Add offline computer variant support

Except for crazyhouse in practice mode for now.

Author: veloce

lib/src/model/offline_computer/offline_computer_game_controller.dart

@@ -10,6 +10,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:freezed_annotation/freezed_annotation.dart';
 import 'package:lichess_mobile/src/model/analysis/analysis_controller.dart';
 import 'package:lichess_mobile/src/model/common/chess.dart';
+import 'package:lichess_mobile/src/model/common/chess960.dart';
 import 'package:lichess_mobile/src/model/common/eval.dart';
 import 'package:lichess_mobile/src/model/common/id.dart';
 import 'package:lichess_mobile/src/model/common/perf.dart';
@@ -112,13 +113,15 @@ class OfflineComputerGameController extends Notifier<OfflineComputerGameState> {
     required Side playerSide,
     required bool casual,
     required bool practiceMode,
+    Variant variant = Variant.standard,
     String? initialFen,
   }) {
     state = OfflineComputerGameState.initial(
       stockfishLevel: stockfishLevel,
       playerSide: playerSide,
       casual: casual,
       practiceMode: practiceMode,
+      variant: variant,
       initialFen: initialFen,
     );
 
@@ -383,7 +386,7 @@ class OfflineComputerGameController extends Notifier<OfflineComputerGameState> {
     return EvalWork(
       id: state.game.id,
       stockfishFlavor: _kComputerStockfishFlavor,
-      variant: Variant.standard,
+      variant: state.game.meta.variant,
       threads: numberOfCoresForEvaluation,
       hashSize: ref.read(evaluationServiceProvider).maxMemory,
       searchTime: _kMoveEvalMaxSearchTime,
@@ -640,7 +643,7 @@ class OfflineComputerGameController extends Notifier<OfflineComputerGameState> {
 
       final work = MoveWork(
         id: state.game.id,
-        variant: Variant.standard,
+        variant: state.game.meta.variant,
         hashSize: evaluationService.maxMemory,
         initialPosition: state.game.initialPosition,
         steps: steps,
@@ -772,7 +775,7 @@ class OfflineComputerGameController extends Notifier<OfflineComputerGameState> {
       final work = EvalWork(
         id: state.game.id,
         stockfishFlavor: _kComputerStockfishFlavor,
-        variant: Variant.standard,
+        variant: state.game.meta.variant,
         threads: numberOfCoresForEvaluation,
         hashSize: evaluationService.maxMemory,
         searchTime: _kHintsMaxSearchTime,
@@ -868,26 +871,42 @@ sealed class OfflineComputerGameState with _$OfflineComputerGameState {
   factory OfflineComputerGameState.initial({
     required StockfishLevel stockfishLevel,
     required Side playerSide,
+    Variant variant = Variant.standard,
     bool casual = true,
     bool practiceMode = false,
     String? initialFen,
   }) {
-    final position = initialFen != null
-        ? Chess.fromSetup(Setup.parseFen(initialFen))
-        : Chess.initial;
+    final Position position;
+    final Variant effectiveVariant;
+    final String? effectiveInitialFen;
+
+    if (initialFen != null) {
+      position = Chess.fromSetup(Setup.parseFen(initialFen));
+      effectiveVariant = Variant.fromPosition;
+      effectiveInitialFen = initialFen;
+    } else if (variant == Variant.chess960) {
+      position = randomChess960Position();
+      effectiveVariant = Variant.chess960;
+      effectiveInitialFen = position.fen;
+    } else {
+      position = variant.initialPosition;
+      effectiveVariant = variant;
+      effectiveInitialFen = null;
+    }
+
     final sessionId = StringId('ocg_${_random.nextInt(1 << 32).toRadixString(16).padLeft(8, '0')}');
     return OfflineComputerGameState(
       game: OfflineComputerGame(
         id: sessionId,
         steps: [GameStep(position: position)].lock,
         status: GameStatus.started,
-        initialFen: initialFen,
+        initialFen: effectiveInitialFen,
         meta: GameMeta(
           createdAt: DateTime.now(),
           rated: false,
-          variant: initialFen != null ? Variant.fromPosition : Variant.standard,
+          variant: effectiveVariant,
           speed: Speed.classical,
-          perf: Perf.classical,
+          perf: Perf.fromVariantAndSpeed(effectiveVariant, Speed.classical),
         ),
         playerSide: playerSide,
         stockfishLevel: stockfishLevel,

lib/src/model/offline_computer/offline_computer_game_preferences.dart

@@ -1,6 +1,7 @@
 import 'package:dartchess/dartchess.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:freezed_annotation/freezed_annotation.dart';
+import 'package:lichess_mobile/src/model/common/chess.dart';
 import 'package:lichess_mobile/src/model/game/offline_computer_game.dart';
 import 'package:lichess_mobile/src/model/settings/preferences_storage.dart';
 
@@ -39,6 +40,10 @@ class OfflineComputerGamePreferences extends Notifier<OfflineComputerGamePrefs>
     return save(state.copyWith(sideChoice: sideChoice));
   }
 
