import 'dart:async';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:provider/provider.dart';
import 'package:shared_preferences_platform_interface/in_memory_shared_preferences_async.dart';
import 'package:shared_preferences_platform_interface/shared_preferences_async_platform_interface.dart';

import 'package:fruitshorts/core/data/models/auth_session.dart';
import 'package:fruitshorts/core/data/remote/auth_api.dart';
import 'package:fruitshorts/core/data/remote/api_client.dart';
import 'package:fruitshorts/core/data/services/auth_controller.dart';
import 'package:fruitshorts/core/data/services/auth_session_store.dart';
import 'package:fruitshorts/core/platform/haptics.dart';
import 'package:fruitshorts/l10n/app_localizations.dart';
import 'package:fruitshorts/pages/auth/auth_view.dart';

import '../support/fake_http_adapter.dart';
import '../support/fake_haptics.dart';

/// 登录/注册页的可读证据：校验提示 + 登录/注册切换 + 未登录时不会去发请求。
void main() {
  setUp(() {
    SharedPreferencesAsyncPlatform.instance =
        InMemorySharedPreferencesAsync.empty();
  });

  Future<void> pumpAuthPage(
    WidgetTester tester, {
    bool signUp = false,
    AuthApi? api,
    FakeHaptics? haptics,
  }) async {
    final auth = AuthController(
      api ??
          AuthApi(
            // 这个测试不联网：请求一律 500，正好用于验证"本地校验没过就不发请求"
            ApiClient(
              baseUrl: 'http://127.0.0.1:1',
              adapter: FakeHttpAdapter(
                (_) async => FakeHttpResponse('{}', 500),
              ),
            ),
          ),
      AuthSessionStore(),
    );
    await tester.pumpWidget(
      MultiProvider(
        providers: [
          ChangeNotifierProvider<AuthController>.value(value: auth),
          Provider<Haptics>.value(value: haptics ?? FakeHaptics()),
        ],
        child: MaterialApp(
          locale: const Locale('en'),
          localizationsDelegates: AppLocalizations.localizationsDelegates,
          supportedLocales: AppLocalizations.supportedLocales,
          home: AuthPage(signUpMode: signUp),
        ),
      ),
    );
    await tester.pumpAndSettle();
    await tester.ensureVisible(find.byKey(const Key('auth-entry-email')));
    await tester.tap(find.byKey(const Key('auth-entry-email')));
    await tester.pumpAndSettle();
  }

  testWidgets('should_show_email_error_and_stay_on_page_when_form_is_empty', (
    tester,
  ) async {
    await pumpAuthPage(tester);

    expect(find.text('Welcome back'), findsOneWidget);

    await tester.tap(find.byType(FilledButton));
    await tester.pumpAndSettle();

    expect(find.text('Enter your email'), findsOneWidget);
    expect(find.text('Welcome back'), findsOneWidget);
    expect(find.byKey(const Key('centered-toast')), findsNothing);
  });

  testWidgets(
    'should_reject_weak_password_locally_when_only_letters_are_typed',
    (tester) async {
      await pumpAuthPage(tester);

      await tester.enterText(find.byType(TextField).first, 'a@b.com');
      await tester.enterText(find.byType(TextField).last, 'abcdefgh');
      await tester.tap(find.byType(FilledButton));
      await tester.pumpAndSettle();

      expect(
        find.text('Password needs both letters and numbers'),
        findsOneWidget,
      );
      expect(find.byKey(const Key('centered-toast')), findsNothing);
    },
  );

  testWidgets('should_show_centered_toast_when_login_api_returns_an_error', (
    tester,
  ) async {
    final api = _FailingAuthApi(loginMessage: 'Invalid email or password');
    await pumpAuthPage(tester, api: api);
    await _enterValidCredentials(tester);

    await tester.ensureVisible(find.byKey(const Key('auth-submit')));
    await tester.tap(find.byKey(const Key('auth-submit')));
    await tester.pumpAndSettle();

    final toast = find.byKey(const Key('centered-toast'));
    expect(toast, findsOneWidget);
    expect(find.text('Sign in to continue'), findsOneWidget);
    expect(find.byType(AlertDialog), findsNothing);
    expect(api.loginCalls, 1);
    expect(
      tester.getCenter(toast),
      offsetMoreOrLessEquals(
        tester.getCenter(find.byType(Scaffold)),
        epsilon: 1,
      ),
    );
    expect(
      tester
          .widget<FilledButton>(find.byKey(const Key('auth-submit')))
          .onPressed,
      isNotNull,
    );

