Add fetch_by_acct and fetch_by_various methods to Remote_Actors (#2235)

Author: pfefferle

.github/changelog/2235-from-description

@@ -0,0 +1,4 @@
+Significance: minor
+Type: changed
+
+Added support for fetching actors by account identifiers and improved reliability of actor retrieval.

includes/collection/class-remote-actors.php

@@ -202,6 +202,29 @@ public static function get_by_uri( $actor_uri ) {
 		return \get_post( $post_id );
 	}
 
+	/**
+	 * Fetch a remote actor post by either actor URI or acct, fetching from remote if not found locally.
+	 *
+	 * @param string $uri_or_acct The actor URI or acct identifier.
+	 *
+	 * @return \WP_Post|\WP_Error Post object or WP_Error if not found.
+	 */
+	public static function fetch_by_various( $uri_or_acct ) {
+		if ( \filter_var( $uri_or_acct, FILTER_VALIDATE_URL ) ) {
+			return self::fetch_by_uri( $uri_or_acct );
+		}
+
+		if ( preg_match( '/^@?' . ACTIVITYPUB_USERNAME_REGEXP . '$/i', $uri_or_acct ) ) {
+			return self::fetch_by_acct( $uri_or_acct );
+		}
+
+		return new \WP_Error(
+			'activitypub_invalid_actor_identifier',
+			'The actor identifier is not supported',
+			array( 'status' => 400 )
+		);
+	}
+
 	/**
 	 * Lookup a remote actor post by actor URI (guid), fetching from remote if not found locally.
 	 *
@@ -239,6 +262,45 @@ public static function fetch_by_uri( $actor_uri ) {
 		return \get_post( $post_id );
 	}
 
+	/**
+	 * Fetch a remote actor post by acct, fetching from remote if not found locally.
+	 *
+	 * @param string $acct The acct identifier.
+	 *
+	 * @return \WP_Post|\WP_Error Post object or WP_Error if not found.
+	 */
+	public static function fetch_by_acct( $acct ) {
+		$acct = Sanitize::webfinger( $acct );
+
+		// Check local DB for acct post meta.
+		global $wpdb;
+		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
+		$post_id = $wpdb->get_var(
+			$wpdb->prepare(
+				"SELECT post_id FROM $wpdb->postmeta WHERE meta_key='_activitypub_acct' AND meta_value=%s",
+				$acct
+			)
+		);
+
+		if ( $post_id ) {
+			return \get_post( $post_id );
+		}
+
+		$profile_uri = Webfinger::resolve( $acct );
+
+		if ( \is_wp_error( $profile_uri ) ) {
+			return $profile_uri;
+		}
+
+		$post = self::fetch_by_uri( $profile_uri );
+
+		if ( ! \is_wp_error( $post ) ) {
+			\update_post_meta( $post->ID, '_activitypub_acct', $acct );
+		}
+
+		return $post;
+	}
+
 	/**
 	 * Store an error that occurred when sending an ActivityPub message to a follower.
 	 *

includes/functions.php

@@ -85,7 +85,7 @@ function get_webfinger_resource( $user_id ) {
  *
  * @return array|\WP_Error The Actor profile as array or WP_Error on failure.
  */
-function get_remote_metadata_by_actor( $actor, $cached = true ) {
+function get_remote_metadata_by_actor( $actor, $cached = true ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable, Generic.CodeAnalysis.UnusedFunctionParameter.FoundAfterLastUsed
 	/**
 	 * Filters the metadata before it is retrieved from a remote actor.
 	 *
@@ -101,7 +101,13 @@ function get_remote_metadata_by_actor( $actor, $cached = true ) {
 		return $pre;
 	}
 
-	return Http::get_remote_object( $actor, $cached );
+	$remote_actor = Remote_Actors::fetch_by_various( $actor );
+
+	if ( is_wp_error( $remote_actor ) ) {
+		return $remote_actor;
+	}
+
+	return json_decode( $remote_actor->post_content, true );
 }
 
 /**