Add undo support for Like and Announce activities (#2295)

Author: pfefferle

.github/changelog/2295-from-description

@@ -0,0 +1,4 @@
+Significance: minor
+Type: changed
+
+Extended inbox support for undoing Like, Create, and Announce activities, with refactored undo logic and improved activity persistence.

includes/collection/class-inbox.php

@@ -9,6 +9,7 @@
 
 use Activitypub\Activity\Activity;
 use Activitypub\Activity\Base_Object;
+use Activitypub\Comment;
 
 use function Activitypub\is_activity_public;
 use function Activitypub\object_to_uri;
@@ -140,4 +141,94 @@ public static function get( $guid, $user_id ) {
 
 		return \get_post( $post_id );
 	}
+
+	/**
+	 * Get an inbox item by its GUID.
+	 *
+	 * @param string $guid The GUID of the inbox item.
+	 *
+	 * @return \WP_Post|\WP_Error The inbox item or WP_Error.
+	 */
+	public static function get_by_guid( $guid ) {
+		global $wpdb;
+		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
+		$post_id = $wpdb->get_var(
+			$wpdb->prepare(
+				"SELECT ID FROM $wpdb->posts WHERE guid=%s AND post_type=%s",
+				\esc_url( $guid ),
+				self::POST_TYPE
+			)
+		);
+
+		if ( ! $post_id ) {
+			return new \WP_Error(
+				'activitypub_inbox_item_not_found',
+				\__( 'Inbox item not found', 'activitypub' ),
+				array( 'status' => 404 )
+			);
+		}
+
+		return \get_post( $post_id );
+	}
+
+	/**
+	 * Undo a received activity.
+	 *
+	 * @param string $id The ID of the inbox item to be removed.
+	 *
+	 * @return bool|\WP_Error True on success, WP_Error on failure.
+	 */
+	public static function undo( $id ) {
+		$inbox_item = self::get_by_guid( $id );
+
+		if ( \is_wp_error( $inbox_item ) ) {
+			// If inbox entry not found, return the error.
+			return $inbox_item;
+		}
+
+		$type = \get_post_meta( $inbox_item->ID, '_activitypub_activity_type', true );
+
+		switch ( $type ) {
+			case 'Follow':
+				$actor        = \get_post_meta( $inbox_item->ID, '_activitypub_activity_remote_actor', true );
+				$remote_actor = Remote_Actors::get_by_uri( $actor );
+
+				if ( \is_wp_error( $remote_actor ) ) {
+					return $remote_actor;
+				}
+
+				return Followers::remove( $remote_actor, $inbox_item->post_author );
+
+			case 'Like':
+			case 'Create':
+			case 'Announce':
+				if ( ACTIVITYPUB_DISABLE_INCOMING_INTERACTIONS ) {
+					return new \WP_Error(
+						'activitypub_inbox_undo_interactions_disabled',
+						\__( 'Undo is not possible because incoming interactions are disabled.', 'activitypub' ),
+						array( 'status' => 403 )
+					);
+				}
+
+				$result = Comment::object_id_to_comment( esc_url_raw( $inbox_item->guid ) );
+
+				if ( empty( $result ) ) {
+					return new \WP_Error(
+						'activitypub_inbox_undo_comment_not_found',
+						\__( 'Undo is not possible because the comment was not found.', 'activitypub' ),
+						array( 'status' => 404 )
+					);
+				}
+
+				return \wp_delete_comment( $result, true );
+
+			default:
+				return new \WP_Error(
+					'activitypub_inbox_undo_unsupported',
+					// Translators: %s is the activity type.
+					\sprintf( \__( 'Undo is not supported for %s activities.', 'activitypub' ), $type ),
+					array( 'status' => 400 )
+				);
+		}
+	}
 }