    await _pumpToastAway(tester);
    expect(toast, findsNothing);
  });

  testWidgets('should_show_centered_toast_when_register_api_returns_an_error', (
    tester,
  ) async {
    final api = _FailingAuthApi(registerMessage: 'Email already exists');
    await pumpAuthPage(tester, signUp: true, api: api);
    await _enterValidCredentials(tester);

    await tester.ensureVisible(find.byKey(const Key('auth-submit')));
    await tester.tap(find.byKey(const Key('auth-submit')));
    await tester.pumpAndSettle();

    expect(find.byKey(const Key('centered-toast')), findsOneWidget);
    expect(find.text('Email already exists'), findsOneWidget);
    expect(find.byType(AlertDialog), findsNothing);
    expect(api.registerCalls, 1);

    await _pumpToastAway(tester);
    expect(find.byKey(const Key('centered-toast')), findsNothing);
  });

  testWidgets(
    'should_show_network_error_when_login_throws_an_unknown_exception',
    (tester) async {
      final api = _FailingAuthApi(loginThrowsUnknown: true);
      await pumpAuthPage(tester, api: api);
      await _enterValidCredentials(tester);

      await tester.ensureVisible(find.byKey(const Key('auth-submit')));
      await tester.tap(find.byKey(const Key('auth-submit')));
      await tester.pumpAndSettle();

      expect(find.byKey(const Key('centered-toast')), findsOneWidget);
      expect(find.text('Network error, please try again'), findsOneWidget);
      expect(find.byType(AlertDialog), findsNothing);

      await _pumpToastAway(tester);
      expect(find.byKey(const Key('centered-toast')), findsNothing);
    },
  );

  testWidgets(
    'should_flip_between_sign_in_and_sign_up_when_switch_link_is_tapped',
    (tester) async {
      await pumpAuthPage(tester);
      expect(find.text('Welcome back'), findsOneWidget);

      await tester.tap(find.text('New here? Create an account'));
      await tester.pumpAndSettle();

      expect(find.text('Create your account'), findsOneWidget);
      expect(find.text('Already have an account? Sign in'), findsOneWidget);
    },
  );

  testWidgets('should_show_brand_and_form_accessibility_when_page_opens', (
    tester,
  ) async {
    await pumpAuthPage(tester);

    expect(find.text('FruitShorts'), findsOneWidget);
    expect(find.text('Short dramas made for Indonesia'), findsOneWidget);
    final email = tester.widget<TextField>(find.byKey(const Key('auth-email')));
    final password = tester.widget<TextField>(
      find.byKey(const Key('auth-password')),
    );
    expect(email.autofillHints, contains(AutofillHints.email));
    expect(password.autofillHints, contains(AutofillHints.password));
    expect(
      tester.getSize(find.byKey(const Key('auth-submit'))).height,
      greaterThanOrEqualTo(44),
    );
    expect(
      tester.getSize(find.byKey(const Key('auth-password-visibility'))).height,
      greaterThanOrEqualTo(44),
    );
    expect(
      tester.getSize(find.byKey(const Key('auth-switch-mode'))).height,
      greaterThanOrEqualTo(44),
    );
  });

  testWidgets('should_toggle_password_visibility_when_eye_button_is_tapped', (
    tester,
  ) async {
    await pumpAuthPage(tester);
    expect(
      tester
          .widget<TextField>(find.byKey(const Key('auth-password')))
          .obscureText,
      isTrue,
    );

    await tester.tap(find.byKey(const Key('auth-password-visibility')));
    await tester.pump();

    expect(
      tester
          .widget<TextField>(find.byKey(const Key('auth-password')))
          .obscureText,
      isFalse,
    );
    expect(find.byTooltip('Hide password'), findsOneWidget);
  });

  testWidgets('should_move_focus_from_email_to_password_when_next_is_pressed', (
    tester,
  ) async {
    await pumpAuthPage(tester);
    await tester.tap(find.byKey(const Key('auth-email')));
    await tester.testTextInput.receiveAction(TextInputAction.next);
    await tester.pump();

    expect(
      FocusManager.instance.primaryFocus?.debugLabel,
      'auth-password-focus',
    );
  });

