<?php
/**
* ActivityPub Comment Class
*
* @package Activitypub
*/
namespace Activitypub;
use Activitypub\Collection\Users;
use WP_Comment_Query;
/**
* ActivityPub Comment Class.
*
* This class is a helper/utils class that provides a collection of static
* methods that are used to handle comments.
*/
class Comment {
/**
* Initialize the class, registering WordPress hooks.
*/
public static function init() {
self::register_comment_types();
\add_filter( 'comment_reply_link', array( self::class, 'comment_reply_link' ), 10, 3 );
\add_filter( 'comment_class', array( self::class, 'comment_class' ), 10, 3 );
\add_filter( 'get_comment_link', array( self::class, 'remote_comment_link' ), 11, 3 );
\add_action( 'wp_enqueue_scripts', array( self::class, 'enqueue_scripts' ) );
\add_action( 'pre_get_comments', array( static::class, 'comment_query' ) );
\add_filter( 'get_avatar_comment_types', array( static::class, 'get_avatar_comment_types' ), 99 );
}
/**
* Filter the comment reply link.
*
* We don't want to show the comment reply link for federated comments
* if the user is disabled for federation.
*
* @param string $link The HTML markup for the comment reply link.
* @param array $args An array of arguments overriding the defaults.
* @param \WP_Comment $comment The object of the comment being replied.
*
* @return string The filtered HTML markup for the comment reply link.
*/
public static function comment_reply_link( $link, $args, $comment ) {
if ( self::are_comments_allowed( $comment ) ) {
$user_id = get_current_user_id();
if ( $user_id && self::was_received( $comment ) && \user_can( $user_id, 'activitypub' ) ) {
return self::create_fediverse_reply_link( $link, $args );
}
return $link;
}
$attrs = array(
'selectedComment' => self::generate_id( $comment ),
'commentId' => $comment->comment_ID,
);
$div = sprintf(
'<div class="activitypub-remote-reply" data-attrs="%s"></div>',
esc_attr( wp_json_encode( $attrs ) )
);
return apply_filters( 'activitypub_comment_reply_link', $div );
}
/**
* Create a link to reply to a federated comment.
*
* This function adds a title attribute to the reply link to inform the user
* that the comment was received from the fediverse and the reply will be sent
* to the original author.
*
* @param string $link The HTML markup for the comment reply link.
* @param array $args The args provided by the `comment_reply_link` filter.
*
* @return string The modified HTML markup for the comment reply link.
*/
private static function create_fediverse_reply_link( $link, $args ) {
$str_to_replace = sprintf( '>%s<', $args['reply_text'] );
$replace_with = sprintf(
' title="%s">%s<',
esc_attr__( 'This comment was received from the fediverse and your reply will be sent to the original author', 'activitypub' ),
esc_html__( 'Reply with federation', 'activitypub' )
);
return str_replace( $str_to_replace, $replace_with, $link );
}
/**
* Check if it is allowed to comment to a comment.
*
* Checks if the comment is local only or if the user can comment federated comments.
*
* @param mixed $comment Comment object or ID.
*
* @return boolean True if the user can comment, false otherwise.
*/
public static function are_comments_allowed( $comment ) {
$comment = \get_comment( $comment );
if ( ! self::was_received( $comment ) ) {
return true;
}
$current_user = get_current_user_id();
if ( ! $current_user ) {
return false;
}
if ( is_single_user() && \user_can( $current_user, 'publish_posts' ) ) {
// On a single user site, comments by users with the `publish_posts` capability will be federated as the blog user.
$current_user = Users::BLOG_USER_ID;
}
$is_user_disabled = is_user_disabled( $current_user );
if ( $is_user_disabled ) {
return false;
}
return true;
}
/**
* Check if a comment is federated.
*
* We consider a comment federated if comment was received via ActivityPub.
*
* Use this function to check if it is comment that was received via ActivityPub.
*
* @param mixed $comment Comment object or ID.
*
* @return boolean True if the comment is federated, false otherwise.
