import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:fruitshorts/core/data/services/category_controller.dart';
import 'package:fruitshorts/core/data/services/home_feed_controller.dart';
import 'package:fruitshorts/l10n/app_localizations.dart';
import 'package:fruitshorts/pages/home/home_feed_channel.dart';
import 'package:fruitshorts/pages/recommend/recommend_page.dart';
import 'package:provider/provider.dart';

import '../support/fake_catalog.dart';
import '../support/fake_category.dart';

void main() {
  testWidgets('should_show_skeleton_before_feed_is_loaded', (tester) async {
    await _pumpRecommend(tester, active: false);

    expect(find.byKey(const Key('recommend-feed-skeleton')), findsOneWidget);
    expect(find.byKey(const Key('recommend-feed-empty')), findsNothing);
    expect(find.text('Retry'), findsNothing);
  });

  testWidgets('should_refresh_once_when_parent_rebuilds_repeatedly', (
    tester,
  ) async {
    final fixture = await _pumpRecommend(tester, active: true);

    expect(fixture.controller.refreshCalls, 1);
    for (var index = 0; index < 20; index++) {
      fixture.harnessKey.currentState!.rebuildSameInputs();
      await tester.pump();
    }

    expect(tester.takeException(), isNull);
    expect(fixture.controller.refreshCalls, 1);
  });

  testWidgets('should_refresh_once_when_active_turns_on', (tester) async {
    final fixture = await _pumpRecommend(tester, active: false);
    expect(fixture.controller.refreshCalls, 0);

    fixture.harnessKey.currentState!.update(active: true);
    await tester.pump();

    expect(fixture.controller.refreshCalls, 1);
    fixture.harnessKey.currentState!.rebuildSameInputs();
    await tester.pump();
    expect(fixture.controller.refreshCalls, 1);
  });

  testWidgets('should_refresh_again_when_data_source_changes', (tester) async {
    final fixture = await _pumpRecommend(tester, active: true);
    expect(fixture.controller.refreshCalls, 1);

    fixture.harnessKey.currentState!.update(active: false);
    await tester.pump();
    expect(fixture.controller.refreshCalls, 1);

    fixture.harnessKey.currentState!.update(active: true);
    await tester.pump();
    expect(fixture.controller.refreshCalls, 2);
  });

  testWidgets('should_auto_retry_three_times_then_show_network_error', (
    tester,
  ) async {
    final fixture = await _pumpFailingRecommend(tester);

    expect(fixture.controller.refreshCalls, 1);
    expect(find.byKey(const Key('recommend-feed-skeleton')), findsOneWidget);
    expect(find.byKey(const Key('recommend-feed-empty')), findsNothing);

    for (var attempt = 0; attempt < 3; attempt++) {
      await tester.pump(const Duration(milliseconds: 1500));
      await tester.pump();
      expect(fixture.controller.refreshCalls, attempt + 2);
      if (attempt < 2) {
        expect(
          find.byKey(const Key('recommend-feed-skeleton')),
          findsOneWidget,
        );
        expect(find.byKey(const Key('recommend-feed-empty')), findsNothing);
      }
    }

    final l10n = AppLocalizations.of(
      tester.element(find.byType(RecommendPage)),
    )!;
    expect(fixture.controller.refreshCalls, 4);
    expect(find.byKey(const Key('recommend-feed-skeleton')), findsNothing);
    expect(find.byKey(const Key('recommend-feed-empty')), findsOneWidget);
    expect(find.text(l10n.networkError), findsOneWidget);
    expect(find.text(l10n.retry), findsNothing);
  });

  testWidgets('should_cancel_pending_auto_retry_when_disposed', (tester) async {
    final fixture = await _pumpFailingRecommend(tester);
    expect(fixture.controller.refreshCalls, 1);

    await tester.pumpWidget(const MaterialApp(home: SizedBox.shrink()));
    await tester.pump(const Duration(seconds: 2));

    expect(fixture.controller.refreshCalls, 1);
  });

  testWidgets(
    'should_show_no_stories_without_retry_when_loaded_feed_is_empty',
    (tester) async {
      final fixture = await _pumpEmptyRecommend(tester);

      final l10n = AppLocalizations.of(
        tester.element(find.byType(RecommendPage)),
      )!;
      expect(fixture.controller.refreshCalls, 1);
      expect(find.byKey(const Key('recommend-feed-skeleton')), findsNothing);
      expect(find.byKey(const Key('recommend-feed-empty')), findsOneWidget);
      expect(find.text(l10n.noStories), findsOneWidget);
      expect(find.text(l10n.retry), findsNothing);
    },
  );

  testWidgets('should_not_refresh_after_dispose_when_channel_changes', (
    tester,
  ) async {
    final fixture = await _pumpRecommend(tester, active: true);
    expect(fixture.controller.refreshCalls, 1);

    fixture.harnessKey.currentState!.update(active: true);
    final selection = fixture.controller.selectChannel(HomeFeedChannel.anime);
    await tester.pumpWidget(const MaterialApp(home: SizedBox.shrink()));
    await selection;
    await tester.pump();

    expect(fixture.controller.refreshCalls, 1);
  });
}

Future<_RecommendFixture> _pumpRecommend(
  WidgetTester tester, {
  required bool active,
}) async {
  tester.view.physicalSize = const Size(390, 844);
  tester.view.devicePixelRatio = 1;
  addTearDown(tester.view.resetPhysicalSize);
  addTearDown(tester.view.resetDevicePixelRatio);

  final catalog = FakeCatalogRepository();
  final controller = _RecordingHomeFeedController(catalog);
  final categories = CategoryController(
    FakeCategoryRepository(catalog: catalog),
  );
  final harnessKey = GlobalKey<_RecommendHarnessState>();
  final fixture = _RecommendFixture(
    controller: controller,
    categoryController: categories,
    harnessKey: harnessKey,
  );
  addTearDown(controller.dispose);
  addTearDown(categories.dispose);

  await tester.pumpWidget(fixture.app(active: active));
  await tester.pump();
  return fixture;
}

