import 'package:mqtt5_client/mqtt5_client.dart';
import 'package:mqtt5_client/mqtt5_server_client.dart';

class Mqtt {
  final MqttConfig _config;
  MqttClient? _client;

  Mqtt(this._config);

  static late Mqtt _mqtt;

  static Mqtt getInstance() {
    return _mqtt;
  }

  static void setInstance(Mqtt server) {
    _mqtt = server;
  }

  Future<bool> connect() async {
    if (_client != null) {
      return true;
    }
    _client =
        MqttServerClient.withPort(_config.host, _config.clientId, _config.port);
    _client?.autoReconnect = true;

    await _client?.connect(_config.username, _config.password);
    _client?.updates.listen((List<MqttReceivedMessage<MqttMessage>> message) {
      final recMess = message[0].payload as MqttPublishMessage;
      final payload =
          MqttUtilities.bytesToStringAsString(recMess.payload.message!);
      _config.messgae(message[0].topic!, payload);
    });
    _config.topic?.forEach((topic) {
      subscribe(topic, _config.qos);
    });

    return true;
  }

  void disconnect() {
    _client?.disconnect();
    _client = null;
  }

  void subscribe(String topic, int qos) {
    _client?.subscribe(topic, MqttUtilities.getQosLevel(qos));
  }

  void unSubscribe(String topic) {
    _client?.unsubscribeStringTopic(topic);
  }

  void publish(String topic, String msg, {int qos = 0}) {
    var payload = MqttPayloadBuilder();
    payload.addString(msg);
    _client?.publishMessage(
        topic, MqttUtilities.getQosLevel(qos), payload.payload!);
  }
}

class MqttConfig {
  final String host;
  final int port;
  final String clientId;
  String? username;
  String? password;
  List<String>? topic;
  int qos;
  Function(String topic, String message) messgae;

  MqttConfig(
      {required this.host,
      this.port = 1883,
      required this.clientId,
      required this.messgae,
      this.topic,
      this.qos = 0,
      this.username,
      this.password});
}