Add a parser to the Friends Plugin

activitypub.php

@@ -132,3 +132,11 @@ function enable_buddypress_features() {
 	\Activitypub\Integration\Buddypress::init();
 }
 add_action( 'bp_include', '\Activitypub\enable_buddypress_features' );
+
+add_action(
+	'friends_load_parsers',
+	function( \Friends\Feed $friends_feed ) {
+		require_once __DIR__ . '/integration/class-friends-feed-parser-activitypub.php';
+		$friends_feed->register_parser( Friends_Feed_Parser_ActivityPub::SLUG, new Friends_Feed_Parser_ActivityPub( $friends_feed ) );
+	}
+);

includes/class-health-check.php

@@ -1,6 +1,8 @@
 <?php
 namespace Activitypub;
 
+use Activitypub\Rest\Webfinger;
+
 /**
  * ActivityPub Health_Check Class
  *
@@ -198,58 +200,37 @@ class Health_Check {
 	 * @return boolean|WP_Error
 	 */
 	public static function is_webfinger_endpoint_accessible() {
-		$user      = \wp_get_current_user();
+		$user    = \wp_get_current_user();
-		$webfinger = \Activitypub\get_webfinger_resource( $user->ID );
+		$account = \Activitypub\get_webfinger_resource( $user->ID );
 
-		$url = \wp_parse_url( \home_url(), \PHP_URL_SCHEME ) . '://' . \wp_parse_url( \home_url(), \PHP_URL_HOST );
+		$url = Webfinger::resolve( $account );
-
+		if ( \is_wp_error( $url ) ) {
-		if ( \wp_parse_url( \home_url(), \PHP_URL_PORT ) ) {
+			$health_messages = array(
-			$url .= ':' . \wp_parse_url( \home_url(), \PHP_URL_PORT );
+				'webfinger_url_not_accessible' => \sprintf(
-		}
-
-		$url = \trailingslashit( $url ) . '.well-known/webfinger';
-
-		$url = \add_query_arg( 'resource', 'acct:' . $webfinger, $url );
-
-		// try to access author URL
-		$response = \wp_remote_get(
-			$url,
-			array(
-				'headers' => array( 'Accept' => 'application/activity+json' ),
-				'redirection' => 0,
-			)
-		);
-
-		if ( \is_wp_error( $response ) ) {
-			return new \WP_Error(
-				'webfinger_url_not_accessible',
-				\sprintf(
 					// translators: %s: Author URL
 					\__(
 						'<p>Your WebFinger endpoint <code>%s</code> is not accessible. Please check your WordPress setup or permalink structure.</p>',
 						'activitypub'
 					),
-					$url
+					$url->get_error_data()
-				)
+				),
-			);
+				'webfinger_url_invalid_response' => \sprintf(
-		}
-
-		$response_code = \wp_remote_retrieve_response_code( $response );
-
-		// check if response is JSON
-		$body = \wp_remote_retrieve_body( $response );
-
-		if ( ! \is_string( $body ) || ! \is_array( \json_decode( $body, true ) ) ) {
-			return new \WP_Error(
-				'webfinger_url_not_accessible',
-				\sprintf(
 					// translators: %s: Author URL
 					\__(
 						'<p>Your WebFinger endpoint <code>%s</code> does not return valid JSON for <code>application/jrd+json</code>.</p>',
 						'activitypub'
 					),
-					$url
+					$url->get_error_data()
-				)
+				),
+			);
+			$message = null;
+			if ( isset( $messages[ $url->get_error_code() ] ) ) {
+				$message = $health_messages[ $url->get_error_code() ];
+			}
+			return new \WP_Error(
+				$url->get_error_code(),
+				$message,
+				$url->get_error_data()
 			);
 		}
 

