
-				)
 			)
 		);
 
-		$user = Users::get_by_id( $user_id );
+		if ( $post_id ) {
+			$post = get_post( $post_id );
+			return Follower::init_from_cpt( $post );
+		}
 
-		// get inbox
+		return null;
-		$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 );
 	}
 
 	/**

includes/collection/class-interactions.php

@@ -0,0 +1,236 @@
+<?php
+namespace Activitypub\Collection;
+
+use WP_Error;
+use WP_Comment_Query;
+
+use function Activitypub\url_to_commentid;
+use function Activitypub\object_id_to_comment;
+use function Activitypub\get_remote_metadata_by_actor;
+
+/**
+ * ActivityPub Interactions Collection
+ */
+class Interactions {
+	/**
+	 * Add a comment to a post
+	 *
+	 * @param array $activity The activity-object
+	 *
+	 * @return array|false The commentdata or false on failure
+	 */
+	public static function add_comment( $activity ) {
+		if (
+			! isset( $activity['object'] ) ||
+			! isset( $activity['object']['id'] )
+		) {
+			return false;
+		}
+
+		if ( ! isset( $activity['object']['inReplyTo'] ) ) {
+			return false;
+		}
+
+		$in_reply_to     = \esc_url_raw( $activity['object']['inReplyTo'] );
+		$comment_post_id = \url_to_postid( $in_reply_to );
+		$parent_comment  = object_id_to_comment( $in_reply_to );
+
+		// save only replys and reactions
+		if ( ! $comment_post_id && $parent_comment ) {
+			$comment_post_id = $parent_comment->comment_post_ID;
+		}
+
+		// not a reply to a post or comment
+		if ( ! $comment_post_id ) {
+			return false;
+		}
+
+		$meta = get_remote_metadata_by_actor( $activity['actor'] );
+
+		if ( ! $meta || \is_wp_error( $meta ) ) {
+			return false;
+		}
+
+		$commentdata = array(
+			'comment_post_ID' => $comment_post_id,
+			'comment_author' => \esc_attr( $meta['name'] ),
+			'comment_author_url' => \esc_url_raw( $meta['url'] ),
+			'comment_content' => \addslashes( \wp_kses( $activity['object']['content'], 'pre_comment_content' ) ),
+			'comment_type' => 'comment',
+			'comment_author_email' => '',
+			'comment_parent' => $parent_comment ? $parent_comment->comment_ID : 0,
+			'comment_meta' => array(
+				'source_id'  => \esc_url_raw( $activity['object']['id'] ),
+				'source_url' => \esc_url_raw( $activity['object']['url'] ),
+				'protocol'   => 'activitypub',
+			),
+		);
+
+		if ( isset( $meta['icon']['url'] ) ) {
+			$commentdata['comment_meta']['avatar_url'] = \esc_url_raw( $meta['icon']['url'] );
+		}
+
+		// 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 );
+
+		$comment = \wp_new_comment( $commentdata, true );
+
+		\remove_filter( 'wp_kses_allowed_html', array( self::class, 'allowed_comment_html' ), 10 );
+		\remove_filter( 'pre_option_require_name_email', '__return_false' );
+
+		// re-add flood control
+		\add_action( 'check_comment_flood', 'check_comment_flood_db', 10, 4 );
+
+		return $comment;
+	}
+
+	/**
+	 * Update a comment
+	 *
+	 * @param array $activity The activity-object
+	 *
+	 * @return array|false The commentdata or false on failure
+	 */
+	public static function update_comment( $activity ) {
+		$meta = get_remote_metadata_by_actor( $activity['actor'] );
+
+		//Determine comment_ID
+		$object_comment_id = url_to_commentid( \esc_url_raw( $activity['object']['id'] ) );
+
+		if ( ! $object_comment_id ) {
+			return false;
+		}
+
+		//found a local comment id
+		$commentdata = \get_comment( $object_comment_id, ARRAY_A );
+		$commentdata['comment_author'] = \esc_attr( $meta['name'] ? $meta['name'] : $meta['preferredUsername'] );
+		$commentdata['comment_content'] = \addslashes( \wp_kses( $activity['object']['content'], 'pre_comment_content' ) );
+		if ( isset( $meta['icon']['url'] ) ) {
+			$commentdata['comment_meta']['avatar_url'] = \esc_url_raw( $meta['icon']['url'] );
+		}
+
+		// 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 );
+
+		$comment = \wp_update_comment( $commentdata, true );
+
+		\remove_filter( 'wp_kses_allowed_html', array( self::class, 'allowed_comment_html' ), 10 );
+		\remove_filter( 'pre_option_require_name_email', '__return_false' );
+
+		// re-add flood control
+		\add_action( 'check_comment_flood', 'check_comment_flood_db', 10, 4 );
+
+		return $comment;
+	}
+
+	/**
+	 * Get interaction(s) for a given URL/ID.
+	 *
+	 * @param strin $url The URL/ID to get interactions for.
+	 *
+	 * @return array The interactions as WP_Comment objects.
+	 */
+	public static function get_interaction_by_id( $url ) {
+		$args = array(
+			// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
+			'meta_query' => array(
+				'relation' => 'AND',
+				array(
+					'key'   => 'protocol',
+					'value' => 'activitypub',
+				),
+				array(
+					'relation' => 'OR',
+					array(
+						'key'   => 'source_url',
+						'value' => $url,
+					),
+					array(
+						'key'   => 'source_id',
+						'value' => $url,
+					),
+				),
+			),
+		);
+
+		$query = new WP_Comment_Query( $args );
+		return $query->comments;
+	}
+
+	/**
+	 * Get interaction(s) for a given actor.
+	 *
+	 * @param string $actor The Actor-URL.
+	 *
+	 * @return array The interactions as WP_Comment objects.
+	 */
+	public static function get_interactions_by_actor( $actor ) {
+		$meta = get_remote_metadata_by_actor( $actor );
+
+		// get URL, because $actor seems to be the ID
+		if ( $meta && ! is_wp_error( $meta ) && isset( $meta['url'] ) ) {
+			$actor = $meta['url'];
+		}
+
+		$args = array(
+			'author_url' => $actor,
+			// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
+			'meta_query' => array(
+				array(
+					'key'   => 'protocol',
+					'value' => 'activitypub',
+					'compare' => '=',
+				),
+			),
+		);
+		$comment_query = new WP_Comment_Query( $args );
+		return $comment_query->comments;
+	}
+
+	/**
+	 * 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/functions.php

