// Author: fruit.com.cn

import 'package:flutter_test/flutter_test.dart';
import 'package:fruitshorts/core/data/models/download_license.dart';
import 'package:fruitshorts/core/data/models/download_policy.dart';
import 'package:fruitshorts/core/data/remote/api_exception.dart';
import 'package:fruitshorts/core/data/repositories/download_repository.dart';
import 'package:fruitshorts/core/data/services/download_controller.dart';

DownloadPolicy _policy({bool wifiOnly = true, int remaining = 19}) =>
    DownloadPolicy(
      maxPerDevice: 20,
      licenseDays: 30,
      wifiOnly: wifiOnly,
      maxQuality: 'AUTO',
      maxStorageBytes: 0,
      used: 20 - remaining,
      remaining: remaining,
      expirePolicyText: '30 days',
    );

DownloadLicense _license(String episodeId) => DownloadLicense(
  licenseId: 'license-$episodeId',
  dramaId: 'drama-1',
  dramaTitle: 'The Signal',
  episodeId: episodeId,
  episodeNo: 1,
  deviceId: 'device-9',
  quality: '720P',
  playUrl: '',
  licenseKey: '',
  status: 'ACTIVE',
  grantedAt: DateTime(2026, 10, 17),
  expireAt: DateTime(2026, 11, 16),
  taskStatus: 'QUEUED',
  progressPercent: 0,
  downloadedBytes: 0,
  totalBytes: 100,
  errorMsg: '',
);

void main() {
  test('should_load_policy_and_licenses_when_page_opens', () async {
    final repository = ScriptedDownloadRepository(
      policy: _policy(),
      licenses: [_license('1')],
    );
    final controller = DownloadController(repository);

    await controller.load();

    expect(controller.loading, isFalse);
    expect(controller.error, isNull);
    expect(controller.policy?.remaining, 19);
    expect(controller.licenses.single.taskStatus, 'QUEUED');
  });

  test('should_show_backend_message_when_grant_is_rejected', () async {
    final repository = ScriptedDownloadRepository(
      policy: _policy(),
      grantError: const ApiException(200003, 'download quota is full'),
    );
    final controller = DownloadController(repository);

    final result = await controller.grant('episode-1');

    expect(result.ok, isFalse);
    expect(result.message, 'download quota is full');
  });

  test('should_rollback_wifi_setting_when_update_fails', () async {
    final repository = ScriptedDownloadRepository(
      policy: _policy(wifiOnly: true),
      failSettings: true,
    );
    final controller = DownloadController(repository);
    await controller.load();

    final ok = await controller.updateSettings(wifiOnly: false);

    expect(ok, isFalse);
    expect(controller.policy?.wifiOnly, isTrue);
  });

  test('should_restore_license_when_delete_fails', () async {
    final repository = ScriptedDownloadRepository(
      policy: _policy(),
      licenses: [_license('1'), _license('2')],
      failRemove: true,
    );
    final controller = DownloadController(repository);
    await controller.load();

    final ok = await controller.remove('1');

    expect(ok, isFalse);
    expect(controller.licenses.map((item) => item.episodeId), ['1', '2']);
  });

  test('should_restore_licenses_when_clear_fails', () async {
    final repository = ScriptedDownloadRepository(
      policy: _policy(),
      licenses: [_license('1'), _license('2')],
      failClear: true,
    );
    final controller = DownloadController(repository);
    await controller.load();

    final ok = await controller.clear();

    expect(ok, isFalse);
    expect(controller.licenses, hasLength(2));
  });
}

class ScriptedDownloadRepository implements DownloadRepository {
  ScriptedDownloadRepository({
    required this.policy,
    this.licenses = const [],
    this.grantError,
    this.failSettings = false,
    this.failRemove = false,
    this.failClear = false,
  });

  DownloadPolicy policy;
  List<DownloadLicense> licenses;
  ApiException? grantError;
  bool failSettings;
  bool failRemove;
  bool failClear;

  @override
  Future<DownloadPolicy> fetchPolicy() async => policy;

  @override
  Future<List<DownloadLicense>> list() async => licenses;

  @override
  Future<DownloadLicense> grant(String episodeId, {String? quality}) async {
    if (grantError != null) throw grantError!;
    return _license(episodeId);
  }

  @override
  Future<void> updateSettings({bool? wifiOnly, String? maxQuality}) async {
    if (failSettings) throw StateError('settings unavailable');
  }

  @override
  Future<DownloadLicense> refreshUrl(String episodeId) async =>
      _license(episodeId);

  @override
  Future<DownloadLicense> reportProgress(
    String episodeId, {
    String? deviceId,
    String? status,
    int? progressPercent,
    int? downloadedBytes,
    int? totalBytes,
    String? errorMsg,
  }) async => _license(episodeId);

  @override
  Future<void> remove(String episodeId) async {
    if (failRemove) throw StateError('remove unavailable');
    licenses = licenses.where((item) => item.episodeId != episodeId).toList();
  }

  @override
  Future<int> clear() async {
    if (failClear) throw StateError('clear unavailable');
    final count = licenses.length;
    licenses = const [];
    return count;
  }
}