mchess-client/lib/chess_bloc/chess_bloc.dart

import 'dart:convert';

import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:mchess/api/move.dart';
import 'package:mchess/api/websocket_message.dart';
import 'package:mchess/chess_bloc/chess_events.dart';
import 'package:mchess/chess_bloc/chess_position.dart';
import 'package:mchess/connection/ws_connection.dart';
import 'package:mchess/utils/chess_utils.dart';
import 'dart:developer';

class ChessBloc extends Bloc<ChessEvent, ChessBoardState> {
  static final ChessBloc _instance = ChessBloc._internal();
  static ChessColor turnColor = ChessColor.white;
  static ChessColor? myColor = ChessColor.white;

  static ChessColor? getSidesColor() {
    return myColor;
  }

  ChessBloc._internal() : super(ChessBoardState.init()) {
    on<InitBoard>(initBoard);
    on<ColorDetermined>(flipBoard);
    on<ReceivedMove>(moveHandler);
    on<OwnPieceMoved>(ownMoveHandler);
    on<InvalidMovePlayed>(invalidMoveHandler);
  }

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

  factory ChessBloc() {
    return _instance;
  }

  void initBoard(InitBoard event, Emitter<ChessBoardState> emit) {
    ChessPosition.getInstance().resetToStartingPosition();
    emit(ChessBoardState(ChessColor.white, ChessColor.white,
        ChessPosition.getInstance().currentPosition));
  }

  void flipBoard(ColorDetermined event, Emitter<ChessBoardState> emit) {
    log("My Color is $myColor");
    myColor = event.myColor;
    emit(ChessBoardState(event.myColor, state.newTurnColor, state.position));
  }

  void moveHandler(ReceivedMove event, Emitter<ChessBoardState> emit) {
    log('opponentMoveHandler()');
    ChessPosition.getInstance().recordMove(event.startSquare, event.endSquare);
    var newPosition = ChessPosition.getInstance().currentPosition;

    turnColor = state.newTurnColor == ChessColor.white
        ? ChessColor.black
        : ChessColor.white;

    emit(
      ChessBoardState(
        state.bottomColor,
        turnColor,
        newPosition,
      ),
    );
  }

  void ownMoveHandler(OwnPieceMoved event, Emitter<ChessBoardState> emit) {
    log('ownMoveHandler()');

    var start = ApiCoordinate(
        col: event.startSquare.column, row: event.startSquare.row);
    var end =
        ApiCoordinate(col: event.endSquare.column, row: event.endSquare.row);
    var apiMove = ApiMove(startSquare: start, endSquare: end);
    var apiMessage = ApiWebsocketMessage(
        type: MessageType.move, move: apiMove, color: null, reason: null);

    ServerConnection.getInstance().send(jsonEncode(apiMessage));

    //Temporary chess position until server responds with acknowledgement
    var move = ChessMove.fromApiMove(apiMove);
    var tempPosition = ChessPosition.getInstance().copyOfCurrentPosition;
    tempPosition[move.to] = tempPosition[move.from] ?? const ChessPiece.none();
    tempPosition[move.from] = const ChessPiece.none();

    emit(
      ChessBoardState(
        state.bottomColor,
        turnColor,
        tempPosition,
      ),
    );
  }

  void invalidMoveHandler(
      InvalidMovePlayed event, Emitter<ChessBoardState> emit) {
    emit(
      ChessBoardState(
        state.bottomColor,
        turnColor,
        ChessPosition.getInstance().currentPosition,
      ),
    );
  }
}

class ChessBoardState {
  late ChessColor bottomColor;
  final ChessColor newTurnColor;
  final Map<ChessCoordinate, ChessPiece> position;

  ChessBoardState._(this.bottomColor, this.newTurnColor, this.position);

  factory ChessBoardState(
    ChessColor bottomColor,
    ChessColor turnColor,
    Map<ChessCoordinate, ChessPiece> position,
  ) {
    return ChessBoardState._(bottomColor, turnColor, position);
  }

  factory ChessBoardState.init() {
    ChessColor bottomColor = ChessColor.white;
    ChessColor turnColor = ChessColor.white;

    ChessPosition.getInstance().resetToStartingPosition();

    return ChessBoardState(
        bottomColor, turnColor, ChessPosition.getInstance().currentPosition);
  }

  void logPosition(Map<ChessCoordinate, ChessPiece> pos) {
    // for (int i = 0; i < 7; i++)
  }
}