laipower/wp-content/plugins/activitypub/includes/class-comment.php

<?php

namespace Activitypub;

use Activitypub\Collection\Users;
use WP_Comment_Query;

use function Activitypub\is_user_disabled;
use function Activitypub\is_single_user;

/**
 * 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() {
		\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' ) );
	}

	/**
	 * 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 int 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;
	}

	/**
	 * 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 ) {
		if ( ! $comment || is_admin() ) {
			return $comment_link;
		}

		$comment_meta = \get_comment_meta( $comment->comment_ID );

		if ( ! empty( $comment_meta['source_url'][0] ) ) {
			return $comment_meta['source_url'][0];
		} elseif ( ! empty( $comment_meta['source_id'][0] ) ) {
			return $comment_meta['source_id'][0];
		}

		return $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 );
		$comment_meta = \get_comment_meta( $comment->comment_ID );

		// show external comment ID if it exists
		if ( ! empty( $comment_meta['source_id'][0] ) ) {
			return $comment_meta['source_id'][0];
		} elseif ( ! empty( $comment_meta['source_url'][0] ) ) {
			return $comment_meta['source_url'][0];
		}

		// 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,
				'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__ ),
				[ 'wp-components' ],
				$assets['version']
			);
		}
	}
}