Use position to build board

Now the client considers the position sent by the server to build the
position on the board.

lib/api/websocket_message.dart

@@ -22,12 +22,15 @@ class ApiWebsocketMessage {
   final ApiMove? move;
   final ApiColor? color;
   final String? reason;
+  final String? position;
 
-  ApiWebsocketMessage(
+  ApiWebsocketMessage({
-      {required this.type,
+    required this.type,
     required this.move,
     required this.color,
-      required this.reason});
+    required this.reason,
+    required this.position,
+  });
 
   factory ApiWebsocketMessage.fromJson(Map<String, dynamic> json) {
     final type = MessageType.fromJson(json['messageType']);
@@ -38,14 +41,18 @@ class ApiWebsocketMessage {
           type: type,
           move: null,
           color: ApiColor.fromJson(json['color']),
-            reason: null);
+          reason: null,
+          position: null,
+        );
         break;
       case MessageType.move:
         ret = ApiWebsocketMessage(
           type: type,
           move: ApiMove.fromJson(json['move']),
           color: null,
-            reason: null);
+          reason: null,
+          position: json['position'],
+        );
         break;
       case MessageType.invalidMove:
         ret = ApiWebsocketMessage(
@@ -53,6 +60,7 @@ class ApiWebsocketMessage {
           move: ApiMove.fromJson(json['move']),
           color: null,
           reason: json['reason'],
+          position: null,
         );
     }
     return ret;

lib/chess_bloc/chess_bloc.dart

@@ -21,7 +21,7 @@ class ChessBloc extends Bloc<ChessEvent, ChessBoardState> {
     on<InitBoard>(initBoard);
     on<ColorDetermined>(flipBoard);
     on<ReceivedMove>(moveHandler);
-    on<ReceivedPromotion>(promotionHandler);
+    on<ReceivedPosition>(positionHandler);
     on<OwnPieceMoved>(ownMoveHandler);
     on<OwnPromotionPlayed>(ownPromotionHandler);
     on<InvalidMovePlayed>(invalidMoveHandler);
@@ -49,96 +49,18 @@ class ChessBloc extends Bloc<ChessEvent, ChessBoardState> {
   }
 
   void moveHandler(ReceivedMove event, Emitter<ChessBoardState> emit) {
-    log('opponentMoveHandler()');
-
-    var move = ChessMove(from: event.startSquare, to: event.endSquare);
-    bool wasEnPassant = move.wasEnPassant();
-    bool wasCastling = move.wasCastling();
-
-    var oldPosition = ChessPosition.getInstance().copyOfCurrentPosition;
     ChessPosition.getInstance().recordMove(event.startSquare, event.endSquare);
-    var newPosition = ChessPosition.getInstance().currentPosition;
-
-    if (wasEnPassant) {
-      if (turnColor == ChessColor.white) {
-        newPosition[ChessCoordinate(
-                event.endSquare.column, event.endSquare.row - 1)] =
-            const ChessPiece.none();
-      } else {
-        newPosition[ChessCoordinate(
-                event.endSquare.column, event.endSquare.row + 1)] =
-            const ChessPiece.none();
-      }
-    } else if (wasCastling) {
-      ChessPiece rookToMove;
-      ChessPiece kingToMove;
-      if (move.to.column == 7) {
-        rookToMove = oldPosition[ChessCoordinate(8, move.to.row)]!;
-        newPosition[ChessCoordinate(6, move.to.row)] = rookToMove;
-        newPosition[ChessCoordinate(8, move.to.row)] = const ChessPiece.none();
-
-        kingToMove = oldPosition[ChessCoordinate(5, move.to.row)]!;
-        newPosition[ChessCoordinate(7, move.to.row)] = kingToMove;
-        newPosition[ChessCoordinate(5, move.to.row)] = const ChessPiece.none();
-      }
-      if (move.to.column == 3) {
-        rookToMove = oldPosition[ChessCoordinate(1, move.to.row)]!;
-        newPosition[ChessCoordinate(4, move.to.row)] = rookToMove;
-        newPosition[ChessCoordinate(1, move.to.row)] = const ChessPiece.none();
-
-        kingToMove = oldPosition[ChessCoordinate(5, move.to.row)]!;
-        newPosition[ChessCoordinate(3, move.to.row)] = kingToMove;
-        newPosition[ChessCoordinate(5, move.to.row)] = const ChessPiece.none();
-      }
   }
 
