import 'package:flutter_test/flutter_test.dart';
import 'package:timezone/data/latest.dart' as tzdata;
import 'package:hepan_everyday/app/app_controller.dart';
import 'package:hepan_everyday/domain/app_snapshot.dart';
import 'package:hepan_everyday/domain/app_settings.dart';
import 'package:hepan_everyday/domain/semester.dart';
import 'package:hepan_everyday/domain/course.dart';
import 'package:hepan_everyday/data/json_schedule_import.dart';

import '../support/fakes.dart';
import '../domain/schedule_engine_test.dart' show course;
import '../services/calendar_service_test.dart' show CalendarProvider;

import 'package:hepan_everyday/services/android_calendar_service.dart';

void main() {
  setUpAll(tzdata.initializeTimeZones);
  late MemoryStore store;
  late FakeNotifications notifications;
  late FakeCalendar calendar;
  late AppController controller;
  setUp(() {
    store = MemoryStore(
      AppSnapshot(
        courses: [course()],
        settings: AppSettings(
          semester: Semester(startDate: DateTime(2026, 9, 9), totalWeeks: 5),
        ),
      ),
    );
    notifications = FakeNotifications();
    calendar = FakeCalendar();
    controller = AppController(
      store,
      notifications,
      calendar,
      () => DateTime.utc(2026, 9, 8),
    );
  });
  tearDown(() => controller.dispose());
  test('turning off after interrupted first sync cleans events even without saved IDs', () async {
    store.value = store.value!.copyWith(
      courses: [
        course(id: 'a'),
        course(id: 'b'),
      ],
    );
    final provider = CalendarProvider()..failAfterFirst = true;
    final interrupted = AppController(
      store,
      notifications,
      AndroidCalendarService(provider),
      controller.clock,
    );
    await interrupted.initialize();
    await interrupted.enableCalendarFromUserAction('local');
    expect(interrupted.calendarSyncError, isNotNull);
    expect(provider.records, hasLength(1));
    provider.failAfterFirst = false;
    await interrupted.disableCalendar(deleteEvents: true);
    expect(provider.records, isEmpty);
    interrupted.dispose();
  });
  test(
    'failed calendar cleanup is retried after reopening while sync is off',
    () async {
      final provider = CleanupCalendar()..failDelete = true;
      final first = AppController(
        store,
        notifications,
        provider,
        controller.clock,
      );
      await first.initialize();
      await first.disableCalendar(deleteEvents: true);
      expect(first.lastError, isNotNull);
      first.dispose();
      provider.failDelete = false;
      final reopened = AppController(
        store,
        notifications,
        provider,
        controller.clock,
      );
      await reopened.initialize();
      expect(provider.deletions, 2);
      expect(reopened.snapshot.settings.calendarEnabled, isFalse);
      reopened.dispose();
    },
  );
  test(
    'notification cleanup failure does not prevent calendar cleanup',
    () async {
      final broken = AppController(
        store,
        BrokenCancellation(),
        calendar,
        controller.clock,
      );
      await broken.initialize();
      await broken.clearCourses();
      expect(calendar.deletions, 1);
      expect(broken.snapshot.courses, isEmpty);
      broken.dispose();
    },
  );
  test(
    'denied calendar permission and unavailable calendars stay off',
    () async {
      await controller.initialize();
      calendar.access = false;
      await controller.enableCalendarFromUserAction('local');
      expect(controller.snapshot.settings.calendarEnabled, isFalse);
      expect(controller.calendarSyncError, isNotNull);
      calendar.access = true;
      await controller.enableCalendarFromUserAction('readonly-or-missing');
      expect(controller.snapshot.settings.calendarEnabled, isFalse);
      expect(calendar.synchronizations, 0);
    },
  );
  test('a new successful demo action clears a stale save error', () async {
    await controller.initialize();
    store.failSave = true;
    await controller.updateSettings(
      controller.snapshot.settings.copyWith(reminderMinutes: 30),
    );
    expect(controller.lastError, isNotNull);
    await controller.showDemo();
    expect(controller.lastError, isNull);
  });
  test(
    'refresh after corrupt storage never reconciles an empty timetable',
    () async {
      final damaged = AppController(
        DamagedStore(),
        notifications,
        calendar,
        () => DateTime.utc(2026, 9, 8),
      );
      await damaged.initialize();
      await damaged.refreshServices();
      expect(notifications.reconciliations, 0);
      expect(damaged.storageReady, isFalse);
      damaged.dispose();
    },
  );
  test('failed saving does not change currently visible settings', () async {
    await controller.initialize();
    store.failSave = true;
    await controller.updateSettings(
      controller.snapshot.settings.copyWith(reminderMinutes: 30),
    );
    expect(controller.snapshot.settings.reminderMinutes, 15);
    expect(controller.lastError, isNotNull);
  });
  test('concurrent settings changes persist in user action order', () async {
    await controller.initialize();
    await Future.wait([
      controller.updateSettings(
        controller.snapshot.settings.copyWith(reminderMinutes: 30),
      ),
      controller.updateSettings(
        controller.snapshot.settings.copyWith(reminderMinutes: 60),
      ),
    ]);
    expect(store.value!.settings.reminderMinutes, 60);
  });
  test('demo cannot replace real courses or create real reminders', () async {
    await controller.initialize();
    final previous = notifications.reconciliations;
    await controller.showDemo();
    expect(controller.isDemo, isTrue);
    expect(store.value!.courses.single.id, 'math');
    expect(notifications.reconciliations, previous);
    expect(calendar.synchronizations, 0);
  });
  test('unconfirmed empty import preserves saved timetable', () async {
    await controller.initialize();
    await controller.applyImport(
      const ImportDraft(
        courses: [],
        explicitlyEmpty: false,
        source: CourseSource.file,
        parserVersion: 'json-v1',
      ),
      confirmedEmpty: false,
    );
    expect(controller.snapshot.courses.single.id, 'math');
    expect(controller.lastError, isNotNull);
  });
  test(
    'clearing courses cancels owned notifications and calendar events',
    () async {
      await controller.initialize();
      await controller.clearCourses();
      expect(store.value!.courses, isEmpty);
      expect(notifications.cancellations, 1);
      expect(calendar.deletions, 1);
    },
  );
}

class DamagedStore extends MemoryStore {
  @override
  Future<AppSnapshot?> load() async => throw const FormatException('damaged');
}

class CleanupCalendar extends FakeCalendar {
  bool failDelete = false;
  @override
  Future<void> deleteOwned(Map<String, String> ids) async {
    deletions++;
    if (failDelete) {
      throw StateError('denied');
    }
  }
}

class BrokenCancellation extends FakeNotifications {
  @override
  Future<void> cancelOwned() async => throw StateError('denied');
}