game_controller.dart

import 'dart:async';

import 'package:collection/collection.dart';
import 'package:dartchess/dartchess.dart';
import 'package:deep_pick/deep_pick.dart';
import 'package:fast_immutable_collections/fast_immutable_collections.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/services.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:freezed_annotation/freezed_annotation.dart';
import 'package:lichess_mobile/src/binding.dart';
import 'package:lichess_mobile/src/model/account/account_preferences.dart';
import 'package:lichess_mobile/src/model/account/account_service.dart';
import 'package:lichess_mobile/src/model/account/ongoing_game.dart';
import 'package:lichess_mobile/src/model/analysis/analysis_controller.dart';
import 'package:lichess_mobile/src/model/chat/chat_controller.dart';
import 'package:lichess_mobile/src/model/clock/chess_clock.dart';
import 'package:lichess_mobile/src/model/common/chess.dart';
import 'package:lichess_mobile/src/model/common/id.dart';
import 'package:lichess_mobile/src/model/common/service/move_feedback.dart';
import 'package:lichess_mobile/src/model/common/service/sound_service.dart';
import 'package:lichess_mobile/src/model/common/socket.dart';
import 'package:lichess_mobile/src/model/common/speed.dart';
import 'package:lichess_mobile/src/model/correspondence/correspondence_service.dart';
import 'package:lichess_mobile/src/model/game/exported_game.dart';
import 'package:lichess_mobile/src/model/game/game.dart';
import 'package:lichess_mobile/src/model/game/game_repository.dart';
import 'package:lichess_mobile/src/model/game/game_socket_events.dart';
import 'package:lichess_mobile/src/model/game/game_status.dart';
import 'package:lichess_mobile/src/model/game/game_storage.dart';
import 'package:lichess_mobile/src/model/game/material_diff.dart';
import 'package:lichess_mobile/src/model/game/playable_game.dart';
import 'package:lichess_mobile/src/model/settings/board_preferences.dart';
import 'package:lichess_mobile/src/network/socket.dart';
import 'package:lichess_mobile/src/utils/rate_limit.dart';
import 'package:logging/logging.dart';

part 'game_controller.freezed.dart';

/// A provider for [GameController].
final gameControllerProvider = AsyncNotifierProvider.autoDispose
    .family<GameController, GameState, GameFullId>(
      GameController.new,
      name: 'GameControllerProvider',
    );

class GameController extends AsyncNotifier<GameState> {
  GameController(this.gameFullId);

  final GameFullId gameFullId;

  final _logger = Logger('GameController');

  StreamSubscription<SocketEvent>? _socketSubscription;

  /// Tracks moves that were played on the board, sent to the server, possibly
  /// acked, but without a move response from the server yet.
  /// After a delay, it will trigger a reload. This might fix bugs where the
  /// board is in a transient, dirty state, where clocks don't tick, eventually
  /// causing the player to flag.
  /// It will also help with lila-ws restarts.
  Timer? _transientMoveTimer;

  /// Callback to be called when a full reload is needed.
  VoidCallback? _onFullReload;

  final _onFlagThrottler = Throttler(const Duration(milliseconds: 500));

  static Uri socketUri(GameFullId gameFullId) => Uri(path: '/play/$gameFullId/v6');

  SocketPool get _socketPool => ref.read(socketPoolProvider);

  ChessClock? _clock;
  late SocketClient _socketClient;

  GameRepository get _gameRepository => ref.read(gameRepositoryProvider);

  @override
  Future<GameState> build() {
    _socketClient = _openSocket();

    _onFullReload = () {
      _logger.warning('full reload triggered');
      ref.invalidateSelf();
    };

    ref.onDispose(() {
      _socketSubscription?.cancel();
      _transientMoveTimer?.cancel();
      _clock?.dispose();
      _clock = null;
      _onFlagThrottler.cancel();
      _onFullReload = null;
    });

    _socketSubscription?.cancel();
    _socketSubscription = _socketClient.stream.listen(_handleSocketEvent);

    return _socketClient.stream.firstWhere((e) => e.topic == 'full').then((event) {
      final fullEvent = GameFullEvent.fromJson(event.data as Map<String, dynamic>);
      _socketClient.version = fullEvent.socketEventVersion;

      final game = fullEvent.game;