-    turnColor = state.newTurnColor == ChessColor.white
+  void positionHandler(
-        ? ChessColor.black
+    ReceivedPosition event,
-        : ChessColor.white;
-
-    emit(
-      ChessBoardState(
-        state.bottomColor,
-        turnColor,
-        newPosition,
-      ),
-    );
-  }
-
-  void promotionHandler(
-    ReceivedPromotion event,
     Emitter<ChessBoardState> emit,
   ) {
-    var pieceAtStartSquare = ChessPosition.getInstance().getPieceAt(
-        ChessCoordinate(event.startSquare.column, event.startSquare.row));
-    if (pieceAtStartSquare == null) {
-      log('received a promotion but start square was empty');
-      return;
-    }
-
-    ChessPieceClass pieceClass = ChessPieceClass.none;
-    for (var piece in chessPiecesShortName.entries) {
-      if (piece.value == event.piece) {
-        pieceClass = piece.key.pieceClass;
-        break;
-      }
-    }
-    var newPosition = ChessPosition.getInstance().currentPosition;
-    newPosition[
-            ChessCoordinate(event.startSquare.column, event.startSquare.row)] =
-        const ChessPiece.none();
-    newPosition[ChessCoordinate(event.endSquare.column, event.endSquare.row)] =
-        ChessPiece(pieceClass, pieceAtStartSquare.color);
-
     turnColor = state.newTurnColor == ChessColor.white
         ? ChessColor.black
         : ChessColor.white;
 
-    emit(ChessBoardState(
+    emit(ChessBoardState(state.bottomColor, turnColor, event.position));
-      state.bottomColor,
-      turnColor,
-      newPosition,
-    ));
   }
 
   void ownMoveHandler(OwnPieceMoved event, Emitter<ChessBoardState> emit) {
@@ -146,7 +68,12 @@ class ChessBloc extends Bloc<ChessEvent, ChessBoardState> {
     var apiMove =
         ChessMove(from: event.startSquare, to: event.endSquare).toApiMove();
     var apiMessage = ApiWebsocketMessage(
-        type: MessageType.move, move: apiMove, color: null, reason: null);
+      type: MessageType.move,
+      move: apiMove,
+      color: null,
+      reason: null,
+      position: null,
+    );
 
     ServerConnection.getInstance().send(jsonEncode(apiMessage));
 
@@ -176,6 +103,7 @@ class ChessBloc extends Bloc<ChessEvent, ChessBoardState> {
       move: apiMove,
       color: null,
       reason: null,
+      position: null,
     );
     log(jsonEncode(message));
     ServerConnection.getInstance().send(jsonEncode(message));

lib/chess_bloc/chess_events.dart

@@ -1,3 +1,4 @@
+import 'package:mchess/chess_bloc/chess_position.dart';
 import 'package:mchess/utils/chess_utils.dart';
 
 abstract class ChessEvent {}
@@ -9,15 +10,10 @@ class ReceivedMove extends ChessEvent {
   ReceivedMove({required this.startSquare, required this.endSquare});
 }
 
-class ReceivedPromotion extends ChessEvent {
+class ReceivedPosition extends ChessEvent {
-  final ChessCoordinate startSquare;
+    final ChessPositionType position;
-  final ChessCoordinate endSquare;
-  final String piece;
 
-  ReceivedPromotion(
+    ReceivedPosition({required this.position});
-      {required this.startSquare,
-      required this.endSquare,
-      required this.piece});
 }
 
 class OwnPieceMoved extends ChessEvent {

lib/chess_bloc/chess_position.dart

@@ -1,31 +1,96 @@
 import 'dart:developer';
+
 import 'package:mchess/utils/chess_utils.dart';
 
-typedef ChessPositionType = Map<ChessCoordinate, ChessPiece>;
 typedef ChessMoveHistory = List<ChessMove>;
+typedef ChessPositionType = Map<ChessCoordinate, ChessPiece>;
 
 class ChessPosition {
   static ChessPosition _instance = ChessPosition._internal();
   static ChessMoveHistory history = ChessMoveHistory.empty(growable: true);
   final ChessPositionType position;
 