*/
public static function was_received( $comment ) {
$comment = \get_comment( $comment );
if ( ! $comment ) {
return false;
}
$protocol = \get_comment_meta( $comment->comment_ID, 'protocol', true );
if ( 'activitypub' === $protocol ) {
return true;
}
return false;
}
/**
* Check if a comment was federated.
*
* This function checks if a comment was federated via ActivityPub.
*
* @param mixed $comment Comment object or ID.
*
* @return boolean True if the comment was federated, false otherwise.
*/
public static function was_sent( $comment ) {
$comment = \get_comment( $comment );
if ( ! $comment ) {
return false;
}
$status = \get_comment_meta( $comment->comment_ID, 'activitypub_status', true );
if ( $status ) {
return true;
}
return false;
}
/**
* Check if a comment is local only.
*
* This function checks if a comment is local only and was not sent or received via ActivityPub.
*
* @param mixed $comment Comment object or ID.
*
* @return boolean True if the comment is local only, false otherwise.
*/
public static function is_local( $comment ) {
if ( self::was_sent( $comment ) || self::was_received( $comment ) ) {
return false;
}
return true;
}
/**
* Check if a comment should be federated.
*
* We consider a comment should be federated if it is authored by a user that is
* not disabled for federation and if it is a reply directly to the post or to a
* federated comment.
*
* Use this function to check if a comment should be federated.
*
* @param mixed $comment Comment object or ID.
*
* @return boolean True if the comment should be federated, false otherwise.
*/
public static function should_be_federated( $comment ) {
// We should not federate federated comments.
if ( self::was_received( $comment ) ) {
return false;
}
$comment = \get_comment( $comment );
$user_id = $comment->user_id;
// Comments without user can't be federated.
if ( ! $user_id ) {
return false;
}
if ( is_single_user() && \user_can( $user_id, 'publish_posts' ) ) {
// On a single user site, comments by users with the `publish_posts` capability will be federated as the blog user.
$user_id = Users::BLOG_USER_ID;
}
$is_user_disabled = is_user_disabled( $user_id );
// User is disabled for federation.
if ( $is_user_disabled ) {
return false;
}
// It is a comment to the post and can be federated.
if ( empty( $comment->comment_parent ) ) {
return true;
}
// Check if parent comment is federated.
$parent_comment = \get_comment( $comment->comment_parent );
return ! self::is_local( $parent_comment );
}
/**
* 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|false Comment object, or false on failure.
*/
public static 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 string|null Comment ID or null if not found.
*/
public static function url_to_commentid( $url ) {
if ( ! $url || ! filter_var( $url, \FILTER_VALIDATE_URL ) ) {
return null;
}
// Check for local comment.
if ( \wp_parse_url( \home_url(), \PHP_URL_HOST ) === \wp_parse_url( $url, \PHP_URL_HOST ) ) {
$query = \wp_parse_url( $url, \PHP_URL_QUERY );
if ( $query ) {
parse_str( $query, $params );
if ( ! empty( $params['c'] ) ) {
$comment = \get_comment( $params['c'] );
if ( $comment ) {
return $comment->comment_ID;
}
}
}
}
$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;
}
/**
* Filters the CSS classes to add an ActivityPub class.
*
* @param string[] $classes An array of comment classes.
* @param string[] $css_class An array of additional classes added to the list.
* @param string $comment_id The comment ID as a numeric string.
*
* @return string[] An array of classes.
*/
public static function comment_class( $classes, $css_class, $comment_id ) {
// Check if ActivityPub comment.
if ( 'activitypub' === get_comment_meta( $comment_id, 'protocol', true ) ) {
$classes[] = 'activitypub-comment';
}
return $classes;
}
/**
* Gets the public comment id via the WordPress comments meta.
*
* @param int $wp_comment_id The internal WordPress comment ID.
* @param bool $fallback Whether the code should fall back to `source_url` if `source_id` is not set.
*
* @return string|null The ActivityPub id/url of the comment.