      // Play "dong" sound when this is a new game and we're playing it (not spectating)
      final isMyGame = game.youAre != null;
      final noMovePlayed = game.steps.length == 1;
      if (isMyGame && noMovePlayed && game.status == GameStatus.started) {
        ref.read(soundServiceProvider).play(Sound.dong);
      }

      if (game.clock != null) {
        _clock = ChessClock(
          whiteTime: game.clock!.white,
          blackTime: game.clock!.black,
          emergencyThreshold: game.meta.clock?.emergency,
          onEmergency: onClockEmergency,
          onFlag: onFlag,
        );
        if (game.clock!.running) {
          final pos = game.lastPosition;
          if (pos.fullmoves > 1) {
            _clock!.startSide(pos.turn);
          }
        }
      }

      if (game.finished) {
        _onFinishedGameLoad(fullEvent.game);
      }

      return GameState(
        gameFullId: gameFullId,
        game: game,
        stepCursor: game.steps.length - 1,
        liveClock: _clock != null ? (white: _clock!.whiteTime, black: _clock!.blackTime) : null,
      );
    });
  }

  void onForegroundLost() {
    if (_socketClient.isDisposed) {
      assert(false, 'socket client should not be disposed here');
      return;
    }
    if (!state.hasValue || !state.requireValue.game.playable) {
      return;
    }
    // real time games need the socket to stay connected otherwise lichess will think the player leaved
    // correspondence games can and should close the socket when the app is in background (because lichess won't send the push notification update when the player is still connected to the socket)
    if (state.requireValue.game.meta.speed == Speed.correspondence) {
      _socketClient.close();
    }
  }

  void onFocusRegained() {
    if (_socketClient.isDisposed) {
      assert(false, 'socket client should not be disposed here');
      return;
    }

    if (!state.hasValue) {
      return;
    }

    final currentClient = ref.read(socketPoolProvider).currentClient;
    if (currentClient.route != _socketClient.route) {
      _socketClient = _openSocket();
    } else if (!_socketClient.isConnected) {
      _socketClient.connect();
    }
  }

  void userMove(NormalMove move, {bool? isDrop, bool? isPremove}) {
    final curState = state.requireValue;

    if (isPromotionPawnMove(curState.game.lastPosition, move)) {
      state = AsyncValue.data(curState.copyWith(promotionMove: move));
      return;
    }

    if (curState.shouldConfirmMove && isPremove != true) {
      state = AsyncValue.data(curState.copyWith(moveToConfirm: move));
      return;
    }

    final (newPos, newSan) = curState.game.lastPosition.makeSan(move);
    final sanMove = SanMove(newSan, move);
    final newStep = GameStep(
      position: newPos,
      sanMove: sanMove,
      diff: MaterialDiff.fromBoard(newPos.board),
    );

    state = AsyncValue.data(
      curState.copyWith(
        game: curState.game.copyWith(steps: curState.game.steps.add(newStep)),
        stepCursor: curState.stepCursor + 1,
        promotionMove: null,
        premove: null,
      ),
    );

    _playMoveFeedback(sanMove, skipAnimationDelay: isDrop ?? false);

    _sendMoveToSocket(
      move,
      isPremove: isPremove ?? false,
      // same logic as web client
      // we want to send client lag only at the beginning of the game when the clock is not running yet
      withLag: curState.game.clock != null && curState.activeClockSide == null,
    );
  }

  void onPromotionSelection(Role? role) {
    final curState = state.requireValue;
    if (role == null) {
      state = AsyncValue.data(curState.copyWith(promotionMove: null));
      return;
    }
    if (curState.promotionMove == null) {
      assert(false, 'promotionMove must not be null on promotion select');
      return;
    }

    final move = curState.promotionMove!.withPromotion(role);
    userMove(move, isDrop: true);
  }

  /// Called if the player cancels the move when confirm move preference is enabled
  void cancelMove() {
    final curState = state.requireValue;
    if (curState.game.steps.isEmpty) {
      assert(false, 'game steps cannot be empty on cancel move');
      return;
    }
    final (GameState newState, bool _) = _tryCancelMoveConfirmation(curState);
    state = AsyncValue.data(newState);
  }

  (GameState, bool) _tryCancelMoveConfirmation(GameState curState) {
    if (curState.moveToConfirm == null) {
      return (curState, false);
    }
    return (curState.copyWith(moveToConfirm: null), true);
  }

  /// Called if the player confirms the move when confirm move preference is enabled
  void confirmMove() {
    final curState = state.requireValue;
    final moveToConfirm = curState.moveToConfirm;
    if (moveToConfirm == null) {
      assert(false, 'moveToConfirm must not be null on confirm move');
      return;
    }

    final (newPos, newSan) = curState.game.lastPosition.makeSan(moveToConfirm);
    final sanMove = SanMove(newSan, moveToConfirm);
    final newStep = GameStep(
      position: newPos,
      sanMove: sanMove,
      diff: MaterialDiff.fromBoard(newPos.board),
    );

    state = AsyncValue.data(
      curState.copyWith(
        game: curState.game.copyWith(steps: curState.game.steps.add(newStep)),
        stepCursor: curState.stepCursor + 1,
        moveToConfirm: null,
      ),
    );
    _sendMoveToSocket(
      moveToConfirm,
      isPremove: false,
      // same logic as web client
      // we want to send client lag only at the beginning of the game when the clock is not running yet
      withLag: curState.game.clock != null && curState.activeClockSide == null,
    );
  }