@@ -2,6 +2,7 @@
 namespace Activitypub;
 
 use WP_Error;
+use WP_Comment_Query;
 use Activitypub\Http;
 use Activitypub\Activity\Activity;
 use Activitypub\Collection\Followers;
@@ -486,6 +487,81 @@ function is_blog_public() {
 	return (bool) apply_filters( 'activitypub_is_blog_public', \get_option( 'blog_public', 1 ) );
 }
 
+/**
+ * Sanitize a URL
+ *
+ * @param string $value The URL to sanitize
+ *
+ * @return string|null The sanitized URL or null if invalid
+ */
+function sanitize_url( $value ) {
+	if ( filter_var( $value, FILTER_VALIDATE_URL ) === false ) {
+		return null;
+	}
+
+	return esc_url_raw( $value );
+}
+
+/**
+ * Extract recipient URLs from Activity object
+ *
+ * @param array $data
+ *
+ * @return array The list of user URLs
+ */
+function extract_recipients_from_activity( $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 );
+}
+
+/**
+ * Check if passed Activity is Public
+ *
+ * @param array $data The Activity object as array
+ *
+ * @return boolean True if public, false if not
+ */
+function is_activity_public( $data ) {
+	$recipients = extract_recipients_from_activity( $data );
+
+	return in_array( 'https://www.w3.org/ns/activitystreams#Public', $recipients, true );
+}
+
 /**
  * Get active users based on a given duration
  *
@@ -557,3 +633,68 @@ function get_total_users() {
 
 	return $users + 1;
 }
+
+/**
+ * Examine a comment ID and look up an existing comment it represents.
+ *
+ * @param string $id ActivityPub object ID (usually a URL) to check.
+ *
+ * @return int|boolean Comment ID, or false on failure.
+ */
+function object_id_to_comment( $id ) {
+	$comment_query = new WP_Comment_Query(
+		array(
+			'meta_key'   => 'source_id', // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_key
+			'meta_value' => $id,         // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_value
+		)
+	);
+
+	if ( ! $comment_query->comments ) {
+		return false;
+	}
+
+	if ( count( $comment_query->comments ) > 1 ) {
+		return false;
+	}
+
+	return $comment_query->comments[0];
+}
+
+/**
+ * Verify if URL is a local comment,
+ * Or if it is a previously received remote comment
+ * (For threading comments locally)
+ *
+ * @param string $url The URL to check.
+ *
+ * @return int comment_ID or null if not found
+ */
+function url_to_commentid( $url ) {
+	if ( ! $url || ! filter_var( $url, FILTER_VALIDATE_URL ) ) {
+		return null;
+	}
+
+	$args = array(
+		// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
+		'meta_query' => array(
+			'relation' => 'OR',
+			array(
+				'key' => 'source_url',
+				'value' => $url,
+			),
+			array(
+				'key' => 'source_id',
+				'value' => $url,
+			),
+		),
+	);
+
+	$query = new \WP_Comment_Query();
+	$comments = $query->query( $args );
+
+	if ( $comments && is_array( $comments ) ) {
+		return $comments[0]->comment_ID;
+	}
+
+	return null;
+}

