public static function get_messages( $thread_id = 0 ) {
		$thread_id = (int) $thread_id;
		$messages  = wp_cache_get( $thread_id, 'bp_messages_threads' );

		if ( false === $messages ) {
			global $wpdb;

			$bp = buddypress();

			// Always sort by ASC by default.
			$messages = $wpdb->get_results( $wpdb->prepare( "SELECT * FROM {$bp->messages->table_name_messages} WHERE thread_id = %d ORDER BY date_sent ASC", $thread_id ) );

			wp_cache_set( $thread_id, (array) $messages, 'bp_messages_threads' );
		}

		// Integer casting.
		foreach ( $messages as $key => $data ) {
			$messages[ $key ]->id        = (int) $messages[ $key ]->id;
			$messages[ $key ]->thread_id = (int) $messages[ $key ]->thread_id;
			$messages[ $key ]->sender_id = (int) $messages[ $key ]->sender_id;
		}

		return $messages;
	}