  /// Set or unset a premove.
  void setPremove(NormalMove? move) {
    final curState = state.requireValue;
    state = AsyncValue.data(curState.copyWith(premove: move));
  }

  void cursorAt(int cursor) {
    if (state.hasValue) {
      final currentCursor = state.requireValue.stepCursor;
      if (currentCursor == cursor) {
        return;
      }
      final (newState, _) = _tryCancelMoveConfirmation(state.requireValue);
      state = AsyncValue.data(newState.copyWith(stepCursor: cursor, premove: null));
      final san = state.requireValue.game.stepAt(cursor).sanMove?.san;
      if (san != null) {
        _playReplayMoveSound(san);
        HapticFeedback.lightImpact();
      }
    }
  }

  void cursorForward() {
    if (state.hasValue) {
      final curState = state.requireValue;
      if (curState.stepCursor < curState.game.steps.length - 1) {
        state = AsyncValue.data(
          curState.copyWith(
            stepCursor: curState.stepCursor + 1,
            premove: null,
            promotionMove: null,
          ),
        );
        final san = curState.game.stepAt(curState.stepCursor + 1).sanMove?.san;
        if (san != null) {
          _playReplayMoveSound(san);
        }
      }
    }
  }

  void cursorBackward() {
    if (state.hasValue) {
      final curState = state.requireValue;
      if (curState.stepCursor > 0) {
        final (newState, didCancel) = _tryCancelMoveConfirmation(curState);
        state = AsyncValue.data(
          newState.copyWith(
            stepCursor: didCancel ? newState.stepCursor : newState.stepCursor - 1,
            premove: null,
            promotionMove: null,
          ),
        );
        final san = state.requireValue.game.stepAt(state.requireValue.stepCursor).sanMove?.san;
        if (san != null) {
          _playReplayMoveSound(san);
        }
      }
    }
  }

  Future<void> toggleBookmark() async {
    if (state.hasValue) {
      final toggledBookmark = !(state.requireValue.game.bookmarked ?? false);
      await ref
          .read(accountServiceProvider)
          .setGameBookmark(gameFullId.gameId, bookmark: toggledBookmark);
      state = AsyncValue.data(
        state.requireValue.copyWith(
          game: state.requireValue.game.copyWith(bookmarked: toggledBookmark),
        ),
      );
    }
  }

  void toggleMoveConfirmation() {
    final curState = state.requireValue;
    state = AsyncValue.data(
      curState.copyWith(moveConfirmSettingOverride: !(curState.moveConfirmSettingOverride ?? true)),
    );
  }

  void toggleZenMode() {
    final curState = state.requireValue;
    state = AsyncValue.data(
      curState.copyWith(zenModeGameSetting: !(curState.zenModeGameSetting ?? false)),
    );
  }

  void toggleAutoQueen() {
    final curState = state.requireValue;
    state = AsyncValue.data(
      curState.copyWith(autoQueenSettingOverride: !(curState.autoQueenSettingOverride ?? true)),
    );
  }

  void onToggleChat(bool isChatEnabled) {
    if (isChatEnabled) {
      // if chat is enabled, we need to resync the game data to get the chat messages
      _reloadGame();
    }
  }

  /// Play a sound when the clock is about to run out
  Future<void> onClockEmergency(Side activeSide) async {
    if (activeSide != state.value?.game.youAre) return;
    final shouldPlay = await ref.read(clockSoundProvider.future);
    if (shouldPlay) {
      ref.read(soundServiceProvider).play(Sound.lowTime);
    }
  }

  void onFlag() {
    _onFlagThrottler(() {
      if (state.hasValue) {
        _socketClient.send('flag', state.requireValue.game.sideToMove.name);
      }
    });
  }

  void moreTime() {
    _socketClient.send('moretime', null);
  }

  void berserk() {
    if (state.value?.canBerserk == true && state.value?.hasBerserked == false) {
      _socketClient.send('berserk', null);
    }
  }

  void abortGame() {
    _socketClient.send('abort', null);
  }

  void resignGame() {
    _socketClient.send('resign', null);
  }

  void forceResign() {
    _socketClient.send('resign-force', null);
  }

  void forceDraw() {
    _socketClient.send('draw-force', null);
  }

  void claimDraw() {
    _socketClient.send('draw-claim', null);
  }

  void offerOrAcceptDraw() {
    _socketClient.send('draw-yes', null);
  }

  void cancelOrDeclineDraw() {
    _socketClient.send('draw-no', null);
  }

  void offerTakeback() {
    _socketClient.send('takeback-yes', null);
  }

  void acceptTakeback() {
    _socketClient.send('takeback-yes', null);
    setPremove(null);
  }