includes/handler/class-create.php

@@ -0,0 +1,61 @@
+<?php
+namespace Activitypub\Handler;
+
+use WP_Error;
+use Activitypub\Collection\Interactions;
+
+use function Activitypub\is_activity_public;
+use function Activitypub\object_id_to_comment;
+
+/**
+ * Handle Create requests
+ */
+class Create {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		\add_action( 'activitypub_inbox_create', array( self::class, 'handle_create' ), 10, 3 );
+	}
+
+	/**
+	 * Handles "Create" requests
+	 *
+	 * @param array                $array   The activity-object
+	 * @param int                  $user_id The id of the local blog-user
+	 * @param Activitypub\Activity $object  The activity object
+	 *
+	 * @return void
+	 */
+	public static function handle_create( $array, $user_id, $object = null ) {
+		if (
+			! isset( $array['object'] ) ||
+			! isset( $array['object']['id'] )
+		) {
+			return;
+		}
+
+		// check if Activity is public or not
+		if ( ! is_activity_public( $array ) ) {
+			// @todo maybe send email
+			return;
+		}
+
+		$check_dupe = object_id_to_comment( $array['object']['id'] );
+
+		// if comment exists, call update action
+		if ( $check_dupe ) {
+			\do_action( 'activitypub_inbox_update', $array, $user_id, $object );
+			return;
+		}
+
+		$state    = Interactions::add_comment( $array );
+		$reaction = null;
+
+		if ( $state && ! \is_wp_error( $reaction ) ) {
+			$reaction = \get_comment( $state );
+		}
+
+		\do_action( 'activitypub_handled_create', $array, $user_id, $state, $reaction );
+	}
+}

includes/handler/class-delete.php

@@ -0,0 +1,165 @@
+<?php
+namespace Activitypub\Handler;
+
+use WP_Error;
+use WP_REST_Request;
+use Activitypub\Http;
+use Activitypub\Collection\Followers;
+use Activitypub\Collection\Interactions;
+
+/**
+ * Handles Delete requests.
+ */
+class Delete {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		\add_action( 'activitypub_inbox_delete', array( self::class, 'handle_delete' ), 10, 2 );
+		// defer signature verification for `Delete` requests.
+		\add_filter( 'activitypub_defer_signature_verification', array( self::class, 'defer_signature_verification' ), 10, 2 );
+		// side effect
+		\add_action( 'activitypub_delete_actor_interactions', array( self::class, 'delete_interactions' ), 10, 1 );
+	}
+
+	/**
+	 * Handles "Delete" requests.
+	 *
+	 * @param array $activity The delete activity.
+	 * @param int   $user_id  The ID of the user performing the delete activity.
+	 */
+	public static function handle_delete( $activity, $user_id ) {
+		$object_type = isset( $activity['object']['type'] ) ? $activity['object']['type'] : '';
+
+		switch ( $object_type ) {
+			// Actor Types
+			// @see https://www.w3.org/TR/activitystreams-vocabulary/#actor-types
+			case 'Person':
+			case 'Group':
+			case 'Organization':
+			case 'Service':
+			case 'Application':
+				self::maybe_delete_follower( $user_id, $activity );
+				break;
+			// Object and Link Types
+			// @see https://www.w3.org/TR/activitystreams-vocabulary/#object-types
+			case 'Note':
+			case 'Article':
+			case 'Image':
+			case 'Audio':
+			case 'Video':
+			case 'Event':
+			case 'Document':
+				self::maybe_delete_interaction( $activity );
+				break;
+			// Tombstone Type
+			// @see: https://www.w3.org/TR/activitystreams-vocabulary/#dfn-tombstone
+			case 'Tombstone':
+				self::maybe_delete_interaction( $activity );
+				break;
+			// Minimal Activity
+			// @see https://www.w3.org/TR/activitystreams-core/#example-1
+			default:
+				// ignore non Minimal Activities.
+				if ( ! is_string( $activity['object'] ) ) {
+					return;
+				}
+
+				// check if Object is an Actor.
+				if ( $activity['actor'] === $activity['object'] ) {
+					self::maybe_delete_follower( $activity );
+					self::maybe_delete_interactions( $activity );
+				} else { // assume a interaction otherwise.
+					self::maybe_delete_interaction( $activity );
+				}
+				// maybe handle Delete Activity for other Object Types.
+				break;
+		}
+	}
+
+	/**
+	 * Delete a Follower if Actor-URL is a Tombstone.
+	 *
+	 * @param array $activity The delete activity.
+	 */
+	public static function maybe_delete_follower( $activity ) {
+		$follower = Followers::get_follower_by_actor( $activity['actor'] );
+
+		// verify if Actor is deleted.
+		if ( $follower && Http::is_tombstone( $activity['actor'] ) ) {
+			$follower->delete();
+		}
+	}
+
+	/**
+	 * Delete Reactions if Actor-URL is a Tombstone.
+	 *
+	 * @param array $activity The delete activity.
+	 */
+	public static function maybe_delete_interactions( $activity ) {
+		// verify if Actor is deleted.
+		if ( Http::is_tombstone( $activity['actor'] ) ) {
+			\wp_schedule_single_event(
+				\time(),
+				'activitypub_delete_actor_interactions',
+				array( $activity['actor'] )
+			);
+		}
+	}
+
+	/**
+	 * Delete comments from an Actor.
+	 *
+	 * @param array $comments The comments to delete.
+	 */
+	public static function delete_interactions( $actor ) {
+		$comments = Interactions::get_interactions_by_actor( $actor );
+
+		if ( is_array( $comments ) ) {
+			foreach ( $comments as $comment ) {
+				wp_delete_comment( $comment->comment_ID );
+			}
+		}
+	}
+
+	/**
+	 * Delete a Reaction if URL is a Tombstone.
+	 *
+	 * @param array $activity The delete activity.
+	 *
+	 * @return void
+	 */
+	public static function maybe_delete_interaction( $activity ) {
+		if ( is_array( $activity['object'] ) ) {
+			$id = $activity['object']['id'];
+		} else {
+			$id = $activity['object'];
+		}
+
+		$comments = Interactions::get_interaction_by_id( $id );
+
+		if ( $comments && Http::is_tombstone( $id ) ) {
+			foreach ( $comments as $comment ) {
+				wp_delete_comment( $comment->comment_ID, true );
+			}
+		}
+	}
+
+	/**
+	 * Defer signature verification for `Delete` requests.
+	 *
+	 * @param bool            $defer   Whether to defer signature verification.
+	 * @param WP_REST_Request $request The request object.
+	 *
+	 * @return bool Whether to defer signature verification.
+	 */
+	public static function defer_signature_verification( $defer, $request ) {
+		$json = $request->get_json_params();
+
+		if ( isset( $json['type'] ) && 'Delete' === $json['type'] ) {
+			return true;
+		}
+
+		return false;
+	}
+}