-  static ChessPosition getInstance() {
-    return _instance;
-  }
-
   ChessPosition({required this.position});
 
   factory ChessPosition._internal() {
     return ChessPosition(position: _getStartingPosition());
   }
 
-  ChessPositionType get currentPosition => position;
   ChessPositionType get copyOfCurrentPosition => Map.from(position);
+
+  ChessPositionType get currentPosition => position;
   ChessMove? get lastMove {
     if (history.isEmpty) return null;
     return history.last;
   }
 
+  ChessPositionType fromPGNString(String pgn) {
+    ChessPositionType pos = {};
+    List<String> rowStrings;
+
+    rowStrings = pgn.split('/');
+
+    for (int row = 1; row <= 8; row++) {
+      for (int col = 1; col <= 8; col++) {
+        var piece = rowStrings.elementAt(row - 1)[col - 1];
+        if (piece == '-') {
+          continue;
+        }
+        pos[ChessCoordinate(col, row)] = pieceFromShortname[piece]!;
+      }
+    }
+
+    return pos;
+  }
+
+  ChessPiece? getPieceAt(ChessCoordinate coordinate) {
+    return position[ChessCoordinate(coordinate.column, coordinate.row)];
+  }
+
+  void logHistory(ChessMoveHistory hist) {
+    for (var element in hist) {
+      log('${element.from.toAlphabetical()} -> ${element.to.toAlphabetical()}');
+    }
+  }
+
+  void logPosition(ChessPositionType p) {
+    String logString = '';
+
+    for (int row = 8; row > 0; row--) {
+      for (int col = 1; col <= 8; col++) {
+        var coord = ChessCoordinate(col, row);
+        if (p.containsKey(coord)) {
+          logString = '$logString ${p[coord]?.shortName}';
+        } else {
+          logString = '$logString .';
+        }
+      }
+      logString = '$logString\n';
+    }
+
+    log(logString);
+  }
+
+  void recordMove(ChessCoordinate from, ChessCoordinate to) {
+    position[to] = position[from] ?? const ChessPiece.none();
+    position[from] = const ChessPiece.none();
+
+    history.add(ChessMove(from: from, to: to));
+
+    logPosition(position);
+
+    logHistory(history);
+  }
+
+  void resetToStartingPosition() {
+    history = ChessMoveHistory.empty(growable: true);
+    _instance = ChessPosition(position: _getStartingPosition());
+  }
+
+  static ChessPosition getInstance() {
+    return _instance;
+  }
+
   static ChessPositionType _getStartingPosition() {
     ChessPositionType pos = {};
 
@@ -72,48 +137,4 @@ class ChessPosition {
 
     return pos;
   }
-
-  ChessPiece? getPieceAt(ChessCoordinate coordinate) {
-    return position[ChessCoordinate(coordinate.column, coordinate.row)];
-  }
-
-  void resetToStartingPosition() {
-    history = ChessMoveHistory.empty(growable: true);
-    _instance = ChessPosition(position: _getStartingPosition());
-  }
-
-  void recordMove(ChessCoordinate from, ChessCoordinate to) {
-    position[to] = position[from] ?? const ChessPiece.none();
-    position[from] = const ChessPiece.none();
-
-    history.add(ChessMove(from: from, to: to));
-
-    logPosition(position);
-
-    logHistory(history);
-  }
-
-  void logPosition(ChessPositionType p) {
-    String logString = '';
-
-    for (int row = 8; row > 0; row--) {
-      for (int col = 1; col <= 8; col++) {
-        var coord = ChessCoordinate(col, row);
-        if (p.containsKey(coord)) {
-          logString = '$logString ${p[coord]?.shortName}';
-        } else {
-          logString = '$logString .';
-        }
-      }
-      logString = '$logString\n';
-    }
-
-    log(logString);
-  }
-
-  void logHistory(ChessMoveHistory hist) {
-    for (var element in hist) {
-      log('${element.from.toAlphabetical()} -> ${element.to.toAlphabetical()}');
-    }
-  }
 }