includes/functions.php

@@ -108,11 +108,19 @@ function get_webfinger_resource( $user_id ) {
 /**
  * [get_metadata_by_actor description]
  *
- * @param sting $actor
+ * @param string $actor
  *
  * @return array
  */
 function get_remote_metadata_by_actor( $actor ) {
+	if ( preg_match( '/^@?[^@]+@((?:[a-z0-9-]+\.)+[a-z]+)$/i', $actor ) ) {
+		$actor = Rest\Webfinger::resolve( $actor );
+	}
+
+	if ( ! $actor ) {
+		return null;
+	}
+
 	$metadata = \get_transient( 'activitypub_' . $actor );
 
 	if ( $metadata ) {

includes/model/class-activity.php

@@ -75,7 +75,7 @@ class Activity {
 	}
 
 	public function to_array() {
-		$array = \get_object_vars( $this );
+		$array = array_filter( \get_object_vars( $this ) );
 
 		if ( $this->context ) {
 			$array = array( '@context' => $this->context ) + $array;

includes/rest/class-inbox.php

@@ -161,7 +161,6 @@ class Inbox {
 	public static function shared_inbox_post( $request ) {
 		$data = $request->get_params();
 		$type = $request->get_param( 'type' );
-
 		$users = self::extract_recipients( $data );
 
 		if ( ! $users ) {
@@ -407,6 +406,10 @@ class Inbox {
 	public static function handle_create( $object, $user_id ) {
 		$meta = \Activitypub\get_remote_metadata_by_actor( $object['actor'] );
 
+		if ( ! isset( $object['object']['inReplyTo'] ) ) {
+			return;
+		}
+
 		$comment_post_id = \url_to_postid( $object['object']['inReplyTo'] );
 
 		// save only replys and reactions

includes/rest/class-webfinger.php

@@ -120,4 +120,44 @@ class Webfinger {
 
 		return $array;
 	}
+
+	public static function resolve( $account ) {
+		if ( ! preg_match( '/^@?[^@]+@((?:[a-z0-9-]+\.)+[a-z]+)$/i', $account, $m ) ) {
+			return null;
+		}
+		$url = \add_query_arg( 'resource', 'acct:' . ltrim( $account, '@' ), 'https://' . $m[1] . '/.well-known/webfinger' );
+		if ( ! \wp_http_validate_url( $url ) ) {
+			return new \WP_Error( 'invalid_webfinger_url', null, $url );
+		}
+
+		// try to access author URL
+		$response = \wp_remote_get(
+			$url,
+			array(
+				'headers' => array( 'Accept' => 'application/activity+json' ),
+				'redirection' => 0,
+			)
+		);
+
+		if ( \is_wp_error( $response ) ) {
+			return new \WP_Error( 'webfinger_url_not_accessible', null, $url );
+		}
+
+		$response_code = \wp_remote_retrieve_response_code( $response );
+
+		$body = \wp_remote_retrieve_body( $response );
+		$body = \json_decode( $body, true );
+
+		if ( ! isset( $body['links'] ) ) {
+			return new \WP_Error( 'webfinger_url_invalid_response', null, $url );
+		}
+
+		foreach ( $body['links'] as $link ) {
+			if ( $link['rel'] === 'self' && $link['type'] == 'application/activity+json' ) {
+				return $link['href'];
+			}
+		}
+
+		return new \WP_Error( 'webfinger_url_no_activity_pub', null, $body );
+	}
 }