  void cancelOrDeclineTakeback() {
    _socketClient.send('takeback-no', null);
  }

  void proposeOrAcceptRematch() {
    _socketClient.send('rematch-yes', null);
  }

  void declineRematch() {
    _socketClient.send('rematch-no', null);
  }

  SocketClient _openSocket() {
    return _socketPool.open(
      socketUri(gameFullId),
      forceReconnect: true,
      onEventGapFailure: () {
        _onFullReload?.call();
      },
    );
  }

  /// Update the internal clock on clock server event
  void _updateClock({
    required Duration white,
    required Duration black,
    required Side? activeSide,
    Duration? lag,
  }) {
    _clock?.setTimes(whiteTime: white, blackTime: black);
    if (activeSide != null) {
      _clock?.startSide(activeSide, delay: lag);
    } else {
      _clock?.stop();
    }
  }

  void _sendMoveToSocket(Move move, {required bool isPremove, required bool withLag}) {
    final thinkTime = _clock?.stop();
    final moveTime = _clock != null
        ? isPremove == true
              ? Duration.zero
              : thinkTime
        : null;
    _socketClient.send(
      'move',
      {
        'u': move.uci,
        if (moveTime != null) 's': (moveTime.inMilliseconds * 0.1).round().toRadixString(36),
      },
      ackable: true,
      withLag: _clock != null && (moveTime == null || withLag),
    );

    _transientMoveTimer = Timer(const Duration(seconds: 10), _reloadGame);
  }

  /// Move feedback while playing
  void _playMoveFeedback(SanMove sanMove, {bool skipAnimationDelay = false}) {
    final animationDuration = ref.read(effectivePieceAnimationDurationProvider);

    final delay = animationDuration ~/ 2;

    if (skipAnimationDelay || delay <= Duration.zero) {
      _moveFeedback(sanMove);
    } else {
      Timer(delay, () {
        _moveFeedback(sanMove);
      });
    }
  }

  void _moveFeedback(SanMove sanMove) {
    final isCheck = sanMove.san.contains('+');
    if (sanMove.san.contains('x')) {
      ref.read(moveFeedbackServiceProvider).captureFeedback(check: isCheck);
    } else {
      ref.read(moveFeedbackServiceProvider).moveFeedback(check: isCheck);
    }
  }

  /// Play the sound when replaying moves
  void _playReplayMoveSound(String san) {
    final soundService = ref.read(soundServiceProvider);
    if (san.contains('x')) {
      soundService.play(Sound.capture);
    } else {
      soundService.play(Sound.move);
    }
  }

  /// Reload game
  void _reloadGame() {
    _logger.info('Reloading game data');
    _socketClient.connect();
  }

  void _handleSocketEvent(SocketEvent event, [bool hasRetried = false]) {
    if (!state.hasValue) {
      if (event.version != null) {
        _logger.warning('received $event while game state not yet available');
        // not sure whether this can happen so log it
        LichessBinding.instance.firebaseCrashlytics.recordError(
          'received $event while game state not yet available',
          null,
          reason: 'versioned socket event received before game state available',
          information: ['event.type: ${event.topic}'],
        );
      }
      return;
    }

    switch (event.topic) {
      // First message sent when the socket is reconnected
      case 'full':
        final fullEvent = GameFullEvent.fromJson(event.data as Map<String, dynamic>);
        _socketClient.version = fullEvent.socketEventVersion;

        final curState = state.requireValue;

        final newGame = fullEvent.game;
        final isOpponentOnGame =
            newGame.playerOf(newGame.youAre?.opposite ?? Side.white).onGame ?? false;
        final hasSameNumberOfSteps = newGame.steps.length == curState.game.steps.length;

        state = AsyncValue.data(
          state.requireValue.copyWith(
            game: newGame,
            stepCursor: hasSameNumberOfSteps ? curState.stepCursor : newGame.steps.length - 1,
            premove: hasSameNumberOfSteps ? curState.premove : null,
            promotionMove: hasSameNumberOfSteps ? curState.promotionMove : null,
            moveToConfirm: hasSameNumberOfSteps ? curState.moveToConfirm : null,
            opponentLeftCountdown: isOpponentOnGame
                ? null
                : state.requireValue.opponentLeftCountdown,
          ),
        );

        if (newGame.clock != null) {
          _updateClock(
            white: newGame.clock!.white,
            black: newGame.clock!.black,
            activeSide: state.requireValue.activeClockSide,
          );
        }

      // Server asking for a resync
      case 'resync':
        _onFullReload?.call();

