1043 add castling method option v2

lib/src/model/game/game_controller.dart

@@ -954,10 +954,34 @@ class GameState with _$GameState {
   }) = _GameState;
 
   /// The [Position] and its legal moves at the current cursor.
-  (Position, IMap<Square, ISet<Square>>) get currentPosition {
+  (Position, IMap<Square, ISet<Square>>) getCurrentPosition(CastlingMethod castlingMethod) {
     final position = game.positionAt(stepCursor);
     final legalMoves = makeLegalMoves(position, isChess960: game.meta.variant == Variant.chess960);
-    return (position, legalMoves);
+
+    final Map<Square, Square> castlingMap = {
+      Square.a1: Square.c1,
+      Square.a8: Square.c8,
+      Square.h1: Square.g1,
+      Square.h8: Square.g8,
+    };
+
+    MapEntry<Square, ISet<Square>> mapper(Square sq, ISet<Square> moves) {
+      return MapEntry(
+        sq,
+        position.board.kings.squares.contains(sq) && //king move
+                position.castles.castlingRights.squares.intersectsWith(
+                  moves, //king can castle
+                )
+            ? (switch (castlingMethod) {
+              CastlingMethod.kingOverRook => moves.removeAll(castlingMap.values),
+              CastlingMethod.kingTwoSquares => moves.removeAll(castlingMap.keys),
+              _ => moves,
+            })
+            : moves,
+      );
+    }
+
+    return (position, legalMoves.map(mapper));
   }
 
   /// Whether the zen mode is active

lib/src/model/settings/board_preferences.dart

@@ -44,6 +44,10 @@ class BoardPreferences extends _$BoardPreferences with PreferencesStorage<BoardP
     await save(state.copyWith(pieceShiftMethod: pieceShiftMethod));
   }
 
+  Future<void> setCastlingMethod(CastlingMethod castlingMethod) {
+    return save(state.copyWith(castlingMethod: castlingMethod));
+  }
+
   Future<void> toggleHapticFeedback() {
     return save(state.copyWith(hapticFeedback: !state.hapticFeedback));
   }
@@ -125,6 +129,7 @@ class BoardPrefs with _$BoardPrefs implements Serializable {
     required ClockPosition clockPosition,
     @JsonKey(defaultValue: PieceShiftMethod.either, unknownEnumValue: PieceShiftMethod.either)
     required PieceShiftMethod pieceShiftMethod,
+    required CastlingMethod castlingMethod,
 
     /// Whether to enable shape drawings on the board for games and puzzles.
     @JsonKey(defaultValue: true) required bool enableShapeDrawings,
@@ -150,6 +155,7 @@ class BoardPrefs with _$BoardPrefs implements Serializable {
     materialDifferenceFormat: MaterialDifferenceFormat.materialDifference,
     clockPosition: ClockPosition.right,
     pieceShiftMethod: PieceShiftMethod.either,
+    castlingMethod: CastlingMethod.either,
     enableShapeDrawings: true,
     magnifyDraggedPiece: true,
     dragTargetKind: DragTargetKind.circle,
@@ -347,6 +353,19 @@ enum ClockPosition {
   };
 }
 
+enum CastlingMethod {
+  kingOverRook,
+  kingTwoSquares,
+  either;
+
+  // TODO: l10n
+  String get label => switch (this) {
+    CastlingMethod.kingOverRook => 'Move king over rook',
+    CastlingMethod.kingTwoSquares => 'Move king two squares',
+    CastlingMethod.either => 'Either',
+  };
+}
+
 String dragTargetKindLabel(DragTargetKind kind) => switch (kind) {
   DragTargetKind.circle => 'Circle',
   DragTargetKind.square => 'Square',

lib/src/view/game/game_body.dart

@@ -103,7 +103,9 @@ class GameBody extends ConsumerWidget {
 
     return gameStateAsync.when(
       data: (gameState) {
-        final (position, legalMoves) = gameState.currentPosition;
+        final (position, legalMoves) = gameState.getCurrentPosition(
+          boardPreferences.castlingMethod,
+        );
         final youAre = gameState.game.youAre ?? Side.white;
         final archivedBlackClock = gameState.game.archivedBlackClockAt(gameState.stepCursor);
         final archivedWhiteClock = gameState.game.archivedWhiteClockAt(gameState.stepCursor);

lib/src/view/settings/board_settings_screen.dart

@@ -75,6 +75,34 @@ class _Body extends ConsumerWidget {
                 }
               },
             ),
+            SettingsListTile(
+              settingsLabel: Text(
+                context.l10n.preferencesCastleByMovingTheKingTwoSquaresOrOntoTheRook,
+              ),
+              settingsValue: boardPrefs.castlingMethod.name,
+              showCupertinoTrailingValue: false,
+              onTap: () {
+                if (Theme.of(context).platform == TargetPlatform.android) {
+                  showChoicePicker(
+                    context,
+                    choices: CastlingMethod.values,
+                    selectedItem: boardPrefs.castlingMethod,
+                    labelBuilder: (t) => Text(t.label),
+                    onSelectedItemChanged: (CastlingMethod? value) {
+                      ref
+                          .read(boardPreferencesProvider.notifier)
+                          .setCastlingMethod(value ?? CastlingMethod.either);
+                    },
+                  );
+                } else {
+                  pushPlatformRoute(
+                    context,
+                    title: context.l10n.preferencesCastleByMovingTheKingTwoSquaresOrOntoTheRook,
+                    builder: (context) => const CastlingMethodSettingsScreen(),
+                  );
+                }
+              },
+            ),
             SwitchSettingTile(
               title: Text(context.l10n.mobilePrefMagnifyDraggedPiece),
               value: boardPrefs.magnifyDraggedPiece,
@@ -271,6 +299,38 @@ class PieceShiftMethodSettingsScreen extends ConsumerWidget {
   }
 }
 
+class CastlingMethodSettingsScreen extends ConsumerWidget {
+  const CastlingMethodSettingsScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final castlingMethod = ref.watch(
+      boardPreferencesProvider.select((state) => state.castlingMethod),
+    );
+
+    void onChanged(CastlingMethod? value) {
+      ref.read(boardPreferencesProvider.notifier).setCastlingMethod(value ?? CastlingMethod.either);
+    }
+
+    return CupertinoPageScaffold(
+      navigationBar: const CupertinoNavigationBar(),
+      child: SafeArea(
+        child: ListView(
+          children: [
+            ChoicePicker(
+              notchedTile: true,
+              choices: CastlingMethod.values,
+              selectedItem: castlingMethod,
+              titleBuilder: (t) => Text(t.label),
+              onSelectedItemChanged: onChanged,
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
 class BoardClockPositionScreen extends ConsumerWidget {
   const BoardClockPositionScreen({super.key});
 
@@ -369,3 +429,11 @@ String pieceShiftMethodl10n(BuildContext context, PieceShiftMethod pieceShiftMet
       PieceShiftMethod.drag => context.l10n.preferencesDragPiece,
       PieceShiftMethod.tapTwoSquares => 'Tap two squares',
     };
+
+String castlingMethodl10n(BuildContext context, CastlingMethod castlingMethod) =>
+    switch (castlingMethod) {
+      // TODO add this to mobile translations
+      CastlingMethod.kingOverRook => context.l10n.preferencesCastleByMovingOntoTheRook,
+      CastlingMethod.kingTwoSquares => context.l10n.preferencesCastleByMovingTwoSquares,
+      CastlingMethod.either => 'Either',
+    };