import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:fruitshorts/core/data/models/drama.dart';
import 'package:fruitshorts/core/data/models/play_ticket.dart';
import 'package:fruitshorts/core/data/models/player_port.dart';
import 'package:fruitshorts/core/data/models/download_license.dart';
import 'package:fruitshorts/core/data/models/download_policy.dart';
import 'package:fruitshorts/core/data/repositories/download_repository.dart';
import 'package:fruitshorts/core/data/services/android_picture_in_picture.dart';
import 'package:fruitshorts/core/data/services/download_controller.dart';
import 'package:fruitshorts/core/data/services/download_storage.dart';
import 'package:fruitshorts/core/data/services/playback_session.dart';
import 'package:fruitshorts/pages/player/player_logic.dart';
import 'package:fruitshorts/pages/player/player_view.dart';

import '../support/fake_watch_history.dart';
import 'package:fruitshorts/core/data/repositories/playback_repository.dart';

Drama _drama(
  String id, {
  List<int> numbers = const [1, 2, 3],
  bool isFree = true,
}) => Drama(
  id: id,
  title: id,
  synopsis: 'synopsis',
  posterUrl: '/files/poster.png',
  episodes: [
    for (final number in numbers)
      Episode(
        id: '$id-$number',
        number: number,
        title: 'Episode $number',
        // 与后端一致：只有可播放的剧集才带地址，锁定集为空
        videoUrl: isFree ? 'https://example.test/clip.mp4' : '',
        isFree: isFree,
      ),
  ],
);

AndroidPictureInPicture _pip() =>
    AndroidPictureInPicture(channel: const MethodChannel('test/player_logic/pip'));

PlayerLogic _logic(
  FakeWatchHistory history, {
  PlaybackRepository? playback,
}) => PlayerLogic(
  history: history,
  playback: playback ?? FakePlaybackRepository(),
  pictureInPicture: _pip(),
);

/// Drains the session's serialized work so a test never ends mid-disposal.
///
/// `start` kicks off selection without awaiting it, so the first read of
/// `playbackSettled` can still be the untouched initial future. Pumping the
/// event queue between reads closes that race.
Future<void> _drain(PlayerLogic logic) async {
  for (var attempt = 0; attempt < 4; attempt++) {
    await pumpEventQueue();
    await logic.session.playbackSettled;
    await logic.session.preloadSettled;
  }
}

void main() {
  TestWidgetsFlutterBinding.ensureInitialized();

  group('displayEpisode', () {
    test('should_fall_back_until_episode_number_is_picked_for_that_drama_when_resolving', () {
      final logic = _logic(FakeWatchHistory());
      final drama = _drama('signal');
      final fallback = drama.episodes.first;

      expect(logic.displayEpisode(drama, fallback).number, 1);

      logic.pickedEpisode['signal'] = 3;
      expect(logic.displayEpisode(drama, fallback).number, 3);

      // Picks are scoped to their own drama.
      final city = _drama('city');
      expect(logic.displayEpisode(city, city.episodes.first).number, 1);
    });

    test('should_stop_overriding_fallback_when_picked_number_is_unknown', () {
      final logic = _logic(FakeWatchHistory());
      final drama = _drama('signal');
      final fallback = drama.episodes.first;

      logic.pickedEpisode['signal'] = 99;

      expect(logic.displayEpisode(drama, fallback).number, 1);
    });
  });

  group('nextVisibleIndex', () {
    test('should_walk_visible_list_and_stop_at_the_end_when_advancing', () {
      final logic = _logic(FakeWatchHistory());
      logic.visibleIndices = [0, 2, 4];

      expect(logic.nextVisibleIndex(0), 2);
      expect(logic.nextVisibleIndex(2), 4);
      expect(logic.nextVisibleIndex(4), isNull);
    });

    test('should_have_no_successor_when_index_is_outside_visible_list', () {
      final logic = _logic(FakeWatchHistory());
      logic.visibleIndices = [0, 2, 4];

      expect(logic.nextVisibleIndex(1), isNull);
      expect(logic.nextVisibleIndex(9), isNull);
      expect(logic.nextVisibleIndex(-1), isNull);
    });

