mchess-client/lib/connection/ws_connection.dart

import 'dart:convert';
import 'dart:developer';
import 'package:flutter/foundation.dart';
import 'package:mchess/api/move.dart';
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/api/register.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;
  Stream broadcast = const Stream.empty();

  static final ServerConnection _instance = ServerConnection._internal();

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

  factory ServerConnection() {
    return _instance;
  }

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

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

  void connect(String playerID, lobbyID) {
    if (wasConnected) channel.sink.close();

    if (kDebugMode) {
      channel =
          WebSocketChannel.connect(Uri.parse('ws://localhost:8080/api/ws'));
    } else {
      channel =
          WebSocketChannel.connect(Uri.parse('wss://chess.sw-gross.de:8080'));
    }
    send(jsonEncode(WebsocketMessageIdentifyPlayer(
        playerID: (playerID), lobbyID: (lobbyID))));

    log(channel.closeCode.toString());

    wasConnected = true;

    broadcast = channel.stream.asBroadcastStream();

    broadcast.listen(handleIncomingData);
  }

  void handleIncomingData(dynamic data) {
    log("Data received:");
    log(data);
    var apiMove = ApiMove.fromJson(jsonDecode(data));

//Todo: Implement status messages
// e.g. to tell the client that both players connected, who is playing which color and so on

    var move = ChessMove.fromApiMove(apiMove);
    if (move == 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: ${move.from} to: ${move.to}');
      log('Move received : ${move.from.toAlphabetical()}->${move.to.toAlphabetical()}');

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