wordpress-activitypub/includes/functions.php
2023-10-27 08:27:12 -06:00

721 lines
18 KiB
PHP

<?php
namespace Activitypub;
use WP_Error;
use Activitypub\Http;
use Activitypub\Activity\Activity;
use Activitypub\Collection\Followers;
/**
* Returns the ActivityPub default JSON-context
*
* @return array the activitypub context
*/
function get_context() {
$context = Activity::CONTEXT;
return \apply_filters( 'activitypub_json_context', $context );
}
function safe_remote_post( $url, $body, $user_id ) {
return Http::post( $url, $body, $user_id );
}
function safe_remote_get( $url ) {
return Http::get( $url );
}
/**
* Returns a users WebFinger "resource"
*
* @param int $user_id The User-ID.
*
* @return string The User-Resource.
*/
function get_webfinger_resource( $user_id ) {
return Webfinger::get_user_resource( $user_id );
}
/**
* Requests the Meta-Data from the Actors profile
*
* @param string $actor The Actor URL.
* @param bool $cached If the result should be cached.
*
* @return array|WP_Error The Actor profile as array or WP_Error on failure.
*/
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 ) ) {
$metadata = new WP_Error( 'activitypub_no_valid_actor_url', \__( 'The "actor" is no valid URL', 'activitypub' ), array( 'status' => 400, 'actor' => $actor ) );
return $metadata;
}
$response = Http::get( $actor );
if ( \is_wp_error( $response ) ) {
return $response;
}
$metadata = \wp_remote_retrieve_body( $response );
$metadata = \json_decode( $metadata, true );
if ( ! $metadata ) {
$metadata = new WP_Error( 'activitypub_invalid_json', \__( 'No valid JSON data', 'activitypub' ), array( 'status' => 400, 'actor' => $actor ) );
return $metadata;
}
\set_transient( $transient_key, $metadata, WEEK_IN_SECONDS );
return $metadata;
}
/**
* Returns the followers of a given user.
*
* @param int $user_id The User-ID.
*
* @return array The followers.
*/
function get_followers( $user_id ) {
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 ) {
return Followers::count_followers( $user_id );
}
/**
* Examine a url and try to determine the author ID it represents.
*
* Checks are supposedly from the hosted site blog.
*
* @param string $url Permalink to check.
*
* @return int User ID, or 0 on failure.
*/
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 ) ) {
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] );
if ( $id ) {
return $id;
}
}
// check to see if we are using rewrite rules
$rewrite = $wp_rewrite->wp_rewrite_rules();
// not using rewrite rules, and 'author=N' method failed, so we're out of options
if ( empty( $rewrite ) ) {
return 0;
}
// generate rewrite rule for the author url
$author_rewrite = $wp_rewrite->get_author_permastruct();
$author_regexp = \str_replace( '%author%', '', $author_rewrite );
// 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] );
if ( $user ) {
return $user->ID;
}
}
return 0;
}
/**
* Examine a comment ID and look up an existing comment it represents.
*
* @param string $id ActivityPub object ID (usually a URL) to check.
*
* @return WP_Comment, or undef if no comment could be found.
*/
function object_id_to_comment( $id ) {
$comment_query = new \WP_Comment_Query(
array(
'meta_key' => 'source_id',
'meta_value' => $id,
)
);
if ( ! $comment_query->comments ) {
return;
}
if ( count( $comment_query->comments ) > 1 ) {
\error_log( "More than one comment under {$id}" );
return;
}
return $comment_query->comments[0];
}
/**
* Examine an activity object and find the post that the specified URL field refers to.
*
* @param string $field_name The name of the URL field in the object to query.
*
* @return int Post ID, or null on failure.
