// HomeBloc 单元测试
//
// 覆盖：首页数据加载、今日日记检查、心情统计、连续天数计算、离线容错
// 使用 InMemoryJournalRepository 作为测试替身

import 'package:flutter_test/flutter_test.dart';
import 'package:nuanji_app/data/models/journal_element.dart';
import 'package:nuanji_app/data/models/journal_entry.dart';
import 'package:nuanji_app/data/repositories/journal_repository.dart';
import 'package:nuanji_app/features/home/bloc/home_bloc.dart';

void main() {
  group('HomeBloc', () {
    late HomeBloc bloc;
    late InMemoryJournalRepository repo;

    setUp(() {
      repo = InMemoryJournalRepository();
      bloc = HomeBloc(journalRepository: repo);
    });

    tearDown(() {
      bloc.close();
    });

    // ===== 辅助 =====

    /// 收集事件触发后的最终状态
    Future<HomeState> dispatch(HomeEvent event) async {
      bloc.add(event);
      await Future<void>.delayed(const Duration(milliseconds: 50));
      return bloc.state;
    }

    /// 创建测试日记条目
    JournalEntry _makeEntry({
      required String id,
      required DateTime date,
      Mood mood = Mood.happy,
    }) {
      return JournalEntry(
        id: id,
        authorId: 'user-1',
        title: '测试日记',
        date: date,
        mood: mood,
        createdAt: date,
        updatedAt: date,
      );
    }

    /// 获取当天零时的 DateTime
    DateTime _today() {
      final now = DateTime.now();
      return DateTime(now.year, now.month, now.day);
    }

    /// 往前推 n 天的日期
    DateTime _daysAgo(int n) {
      return _today().subtract(Duration(days: n));
    }

    /// 向仓库批量添加日记
    Future<void> _seed(List<JournalEntry> entries) async {
      for (final e in entries) {
        await repo.createJournal(e);
      }
    }

    // ===== 1. HomeLoadData 成功 → HomeLoading → HomeLoaded with journals =====

    test('HomeLoadData 成功时状态经过 HomeLoading 到达 HomeLoaded', () async {
      final states = <HomeState>[];
      final subscription = bloc.stream.listen(states.add);

      await repo.createJournal(_makeEntry(
        id: 'j-1',
        date: _today(),
      ));

      bloc.add(const HomeLoadData());
      await Future<void>.delayed(const Duration(milliseconds: 50));

      subscription.cancel();

      // 至少经历 HomeLoading → HomeLoaded
      expect(states, contains(isA<HomeLoading>()));
      expect(states.last, isA<HomeLoaded>());

      final loaded = states.last as HomeLoaded;
      expect(loaded.recentJournals.length, 1);
      expect(loaded.recentJournals.first.id, 'j-1');
    });

    // ===== 2. HomeLoadData 有今日日记 → hasTodayEntry = true =====

    test('HomeLoadData 有今日日记 → hasTodayEntry = true', () async {
      await _seed([
        _makeEntry(id: 'j-today', date: _today()),
      ]);

      final state = await dispatch(const HomeLoadData());
      final loaded = state as HomeLoaded;

      expect(loaded.hasTodayEntry, isTrue);
    });

    // ===== 3. HomeLoadData 无今日日记 → hasTodayEntry = false =====

    test('HomeLoadData 无今日日记 → hasTodayEntry = false', () async {
      await _seed([
        _makeEntry(id: 'j-yesterday', date: _daysAgo(1)),
      ]);

      final state = await dispatch(const HomeLoadData());
      final loaded = state as HomeLoaded;

      expect(loaded.hasTodayEntry, isFalse);
    });

    // ===== 4. HomeLoadData 计算最常用心情 topMood → happy(3次) vs calm(1次) =====

    test('HomeLoadData topMood 为出现次数最多的心情', () async {
      await _seed([
        _makeEntry(id: 'j-1', date: _daysAgo(0), mood: Mood.happy),
        _makeEntry(id: 'j-2', date: _daysAgo(1), mood: Mood.happy),
        _makeEntry(id: 'j-3', date: _daysAgo(2), mood: Mood.happy),
        _makeEntry(id: 'j-4', date: _daysAgo(3), mood: Mood.calm),
      ]);

      final state = await dispatch(const HomeLoadData());
      final loaded = state as HomeLoaded;

      expect(loaded.topMood, Mood.happy);
    });

