BBP_Forums_Group_Extension::maybe_map_permalink_to_group( int $post_id,  $url = false )

	private function maybe_map_permalink_to_group( $post_id = 0, $url = false ) {

		switch ( get_post_type( $post_id ) ) {

			// Reply
			case bbp_get_reply_post_type() :
				$topic_id = bbp_get_reply_topic_id( $post_id );
				$forum_id = bbp_get_reply_forum_id( $post_id );
				$url_end  = trailingslashit( $this->reply_slug ) . get_post_field( 'post_name', $post_id );
				break;

			// Topic
			case bbp_get_topic_post_type() :
				$topic_id = $post_id;
				$forum_id = bbp_get_topic_forum_id( $post_id );
				$url_end  = trailingslashit( $this->topic_slug ) . get_post_field( 'post_name', $post_id );
				break;

			// Forum
			case bbp_get_forum_post_type() :
				$forum_id = $post_id;
				$url_end  = ''; //get_post_field( 'post_name', $post_id );
				break;

			// Unknown
			default :
				return $url;
				break;
		}

		// Get group ID's for this forum
		$group_ids = bbp_get_forum_group_ids( $forum_id );

		// Bail if the post isn't associated with a group
		if ( empty( $group_ids ) )
			return $url;

		// @todo Multiple group forums/forum groups
		$group_id = $group_ids[0];
		$group    = groups_get_group( array( 'group_id' => $group_id ) );

		if ( bp_is_group_admin_screen( $this->slug ) ) {
			$group_permalink = trailingslashit( bp_get_group_admin_permalink( $group ) );
		} else {
			$group_permalink = trailingslashit( bp_get_group_permalink( $group ) );
		}

		return trailingslashit( trailingslashit( $group_permalink . $this->slug ) . $url_end );
	}