*/
public static function get_source_id( $wp_comment_id, $fallback = true ) {
$comment_meta = \get_comment_meta( $wp_comment_id );
if ( ! empty( $comment_meta['source_id'][0] ) ) {
return $comment_meta['source_id'][0];
} elseif ( ! empty( $comment_meta['source_url'][0] ) && $fallback ) {
return $comment_meta['source_url'][0];
}
return null;
}
/**
* Gets the public comment url via the WordPress comments meta.
*
* @param int $wp_comment_id The internal WordPress comment ID.
* @param bool $fallback Whether the code should fall back to `source_id` if `source_url` is not set.
*
* @return string|null The ActivityPub id/url of the comment.
*/
public static function get_source_url( $wp_comment_id, $fallback = true ) {
$comment_meta = \get_comment_meta( $wp_comment_id );
if ( ! empty( $comment_meta['source_url'][0] ) ) {
return $comment_meta['source_url'][0];
} elseif ( ! empty( $comment_meta['source_id'][0] ) && $fallback ) {
return $comment_meta['source_id'][0];
}
return null;
}
/**
* Link remote comments to source url.
*
* @param string $comment_link The comment link.
* @param object|\WP_Comment $comment The comment object.
*
* @return string $url
*/
public static function remote_comment_link( $comment_link, $comment ) {
if ( ! $comment || is_admin() ) {
return $comment_link;
}
$public_comment_link = self::get_source_url( $comment->comment_ID );
return $public_comment_link ?? $comment_link;
}
/**
* Generates an ActivityPub URI for a comment
*
* @param \WP_Comment|int $comment A comment object or comment ID.
*
* @return string ActivityPub URI for comment
*/
public static function generate_id( $comment ) {
$comment = \get_comment( $comment );
// Show external comment ID if it exists.
$public_comment_link = self::get_source_id( $comment->comment_ID );
if ( $public_comment_link ) {
return $public_comment_link;
}
// Generate URI based on comment ID.
return \add_query_arg( 'c', $comment->comment_ID, \trailingslashit( \home_url() ) );
}
/**
* Check if a post has remote comments
*
* @param int $post_id The post ID.
*
* @return bool True if the post has remote comments, false otherwise.
*/
private static function post_has_remote_comments( $post_id ) {
$comments = \get_comments(
array(
'post_id' => $post_id,
// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
'meta_query' => array(
'relation' => 'AND',
array(
'key' => 'protocol',
'value' => 'activitypub',
'compare' => '=',
),
array(
'key' => 'source_id',
'compare' => 'EXISTS',
),
),
)
);
return ! empty( $comments );
}
/**
* Enqueue scripts for remote comments
*/
public static function enqueue_scripts() {
if ( ! \is_singular() || \is_user_logged_in() ) {
// Only on single pages, only for logged-out users.
return;
}
if ( ! \post_type_supports( \get_post_type(), 'activitypub' ) ) {
// Post type does not support ActivityPub.
return;
}
if ( ! \comments_open() || ! \get_comments_number() ) {
// No comments, no need to load the script.
return;
}
if ( ! self::post_has_remote_comments( \get_the_ID() ) ) {
// No remote comments, no need to load the script.
return;
}
$handle = 'activitypub-remote-reply';
$data = array(
'namespace' => ACTIVITYPUB_REST_NAMESPACE,
);
$js = sprintf( 'var _activityPubOptions = %s;', wp_json_encode( $data ) );
$asset_file = ACTIVITYPUB_PLUGIN_DIR . 'build/remote-reply/index.asset.php';
if ( \file_exists( $asset_file ) ) {
$assets = require_once $asset_file;
\wp_enqueue_script(
$handle,
\plugins_url( 'build/remote-reply/index.js', __DIR__ ),
$assets['dependencies'],
$assets['version'],
true
);
\wp_add_inline_script( $handle, $js, 'before' );
\wp_enqueue_style(
$handle,
\plugins_url( 'build/remote-reply/style-index.css', __DIR__ ),
array( 'wp-components' ),
$assets['version']
);
}
}
/**
* Return the registered custom comment types.
*
* @return array The registered custom comment types
*/
public static function get_comment_types() {
global $activitypub_comment_types;
return $activitypub_comment_types;
}
/**
* Is this a registered comment type.
