bbp_update_topic_walker( int $topic_id, string $last_active_time = '', int $forum_id, int $reply_id, bool $refresh = true )

function bbp_update_topic_walker( $topic_id, $last_active_time = '', $forum_id = 0, $reply_id = 0, $refresh = true ) {

	// Validate topic_id
	$topic_id  = bbp_get_topic_id( $topic_id );

	// Define local variable(s)
	$active_id = 0;

	// Topic was passed
	if ( !empty( $topic_id ) ) {

		// Get the forum ID if none was passed
		if ( empty( $forum_id )  ) {
			$forum_id = bbp_get_topic_forum_id( $topic_id );
		}

		// Set the active_id based on topic_id/reply_id
		$active_id = empty( $reply_id ) ? $topic_id : $reply_id;
	}

	// Get topic ancestors
	$ancestors = array_values( array_unique( array_merge( array( $forum_id ), (array) get_post_ancestors( $topic_id ) ) ) );

	// Topic status
	$topic_status = get_post_status( $topic_id );

	// If we want a full refresh, unset any of the possibly passed variables
	if ( true === $refresh ) {
		$forum_id = $topic_id = $reply_id = $active_id = $last_active_time = 0;
		$topic_status = bbp_get_public_status_id();
	}

	// Loop through ancestors
	if ( !empty( $ancestors ) ) {
		foreach ( $ancestors as $ancestor ) {

			// If ancestor is a forum, update counts
			if ( bbp_is_forum( $ancestor ) ) {

				// Update the forum
				bbp_update_forum( array(
					'forum_id'           => $ancestor,
					'last_topic_id'      => $topic_id,
					'last_reply_id'      => $reply_id,
					'last_active_id'     => $active_id,
					'last_active_time'   => 0,
					'last_active_status' => $topic_status
				) );
			}
		}
	}
}