import 'package:flutter_test/flutter_test.dart';
import 'package:timezone/data/latest.dart' as tzdata;
import 'package:hepan_everyday/services/android_calendar_service.dart';
import 'package:hepan_everyday/services/calendar_service.dart';
import 'package:hepan_everyday/domain/schedule_engine.dart';

import '../domain/schedule_engine_test.dart' show course;

class CalendarProvider extends CalendarGateway {
  bool access = true, failAfterFirst = false;
  final records = <String, CalendarRecord>{};
  final drafts = <String, CalendarEventDraft>{};
  int inserts = 0;
  @override
  Future<bool> requestAccess() async => access;
  @override
  Future<List<DeviceCalendar>> calendars() async => [
    const DeviceCalendar('local', '专用测试日历'),
  ];
  @override
  Future<List<CalendarRecord>> ownedEvents(String calendarId) async {
    if (!access) throw StateError('permission denied');
    return records.values.where((r) => r.calendarId == calendarId).toList();
  }

  @override
  Future<String> save(CalendarEventDraft event, String? eventId) async {
    if (failAfterFirst && inserts >= 1) {
      throw StateError('provider unavailable');
    }
    final id = eventId ?? '${++inserts}';
    records[id] = CalendarRecord(
      id: id,
      key: event.key,
      calendarId: event.calendarId,
      owned: true,
    );
    drafts[id] = event;
    return id;
  }

  @override
  Future<void> delete(String eventId, String expectedKey) async {
    final r = records[eventId];
    if (r?.owned == true && r?.key == expectedKey) {
      records.remove(eventId);
      drafts.remove(eventId);
    }
  }
}

void main() {
  setUpAll(tzdata.initializeTimeZones);
  final term = Semester(startDate: DateTime(2026, 9, 9), totalWeeks: 5);
  late CalendarProvider provider;
  late AndroidCalendarService service;
  setUp(() {
    provider = CalendarProvider();
    service = AndroidCalendarService(provider);
  });
  test(
    'repeat import creates one event with UTC instants and school metadata',
    () async {
      final events = ScheduleEngine.occurrences([course(last: 2)], term);
      final ids = await service.sync(events, 'local', {});
      expect(ids, hasLength(1));
      await service.sync(events, 'local', ids);
      expect(provider.records, hasLength(1));
      expect(provider.inserts, 1);
      final event = provider.drafts.values.single;
      expect(
        event.startMs,
        DateTime.utc(2026, 9, 9, 0, 30).millisecondsSinceEpoch,
      );
      expect(
        event.endMs,
        DateTime.utc(2026, 9, 9, 2, 5).millisecondsSinceEpoch,
      );
      expect(event.description, contains('示例教师'));
    },
  );
  test(
    'lost mapping after an interrupted sync recovers via owned event identity',
    () async {
      final events = ScheduleEngine.occurrences([
        course(id: 'a'),
        course(id: 'b'),
      ], term);
      provider.failAfterFirst = true;
      await expectLater(service.sync(events, 'local', {}), throwsStateError);
      expect(provider.records, hasLength(1));
      provider.failAfterFirst = false;
      await service.sync(events, 'local', {});
      expect(provider.records, hasLength(2));
      expect(provider.inserts, 2);
    },
  );
  test(
    'manual deletion is repaired and unrelated events are preserved',
    () async {
      final events = ScheduleEngine.occurrences([course()], term);
      final ids = await service.sync(events, 'local', {});
      expect(ids, hasLength(1));
      provider.records.clear();
      provider.records['private'] = const CalendarRecord(
        id: 'private',
        key: 'private',
        calendarId: 'local',
        owned: false,
      );
      final updated = await service.sync(events, 'local', ids);
      expect(updated, hasLength(1));
      expect(provider.records, hasLength(2));
      await service.deleteOwned(updated);
      expect(provider.records.keys, ['private']);
    },
  );
  test(
    'changed ownership marker cannot be deleted using an old stored mapping',
    () async {
      provider.records['17'] = const CalendarRecord(
        id: '17',
        key: 'math/2026-09-09',
        calendarId: 'local',
        owned: false,
      );
      await service.deleteOwned({'math/2026-09-09': '17'});
      expect(provider.records.keys, ['17']);
    },
  );
  test('replacing timetable removes stale owned events within selected calendar only', () async {
    provider.records['other'] = const CalendarRecord(
      id: 'other',
      key: 'old',
      calendarId: 'different',
      owned: true,
    );
    final events = ScheduleEngine.occurrences([course()], term);
    final ids = await service.sync(events, 'local', {});
    expect(ids, hasLength(1));
    await service.sync([], 'local', ids);
    expect(provider.records.keys, ['other']);
  });
}