  testWidgets('should_disable_form_and_submit_while_done_action_is_pending', (
    tester,
  ) async {
    final api = _PendingAuthApi();
    final haptics = FakeHaptics();
    await pumpAuthPage(tester, api: api, haptics: haptics);
    await tester.enterText(find.byKey(const Key('auth-email')), 'a@b.com');
    await tester.enterText(find.byKey(const Key('auth-password')), 'abcd1234');
    await tester.tap(find.byKey(const Key('auth-password')));
    await tester.testTextInput.receiveAction(TextInputAction.done);
    await tester.pump();

    expect(api.loginCalls, 1);
    expect(haptics.lightImpacts, 1);
    expect(
      tester.widget<TextField>(find.byKey(const Key('auth-email'))).enabled,
      isFalse,
    );
    expect(
      tester.widget<TextField>(find.byKey(const Key('auth-password'))).enabled,
      isFalse,
    );
    expect(
      tester
          .widget<IconButton>(find.byKey(const Key('auth-password-visibility')))
          .onPressed,
      isNull,
    );
    expect(
      tester
          .widget<FilledButton>(find.byKey(const Key('auth-submit')))
          .onPressed,
      isNull,
    );
    expect(
      tester
          .widget<TextButton>(find.byKey(const Key('auth-switch-mode')))
          .onPressed,
      isNull,
    );

    api.release();
    await tester.pumpAndSettle();
  });

  testWidgets('should_render_validation_error_with_theme_semantic_color', (
    tester,
  ) async {
    await pumpAuthPage(tester);
    await tester.enterText(find.byKey(const Key('auth-email')), 'a@b.com');
    await tester.enterText(find.byKey(const Key('auth-password')), 'abcdefgh');
    await tester.tap(find.byKey(const Key('auth-submit')));
    await tester.pumpAndSettle();

    final errorFinder = find.byKey(const Key('auth-error'));
    final error = tester.widget<Text>(errorFinder);
    final expected = Theme.of(tester.element(errorFinder)).colorScheme.error;
    expect(error.style?.color, expected);
  });

  testWidgets(
    'should_keep_submit_reachable_when_keyboard_opens_on_small_screen',
    (tester) async {
      tester.view.physicalSize = const Size(320, 568);
      tester.view.devicePixelRatio = 1;
      tester.view.viewInsets = const FakeViewPadding(bottom: 260);
      addTearDown(tester.view.resetPhysicalSize);
      addTearDown(tester.view.resetDevicePixelRatio);
      addTearDown(tester.view.resetViewInsets);

      await pumpAuthPage(tester);
      await tester.scrollUntilVisible(
        find.byKey(const Key('auth-submit')),
        120,
        scrollable: find
            .descendant(
              of: find.byKey(const Key('auth-scroll')),
              matching: find.byType(Scrollable),
            )
            .first,
      );
      await tester.pumpAndSettle();

      expect(
        find.byKey(const Key('auth-submit')).hitTestable(),
        findsOneWidget,
      );
      expect(tester.takeException(), isNull);
    },
  );

  testWidgets('should_keep_password_above_ios_keyboard', (tester) async {
    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
    addTearDown(() => debugDefaultTargetPlatformOverride = null);
    tester.view.physicalSize = const Size(390, 844);
    tester.view.devicePixelRatio = 1;
    tester.view.viewInsets = const FakeViewPadding(bottom: 300);
    addTearDown(tester.view.resetPhysicalSize);
    addTearDown(tester.view.resetDevicePixelRatio);
    addTearDown(tester.view.resetViewInsets);

    await pumpAuthPage(tester);
    await tester.tap(find.byKey(const Key('auth-password')));
    await tester.pumpAndSettle();

    _expectAboveKeyboard(tester, const Key('auth-password'), 300);
    debugDefaultTargetPlatformOverride = null;
  });

  testWidgets('should_keep_signup_password_above_ios_keyboard', (tester) async {
    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
    addTearDown(() => debugDefaultTargetPlatformOverride = null);
    tester.view.physicalSize = const Size(390, 844);
    tester.view.devicePixelRatio = 1;
    tester.view.viewInsets = const FakeViewPadding(bottom: 300);
    addTearDown(tester.view.resetPhysicalSize);
    addTearDown(tester.view.resetDevicePixelRatio);
    addTearDown(tester.view.resetViewInsets);

    await pumpAuthPage(tester, signUp: true);
    await tester.tap(find.byKey(const Key('auth-password')));
    await tester.pumpAndSettle();