Future<_StatefulRecommendFixture> _pumpFailingRecommend(
  WidgetTester tester,
) async {
  tester.view.physicalSize = const Size(390, 844);
  tester.view.devicePixelRatio = 1;
  addTearDown(tester.view.resetPhysicalSize);
  addTearDown(tester.view.resetDevicePixelRatio);

  final catalog = FakeCatalogRepository();
  final controller = _StatefulHomeFeedController(catalog);
  final categories = CategoryController(
    FakeCategoryRepository(catalog: catalog),
  );
  addTearDown(controller.dispose);
  addTearDown(categories.dispose);

  final fixture = _StatefulRecommendFixture(
    controller: controller,
    categoryController: categories,
  );
  await tester.pumpWidget(fixture.app());
  await tester.pump();
  await tester.pump(const Duration(milliseconds: 1));
  return fixture;
}

Future<_StatefulRecommendFixture> _pumpEmptyRecommend(
  WidgetTester tester,
) async {
  tester.view.physicalSize = const Size(390, 844);
  tester.view.devicePixelRatio = 1;
  addTearDown(tester.view.resetPhysicalSize);
  addTearDown(tester.view.resetDevicePixelRatio);

  final catalog = FakeCatalogRepository();
  final controller = _StatefulHomeFeedController(catalog, fail: false);
  final categories = CategoryController(
    FakeCategoryRepository(catalog: catalog),
  );
  addTearDown(controller.dispose);
  addTearDown(categories.dispose);

  final fixture = _StatefulRecommendFixture(
    controller: controller,
    categoryController: categories,
  );
  await tester.pumpWidget(fixture.app());
  await tester.pump();
  await tester.pump(const Duration(milliseconds: 1));
  return fixture;
}

class _RecommendFixture {
  const _RecommendFixture({
    required this.controller,
    required this.categoryController,
    required this.harnessKey,
  });

  final _RecordingHomeFeedController controller;
  final CategoryController categoryController;
  final GlobalKey<_RecommendHarnessState> harnessKey;

  Widget app({required bool active}) {
    return MaterialApp(
      localizationsDelegates: AppLocalizations.localizationsDelegates,
      supportedLocales: AppLocalizations.supportedLocales,
      home: ChangeNotifierProvider<CategoryController>.value(
        value: categoryController,
        child: _RecommendHarness(
          key: harnessKey,
          controller: controller,
          active: active,
        ),
      ),
    );
  }
}

class _StatefulRecommendFixture {
  const _StatefulRecommendFixture({
    required this.controller,
    required this.categoryController,
  });

  final _StatefulHomeFeedController controller;
  final CategoryController categoryController;

  Widget app() {
    return MaterialApp(
      localizationsDelegates: AppLocalizations.localizationsDelegates,
      supportedLocales: AppLocalizations.supportedLocales,
      home: ChangeNotifierProvider<CategoryController>.value(
        value: categoryController,
        child: RecommendPage(
          feedController: controller,
          active: true,
          videoOnly: true,
          onSearch: () {},
        ),
      ),
    );
  }
}

class _RecommendHarness extends StatefulWidget {
  const _RecommendHarness({
    super.key,
    required this.controller,
    required this.active,
  });

  final HomeFeedController controller;
  final bool active;

  @override
  State<_RecommendHarness> createState() => _RecommendHarnessState();
}

class _RecommendHarnessState extends State<_RecommendHarness> {
  late HomeFeedController _controller;
  late bool _active;

  @override
  void initState() {
    super.initState();
    _controller = widget.controller;
    _active = widget.active;
  }

  void rebuildSameInputs() {
    setState(() {});
  }

  void update({required bool active}) {
    setState(() {
      _active = active;
    });
  }

  @override
  Widget build(BuildContext context) {
    return RecommendPage(
      feedController: _controller,
      active: _active,
      videoOnly: true,
      onSearch: () {},
    );
  }
}

class _RecordingHomeFeedController extends HomeFeedController {
  _RecordingHomeFeedController(super.repository);

  int refreshCalls = 0;

  @override
  Future<bool> refreshCurrent() async {
    refreshCalls++;
    notifyListeners();
    return true;
  }
}

class _StatefulHomeFeedController extends HomeFeedController {
  _StatefulHomeFeedController(super.repository, {this.fail = true});

  final bool fail;
  int refreshCalls = 0;
  bool _loaded = false;
  bool _isLoading = false;
  String? _lastError;

  @override
  bool get loaded => _loaded;

  @override
  bool get isLoading => _isLoading;

  @override
  String? get lastError => _lastError;

  @override
  Future<bool> refreshCurrent() async {
    refreshCalls++;
    _isLoading = true;
    _lastError = null;
    notifyListeners();
    await Future<void>.delayed(Duration.zero);
    _isLoading = false;
    _loaded = true;
    if (fail) _lastError = 'network error';
    notifyListeners();
    return !fail;
  }
}