      // Server asking for a reload, or in some cases the reload itself contains
      // another topic message
      case 'reload':
        if (event.data is Map<String, dynamic>) {
          final data = event.data as Map<String, dynamic>;
          if (data['t'] == null) {
            _reloadGame();
            return;
          }
          final reloadEvent = SocketEvent(topic: data['t'] as String, data: data['d']);
          _handleSocketEvent(reloadEvent);
        } else {
          _reloadGame();
        }

      // Move event, received after sending a move or receiving a move from the
      // opponent
      case 'move':
        final curState = state.requireValue;
        final data = MoveEvent.fromJson(event.data as Map<String, dynamic>);
        final playedSide = data.ply.isOdd ? Side.white : Side.black;

        GameState newState = curState.copyWith(
          game: curState.game.copyWith(
            isThreefoldRepetition: data.threefold,
            winner: data.winner,
            status: data.status ?? curState.game.status,
            // Update forecast: keep only the lines with the move that was just played and remove the first move
            correspondenceForecast: curState.game.correspondenceForecast
                ?.where((line) => line.firstOrNull?.move.uci == data.uci)
                .map((line) => line.removeAt(0))
                .where((line) => line.isNotEmpty)
                .toIList(),
          ),
        );

        if (playedSide == curState.game.youAre) {
          _transientMoveTimer?.cancel();
        }

        // add opponent move
        if (data.ply == curState.game.lastPly + 1) {
          final lastPos = curState.game.lastPosition;
          final move = Move.parse(data.uci)!;
          final sanMove = SanMove(data.san, move);
          final newPos = lastPos.playUnchecked(move);
          final newStep = GameStep(
            sanMove: sanMove,
            position: newPos,
            diff: MaterialDiff.fromBoard(newPos.board),
          );

          newState = newState.copyWith(
            game: newState.game.copyWith(steps: newState.game.steps.add(newStep)),
          );

          if (!curState.isReplaying) {
            newState = newState.copyWith(stepCursor: newState.stepCursor + 1);

            _playMoveFeedback(sanMove);
          }
        }

        if (data.clock != null) {
          final lag = newState.game.playable && newState.game.isMyTurn
              // my own clock doesn't need to be compensated for
              ? Duration.zero
              // server will send the lag only if it's more than 10ms
              // default lag of 10ms is also used by web client
              : data.clock?.lag ?? const Duration(milliseconds: 10);

          _updateClock(
            white: data.clock!.white,
            black: data.clock!.black,
            lag: lag,
            activeSide: newState.activeClockSide,
          );

          if (newState.game.clock != null) {
            // we don't rely on these values to display the clock, but let's keep
            // the game object in sync
            newState = newState.copyWith.game.clock!(
              white: data.clock!.white,
              black: data.clock!.black,
            );
          } else if (newState.game.correspondenceClock != null) {
            newState = newState.copyWith.game.correspondenceClock!(
              white: data.clock!.white,
              black: data.clock!.black,
            );
          }
        }

        if (newState.game.expiration != null) {
          if (newState.game.steps.length > 2) {
            newState = newState.copyWith.game(expiration: null);
          } else {
            newState = newState.copyWith.game(
              expiration: (
                idle: newState.game.expiration!.idle,
                timeToMove: curState.game.expiration!.timeToMove,
                movedAt: DateTime.now(),
              ),
            );
          }
        }

        if (curState.game.meta.speed == Speed.correspondence) {
          ref.read(correspondenceServiceProvider).updateStoredGame(gameFullId, newState.game);
          ref.read(ongoingGamesProvider.notifier).updateGame(gameFullId, newState.game);
        }

        if (!curState.isReplaying &&
            playedSide == curState.game.youAre?.opposite &&
            curState.premove != null) {
          scheduleMicrotask(() {
            final postMovePremove = state.value?.premove;
            final postMovePosition = state.value?.game.lastPosition;
            if (postMovePremove != null && postMovePosition?.isLegal(postMovePremove) == true) {
              userMove(postMovePremove, isPremove: true);
            }
          });
        }

        state = AsyncValue.data(newState);