includes/handler/class-inbox.php

@@ -41,7 +41,7 @@ public static function handle_inbox_requests( $data, $user_id, $type, $activity
 		 *
 		 * @param array $activity_types The activity types to persist in the inbox.
 		 */
-		$activity_types = \apply_filters( 'activitypub_persist_inbox_activity_types', array( 'Create', 'Update', 'Follow' ) );
+		$activity_types = \apply_filters( 'activitypub_persist_inbox_activity_types', array( 'Create', 'Update', 'Follow', 'Like', 'Announce' ) );
 		$activity_types = \array_map( 'Activitypub\camel_to_snake_case', $activity_types );
 
 		if ( ! \in_array( \strtolower( $type ), $activity_types, true ) ) {

includes/handler/class-undo.php

@@ -7,10 +7,7 @@
 
 namespace Activitypub\Handler;
 
-use Activitypub\Collection\Actors;
-use Activitypub\Collection\Followers;
-use Activitypub\Collection\Remote_Actors;
-use Activitypub\Comment;
+use Activitypub\Collection\Inbox as Inbox_Collection;
 
 use function Activitypub\object_to_uri;
 
@@ -33,35 +30,11 @@ public static function init() {
 	 * @param int|null $user_id  The ID of the user who initiated the "Undo" activity.
 	 */
 	public static function handle_undo( $activity, $user_id ) {
-		$type    = $activity['object']['type'];
 		$success = false;
-		$result  = null;
+		$result  = Inbox_Collection::undo( object_to_uri( $activity['object'] ) );
 
-		// Handle "Unfollow" requests.
-		if ( 'Follow' === $type ) {
-			$user_id = Actors::get_id_by_resource( object_to_uri( $activity['object']['object'] ) );
-
-			if ( ! \is_wp_error( $user_id ) ) {
-				$post = Remote_Actors::get_by_uri( object_to_uri( $activity['actor'] ) );
-
-				if ( ! \is_wp_error( $post ) ) {
-					$success = Followers::remove( $post, $user_id );
-				}
-			}
-		}
-
-		// Handle "Undo" requests for "Like" and "Create" activities.
-		if ( in_array( $type, array( 'Like', 'Create', 'Announce' ), true ) ) {
-			if ( ! ACTIVITYPUB_DISABLE_INCOMING_INTERACTIONS ) {
-				$object_id = object_to_uri( $activity['object'] );
-				$result    = Comment::object_id_to_comment( esc_url_raw( $object_id ) );
-
-				if ( empty( $result ) ) {
-					$success = false;
-				} else {
-					$success = \wp_delete_comment( $result, true );
-				}
-			}
+		if ( $result && ! \is_wp_error( $result ) ) {
+			$success = true;
 		}
 
 		/**
@@ -99,11 +72,11 @@ public static function validate_object( $valid, $param, $request ) {
 			return false;
 		}
 
-		if ( ! \is_array( $activity['object'] ) ) {
+		if ( ! \is_array( $activity['object'] ) && ! \is_string( $activity['object'] ) ) {
 			return false;
 		}
 
-		if ( ! isset( $activity['object']['id'], $activity['object']['type'], $activity['object']['actor'], $activity['object']['object'] ) ) {
+		if ( \is_array( $activity['object'] ) && ! isset( $activity['object']['id'] ) ) {
 			return false;
 		}
 

includes/rest/trait-collection.php

@@ -23,6 +23,7 @@ trait Collection {
 	 *
 	 * @param array            $response The collection response array.
 	 * @param \WP_REST_Request $request  The request object.
+	 *
 	 * @return array|\WP_Error The response array with navigation links or WP_Error on invalid page.
 	 */
 	public function prepare_collection_response( $response, $request ) {
@@ -76,6 +77,7 @@ public function prepare_collection_response( $response, $request ) {
 	 * that controllers can use to compose their full schema by passing in their item schema.
 	 *
 	 * @param array $item_schema Optional. The schema for the items in the collection. Default empty array.
+	 *
 	 * @return array The collection schema.
 	 */
 	public function get_collection_schema( $item_schema = array() ) {