    test('should_have_no_successor_when_visible_list_is_empty', () {
      final logic = _logic(FakeWatchHistory());
      logic.visibleIndices = [];

      expect(logic.nextVisibleIndex(0), isNull);
    });
  });

  test('should_play_local_file_without_ticket_when_episode_is_downloaded',
      () async {
    final playback = FakePlaybackRepository();
    final downloads = DownloadController(
      _EmptyDownloadRepository(),
      storage: _LocalStorage(),
    );
    await downloads.restore();
    final drama = _drama('signal');
    final logic = PlayerLogic(
      history: FakeWatchHistory(),
      playback: playback,
      pictureInPicture: _pip(),
      downloads: downloads,
    );
    logic.attach(
      PlayerPage(drama: drama, initialIndex: 0),
      isMounted: () => true,
    );

    logic.start(factory: _RecordingFactory().create, coordinator: PlaybackCoordinator());
    await pumpEventQueue();
    await logic.session.playbackSettled;

    expect(playback.requests, isEmpty);
    expect(logic.sessionEpisodes.first.videoUrl, 'file:///local/signal-1.mp4');
  });

  group('surface flags', () {
    test('should_set_immersive_when_picture_in_picture_callback_fires', () async {
      final factory = _RecordingFactory();
      final drama = _drama('signal');
      final logic = _logic(FakeWatchHistory());
      final immersive = <bool>[];
      logic.attach(
        PlayerPage(drama: drama, initialIndex: 0),
        isMounted: () => true,
      );
      logic.onImmersiveChanged = immersive.add;
      logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
      await _drain(logic);

      logic.onPipChanged(true);

      expect(logic.pip, isTrue);
      expect(logic.pipPreparing, isFalse);
      expect(logic.immersive, isTrue);
      expect(logic.chromeHidden, isTrue);
      expect(immersive.last, isTrue);

      logic.onPipChanged(false);
      expect(logic.pip, isFalse);
      expect(logic.immersive, isFalse);

      logic.dispose();
      await _drain(logic);
    });

    test('should_ignore_picture_in_picture_callback_when_unmounted', () {
      final logic = _logic(FakeWatchHistory());
      logic.isMounted = () => false;

      logic.onPipChanged(true);

      expect(logic.pip, isFalse);
    });
  });

  group('history writes', () {
    test('should_serialize_progress_writes_in_call_order_when_saving', () async {
      final history = FakeWatchHistory();
      final logic = _logic(history);
      final drama = _drama('signal');

      await logic.queueProgress(
        drama,
        drama.episodes[0],
        const Duration(seconds: 1),
      );
      await logic.queueProgress(
        drama,
        drama.episodes[1],
        const Duration(seconds: 2),
      );

      expect(history.writes, ['signal-1|1000|false', 'signal-2|2000|false']);
    });

    test('should_keep_later_writes_when_an_earlier_write_fails', () async {
      final history = FakeWatchHistory();
      final logic = _logic(history);
      final drama = _drama('signal');

      history.failWrites = true;
      await logic.queueProgress(
        drama,
        drama.episodes[0],
        const Duration(seconds: 1),
      );

      history.failWrites = false;
      await logic.queueProgress(
        drama,
        drama.episodes[1],
        const Duration(seconds: 2),
      );

      expect(history.writes, ['signal-2|2000|false']);
    });

    test('should_write_nothing_when_no_player_is_tracked', () async {
      final history = FakeWatchHistory();
      final logic = _logic(history);

      await logic.saveCurrentProgress();
      await logic.saveCurrentProgress();

      expect(history.writes, isEmpty);
      expect(history.reads, isEmpty);
    });
  });

  group('start', () {
    test('should_play_single_series_when_route_is_detail', () async {
      final factory = _RecordingFactory();
      final drama = _drama('signal');
      final logic = _logic(FakeWatchHistory());
      logic.attach(
        PlayerPage(drama: drama, initialIndex: 0),
        isMounted: () => true,
      );

      logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
      await _drain(logic);