*/
function object_to_post_id_by_field_name( $object, $field_name ) {
if ( ! isset( $object['object'][ $field_name ] ) ) {
return;
}
$result = \url_to_postid( $object['object'][ $field_name ] );
if ( $result > 0 ) {
return $result;
}
}
/**
* Verify if in_replyto_url is a local Post,
* (For backwards compatibility)
*
* @param string activitypub object id URI
* @return int post_id
*/
function url_to_postid( $in_replyto_url ) {
if ( ! empty( $in_replyto_url ) ) {
$tentative_postid = \url_to_postid( $in_replyto_url );
if ( is_null( $tentative_postid ) ) {
$post_types = \get_option( 'activitypub_support_post_types', array( 'post', 'page' ) );
$query_args = array(
'type' => $post_types,
'meta_query' => array(
array(
'key' => 'activitypub_canonical_url',
'value' => $in_replyto_url,
),
),
);
$posts_query = new \WP_Query();
$posts = $posts_query->query( $query_args );
$found_post_ids = array();
if ( $posts ) {
foreach ( $posts as $post ) {
$found_post_ids[] = $post->comment_ID;
}
return $found_post_ids[0];
}
} else {
return $tentative_postid;
}
}
return null;
}
/**
* Verify if in_replyto_url is a local comment,
* Or if it is a previously received remote comment
* (For threading comments locally)
*
* @param string activitypub object id URI
* @return int comment_id
*/
function url_to_commentid( $in_replyto_url ) {
if ( empty( $in_replyto_url ) ) {
return null;
}
//rewrite for activitypub object id simplification
$url_maybe_id = \wp_parse_url( $in_replyto_url );
if ( site_url() === $url_maybe_id['scheme'] . '://' . $url_maybe_id['host'] && ! empty( $url_maybe_id['query'] ) ) {
//is local post or comment
\parse_str( $url_maybe_id['query'], $reply_query );
if ( isset( $reply_query['replytocom'] ) ) {
//is local comment
return $reply_query['replytocom'];
}
} else {
//is remote url
//verify if in_replyto_url corresponds to a previously received comment
$comment_args = array(
'type' => 'activitypub',
'meta_query' => array(
array(
'key' => 'source_url', // $object['object']['id']
'value' => $in_replyto_url,
),
),
);
$comments_query = new \WP_Comment_Query();
$comments = $comments_query->query( $comment_args );
$found_comment_ids = array();
if ( $comments ) {
foreach ( $comments as $comment ) {
$found_comment_ids[] = $comment->comment_ID;
}
return $found_comment_ids[0];
}
}
return null;
}
/**
* Verify if url is a wp_ap_comment,
* Or if it is a previously received remote comment
*
* @return int comment_id
*/
function is_comment() {
$comment_id = get_query_var( 'replytocom', null );
if ( ! is_null( $comment_id ) ) {
$comment = \get_comment( $comment_id );
// Only return local origin comments
if ( $comment->user_id ) {
return $comment_id;
}
}
return null;
}
/**
* Verify if url has a replies query,
* @return bool
*/
function is_replies() {
$replies = get_query_var( 'replies' );
if ( $replies ) {
return $replies;
}
return null;
}
/**
* Get recipients to insert/tag in reply tag from received AP object meta
* @param string $object_id a comment_id to search
* @param boolean $post defaults to searching a comment_id
* @return string space separated webfinger of tagged users
*/
function reply_recipients( $object_id, $post = null ) {
$recipients = null;
if ( $post ) {
//post
$ap_object = \unserialize( \get_post_meta( $object_id, 'ap_object', true ) );
} else {
//comment
$ap_object = \unserialize( \get_comment_meta( $object_id, 'ap_object', true ) );
}
if ( ! empty( $ap_object ) ) {
// Replying to remote comments.
$recipients[] = \ActivityPub\url_to_webfinger( $ap_object['actor'] ); // Reply to Object actor!
if ( ! empty( $ap_object['object']['tag'] ) ) { // Reply to other tagged users.
if ( isset( $ap_object['user_id'] ) ) {
$author_post_url = \get_author_posts_url( $ap_object['user_id'] );// ignore self tag.
foreach ( $ap_object['object']['tag'] as $tag ) { // Other tagged users
if ( $author_post_url === $tag['href'] ) {
continue;
}
if ( in_array( 'Mention', $tag ) ) {
$recipients[] = $tag['name'];
}
}
}
}
return implode( ' ', $recipients );
} else {
// Replying to self with others.
$comment = \get_comment( $object_id );
preg_match_all( '/@' . ACTIVITYPUB_USERNAME_REGEXP . '/', $comment->comment_content, $recipients );
return implode( ' ', $recipients[0] );
}
}
/**
* Add summary to reply
*/
function get_summary( $comment_id ) {
$ap_object = \unserialize( \get_comment_meta( $comment_id, 'ap_object', true ) );
if ( ! empty( $ap_object ) ) {
if ( ! empty( $ap_object['object']['summary'] ) ) {
return \esc_attr( $ap_object['object']['summary'] );
}
}
}
/**
* @param string $user_url
* @return string $webfinger
*/
function url_to_webfinger( $user_url ) {
$user_url = \untrailingslashit( $user_url );
$user_url_array = \explode( '/', $user_url );
$user_name = \end( $user_url_array );
$url_host = \wp_parse_url( $user_url, PHP_URL_HOST );
$webfinger = '@' . $user_name . '@' . $url_host;
return $webfinger;
}
/**
* Determine AP audience of incoming object
* @param string $object
* @return string audience
*/
function get_audience( $object ) {
if ( in_array( AS_PUBLIC, $object['to'] ) ) {
return 'public';
}
if ( in_array( AS_PUBLIC, $object['cc'] ) ) {
return 'unlisted';
}
if ( ! in_array( AS_PUBLIC, $object['to'] ) && ! in_array( AS_PUBLIC, $object['cc'] ) ) {
$author_post_url = get_author_posts_url( $object['user_id'] );
if ( in_array( $author_post_url, $object['cc'] ) ) {
return 'followers_only';
}
if ( in_array( $author_post_url, $object['to'] ) ) {
return 'private';
}
}
}
/**
* 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;
}
// 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 ) );
}