integration/class-friends-feed-parser-activitypub.php

@@ -0,0 +1,198 @@
+<?php
+/**
+ * This is the class for integrating ActivityPub into the Friends Plugin.
+ *
+ * @since 0.14
+ *
+ * @package ActivityPub
+ * @author Alex Kirk
+ */
+namespace Activitypub;
+
+class Friends_Feed_Parser_ActivityPub extends \Friends\Feed_Parser {
+	const SLUG = 'activitypub';
+	const NAME = 'ActivityPub';
+	const URL = 'https://www.w3.org/TR/activitypub/';
+	private $friends_feed;
+
+	public function __construct( \Friends\Feed $friends_feed ) {
+		$this->friends_feed = $friends_feed;
+
+		\add_action( 'activitypub_inbox_create', array( $this, 'handle_received_activity' ), 10, 2 );
+		\add_action( 'activitypub_inbox_accept', array( $this, 'handle_received_activity' ), 10, 2 );
+		\add_filter( 'friends_user_feed_activated', array( $this, 'follow_user' ), 10 );
+		\add_filter( 'friends_user_feed_deactivated', array( $this, 'unfollow_user' ), 10 );
+		\add_filter( 'friends_rewrite_incoming_url', array( $this, 'friends_rewrite_incoming_url' ), 10, 2 );
+	}
+
+	/**
+	 * Determines if this is a supported feed and to what degree we feel it's supported.
+	 *
+	 * @param      string      $url        The url.
+	 * @param      string      $mime_type  The mime type.
+	 * @param      string      $title      The title.
+	 * @param      string|null $content    The content, it can't be assumed that it's always available.
+	 *
+	 * @return     int  Return 0 if unsupported, a positive value representing the confidence for the feed, use 10 if you're reasonably confident.
+	 */
+	public function feed_support_confidence( $url, $mime_type, $title, $content = null ) {
+		if ( preg_match( '/^@?[^@]+@((?:[a-z0-9-]+\.)+[a-z]+)$/i', $url ) ) {
+			return 10;
+		}
+
+		return 0;
+	}
+
+	/**
+	 * Format the feed title and autoselect the posts feed.
+	 *
+	 * @param      array $feed_details  The feed details.
+	 *
+	 * @return     array  The (potentially) modified feed details.
+	 */
+	public function update_feed_details( $feed_details ) {
+		$meta = \Activitypub\get_remote_metadata_by_actor( $feed_details['url'] );
+		if ( $meta && ! is_wp_error( $meta ) ) {
+		if ( isset( $meta['preferredUsername'] ) ) {
+				$feed_details['title'] = $meta['preferredUsername'];
+			}
+			$feed_details['url'] = $meta['id'];
+		}
+
+		return $feed_details;
+	}
+
+	public function friends_rewrite_incoming_url( $url, $incoming_url ) {
+		if ( preg_match( '/^@?[^@]+@((?:[a-z0-9-]+\.)+[a-z]+)$/i', $incoming_url ) ) {
+			$resolved_url = \Activitypub\Rest\Webfinger::resolve( $incoming_url );
+			if ( ! is_wp_error( $resolved_url ) ) {
+				return $resolved_url;
+			}
+		}
+		return $url;
+	}
+
+	/**
+	 * Discover the feeds available at the URL specified.
+	 *
+	 * @param      string $content  The content for the URL is already provided here.
+	 * @param      string $url      The url to search.
+	 *
+	 * @return     array  A list of supported feeds at the URL.
+	 */
+	public function discover_available_feeds( $content, $url ) {
+		$discovered_feeds = array();
+
+		$meta = \Activitypub\get_remote_metadata_by_actor( $url );
+		if ( $meta && ! is_wp_error( $meta ) ) {
+			$discovered_feeds[ $meta['id'] ] = array(
+				'type'        => 'application/activity+json',
+				'rel'         => 'self',
+				'post-format' => 'autodetect',
+				'parser'      => self::SLUG,
+				'autoselect'  => true,
+			);
+		}
+		return $discovered_feeds;
+	}
+
+	/**
+	 * Fetches a feed and returns the processed items.
+	 *
+	 * @param      string $url        The url.
+	 *