+  Future<void> setVariant(Variant variant) {
+    return save(state.copyWith(variant: variant));
+  }
+
   Future<void> setCasual(bool casual) {
     return save(state.copyWith(casual: casual));
   }
@@ -82,6 +87,7 @@ sealed class OfflineComputerGamePrefs with _$OfflineComputerGamePrefs implements
   const factory OfflineComputerGamePrefs({
     required StockfishLevel stockfishLevel,
     required SideChoice sideChoice,
+    @Default(Variant.standard) Variant variant,
     @Default(true) bool casual,
     @Default(false) bool practiceMode,
     @Default(false) bool hideBestMove,
@@ -91,6 +97,7 @@ sealed class OfflineComputerGamePrefs with _$OfflineComputerGamePrefs implements
   static const defaults = OfflineComputerGamePrefs(
     stockfishLevel: StockfishLevel.defaultLevel,
     sideChoice: SideChoice.random,
+    variant: Variant.standard,
     casual: true,
     practiceMode: false,
     hideBestMove: false,

lib/src/view/offline_computer/offline_computer_game_screen.dart

@@ -244,7 +244,7 @@ class _BodyState extends ConsumerState<_Body> {
                     lastMove: gameState.lastMove,
                     shapes: _buildBoardShapes(gameState, boardColorScheme),
                     boardParams: GameBoardParams.interactive(
-                      variant: Variant.standard,
+                      variant: gameState.game.meta.variant,
                       position: gameState.currentPosition,
                       playerSide: gameState.game.finished
                           ? PlayerSide.none
@@ -376,7 +376,7 @@ class _BottomBar extends ConsumerWidget {
                   orientation: gameState.game.playerSide,
                   pgn: gameState.game.makePgn(),
                   isComputerAnalysisAllowed: true,
-                  variant: Variant.standard,
+                  variant: gameState.game.meta.variant,
                 ),
               ),
             ),
@@ -703,6 +703,7 @@ class _NewGameSheet extends ConsumerStatefulWidget {
 class _NewGameSheetState extends ConsumerState<_NewGameSheet> {
   late StockfishLevel _selectedLevel;
   late SideChoice _selectedSideChoice;
+  late Variant _selectedVariant;
   late bool _casual;
   late bool _practiceMode;
 
@@ -718,6 +719,7 @@ class _NewGameSheetState extends ConsumerState<_NewGameSheet> {
     final prefs = ref.read(offlineComputerGamePreferencesProvider);
     _selectedLevel = prefs.stockfishLevel;
     _selectedSideChoice = prefs.sideChoice;
+    _selectedVariant = prefs.variant;
     _casual = prefs.casual;
     _practiceMode = prefs.practiceMode;
   }
@@ -798,14 +800,44 @@ class _NewGameSheetState extends ConsumerState<_NewGameSheet> {
                 );
               },
             ),
+            if (widget.initialFen == null)
+              SettingsListTile(
+                settingsLabel: Text(context.l10n.variant),
+                settingsValue: _selectedVariant.label,
+                onTap: () {
+                  showChoicePicker(
+                    context,
+                    choices: playSupportedVariants
+                        .where((v) => v != Variant.fromPosition)
+                        .toList(),
+                    selectedItem: _selectedVariant,
+                    labelBuilder: (Variant variant) => Text(variant.label),
+                    onSelectedItemChanged: (Variant variant) {
+                      setState(() {
+                        _selectedVariant = variant;
+                        if (variant == Variant.crazyhouse) {
+                          _practiceMode = false;
+                        }
+                      });
+                      ref
+                          .read(offlineComputerGamePreferencesProvider.notifier)
+                          .setVariant(variant);
+                    },
+                  );
+                },
+              ),
             SwitchSettingTile(
               title: const Text('Practice mode'),
               subtitle: const Text('Get feedback on your moves'),
               value: _practiceMode,
-              onChanged: (value) {
-                setState(() => _practiceMode = value);
-                ref.read(offlineComputerGamePreferencesProvider.notifier).setPracticeMode(value);
-              },
+              onChanged: _selectedVariant == Variant.crazyhouse
+                  ? null
+                  : (value) {
+                      setState(() => _practiceMode = value);
+                      ref
+                          .read(offlineComputerGamePreferencesProvider.notifier)
+                          .setPracticeMode(value);
+                    },
             ),
             SwitchSettingTile(
               title: Text(context.l10n.casual),
@@ -832,6 +864,7 @@ class _NewGameSheetState extends ConsumerState<_NewGameSheet> {
                     playerSide: side,
                     casual: _practiceMode || _casual,
                     practiceMode: _practiceMode,
+                    variant: _selectedVariant,
                     initialFen: widget.initialFen,
                   );
               Navigator.pop(context);
@@ -926,7 +959,7 @@ class OfflineComputerGameResultDialog extends StatelessWidget {
                   orientation: game.playerSide,
                   pgn: game.makePgn(),
                   isComputerAnalysisAllowed: true,
-                  variant: Variant.standard,
+                  variant: game.meta.variant,
                 ),
               ),
             );