    // ===== 5. HomeLoadData 计算连续天数 streakDays（连续 3 天）=====

    test('HomeLoadData streakDays 计算从今天开始的连续天数', () async {
      // 今天、昨天、前天 — 连续 3 天
      await _seed([
        _makeEntry(id: 'j-today', date: _daysAgo(0)),
        _makeEntry(id: 'j-yesterday', date: _daysAgo(1)),
        _makeEntry(id: 'j-day-before', date: _daysAgo(2)),
        // 4 天前（中断连续）
        _makeEntry(id: 'j-old', date: _daysAgo(4)),
      ]);

      final state = await dispatch(const HomeLoadData());
      final loaded = state as HomeLoaded;

      expect(loaded.streakDays, 3);
    });

    // ===== 6. HomeLoadData 失败 → HomeLoaded (空数据，离线友好) =====

    test('HomeLoadData 失败时返回空 HomeLoaded（离线友好）', () async {
      // 使用一个会在 getJournals 时抛异常的仓库
      final failingRepo = _FailingJournalRepository();
      final failingBloc = HomeBloc(journalRepository: failingRepo);

      final state = await _dispatchOn(failingBloc, const HomeLoadData());

      expect(state, isA<HomeLoaded>());
      final loaded = state as HomeLoaded;
      expect(loaded.recentJournals, isEmpty);
      expect(loaded.hasTodayEntry, isFalse);
      expect(loaded.topMood, isNull);
      expect(loaded.streakDays, 0);

      failingBloc.close();
    });

    // ===== 7. HomeRefresh → 触发 HomeLoadData =====

    test('HomeRefresh 触发重新加载（经过 Loading → Loaded）', () async {
      final states = <HomeState>[];
      final subscription = bloc.stream.listen(states.add);

      await repo.createJournal(_makeEntry(
        id: 'j-refresh',
        date: _today(),
      ));

      bloc.add(const HomeRefresh());
      await Future<void>.delayed(const Duration(milliseconds: 50));

      subscription.cancel();

      // HomeRefresh 内部 add(HomeLoadData)，所以应有 Loading → Loaded
      expect(states, contains(isA<HomeLoading>()));
      expect(states.last, isA<HomeLoaded>());

      final loaded = states.last as HomeLoaded;
      expect(loaded.recentJournals.length, 1);
    });

    // ===== 8. HomeLoadData 空数据 → HomeLoaded with defaults =====

    test('HomeLoadData 空数据时返回默认 HomeLoaded', () async {
      // 仓库中不添加任何日记
      final state = await dispatch(const HomeLoadData());
      final loaded = state as HomeLoaded;

      expect(loaded.recentJournals, isEmpty);
      expect(loaded.hasTodayEntry, isFalse);
      expect(loaded.topMood, isNull);
      expect(loaded.streakDays, 0);
    });
  });
}

// ===== 测试辅助：总是抛出异常的仓库 =====

/// 模拟仓库失败场景，用于测试离线容错
class _FailingJournalRepository implements JournalRepository {
  @override
  Future<List<JournalEntry>> getJournals({
    DateTime? dateFrom,
    DateTime? dateTo,
    int? page,
    int? pageSize,
    String? mood,
    String? tag,
    String? classId,
  }) async {
    throw Exception('网络不可用');
  }

  @override
  Future<int> getJournalCount() async {
    throw Exception('网络不可用');
  }

  @override
  Future<JournalEntry?> getJournal(String id) async {
    throw UnimplementedError();
  }

  @override
  Future<JournalEntry> createJournal(JournalEntry entry) async {
    throw UnimplementedError();
  }

  @override
  Future<JournalEntry> updateJournal(JournalEntry entry) async {
    throw UnimplementedError();
  }

  @override
  Future<void> deleteJournal(String id) async {
    throw UnimplementedError();
  }

  @override
  Future<List<JournalElement>> getElements(String journalId) async {
    throw UnimplementedError();
  }

  @override
  Future<JournalElement> addElement(JournalElement element) async {
    throw UnimplementedError();
  }

  @override
  Future<JournalElement> updateElement(JournalElement element) async {
    throw UnimplementedError();
  }

  @override
  Future<void> removeElement(String elementId) async {
    throw UnimplementedError();
  }
}

/// 在指定 bloc 上触发事件并等待处理完毕
Future<HomeState> _dispatchOn(HomeBloc bloc, HomeEvent event) async {
  bloc.add(event);
  await Future<void>.delayed(const Duration(milliseconds: 50));
  return bloc.state;
}