import 'dart:io';

import 'package:flutter_test/flutter_test.dart';
import 'package:hepan_everyday/data/file_snapshot_store.dart';
import 'package:hepan_everyday/domain/app_snapshot.dart';
import 'package:hepan_everyday/domain/app_settings.dart';

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

void main() {
  late Directory directory;
  setUp(() async {
    directory = await Directory.systemTemp.createTemp('hepan-test-');
  });
  tearDown(() async {
    await directory.delete(recursive: true);
  });
  for (final badBackup in [false, true]) {
    test(
      'fresh recovery archives corrupt primary and ${badBackup ? 'corrupt' : 'missing'} backup before saving',
      () async {
        await File('${directory.path}/hepan_snapshot.json')
            .writeAsString('damaged primary');
        if (badBackup) {
          await File('${directory.path}/hepan_snapshot.bak')
              .writeAsString('damaged backup');
        }
        final store = FileSnapshotStore(directory);
        await expectLater(store.load(), throwsFormatException);
        await store.startFresh();
        final archives = await directory
            .list()
            .where((e) => e.path.contains('.damaged-'))
            .toList();
        expect(archives, hasLength(badBackup ? 2 : 1));
        final contents = await Future.wait(
          archives.map((e) => File(e.path).readAsString()),
        );
        expect(contents, contains('damaged primary'));
        if (badBackup) {
          expect(contents, contains('damaged backup'));
        }
        expect((await store.load())!.courses, isEmpty);
        await store.save(AppSnapshot(courses: [course()]));
        expect((await store.load())!.courses.single.id, 'math');
      },
    );
  }
  test(
    'reopening restores courses, settings and calendar identifiers',
    () async {
      final original = AppSnapshot(
        settings: AppSettings(reminderMinutes: 30),
        courses: [course()],
        calendarEventIds: {'math/2026-09-09': '17'},
      );
      await FileSnapshotStore(directory).save(original);
      final loaded = await FileSnapshotStore(directory).load();
      expect(loaded, isNotNull);
      expect(loaded!.courses.single.name, '矩阵论');
      expect(loaded.settings.reminderMinutes, 30);
      expect(loaded.calendarEventIds, {'math/2026-09-09': '17'});
    },
  );
  test(
    'damaged snapshot reports failure instead of returning empty courses',
    () async {
      await File('${directory.path}/hepan_snapshot.json')
          .writeAsString('damaged');
      await expectLater(
        FileSnapshotStore(directory).load(),
        throwsFormatException,
      );
    },
  );
  test('valid previous snapshot is available for explicit recovery', () async {
    final store = FileSnapshotStore(directory);
    await store.save(AppSnapshot(settings: AppSettings(reminderMinutes: 15)));
    await store.save(AppSnapshot(settings: AppSettings(reminderMinutes: 30)));
    await File('${directory.path}/hepan_snapshot.json')
        .writeAsString('damaged');
    expect((await store.restoreBackup()).settings.reminderMinutes, 15);
  });
}