+	 * @return     array            An array of feed items.
+	 */
+	public function fetch_feed( $url ) {
+		// There is no feed to fetch, we'll receive items via ActivityPub.
+		return array();
+	}
+
+	/**
+	 * Handles "Create" requests
+	 *
+	 * @param  array $object  The activity-object
+	 * @param  int   $user_id The id of the local blog-user
+	 */
+	public function handle_received_activity( $object, $user_id ) {
+		$user_feed = $this->friends_feed->get_user_feed_by_url( $object['actor'] );
+		if ( is_wp_error( $user_feed ) ) {
+			$meta = \Activitypub\get_remote_metadata_by_actor( $object['actor'] );
+			$user_feed = $this->friends_feed->get_user_feed_by_url( $meta['url'] );
+			if ( is_wp_error( $user_feed ) ) {
+				// We're not following this user.
+				return false;
+			}
+		}
+		switch ( $object['type'] ) {
+			case 'Accept':
+				// nothing to do.
+				break;
+			case 'Create':
+				$this->handle_incoming_post( $object['object'], $user_feed );
+
+		}
+
+		return true;
+	}
+
+	private function map_type_to_post_format( $type ) {
+		return 'status';
+	}
+
+	private function handle_incoming_post( $object, \Friends\User_Feed $user_feed ) {
+		$item = new \Friends\Feed_Item(
+			array(
+				'permalink' => $object['url'],
+				// 'title' => '',
+				'content' => $object['content'],
+				'post_format' => $this->map_type_to_post_format( $object['type'] ),
+				'date' => $object['published'],
+			)
+		);
+
+		$this->friends_feed->process_incoming_feed_items( array( $item ), $user_feed );
+	}
+
+	public function follow_user( \Friends\User_Feed $user_feed ) {
+		if ( self::SLUG != $user_feed->get_parser() ) {
+			return;
+		}
+
+		$meta = \Activitypub\get_remote_metadata_by_actor( $user_feed->get_url() );
+		$to = $meta['id'];
+		$inbox = \Activitypub\get_inbox_by_actor( $to );
+		$user_id = get_current_user_id();
+		$actor = \get_author_posts_url( $user_id );
+
+		$activity = new \Activitypub\Model\Activity( 'Follow', \Activitypub\Model\Activity::TYPE_SIMPLE );
+		$activity->set_to( null );
+		$activity->set_cc( null );
+		$activity->set_actor( \get_author_posts_url( $user_id ) );
+		$activity->set_object( $to );
+		$activity->set_id( $actor . '#follow-' . \preg_replace( '~^https?://~', '', $to ) );
+		$activity = $activity->to_json();
+		\Activitypub\safe_remote_post( $inbox, $activity, $user_id );
+	}
+
+	public function unfollow_user( \Friends\User_Feed $user_feed ) {
+		if ( self::SLUG != $user_feed->get_parser() ) {
+			return;
+		}
+
+		$meta = \Activitypub\get_remote_metadata_by_actor( $user_feed->get_url() );
+		$to = $meta['id'];
+		$inbox = \Activitypub\get_inbox_by_actor( $to );
+		$user_id = get_current_user_id();
+		$actor = \get_author_posts_url( $user_id );
+
+		$activity = new \Activitypub\Model\Activity( 'Unfollow', \Activitypub\Model\Activity::TYPE_SIMPLE );
+		$activity->set_to( null );
+		$activity->set_cc( null );
+		$activity->set_actor( \get_author_posts_url( $user_id ) );
+		$activity->set_object( $to );
+		$activity->set_id( $actor . '#unfollow-' . \preg_replace( '~^https?://~', '', $to ) );
+		$activity = $activity->to_json();
+		\Activitypub\safe_remote_post( $inbox, $activity, $user_id );
+	}
+}

templates/author-json.php

@@ -16,7 +16,7 @@ $json->preferredUsername = \get_the_author_meta( 'login', $author_id ); // phpcs
 $json->url = \get_author_posts_url( $author_id );
 $json->icon = array(
 	'type' => 'Image',
-	'url'  => \get_avatar_url( $author_id, array( 'size' => 120 ) ),
+	'url'  => 'https://akirk.blog/wp-content/uploads/2022/11/alex.kirk-small.jpg',
 );
 
 if ( \has_header_image() ) {