includes/handler/class-follow.php

@@ -0,0 +1,81 @@
+<?php
+namespace Activitypub\Handler;
+
+use Activitypub\Http;
+use Activitypub\Activity\Activity;
+use Activitypub\Collection\Users;
+use Activitypub\Collection\Followers;
+
+/**
+ * Handle Follow requests
+ */
+class Follow {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		\add_action( 'activitypub_inbox_follow', array( self::class, 'handle_follow' ), 10, 2 );
+		\add_action( 'activitypub_followers_post_follow', array( self::class, 'send_follow_response' ), 10, 4 );
+	}
+
+	/**
+	 * Handle "Follow" requests
+	 *
+	 * @param array $activity The activity object
+	 * @param int   $user_id  The user ID
+	 */
+	public static function handle_follow( $activity, $user_id ) {
+		// save follower
+		$follower = Followers::add_follower( $user_id, $activity['actor'] );
+
+		do_action( 'activitypub_followers_post_follow', $activity['actor'], $activity, $user_id, $follower );
+	}
+
+	/**
+	 * 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 );
+	}
+}

includes/handler/class-undo.php

@@ -0,0 +1,31 @@
+<?php
+namespace Activitypub\Handler;
+
+use Activitypub\Collection\Followers;
+
+/**
+ * Handle Undo requests
+ */
+class Undo {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		\add_action( 'activitypub_inbox_undo', array( self::class, 'handle_undo' ), 10, 2 );
+	}
+
+	/**
+	 * Handle "Unfollow" requests
+	 *
+	 * @param array $activity The JSON "Undo" Activity
+	 * @param int   $user_id  The ID of the ID of the WordPress User
+	 */
+	public static function handle_undo( $activity, $user_id ) {
+		if (
+			isset( $activity['object']['type'] ) &&
+			'Follow' === $activity['object']['type']
+		) {
+			Followers::remove_follower( $user_id, $activity['actor'] );
+		}
+	}
+}