lib/connection/ws_connection.dart

@@ -5,6 +5,7 @@ import 'package:mchess/api/websocket_message.dart';
 import 'package:mchess/chess_bloc/chess_bloc.dart';
 import 'package:mchess/chess_bloc/chess_events.dart';
 import 'package:mchess/api/register.dart';
+import 'package:mchess/chess_bloc/chess_position.dart';
 import 'package:mchess/connection_cubit/connection_cubit.dart';
 import 'package:mchess/utils/chess_utils.dart';
 import 'package:web_socket_channel/web_socket_channel.dart';
@@ -86,16 +87,14 @@ class ServerConnection {
   void handleIncomingMoveMessage(ApiWebsocketMessage apiMessage) {
     var move = ChessMove.fromApiMove(apiMessage.move!);
 
-    if (apiMessage.move?.promotionToPiece?.isNotEmpty ?? false) {
+    if (apiMessage.position != null) {
-      ChessBloc.getInstance().add(ReceivedPromotion(
+      ChessBloc.getInstance().add(ReceivedPosition(
-          startSquare: move.from,
+          position:
-          endSquare: move.to,
+              ChessPosition.getInstance().fromPGNString(apiMessage.position!)));
-          piece: apiMessage.move!.promotionToPiece!));
+    }
-    } else {
     ChessBloc.getInstance()
         .add(ReceivedMove(startSquare: move.from, endSquare: move.to));
   }
-  }
 
   void handleInvalidMoveMessage(ApiWebsocketMessage apiMessage) {
     log("invalid move message received, with move: ${apiMessage.move.toString()}");

lib/pages/lobby_selector.dart

@@ -13,25 +13,6 @@ class LobbySelector extends StatelessWidget {
         child: Column(
           mainAxisAlignment: MainAxisAlignment.center,
           children: [
-            //We deactivate random lobbies for now.
-            // ElevatedButton(
-            //   onPressed: () {
-            //     context.push('/prepareRandom');
-            //   },
-            //   child: const Row(
-            //     mainAxisSize: MainAxisSize.min,
-            //     children: [
-            //       Icon(Icons.question_mark),
-            //       SizedBox(
-            //         width: 10,
-            //       ),
-            //       Text('Random')
-            //     ],
-            //   ),
-            // ),
-            // const SizedBox(
-            //   height: 25,
-            // ),
             ElevatedButton(
               onPressed: () {
                 _dialogBuilder(context);
@@ -43,7 +24,7 @@ class LobbySelector extends StatelessWidget {
                   SizedBox(
                     width: 10,
                   ),
-                  Text('Private')
+                  Text('Private game')
                 ],
               ),
             ),

lib/utils/chess_utils.dart

@@ -4,57 +4,6 @@ import 'package:mchess/api/move.dart';
 import 'package:mchess/api/websocket_message.dart';
 import 'package:quiver/core.dart';
 
-import '../chess_bloc/chess_position.dart';
-
-enum ChessPieceClass {
-  none,
-  pawn,
-  bishop,
-  knight,
-  rook,
-  queen,
-  king,
-}
-
-class ChessPieceAssetKey {
-  final ChessPieceClass pieceClass;
-  final ChessColor color;
-
-  ChessPieceAssetKey({required this.pieceClass, required this.color});
-
-  @override
-  bool operator ==(Object other) {
-    return (other is ChessPieceAssetKey &&
-        (pieceClass == other.pieceClass) &&
-        (color == other.color));
-  }
-
-  @override
-  int get hashCode {
-    return hash2(pieceClass, color);
-  }
-}
-
-enum ChessColor {
-  black,
-  white;
-
-  static ChessColor fromApiColor(ApiColor color) {
-    if (color == ApiColor.black) {
-      return black;
-    } else {
-      return white;
-    }
-  }
-
-  ChessColor getOpposite() {
-    if (name == 'black') {
-      return white;
-    } else {
-      return black;
-    }
-  }
-}
 
 Map<ChessPieceAssetKey, String> chessPiecesAssets = {
   ChessPieceAssetKey(
@@ -166,12 +115,56 @@ Map<ChessPieceAssetKey, String> chessPiecesShortName = {
   ): '-',
 };
 