*
* @param string $slug The name of the type.
* @return boolean True if registered.
*/
public static function is_registered_comment_type( $slug ) {
$slug = strtolower( $slug );
$slug = sanitize_key( $slug );
return in_array( $slug, array_keys( self::get_comment_types() ), true );
}
/**
* Return the registered custom comment types names.
*
* @return array The registered custom comment type names.
*/
public static function get_comment_type_names() {
return array_values( wp_list_pluck( self::get_comment_types(), 'type' ) );
}
/**
* Get a comment type.
*
* @param string $type The comment type.
*
* @return array The comment type.
*/
public static function get_comment_type( $type ) {
$type = strtolower( $type );
$type = sanitize_key( $type );
$types = self::get_comment_types();
if ( in_array( $type, array_keys( $types ), true ) ) {
$type_array = $types[ $type ];
} else {
$type_array = array();
}
/**
* Filter the comment type.
*
* @param array $type_array The comment type.
*/
return apply_filters( "activitypub_comment_type_{$type}", $type_array );
}
/**
* Get a comment type attribute.
*
* @param string $type The comment type.
* @param string $attr The attribute to get.
*
* @return mixed The value of the attribute.
*/
public static function get_comment_type_attr( $type, $attr ) {
$type_array = self::get_comment_type( $type );
if ( $type_array && isset( $type_array[ $attr ] ) ) {
$value = $type_array[ $attr ];
} else {
$value = '';
}
/**
* Filter the comment type attribute.
*
* @param mixed $value The value of the attribute.
* @param string $type The comment type.
*/
return apply_filters( "activitypub_comment_type_{$attr}", $value, $type );
}
/**
* Register the comment types used by the ActivityPub plugin.
*/
public static function register_comment_types() {
register_comment_type(
'announce',
array(
'label' => __( 'Reposts', 'activitypub' ),
'singular' => __( 'Repost', 'activitypub' ),
'description' => __( 'A repost on the indieweb is a post that is purely a 100% re-publication of another (typically someone else\'s) post.', 'activitypub' ),
'icon' => '♻️',
'class' => 'p-repost',
'type' => 'repost',
// translators: %1$s username, %2$s object format (post, audio, ...), %3$s URL, %4$s domain.
'excerpt' => __( '… reposted this!', 'activitypub' ),
)
);
register_comment_type(
'like',
array(
'label' => __( 'Likes', 'activitypub' ),
'singular' => __( 'Like', 'activitypub' ),
'description' => __( 'A like is a popular webaction button and in some cases post type on various silos such as Facebook and Instagram.', 'activitypub' ),
'icon' => '👍',
'class' => 'p-like',
'type' => 'like',
// translators: %1$s username, %2$s object format (post, audio, ...), %3$s URL, %4$s domain.
'excerpt' => __( '… liked this!', 'activitypub' ),
)
);
}
/**
* Show avatars on Activities if set.
*
* @param array $types List of avatar enabled comment types.
*
* @return array show avatars on Activities
*/
public static function get_avatar_comment_types( $types ) {
$comment_types = self::get_comment_type_names();
$types = array_merge( $types, $comment_types );
return array_unique( $types );
}
/**
* Excludes likes and reposts from comment queries.
*
* @author Jan Boddez
*
* @see https://github.com/janboddez/indieblocks/blob/a2d59de358031056a649ee47a1332ce9e39d4ce2/includes/functions.php#L423-L432
*
* @param WP_Comment_Query $query Comment count.
*/
public static function comment_query( $query ) {
if ( ! $query instanceof WP_Comment_Query ) {
return;
}
if ( is_admin() || ! is_singular() ) {
return;
}
if ( ! empty( $query->query_vars['type__in'] ) ) {
return;
}
if ( isset( $query->query_vars['count'] ) && true === $query->query_vars['count'] ) {
return;
}
// Exclude likes and reposts by the Webmention plugin.
$query->query_vars['type__not_in'] = self::get_comment_type_names();
}
}