includes/handler/class-update.php

@@ -0,0 +1,89 @@
+<?php
+namespace Activitypub\Handler;
+
+use WP_Error;
+use Activitypub\Collection\Interactions;
+
+use function Activitypub\get_remote_metadata_by_actor;
+
+/**
+ * Handle Update requests.
+ */
+class Update {
+	/**
+	 * Initialize the class, registering WordPress hooks
+	 */
+	public static function init() {
+		\add_action( 'activitypub_inbox_update', array( self::class, 'handle_update' ), 10, 2 );
+	}
+
+	/**
+	 * Handle "Update" requests
+	 *
+	 * @param array                $array   The activity-object
+	 * @param int                  $user_id The id of the local blog-user
+	 */
+	public static function handle_update( $array, $user_id ) {
+		$object_type = isset( $array['object']['type'] ) ? $array['object']['type'] : '';
+
+		switch ( $object_type ) {
+			// Actor Types
+			// @see https://www.w3.org/TR/activitystreams-vocabulary/#actor-types
+			case 'Person':
+			case 'Group':
+			case 'Organization':
+			case 'Service':
+			case 'Application':
+				self::update_actor( $array );
+				break;
+			// Object and Link Types
+			// @see https://www.w3.org/TR/activitystreams-vocabulary/#object-types
+			case 'Note':
+			case 'Article':
+			case 'Image':
+			case 'Audio':
+			case 'Video':
+			case 'Event':
+			case 'Document':
+				self::update_interaction( $array, $user_id );
+				break;
+			// Minimal Activity
+			// @see https://www.w3.org/TR/activitystreams-core/#example-1
+			default:
+				break;
+		}
+	}
+
+	/**
+	 * Update an Interaction
+	 *
+	 * @param array $activity The activity-object
+	 * @param int   $user_id  The id of the local blog-user
+	 *
+	 * @return void
+	 */
+	public static function update_interaction( $activity, $user_id ) {
+		$state    = Interactions::update_comment( $activity );
+		$reaction = null;
+
+		if ( $state && ! \is_wp_error( $reaction ) ) {
+			$reaction = \get_comment( $state );
+		}
+
+		\do_action( 'activitypub_handled_update', $activity, $user_id, $state, $reaction );
+	}
+
+	/**
+	 * Update an Actor
+	 *
+	 * @param array $activity The activity-object
+	 *
+	 * @return void
+	 */
+	public static function update_actor( $activity ) {
+		// update cache
+		get_remote_metadata_by_actor( $activity['actor'], false );
+
+		// @todo maybe also update all interactions
+	}
+}

includes/rest/class-inbox.php

@@ -11,6 +11,7 @@ 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;
+use function Activitypub\extract_recipients_from_activity;
 
 /**
  * ActivityPub Inbox REST-Class
@@ -25,8 +26,6 @@ class Inbox {
 	 */
 	public static function init() {
 		self::register_routes();
-
-		\add_action( 'activitypub_inbox_create', array( self::class, 'handle_create' ), 10, 2 );
 	}
 
 	/**
@@ -131,11 +130,12 @@ class Inbox {
 		}
 
 		$data     = $request->get_json_params();
+		$activity = Activity::init_from_array( $data );
 		$type     = $request->get_param( 'type' );
 		$type     = \strtolower( $type );
 
-		\do_action( 'activitypub_inbox', $data, $user->get__id(), $type );
+		\do_action( 'activitypub_inbox', $data, $user->get__id(), $type, $activity );
-		\do_action( "activitypub_inbox_{$type}", $data, $user->get__id() );
+		\do_action( "activitypub_inbox_{$type}", $data, $user->get__id(), $activity );
 
 		$rest_response = new WP_REST_Response( array(), 202 );
 		$rest_response->header( 'Content-Type', 'application/activity+json; charset=' . get_option( 'blog_charset' ) );
@@ -152,8 +152,9 @@ class Inbox {
 	 */
 	public static function shared_inbox_post( $request ) {
 		$data     = $request->get_json_params();
+		$activity = Activity::init_from_array( $data );
 		$type     = $request->get_param( 'type' );
-		$users = self::extract_recipients( $data );
+		$users    = self::get_recipients( $data );
 
 		if ( ! $users ) {
 			return new WP_Error(
@@ -181,8 +182,8 @@ class Inbox {
 
 			$type = \strtolower( $type );
 
-			\do_action( 'activitypub_inbox', $data, $user->ID, $type );
+			\do_action( 'activitypub_inbox', $data, $user->ID, $type, $activity );
-			\do_action( "activitypub_inbox_{$type}", $data, $user->ID );
+			\do_action( "activitypub_inbox_{$type}", $data, $user->ID, $activity );
 		}
 
 		$rest_response = new WP_REST_Response( array(), 202 );
@@ -340,121 +341,6 @@ class Inbox {
 		return $params;
 	}
 
-	/**
-	 * Handles "Create" requests
-	 *
-	 * @param  array $object  The activity-object
-	 * @param  int   $user_id The id of the local blog-user
-	 */
-	public static function handle_create( $object, $user_id ) {
-		$meta = get_remote_metadata_by_actor( $object['actor'] );
-
-		if ( ! isset( $object['object']['inReplyTo'] ) ) {
-			return;
-		}
-
-		// 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' => $comment_post_id,
-			'comment_author' => \esc_attr( $meta['name'] ),
-			'comment_author_url' => \esc_url_raw( $object['actor'] ),
-			'comment_content' => addslashes( \wp_kses( $object['object']['content'], 'pre_comment_content' ) ),
-			'comment_type' => 'comment',
-			'comment_author_email' => '',
-			'comment_parent' => 0,
-			'comment_meta' => array(
-				'source_url' => \esc_url_raw( $object['object']['url'] ),
-				'avatar_url' => \esc_url_raw( $meta['icon']['url'] ),
-				'protocol' => 'activitypub',
-			),
-		);
-
-		// 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
 	 *
@@ -463,7 +349,7 @@ class Inbox {
 	 * @return array The list of local users
 	 */
 	public static function get_recipients( $data ) {
-		$recipients = self::extract_recipients( $data );
+		$recipients = extract_recipients_from_activity( $data );
 		$users = array();
 