+Map<String, ChessPiece> pieceFromShortname = {
+    'P': ChessPiece(ChessPieceClass.pawn, ChessColor.white),
+    'R': ChessPiece(ChessPieceClass.rook, ChessColor.white),
+    'N': ChessPiece(ChessPieceClass.knight, ChessColor.white),
+    'B': ChessPiece(ChessPieceClass.bishop, ChessColor.white),
+    'K': ChessPiece(ChessPieceClass.king, ChessColor.white),
+    'Q': ChessPiece(ChessPieceClass.queen, ChessColor.white),
+    'p': ChessPiece(ChessPieceClass.pawn, ChessColor.black),
+    'r': ChessPiece(ChessPieceClass.rook, ChessColor.black),
+    'n': ChessPiece(ChessPieceClass.knight, ChessColor.black),
+    'b': ChessPiece(ChessPieceClass.bishop, ChessColor.black),
+    'k': ChessPiece(ChessPieceClass.king, ChessColor.black),
+    'q': ChessPiece(ChessPieceClass.queen, ChessColor.black),
+};
+
+enum ChessColor {
+  black,
+  white;
+
+  ChessColor getOpposite() {
+    if (name == 'black') {
+      return white;
+    } else {
+      return black;
+    }
+  }
+
+  static ChessColor fromApiColor(ApiColor color) {
+    if (color == ApiColor.black) {
+      return black;
+    } else {
+      return white;
+    }
+  }
+}
+
 class ChessCoordinate {
   final int column;
   final int row;
 
   ChessCoordinate(this.column, this.row);
 
+  ChessCoordinate.copyFrom(ChessCoordinate original)
+      : column = original.column,
+        row = original.row;
+
+  factory ChessCoordinate.fromApiCoordinate(ApiCoordinate apiCoordinate) {
+    return ChessCoordinate(apiCoordinate.col, apiCoordinate.row);
+  }
+
   factory ChessCoordinate.fromString(String coordString) {
     var column = int.parse(coordString[0]);
     var row = int.parse(coordString[1]);
@@ -179,38 +172,16 @@ class ChessCoordinate {
     return ChessCoordinate(column, row);
   }
 
-  factory ChessCoordinate.fromApiCoordinate(ApiCoordinate apiCoordinate) {
+  @override
-    return ChessCoordinate(apiCoordinate.col, apiCoordinate.row);
+  int get hashCode {
-  }
+    return hash2(column, row);
-
-  ApiCoordinate toApiCoordinate() {
-    return ApiCoordinate(col: column, row: row);
-  }
-
-  ChessCoordinate.copyFrom(ChessCoordinate original)
-      : column = original.column,
-        row = original.row;
-
-  static String columnIntToColumnString(int col) {
-    String colStr;
-
-    colStr = String.fromCharCode(col + 96);
-
-    return colStr;
-  }
-
-  static int columnStringToColumnInt(String col) {
-    int colInt;
-    colInt = col.codeUnitAt(0) - 96;
-    return colInt;
   }
 
   @override
-  String toString() {
+  operator ==(other) {
-    String rowStr = row.toString();
+    return other is ChessCoordinate &&
-    String colStr = column.toString();
+        other.column == column &&
-
+        other.row == row;
-    return '$colStr$rowStr';
   }
 
   String toAlphabetical() {
@@ -230,16 +201,61 @@ class ChessCoordinate {
     return '$colStr$rowStr';
   }
 
+  ApiCoordinate toApiCoordinate() {
+    return ApiCoordinate(col: column, row: row);
+  }
+
   @override
-  operator ==(other) {
+  String toString() {
-    return other is ChessCoordinate &&
+    String rowStr = row.toString();
-        other.column == column &&
+    String colStr = column.toString();
-        other.row == row;
+
+    return '$colStr$rowStr';
+  }
+
+  static String columnIntToColumnString(int col) {
+    String colStr;
+
+    colStr = String.fromCharCode(col + 96);
+
+    return colStr;
+  }
+
+  static int columnStringToColumnInt(String col) {
+    int colInt;
+    colInt = col.codeUnitAt(0) - 96;
+    return colInt;
+  }
+}
+
+class ChessMove {
+  ChessCoordinate from;
+  ChessCoordinate to;
+
+  ChessMove({required this.from, required this.to});
+
+  factory ChessMove.fromApiMove(ApiMove apiMove) {
+    final start = ChessCoordinate.fromApiCoordinate(apiMove.startSquare);
+    final end = ChessCoordinate.fromApiCoordinate(apiMove.endSquare);
+
+    return ChessMove(from: start, to: end);
   }
 