      expect(logic.queue.length, 3);
      expect(logic.visibleIndices, [0, 1, 2]);
      expect(logic.session.currentIndex, 0);
      expect(factory.created, hasLength(2));
      expect(factory.created.first.plays, 1);

      logic.dispose();
      await _drain(logic);
      expect(factory.live, 0);
    });

    test('should_play_one_episode_per_feed_drama_when_in_home_mode', () async {
      final factory = _RecordingFactory();
      final feed = [_drama('signal'), _drama('city'), _drama('vengeance')];
      final logic = _logic(FakeWatchHistory());
      logic.attach(
        PlayerPage(
          drama: feed.first,
          initialIndex: 0,
          homeMode: true,
          feedDramas: feed,
        ),
        isMounted: () => true,
      );

      logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
      await _drain(logic);

      expect(logic.queue.length, 3);
      expect(logic.queue.entryAt(1).drama.id, 'city');
      expect(logic.queue.entryAt(1).episode.number, 1);
      expect(logic.visibleIndices, [0, 1, 2]);

      logic.dispose();
      await _drain(logic);
    });

    test('should_never_reach_player_factory_when_episode_is_locked', () async {
      final factory = _RecordingFactory();
      final drama = _drama('locked', isFree: false);
      // 锁定的判定权在后端：票据返回不可播 + 无地址，客户端不得自行推断
      final logic = _logic(
        FakeWatchHistory(),
        playback: FakePlaybackRepository(
          ticket: const PlayTicket(
            episodeId: 'locked-1',
            accessible: false,
            accessType: PlayTicket.coinRequired,
            unlockCoin: 30,
          ),
        ),
      );
      logic.attach(
        PlayerPage(drama: drama, initialIndex: 0),
        isMounted: () => true,
      );

      logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
      await _drain(logic);

      expect(logic.session.isLocked, isTrue);
      expect(factory.created, isEmpty);

      logic.dispose();
      await _drain(logic);
    });

    test('should_preload_only_what_follows_when_starting_from_a_later_index', () async {
      final factory = _RecordingFactory();
      final drama = _drama('signal');
      final logic = _logic(FakeWatchHistory());
      logic.attach(
        PlayerPage(drama: drama, initialIndex: 2),
        isMounted: () => true,
      );

      logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
      await _drain(logic);

      expect(logic.session.currentIndex, 2);
      // The last episode has no successor to warm.
      expect(factory.created, hasLength(1));

      logic.dispose();
      await _drain(logic);
    });

    test('should_hold_no_players_when_route_is_inactive', () async {
      final factory = _RecordingFactory();
      final drama = _drama('signal');
      final logic = _logic(FakeWatchHistory());
      logic.attach(
        PlayerPage(drama: drama, initialIndex: 0, active: false),
        isMounted: () => true,
      );

      logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
      await _drain(logic);

      expect(factory.created, isEmpty);
      expect(logic.session.loading, isFalse);

      logic.dispose();
      await _drain(logic);
    });
  });

  group('lifecycle', () {
    test('should_pause_active_player_when_backgrounded_and_play_it_when_resumed', () async {
      final factory = _RecordingFactory();
      final drama = _drama('signal');
      final logic = _logic(FakeWatchHistory());
      logic.attach(
        PlayerPage(drama: drama, initialIndex: 0),
        isMounted: () => true,
      );
      logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
      await _drain(logic);

      final player = factory.created.first;
      expect(player.plays, 1);
      expect(player.pauses, 0);

      logic.onLifecycle(AppLifecycleState.paused);
      await _drain(logic);
      expect(player.pauses, 1);

      logic.onLifecycle(AppLifecycleState.resumed);
      await _drain(logic);
      expect(player.plays, 2);

      logic.dispose();
      await _drain(logic);
    });

    test('should_stop_playing_without_losing_intent_when_route_becomes_inactive', () async {
      final factory = _RecordingFactory();
      final drama = _drama('signal');
      final logic = _logic(FakeWatchHistory());
      final start = PlayerPage(drama: drama, initialIndex: 0);
      logic.attach(start, isMounted: () => true);
      logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
      await _drain(logic);
      final player = factory.created.first;
      expect(player.plays, 1);