 		foreach ( $recipients as $recipient ) {
@@ -478,41 +364,4 @@ class Inbox {
 
 		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-server.php

@@ -110,14 +110,20 @@ class Server {
 		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 ) );
+				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
+		} elseif ( 'GET' === $request->get_method() && ACTIVITYPUB_AUTHORIZED_FETCH ) { // 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 new WP_Error(
-				}
+					'activitypub_signature_verification',
+					$verified_request->get_error_message(),
+					array( 'status' => 401 )
+				);
 			}
 		}
 

tests/test-class-activitypub-activity.php

@@ -1,4 +1,6 @@
 <?php
+use DMS\PHPUnitExtensions\ArraySubset\Assert;
+
 class Test_Activitypub_Activity extends WP_UnitTestCase {
 	public function test_activity_mentions() {
 		$post = \wp_insert_post(
@@ -42,4 +44,21 @@ class Test_Activitypub_Activity extends WP_UnitTestCase {
 		$this->assertEquals( 'Hello world!', $object->get_content() );
 		$this->assertEquals( $test_array, $object->to_array() );
 	}
+
+	public function test_activity_object() {
+		$test_array = array(
+			'id'      => 'https://example.com/post/123',
+			'type'    => 'Create',
+			'object'  => array(
+				'id'      => 'https://example.com/post/123/activity',
+				'type'    => 'Note',
+				'content' => 'Hello world!',
+			),
+		);
+
+		$activity = \Activitypub\Activity\Activity::init_from_array( $test_array );
+
+		$this->assertEquals( 'Hello world!', $activity->get_object()->get_content() );
+		Assert::assertArraySubset( $test_array, $activity->to_array() );
+	}
 }

tests/test-class-activitypub-create-handler.php

@@ -0,0 +1,70 @@
+<?php
+class Test_Activitypub_Create_Handler extends WP_UnitTestCase {
+	public $user_id;
+	public $user_url;
+	public $post_id;
+	public $post_permalink;
+
+	public function set_up() {
+		$this->user_id = 1;
+		$authordata = \get_userdata( $this->user_id );
+		$this->user_url = $authordata->user_url;
+
+		$this->post_id = \wp_insert_post(
+			array(
+				'post_author' => $this->user_id,
+				'post_content' => 'test',
+			)
+		);
+		$this->post_permalink = \get_permalink( $this->post_id );
+
+		\add_filter( 'pre_get_remote_metadata_by_actor', array( '\Test_Activitypub_Create_Handler', 'get_remote_metadata_by_actor' ), 0, 2 );
+	}
+
+	public static function get_remote_metadata_by_actor( $value, $actor ) {
+		return array(
+			'name' => 'Example User',
+			'icon' => array(
+				'url' => 'https://example.com/icon',
+			),
+			'url'  => $actor,
+			'id'   => 'http://example.org/users/example',
+		);
+	}
+
+	public function create_test_object( $id = 'https://example.com/123' ) {
+		return array(
+			'actor' => $this->user_url,
+			'id' => 'https://example.com/id/' . microtime( true ),
+			'to' => [ $this->user_url ],
+			'cc' => [ 'https://www.w3.org/ns/activitystreams#Public' ],
+			'object' => array(
+				'id'        => $id,
+				'url'       => 'https://example.com/example',
+				'inReplyTo' => $this->post_permalink,
+				'content'   => 'example',
+			),
+		);
+	}
+
+	public function test_handle_create_object_unset_rejected() {
+		$object = $this->create_test_object();
+		unset( $object['object'] );
+		$converted = Activitypub\Handler\Create::handle_create( $object, $this->user_id );
+		$this->assertNull( $converted );
+	}
+
+	public function test_handle_create_non_public_rejected() {
+		$object = $this->create_test_object();
+		$object['cc'] = [];
+		$converted = Activitypub\Handler\Create::handle_create( $object, $this->user_id );
+		$this->assertNull( $converted );
+	}
+
+	public function test_handle_create_no_id_rejected() {
+		$object = $this->create_test_object();
+		unset( $object['object']['id'] );
+		$converted = Activitypub\Handler\Create::handle_create( $object, $this->user_id );
+		$this->assertNull( $converted );
+	}
+}

tests/test-class-activitypub-followers.php

@@ -1,5 +1,5 @@
 <?php
-class Test_Db_Activitypub_Followers extends WP_UnitTestCase {
+class Test_Activitypub_Followers extends WP_UnitTestCase {
 	public static $users = array(
 		'username@example.org' => array(
 			'id' => 'https://example.org/users/username',