   @override
   int get hashCode {
-    return hash2(column, row);
+    return hash2(from, to);
+  }
+
+  @override
+  operator ==(other) {
+    return other is ChessMove && other.from == from && other.to == to;
+  }
+
+  ApiMove toApiMove() {
+    var toSquare = to.toApiCoordinate();
+    var fromSquare = from.toApiCoordinate();
+    return ApiMove(
+        startSquare: fromSquare, endSquare: toSquare, promotionToPiece: null);
   }
 }
 
@@ -249,9 +265,6 @@ class ChessPiece extends StatelessWidget {
   final String shortName;
   final Widget? pieceImage;
 
-  const ChessPiece._(
-      this.pieceClass, this.color, this.pieceImage, this.shortName);
-
   factory ChessPiece(ChessPieceClass pieceClass, ChessColor color) {
     Widget? pieceImage;
     String pieceAssetUrl = chessPiecesAssets[
@@ -269,6 +282,9 @@ class ChessPiece extends StatelessWidget {
         pieceImage = null,
         shortName = "-";
 
+  const ChessPiece._(
+      this.pieceClass, this.color, this.pieceImage, this.shortName);
+
   @override
   Widget build(BuildContext context) {
     return SizedBox(
@@ -277,58 +293,33 @@ class ChessPiece extends StatelessWidget {
   }
 }
 
-class ChessMove {
+class ChessPieceAssetKey {
-  ChessCoordinate from;
+  final ChessPieceClass pieceClass;
-  ChessCoordinate to;
+  final ChessColor color;
 
-  ChessMove({required this.from, required this.to});
+  ChessPieceAssetKey({required this.pieceClass, required this.color});
-
-  factory ChessMove.fromApiMove(ApiMove apiMove) {
-    final start = ChessCoordinate.fromApiCoordinate(apiMove.startSquare);
-    final end = ChessCoordinate.fromApiCoordinate(apiMove.endSquare);
-
-    return ChessMove(from: start, to: end);
-  }
-
-  ApiMove toApiMove() {
-    var toSquare = to.toApiCoordinate();
-    var fromSquare = from.toApiCoordinate();
-    return ApiMove(
-        startSquare: fromSquare, endSquare: toSquare, promotionToPiece: null);
-  }
-
-  @override
-  operator ==(other) {
-    return other is ChessMove && other.from == from && other.to == to;
-  }
 
   @override
   int get hashCode {
-    return hash2(from, to);
+    return hash2(pieceClass, color);
   }
 
-  bool wasEnPassant() {
+  @override
-    var pieceMoved = ChessPosition.getInstance().getPieceAt(from);
+  bool operator ==(Object other) {
-    var pieceAtEndSquare = ChessPosition.getInstance().getPieceAt(to);
+    return (other is ChessPieceAssetKey &&
-    if (pieceMoved != null &&
+        (pieceClass == other.pieceClass) &&
-        pieceMoved.pieceClass == ChessPieceClass.pawn &&
+        (color == other.color));
-        pieceAtEndSquare == null &&
-        from.column != to.column) {
-      return true;
   }
-    return false;
 }
 
-  bool wasCastling() {
+enum ChessPieceClass {
-    var pieceMoved = ChessPosition.getInstance().getPieceAt(from);
+  none,
-    if (pieceMoved != null && pieceMoved.pieceClass == ChessPieceClass.king) {
+  pawn,
-      var colDiff = (from.column - to.column).abs();
+  bishop,
-      if (colDiff == 2) {
+  knight,
-        return true;
+  rook,
-      }
+  queen,
-    }
+  king,
-    return false;
-  }
 }
 
 class PieceDragged {