bbp_bump_forum_topic_count( int $forum_id, int $difference = 1, bool $update_ancestors = true )

function bbp_bump_forum_topic_count( $forum_id = 0, $difference = 1, $update_ancestors = true ) {

	// Get some counts
	$forum_id          = bbp_get_forum_id( $forum_id );
	$topic_count       = bbp_get_forum_topic_count( $forum_id, false, true );
	$total_topic_count = bbp_get_forum_topic_count( $forum_id, true,  true );

	// Update this forum id
	update_post_meta( $forum_id, '_bbp_topic_count',       (int) $topic_count       + (int) $difference );
	update_post_meta( $forum_id, '_bbp_total_topic_count', (int) $total_topic_count + (int) $difference );

	// Check for ancestors
	if ( true === $update_ancestors ) {

		// Get post ancestors
		$forum     = get_post( $forum_id );
		$ancestors = get_post_ancestors( $forum );

		// If has ancestors, loop through them...
		if ( !empty( $ancestors ) ) {
			foreach ( (array) $ancestors as $parent_forum_id ) {

				// Get forum counts
				$parent_topic_count       = bbp_get_forum_topic_count( $parent_forum_id, false, true );
				$parent_total_topic_count = bbp_get_forum_topic_count( $parent_forum_id, true,  true );

				// Update counts
				update_post_meta( $parent_forum_id, '_bbp_topic_count',       (int) $parent_topic_count       + (int) $difference );
				update_post_meta( $parent_forum_id, '_bbp_total_topic_count', (int) $parent_total_topic_count + (int) $difference );
			}
		}
	}

	return (int) apply_filters( 'bbp_bump_forum_topic_count', (int) $total_topic_count + (int) $difference, $forum_id, (int) $difference, (bool) $update_ancestors );
}