import 'package:flutter_test/flutter_test.dart';

import 'package:meeyao_qianwen/features/notifications/data/models/notification_item.dart';
import 'package:meeyao_qianwen/features/notifications/data/models/notification_list_result.dart';
import 'package:meeyao_qianwen/features/notifications/data/models/notification_payload.dart';
import 'package:meeyao_qianwen/features/notifications/data/repositories/notification_repository.dart';
import 'package:meeyao_qianwen/features/notifications/presentation/bloc/notification_bloc.dart';

class _FakeNotificationRepository implements NotificationRepository {
  final List<NotificationItem> items = [];
  int unreadCount = 0;
  int markAllReadCallCount = 0;
  bool failMarkRead = false;
  bool failMarkAllRead = false;

  @override
  Future<NotificationListResult> listNotifications({
    int limit = 20,
    String? cursor,
    String locale = 'zh',
  }) async {
    return NotificationListResult(
      items: items,
      hasMore: false,
      nextCursor: null,
    );
  }

  @override
  Future<int> getUnreadCount() async => unreadCount;

  @override
  Future<NotificationItem> markRead({
    required String notificationId,
    String locale = 'zh',
  }) async {
    if (failMarkRead) {
      throw Exception('Mark read failed');
    }
    final idx = items.indexWhere((i) => i.id == notificationId);
    if (idx == -1) {
      throw Exception('Not found');
    }
    items[idx] = items[idx].copyWith(isRead: true);
    unreadCount = unreadCount > 0 ? unreadCount - 1 : 0;
    return items[idx];
  }

  @override
  Future<int> markAllRead() async {
    if (failMarkAllRead) {
      throw Exception('Mark all read failed');
    }
    markAllReadCallCount++;
    final count = unreadCount;
    for (int i = 0; i < items.length; i++) {
      items[i] = items[i].copyWith(isRead: true);
    }
    unreadCount = 0;
    return count;
  }
}

NotificationItem makeItem({
  String id = 'item-1',
  String notificationId = 'notif-1',
  bool isRead = false,
}) {
  return NotificationItem(
    id: id,
    notificationId: notificationId,
    type: 'system',
    title: 'Test',
    body: 'Body',
    payload: const NotificationPayloadNone(),
    isRead: isRead,
    createdAt: DateTime(2026, 4, 10),
  );
}

void main() {
  group('NotificationBloc', () {
    late _FakeNotificationRepository fakeRepo;
    late NotificationBloc bloc;

    setUp(() {
      fakeRepo = _FakeNotificationRepository();
      bloc = NotificationBloc(repository: fakeRepo);
    });

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

    test('initial state has zero unreadCount', () {
      expect(bloc.state.unreadCount, 0);
      expect(bloc.state.items, isEmpty);
    });

    test('RefreshUnreadCount updates unreadCount', () async {
      fakeRepo.unreadCount = 5;
      await bloc.handleEvent(RefreshUnreadCount());
      expect(bloc.state.unreadCount, 5);
    });

    test('MarkNotificationRead marks item as read', () async {
      fakeRepo.items.add(makeItem(id: 'n1', isRead: false));
      await bloc.handleEvent(LoadNotifications());
      await bloc.handleEvent(MarkNotificationRead(notificationId: 'n1'));
      expect(bloc.state.items.first.isRead, true);
      expect(bloc.state.unreadCount, 0);
    });

    test(
      'MarkNotificationRead does not update state when request fails',
      () async {
        fakeRepo.items.add(makeItem(id: 'n1', isRead: false));
        fakeRepo.unreadCount = 1;
        fakeRepo.failMarkRead = true;
        await bloc.handleEvent(LoadNotifications());
        await bloc.handleEvent(RefreshUnreadCount());

        await bloc.handleEvent(MarkNotificationRead(notificationId: 'n1'));
        expect(bloc.state.items.first.isRead, false);
        expect(bloc.state.unreadCount, 1);
      },
    );

    test('MarkAllNotificationsRead marks all as read', () async {
      fakeRepo.items.addAll([
        makeItem(id: 'n1', isRead: false),
        makeItem(id: 'n2', isRead: false),
      ]);
      fakeRepo.unreadCount = 2;
      await bloc.handleEvent(LoadNotifications());

      await bloc.handleEvent(MarkAllNotificationsRead());
      expect(bloc.state.unreadCount, 0);
      expect(bloc.state.items.every((i) => i.isRead), true);
    });

    test(
      'MarkAllNotificationsRead does not update state when request fails',
      () async {
        fakeRepo.items.addAll([
          makeItem(id: 'n1', isRead: false),
          makeItem(id: 'n2', isRead: false),
        ]);
        fakeRepo.unreadCount = 2;
        fakeRepo.failMarkAllRead = true;
        await bloc.handleEvent(LoadNotifications());
        await bloc.handleEvent(RefreshUnreadCount());

        await bloc.handleEvent(MarkAllNotificationsRead());
        expect(bloc.state.unreadCount, 2);
        expect(bloc.state.items.every((i) => !i.isRead), true);
      },
    );

    test(
      'NotificationCreatedEvent adds item and increments unreadCount',
      () async {
        final item = makeItem(id: 'new-1', isRead: false);
        bloc.handleEvent(NotificationCreatedEvent(item: item));
        expect(bloc.state.items.length, 1);
        expect(bloc.state.unreadCount, 1);
      },
    );

    test(
      'NotificationCreatedEvent for read item does not increment unreadCount',
      () async {
        final item = makeItem(id: 'new-1', isRead: true);
        bloc.handleEvent(NotificationCreatedEvent(item: item));
        expect(bloc.state.items.length, 1);
        expect(bloc.state.unreadCount, 0);
      },
    );

    test(
      'NotificationReadUpdatedEvent updates existing item to read',
      () async {
        fakeRepo.items.add(makeItem(id: 'n1', isRead: false));
        fakeRepo.unreadCount = 1;
        await bloc.handleEvent(LoadNotifications());

        bloc.handleEvent(
          NotificationReadUpdatedEvent(notificationId: 'n1', isRead: true),
        );
        expect(bloc.state.items.first.isRead, true);
        expect(bloc.state.unreadCount, 0);
      },
    );

    test('NotificationRevokedEvent removes item', () async {
      fakeRepo.items.add(
        makeItem(id: 'n1', notificationId: 'notif-1', isRead: false),
      );
      fakeRepo.unreadCount = 1;
      await bloc.handleEvent(LoadNotifications());

      bloc.handleEvent(NotificationRevokedEvent(notificationId: 'notif-1'));
      expect(bloc.state.items, isEmpty);
      expect(bloc.state.unreadCount, 0);
    });
  });
}