import "package:nt4/nt4.dart";

class NTUtils{

  static final NTUtils _instance = NTUtils._internal();

  factory NTUtils() {
    return _instance;
  }

  bool isConnected = false;
  bool _isAttemptingToConnect = false;
  String _serverAddress = "";

  NT4Client? ntClient; 

  final Map<String, NT4Subscription> _nt4Subscriptions = {};

  void connect(String serverAddress){
    _serverAddress = serverAddress;
    _isAttemptingToConnect = true;
    ntClient = NT4Client(serverBaseAddress: serverAddress, onConnect: () { isConnected = true; _isAttemptingToConnect = false; }, onDisconnect: () { isConnected = false; });
  }

  String connectionStatus(){
    if(_isAttemptingToConnect){
      return "Attempting to connect to $_serverAddress";
    }
    if(isConnected){
      return "Connected";
    }else{
      return "Not Connected";
    }
  }
  
  NT4Subscription subscribe(String topic){
    if (!_nt4Subscriptions.containsKey(topic))
    {
      NT4Subscription subscrip = ntClient!.subscribe(topic, NT4SubscriptionOptions());
      _nt4Subscriptions[topic] = subscrip;
    }
  
    return _nt4Subscriptions[topic]!;
  }
  
  final Map<String, NT4Topic> _nt4Topics = {};

  NT4Topic getPublicTopic(String topic, String type){
    if(!_nt4Topics.containsKey(topic)){
      NT4Topic top = ntClient!.publishNewTopic(topic, type);
      _nt4Topics[topic] = top;
    }

    return _nt4Topics[topic]!;
  }

  NTUtils._internal();
}