      // End game event
      case 'endData':
        final endData = GameEndEvent.fromJson(event.data as Map<String, dynamic>);
        final curState = state.requireValue;
        GameState newState = curState.copyWith(
          game: curState.game.copyWith(
            status: endData.status,
            winner: endData.winner,
            boosted: endData.boosted,
            white: curState.game.white.copyWith(ratingDiff: endData.ratingDiff?.white),
            black: curState.game.black.copyWith(ratingDiff: endData.ratingDiff?.black),
          ),
          premove: null,
        );

        if (endData.clock != null) {
          newState = newState.copyWith.game.clock!(
            white: endData.clock!.white,
            black: endData.clock!.black,
          );
          _updateClock(
            white: endData.clock!.white,
            black: endData.clock!.black,
            activeSide: newState.activeClockSide,
          );
        }

        if (curState.game.lastPosition.fullmoves > 1) {
          Timer(const Duration(milliseconds: 500), () {
            ref.read(soundServiceProvider).play(Sound.dong);
          });
        }

        if (curState.game.meta.speed == Speed.correspondence) {
          ref.read(correspondenceServiceProvider).updateStoredGame(gameFullId, newState.game);
          ref.read(ongoingGamesProvider.notifier).updateGame(gameFullId, newState.game);
        }

        state = AsyncValue.data(newState);

        if (!newState.game.aborted) {
          _getPostGameData()
              .then((data) {
                final game = _mergePostGameData(state.requireValue.game, data);
                state = AsyncValue.data(state.requireValue.copyWith(game: game));
                _storeGame(game);
              })
              .catchError((Object e, StackTrace s) {
                _logger.warning('Could not get post game data', e, s);
              });
        }

      case 'clockInc':
        final data = event.data as Map<String, dynamic>;
        final side = pick(data['color']).asSideOrNull();
        final newClock = pick(
          data['total'],
        ).letOrNull((it) => Duration(milliseconds: it.asIntOrThrow() * 10));
        final curState = state.requireValue;

        if (side != null && newClock != null) {
          _clock?.setTime(side, newClock);

          // sync game clock object even if it's not used to display the clock
          final newState = side == Side.white
              ? curState.copyWith.game.clock!(white: newClock)
              : curState.copyWith.game.clock!(black: newClock);
          state = AsyncValue.data(newState);
        }

      // Crowd event, sent when a player quits or joins the game
      case 'crowd':
        final data = event.data as Map<String, dynamic>;
        final whiteOnGame = data['white'] as bool?;
        final blackOnGame = data['black'] as bool?;
        final curState = state.requireValue;
        final opponent = curState.game.youAre?.opposite;
        GameState newState = curState;
        if (whiteOnGame != null) {
          newState = newState.copyWith.game(white: newState.game.white.setOnGame(whiteOnGame));
          if (opponent == Side.white && whiteOnGame == true) {
            newState = newState.copyWith(opponentLeftCountdown: null);
          }
        }
        if (blackOnGame != null) {
          newState = newState.copyWith.game(black: newState.game.black.setOnGame(blackOnGame));
          if (opponent == Side.black && blackOnGame == true) {
            newState = newState.copyWith(opponentLeftCountdown: null);
          }
        }
        state = AsyncValue.data(newState);

      // Gone event, sent when the opponent has quit the game for long enough
      // than we can claim victory
      case 'gone':
        final isGone = event.data as bool;
        GameState newState = state.requireValue;
        final youAre = newState.game.youAre;
        newState = newState.copyWith.game(
          white: youAre == Side.white ? newState.game.white : newState.game.white.setGone(isGone),
          black: youAre == Side.black ? newState.game.black : newState.game.black.setGone(isGone),
        );
        state = AsyncValue.data(newState);

      // Event sent when the opponent has quit the game, to display a countdown
      // before claiming victory is possible
      case 'goneIn':
        final timeLeft = Duration(seconds: event.data as int);
        state = AsyncValue.data(
          state.requireValue.copyWith(opponentLeftCountdown: (timeLeft, DateTime.now())),
        );

      // Event sent when a player adds or cancels a draw offer
      case 'drawOffer':
        final side = pick(event.data).asSideOrNull();
        final curState = state.requireValue;
        state = AsyncValue.data(
          curState.copyWith(
            lastDrawOfferAtPly: side != null && side == curState.game.youAre
                ? curState.game.lastPly
                : null,
            game: curState.game.copyWith(
              white: curState.game.white.copyWith(
                offeringDraw: side == null ? null : side == Side.white,
              ),
              black: curState.game.black.copyWith(
                offeringDraw: side == null ? null : side == Side.black,
              ),
            ),
          ),
        );

      // Event sent when a player adds or cancels a takeback offer
      case 'takebackOffers':
        final data = event.data as Map<String, dynamic>;
        final white = pick(data['white']).asBoolOrNull();
        final black = pick(data['black']).asBoolOrNull();
        final curState = state.requireValue;
        state = AsyncValue.data(
          curState.copyWith(
            game: curState.game.copyWith(
              white: curState.game.white.copyWith(proposingTakeback: white ?? false),
              black: curState.game.black.copyWith(proposingTakeback: black ?? false),
            ),
          ),
        );