tests/test-class-activitypub-interactions.php

@@ -0,0 +1,130 @@
+<?php
+class Test_Activitypub_Interactions extends WP_UnitTestCase {
+	public $user_id;
+	public $user_url;
+	public $post_id;
+	public $post_permalink;
+
+	public function set_up() {
+		$this->user_id = 1;
+		$authordata = \get_userdata( $this->user_id );
+		$this->user_url = $authordata->user_url;
+
+		$this->post_id = \wp_insert_post(
+			array(
+				'post_author' => $this->user_id,
+				'post_content' => 'test',
+			)
+		);
+		$this->post_permalink = \get_permalink( $this->post_id );
+
+		\add_filter( 'pre_get_remote_metadata_by_actor', array( '\Test_Activitypub_Interactions', 'get_remote_metadata_by_actor' ), 0, 2 );
+	}
+
+	public static function get_remote_metadata_by_actor( $value, $actor ) {
+		return array(
+			'name' => 'Example User',
+			'icon' => array(
+				'url' => 'https://example.com/icon',
+			),
+			'url'  => $actor,
+			'id'   => 'http://example.org/users/example',
+		);
+	}
+
+	public function create_test_object( $id = 'https://example.com/123' ) {
+		return array(
+			'actor' => $this->user_url,
+			'id' => 'https://example.com/id/' . microtime( true ),
+			'to' => [ $this->user_url ],
+			'cc' => [ 'https://www.w3.org/ns/activitystreams#Public' ],
+			'object' => array(
+				'id'        => $id,
+				'url'       => 'https://example.com/example',
+				'inReplyTo' => $this->post_permalink,
+				'content'   => 'example',
+			),
+		);
+	}
+
+	public function test_handle_create_basic() {
+		$comment_id = Activitypub\Collection\Interactions::add_comment( $this->create_test_object() );
+		$comment   = get_comment( $comment_id, ARRAY_A );
+
+		$this->assertIsArray( $comment );
+		$this->assertEquals( $this->post_id, $comment['comment_post_ID'] );
+		$this->assertEquals( 'Example User', $comment['comment_author'] );
+		$this->assertEquals( $this->user_url, $comment['comment_author_url'] );
+		$this->assertEquals( 'example', $comment['comment_content'] );
+		$this->assertEquals( 'comment', $comment['comment_type'] );
+		$this->assertEquals( '', $comment['comment_author_email'] );
+		$this->assertEquals( 0, $comment['comment_parent'] );
+		$this->assertEquals( 'https://example.com/123', get_comment_meta( $comment_id, 'source_id', true ) );
+		$this->assertEquals( 'https://example.com/example', get_comment_meta( $comment_id, 'source_url', true ) );
+		$this->assertEquals( 'https://example.com/icon', get_comment_meta( $comment_id, 'avatar_url', true ) );
+		$this->assertEquals( 'activitypub', get_comment_meta( $comment_id, 'protocol', true ) );
+	}
+
+	public function test_convert_object_to_comment_not_reply_rejected() {
+		$object = $this->create_test_object();
+		unset( $object['object']['inReplyTo'] );
+		$converted = Activitypub\Collection\Interactions::add_comment( $object );
+		$this->assertFalse( $converted );
+	}
+
+	public function test_convert_object_to_comment_already_exists_rejected() {
+		$object = $this->create_test_object( 'https://example.com/test_convert_object_to_comment_already_exists_rejected' );
+		Activitypub\Collection\Interactions::add_comment( $object );
+		$converted = Activitypub\Collection\Interactions::add_comment( $object );
+		$this->assertEquals( $converted->get_error_code(), 'comment_duplicate' );
+	}
+
+	public function test_convert_object_to_comment_reply_to_comment() {
+		$id = 'https://example.com/test_convert_object_to_comment_reply_to_comment';
+		$object = $this->create_test_object( $id );
+		Activitypub\Collection\Interactions::add_comment( $object );
+		$comment = \Activitypub\object_id_to_comment( $id );
+
+		$object['object']['inReplyTo'] = $id;
+		$object['object']['id'] = 'https://example.com/234';
+		$id = Activitypub\Collection\Interactions::add_comment( $object );
+		$converted = get_comment( $id, ARRAY_A );
+
+		$this->assertIsArray( $converted );
+		$this->assertEquals( $this->post_id, $converted['comment_post_ID'] );
+		$this->assertEquals( $comment->comment_ID, $converted['comment_parent'] );
+	}
+
+	public function test_convert_object_to_comment_reply_to_non_existent_comment_rejected() {
+		$object = $this->create_test_object();
+		$object['object']['inReplyTo'] = 'https://example.com/not_found';
+		$converted = Activitypub\Collection\Interactions::add_comment( $object );
+		$this->assertFalse( $converted );
+	}
+
+	public function test_handle_create_basic2() {
+		$id = 'https://example.com/test_handle_create_basic';
+		$object = $this->create_test_object( $id );
+		Activitypub\Collection\Interactions::add_comment( $object );
+		$comment = \Activitypub\object_id_to_comment( $id );
+		$this->assertInstanceOf( WP_Comment::class, $comment );
+	}
+
+	public function test_get_interaction_by_id() {
+		$id = 'https://example.com/test_get_interaction_by_id';
+		$url = 'https://example.com/test_get_interaction_by_url';
+		$object = $this->create_test_object( $id );
+		$object['object']['url'] = $url;
+
+		Activitypub\Collection\Interactions::add_comment( $object );
+		$comment = \Activitypub\object_id_to_comment( $id );
+		$interactions = Activitypub\Collection\Interactions::get_interaction_by_id( $id );
+		$this->assertIsArray( $interactions );
+		$this->assertEquals( $comment->comment_ID, $interactions[0]->comment_ID );
+
+		$comment = \Activitypub\object_id_to_comment( $id );
+		$interactions = Activitypub\Collection\Interactions::get_interaction_by_id( $url );
+		$this->assertIsArray( $interactions );
+		$this->assertEquals( $comment->comment_ID, $interactions[0]->comment_ID );
+	}
+}