      logic.onPageUpdated(start);
      await _drain(logic);
      expect(player.plays, 1);

      logic.attach(
        PlayerPage(drama: drama, initialIndex: 0, active: false),
        isMounted: () => true,
      );
      logic.onPageUpdated(start);
      await _drain(logic);
      expect(player.pauses, 1);
      expect(logic.session.userWantsPlay, isTrue);

      logic.dispose();
      await _drain(logic);
    });
  });

  group('dispose', () {
    test('should_release_every_player_when_dispose_runs_twice', () async {
      final factory = _RecordingFactory();
      final drama = _drama('signal');
      final logic = _logic(FakeWatchHistory());
      logic.attach(
        PlayerPage(drama: drama, initialIndex: 0),
        isMounted: () => true,
      );
      logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
      await _drain(logic);
      expect(factory.live, greaterThan(0));

      logic.dispose();
      await _drain(logic);

      expect(factory.live, 0);
      expect(() => logic.dispose(), returnsNormally);
    });

    test('should_disable_further_notifications_when_disposed', () async {
      final factory = _RecordingFactory();
      final drama = _drama('signal');
      final logic = _logic(FakeWatchHistory());
      logic.attach(
        PlayerPage(drama: drama, initialIndex: 0),
        isMounted: () => true,
      );
      logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
      await _drain(logic);

      var notifications = 0;
      logic.addListener(() => notifications++);

      logic.dispose();
      await _drain(logic);
      logic.notify();

      expect(notifications, 0);
    });
  });
}

class _LocalStorage implements DownloadStorage {
  @override
  Future<Map<String, String>> restore() async => {
    'signal-1': 'file:///local/signal-1.mp4',
  };

  @override
  Future<String?> localPathFor(String episodeId) async =>
      episodeId == 'signal-1' ? 'file:///local/signal-1.mp4' : null;

  @override
  Future<DownloadedMedia> download({
    required String episodeId,
    required String url,
    DownloadProgress? onProgress,
  }) async => throw UnimplementedError();

  @override
  Future<void> delete(String episodeId) async {}

  @override
  Future<void> clear() async {}
}

class _EmptyDownloadRepository implements DownloadRepository {
  @override
  Future<DownloadPolicy> fetchPolicy() async => const DownloadPolicy(
    maxPerDevice: 20,
    licenseDays: 30,
    wifiOnly: false,
    maxQuality: 'AUTO',
    maxStorageBytes: 0,
    used: 0,
    remaining: 20,
    expirePolicyText: '',
  );

  @override
  Future<List<DownloadLicense>> list() async => const [];

  @override
  Future<DownloadLicense> grant(String episodeId, {String? quality}) async =>
      throw UnimplementedError();

  @override
  Future<void> updateSettings({bool? wifiOnly, String? maxQuality}) async {}

  @override
  Future<DownloadLicense> refreshUrl(String episodeId) async =>
      throw UnimplementedError();

  @override
  Future<DownloadLicense> reportProgress(
    String episodeId, {
    String? deviceId,
    String? status,
    int? progressPercent,
    int? downloadedBytes,
    int? totalBytes,
    String? errorMsg,
  }) async => throw UnimplementedError();

  @override
  Future<void> remove(String episodeId) async {}

  @override
  Future<int> clear() async => 0;
}

/// Counts native-style allocations so leaks are visible to a test.
class _RecordingFactory {
  final List<_RecordingPlayer> created = [];
  int live = 0;

  PlayerPort create(Episode episode) {
    live++;
    final player = _RecordingPlayer(onDispose: () => live--);
    created.add(player);
    return player;
  }
}

class _RecordingPlayer implements PlayerPort {
  _RecordingPlayer({required this.onDispose});

  final void Function() onDispose;
  int plays = 0;
  int pauses = 0;
  bool disposed = false;

  @override
  Future<void> initialize() async {}

  @override
  Future<void> play() async => plays++;

  @override
  Future<void> pause() async => pauses++;

  @override
  Future<void> dispose() async {
    if (disposed) return;
    disposed = true;
    onDispose();
  }
}