      // Event sent when a player adds or cancels a rematch offer
      case 'rematchOffer':
        final side = pick(event.data).asSideOrNull();
        final curState = state.requireValue;
        state = AsyncValue.data(
          curState.copyWith(
            game: curState.game.copyWith(
              white: curState.game.white.copyWith(
                offeringRematch: side == null ? null : side == Side.white,
              ),
              black: curState.game.black.copyWith(
                offeringRematch: side == null ? null : side == Side.black,
              ),
            ),
          ),
        );

      // Event sent when a rematch is taken. Not used for now, except to prevent
      // sending another rematch offer, which should not happen
      case 'rematchTaken':
        final nextId = pick(event.data).asGameIdOrThrow();
        state = AsyncValue.data(state.requireValue.copyWith.game(rematch: nextId));

      // Event sent after a rematch is taken, to redirect to the new game
      case 'redirect':
        final data = event.data as Map<String, dynamic>;
        final fullId = pick(data['id']).asGameFullIdOrThrow();
        state = AsyncValue.data(state.requireValue.copyWith(redirectGameId: fullId));

      case 'analysisProgress':
        final data = ServerEvalEvent.fromJson(event.data as Map<String, dynamic>);
        final curState = state.requireValue;
        state = AsyncValue.data(
          curState.copyWith.game(
            white: curState.game.white.copyWith(analysis: data.analysis?.white),
            black: curState.game.black.copyWith(analysis: data.analysis?.black),
            evals: data.evals,
          ),
        );

      case 'berserk':
        ref.read(soundServiceProvider).play(Sound.berserk);

        final side = pick(event.data).asSideOrNull();
        final curState = state.requireValue;

        state = AsyncValue.data(
          curState.copyWith.game(
            white: curState.game.white.copyWith(
              berserk: side == Side.white || curState.game.white.berserk == true,
            ),
            black: curState.game.black.copyWith(
              berserk: side == Side.black || curState.game.black.berserk == true,
            ),
          ),
        );
    }
  }

  Future<void> _storeGame(PlayableGame game) async {
    if (game.finished) {
      final gameStorage = await ref.read(gameStorageProvider.future);
      final existing = await gameStorage.fetch(gameId: gameFullId.gameId);
      final finishedAt = existing?.data.lastMoveAt ?? DateTime.now();
      await gameStorage.save(game.toExportedGame(finishedAt: finishedAt));
    }
  }

  Future<ExportedGame> _getPostGameData() {
    return _gameRepository.getGame(gameFullId.gameId);
  }

  Future<void> _onFinishedGameLoad(PlayableGame game) async {
    if (game.meta.speed == Speed.correspondence) {
      ref.read(correspondenceServiceProvider).updateStoredGame(gameFullId, game);
    }

    PlayableGame gameWithPostData = game;
    try {
      final result = await _getPostGameData();
      gameWithPostData = _mergePostGameData(game, result, rewriteSteps: true);
    } catch (e, s) {
      _logger.warning('Could not get post game data', e, s);
    }

    await _storeGame(gameWithPostData);

    state = AsyncValue.data(state.requireValue.copyWith(game: gameWithPostData));
  }

  PlayableGame _mergePostGameData(
    PlayableGame game,
    ExportedGame data, {

    /// Whether to rewrite the steps with the clock data from the archived game
    ///
    /// This should not be done when the game has just finished, because we
    /// don't want to confuse the user with a changing clock.
    bool rewriteSteps = false,
  }) {
    IList<GameStep> newSteps = game.steps;
    if (rewriteSteps && game.meta.clock != null && data.clocks != null) {
      final initialTime = game.meta.clock!.initial;
      newSteps = game.steps.mapIndexed((index, element) {
        if (index == 0) {
          return element.copyWith(archivedWhiteClock: initialTime, archivedBlackClock: initialTime);
        }
        final prevClock = index > 1 ? data.clocks![index - 2] : initialTime;
        final stepClock = data.clocks![index - 1];
        return element.copyWith(
          archivedWhiteClock: index.isOdd ? stepClock : prevClock,
          archivedBlackClock: index.isEven ? stepClock : prevClock,
        );
      }).toIList();
    }

    return game.copyWith(
      steps: newSteps,
      clocks: data.clocks,
      meta: game.meta.copyWith(opening: data.meta.opening, division: data.meta.division),
      white: game.white.copyWith(analysis: data.white.analysis),
      black: game.black.copyWith(analysis: data.black.analysis),
      evals: data.evals,
    );
  }
}

typedef LiveGameClock = ({ValueListenable<Duration> white, ValueListenable<Duration> black});

@freezed
sealed class GameState with _$GameState {
  const GameState._();

  const factory GameState({
    required GameFullId gameFullId,
    required PlayableGame game,
    required int stepCursor,
    required LiveGameClock? liveClock,
    int? lastDrawOfferAtPly,
    (Duration, DateTime)? opponentLeftCountdown,