    _expectAboveKeyboard(tester, const Key('auth-password'), 300);
    debugDefaultTargetPlatformOverride = null;
  });

  testWidgets('should_keep_password_above_android_channel_keyboard', (
    tester,
  ) async {
    debugDefaultTargetPlatformOverride = TargetPlatform.android;
    addTearDown(() => debugDefaultTargetPlatformOverride = null);
    const keyboardChannel = MethodChannel('com.stormg.lumadrama/keyboard');
    tester.binding.defaultBinaryMessenger.setMockMethodCallHandler(
      keyboardChannel,
      (call) async => call.method == 'get' ? 300 : null,
    );
    addTearDown(() {
      tester.binding.defaultBinaryMessenger.setMockMethodCallHandler(
        keyboardChannel,
        null,
      );
    });
    tester.view.physicalSize = const Size(390, 844);
    tester.view.devicePixelRatio = 1;
    tester.view.viewInsets = const FakeViewPadding();
    addTearDown(tester.view.resetPhysicalSize);
    addTearDown(tester.view.resetDevicePixelRatio);
    addTearDown(tester.view.resetViewInsets);

    await pumpAuthPage(tester);
    await tester.binding.defaultBinaryMessenger.handlePlatformMessage(
      keyboardChannel.name,
      const StandardMethodCodec().encodeMethodCall(
        const MethodCall('insetsChanged', 300),
      ),
      (_) {},
    );
    await tester.pump();
    await tester.tap(find.byKey(const Key('auth-password')));
    await tester.pumpAndSettle();

    _expectAboveKeyboard(tester, const Key('auth-password'), 300);
    debugDefaultTargetPlatformOverride = null;
  });
}

Future<void> _enterValidCredentials(WidgetTester tester) async {
  await tester.enterText(find.byKey(const Key('auth-email')), 'a@b.com');
  await tester.enterText(find.byKey(const Key('auth-password')), 'abcd1234');
}

Future<void> _pumpToastAway(WidgetTester tester) async {
  await tester.pump(const Duration(seconds: 3));
  await tester.pumpAndSettle();
}

void _expectAboveKeyboard(WidgetTester tester, Key fieldKey, double inset) {
  final screenHeight =
      tester.view.physicalSize.height / tester.view.devicePixelRatio;
  expect(
    tester.getBottomLeft(find.byKey(fieldKey)).dy,
    lessThanOrEqualTo(screenHeight - inset),
  );
}

class _FailingAuthApi extends AuthApi {
  _FailingAuthApi({
    this.loginMessage = 'login failed',
    this.registerMessage = 'register failed',
    this.loginThrowsUnknown = false,
  }) : super(
         ApiClient(
           baseUrl: 'http://127.0.0.1:1',
           adapter: FakeHttpAdapter((_) async => FakeHttpResponse('{}', 500)),
         ),
       );

  final String loginMessage;
  final String registerMessage;
  final bool loginThrowsUnknown;
  int loginCalls = 0;
  int registerCalls = 0;

  @override
  Future<AuthSession> login({
    required String email,
    required String password,
    required String deviceId,
    String platform = '',
    String osVersion = '',
    String appVersion = '',
  }) async {
    loginCalls++;
    if (loginThrowsUnknown) throw StateError('unexpected');
    throw ApiException(401, loginMessage);
  }

  @override
  Future<AuthSession> register({
    required String email,
    required String password,
    required String deviceId,
    String platform = '',
    String osVersion = '',
    String appVersion = '',
  }) async {
    registerCalls++;
    throw ApiException(409, registerMessage);
  }
}

class _PendingAuthApi extends AuthApi {
  _PendingAuthApi()
    : super(
        ApiClient(
          baseUrl: 'http://127.0.0.1:1',
          adapter: FakeHttpAdapter((_) async => FakeHttpResponse('{}', 500)),
        ),
      );

  final _gate = Completer<void>();
  int loginCalls = 0;

  void release() => _gate.complete();

  @override
  Future<AuthSession> login({
    required String email,
    required String password,
    required String deviceId,
    String platform = '',
    String osVersion = '',
    String appVersion = '',
  }) async {
    loginCalls++;
    await _gate.future;
    throw const ApiException(500, 'pending failure');
  }
}