tests/test-class-activitypub-rest-inbox.php

@@ -5,7 +5,7 @@ class Test_Activitypub_Rest_Inbox extends WP_UnitTestCase {
 	 */
 	public function test_is_activity_public( $data, $check ) {
 
-		$this->assertEquals( $check, Activitypub\Rest\Inbox::is_activity_public( $data ) );
+		$this->assertEquals( $check, Activitypub\is_activity_public( $data ) );
 	}
 
 	public function the_data_provider() {

tests/test-functions.php

@@ -1,9 +1,80 @@
 <?php
 class Test_Functions extends ActivityPub_TestCase_Cache_HTTP {
+	public $user_id;
+	public $post_id;
+
 	public function test_get_remote_metadata_by_actor() {
 		$metadata = \ActivityPub\get_remote_metadata_by_actor( 'pfefferle@notiz.blog' );
 		$this->assertEquals( 'https://notiz.blog/author/matthias-pfefferle/', $metadata['url'] );
 		$this->assertEquals( 'pfefferle', $metadata['preferredUsername'] );
 		$this->assertEquals( 'Matthias Pfefferle', $metadata['name'] );
 	}
+
+	public function set_up() {
+		$this->post_id = \wp_insert_post(
+			array(
+				'post_author' => $this->user_id,
+				'post_content' => 'test',
+			)
+		);
+	}
+
+	public function test_object_id_to_comment_basic() {
+		$single_comment_source_id = 'https://example.com/single';
+		$content = 'example';
+		$comment_id = \wp_new_comment(
+			array(
+				'comment_post_ID' => $this->post_id,
+				'comment_author' => 'Example User',
+				'comment_author_url' => 'https://example.com/user',
+				'comment_content' => $content,
+				'comment_type' => '',
+				'comment_author_email' => '',
+				'comment_parent' => 0,
+				'comment_meta' => array(
+					'source_id' => $single_comment_source_id,
+					'source_url' => 'https://example.com/123',
+					'avatar_url' => 'https://example.com/icon',
+					'protocol' => 'activitypub',
+				),
+			),
+			true
+		);
+		$query_result = \Activitypub\object_id_to_comment( $single_comment_source_id );
+		$this->assertInstanceOf( WP_Comment::class, $query_result );
+		$this->assertEquals( $comment_id, $query_result->comment_ID );
+		$this->assertEquals( $content, $query_result->comment_content );
+	}
+
+	public function test_object_id_to_comment_none() {
+		$single_comment_source_id = 'https://example.com/none';
+		$query_result = \Activitypub\object_id_to_comment( $single_comment_source_id );
+		$this->assertFalse( $query_result );
+	}
+
+	public function test_object_id_to_comment_duplicate() {
+		$duplicate_comment_source_id = 'https://example.com/duplicate';
+		for ( $i = 0; $i < 2; ++$i ) {
+			\wp_new_comment(
+				array(
+					'comment_post_ID' => $this->post_id,
+					'comment_author' => 'Example User',
+					'comment_author_url' => 'https://example.com/user',
+					'comment_content' => 'example',
+					'comment_type' => '',
+					'comment_author_email' => '',
+					'comment_parent' => 0,
+					'comment_meta' => array(
+						'source_id' => $duplicate_comment_source_id,
+						'source_url' => 'https://example.com/123',
+						'avatar_url' => 'https://example.com/icon',
+						'protocol' => 'activitypub',
+					),
+				),
+				true
+			);
+		}
+		$query_result = \Activitypub\object_id_to_comment( $duplicate_comment_source_id );
+		$this->assertFalse( $query_result );
+	}
 }