mchess-client/lib/connection/ws_connection.dart

import 'dart:developer';
import 'package:mchess/chess_bloc/chess_bloc.dart';
import 'package:mchess/chess_bloc/chess_events.dart';
import 'package:mchess/chess_bloc/chess_position.dart';
import 'package:mchess/utils/chess_utils.dart';
import 'package:web_socket_channel/web_socket_channel.dart';

class ServerConnection {
  late WebSocketChannel channel;
  late bool wasConnected = false;
  late int counter = 0;
  late Stream broadcast;

  static final ServerConnection _instance = ServerConnection._internal();

  ServerConnection._internal() {
    log("ServerConnection._internal constructor is called");
    connect();
  }

  factory ServerConnection() {
    return _instance;
  }

  factory ServerConnection.getInstance() {
    return ServerConnection();
  }

  void send(String message) {
    channel.sink.add(message);
    counter++;
  }

  void connect() {
    if (wasConnected) channel.sink.close();

    channel =
        WebSocketChannel.connect(Uri.parse('wss://chess.sw-gross.de:8080'));

    log(channel.closeCode.toString());

    wasConnected = true;

    broadcast = channel.stream.asBroadcastStream();

    broadcast.listen((data) {
      log("Data received:");
      log(data);

      var receivedString = data.toString();
      var splitString = receivedString.split(' ');

      if (splitString[0] == "cl") {
        ChessColor onBottom =
            splitString[1] == "white" ? ChessColor.white : ChessColor.black;
        ChessBloc.getInstance().add(ColorDetermined(myColor: onBottom));
        return;
      }

      if (splitString[0] == "bd") {
        if (splitString[1] == "init") ChessBloc.getInstance().add(InitBoard());
      }

      if (splitString[0] == ('mv')) {
        var startSquare = ChessCoordinate.fromString(splitString[1]);
        var endSquare = ChessCoordinate.fromString(splitString[2]);
        if (ChessMove(from: startSquare, to: endSquare) ==
            ChessPosition.getInstance().lastMove) {
          //This is our own move that got resent by the server. Do not process.
        } else {
          log('lastMove: from: ${ChessPosition.getInstance().lastMove.from} to: ${ChessPosition.getInstance().lastMove.to}');
          log('constructed move: from: $startSquare to: $endSquare)}');
          log('Move received : ${startSquare.toAlphabetical()}:${endSquare.toAlphabetical()}');

          ChessBloc.getInstance().add(OpponentPieceMoved(
              startSquare: startSquare, endSquare: endSquare));
        }
      }
    });
  }
}