    /// Promotion waiting to be selected (only if auto queen is disabled)
    NormalMove? promotionMove,

    /// Premove waiting to be played
    NormalMove? premove,

    /// Game only setting to override the account preference
    bool? moveConfirmSettingOverride,

    /// Game only setting to override the account preference
    bool? autoQueenSettingOverride,

    /// Zen mode setting if account preference is set to [Zen.gameAuto]
    bool? zenModeGameSetting,

    /// Set if confirm move preference is enabled and player played a move
    Move? moveToConfirm,

    /// Game full id used to redirect to the new game of the rematch
    GameFullId? redirectGameId,
  }) = _GameState;

  /// The [Position] at the current cursor.
  Position get currentPosition {
    if (moveToConfirm != null) {
      final lastPos = game.lastPosition;
      return lastPos.playUnchecked(moveToConfirm!);
    }
    return game.positionAt(stepCursor);
  }

  /// Whether the zen mode is active
  bool get isZenModeActive => game.playable ? isZenModeEnabled : game.prefs?.zenMode == Zen.yes;

  /// Whether zen mode is enabled by account preference or local game setting
  bool get isZenModeEnabled =>
      zenModeGameSetting ?? game.prefs?.zenMode == Zen.yes || game.prefs?.zenMode == Zen.gameAuto;

  bool get canPremove => game.meta.speed != Speed.correspondence;
  bool get canAutoQueen => autoQueenSettingOverride ?? (game.prefs?.autoQueen == AutoQueen.always);
  bool get canAutoQueenOnPremove =>
      autoQueenSettingOverride ??
      (game.prefs?.autoQueen == AutoQueen.always || game.prefs?.autoQueen == AutoQueen.premove);
  bool get shouldConfirmMove => moveConfirmSettingOverride ?? game.prefs?.submitMove ?? false;

  bool get isReplaying => stepCursor < game.steps.length - 1;
  bool get canGoForward => stepCursor < game.steps.length - 1;
  bool get canGoBackward => stepCursor > 0;

  bool get canBerserk =>
      game.meta.tournament?.berserkable == true &&
      game.playable &&
      game.steps.length <= 2 &&
      game.youAre != null;
  bool get hasBerserked => game.youAre != null && game.playerOf(game.youAre!).berserk == true;

  // Only if this game is part of a tournament
  TournamentMeta? get tournament => game.meta.tournament;

  bool get canGetNewOpponent =>
      !game.playable &&
      game.meta.speed != Speed.correspondence &&
      (game.source == GameSource.lobby || game.source == GameSource.pool);

  bool get canOfferDraw => game.drawable && (lastDrawOfferAtPly ?? -99) < game.lastPly - 20;

  bool get canShowClaimWinCountdown =>
      !game.isMyTurn &&
      game.resignable &&
      (game.meta.rules == null || !game.meta.rules!.contains(GameRule.noClaimWin));

  bool get canOfferRematch => game.rematch == null && game.rematchable;

  /// Time left to move for the active player if an expiration is set
  Duration? get timeToMove {
    if (!game.playable || game.expiration == null) {
      return null;
    }
    final timeLeft =
        game.expiration!.movedAt.difference(DateTime.now()) + game.expiration!.timeToMove;

    if (timeLeft.isNegative) {
      return Duration.zero;
    }
    return timeLeft;
  }

  Side? get activeClockSide {
    if (game.clock == null && game.correspondenceClock == null) {
      return null;
    }
    if (game.status == GameStatus.started) {
      final pos = game.lastPosition;
      if (pos.fullmoves > 1) {
        return pos.turn;
      }
    }

    return null;
  }

  String get analysisPgn => game.makePgn();

  AnalysisOptions get analysisOptions => game.finished
      ? AnalysisOptions.archivedGame(
          orientation: game.youAre ?? Side.white,
          initialMoveCursor: stepCursor,
          gameId: gameFullId.gameId,
        )
      : game.playable && game.meta.speed == Speed.correspondence && game.youAre != null
      ? AnalysisOptions.activeCorrespondenceGame(
          orientation: game.youAre ?? Side.white,
          initialMoveCursor: stepCursor,
          gameFullId: gameFullId,
        )
      : AnalysisOptions.standalone(
          orientation: game.youAre ?? Side.white,
          initialMoveCursor: stepCursor,
          pgn: game.makePgn(),
          variant: game.meta.variant,
          isComputerAnalysisAllowed: false,
        );

  GameChatOptions? get chatOptions => isZenModeActive || game.meta.tournament != null
      ? null
      : GameChatOptions(
          id: gameFullId,
          opponent: game.youAre != null ? game.playerOf(game.youAre!.opposite).user : null,
        );
}