import 'dart:async';
import 'dart:convert';
import 'dart:io';

import 'package:advanced_in_app_review/advanced_in_app_review.dart';
import 'package:app_links/app_links.dart';
import 'package:dio/dio.dart';
import 'package:firebase_analytics/firebase_analytics.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:firebase_crashlytics/firebase_crashlytics.dart';
import 'package:firebase_performance/firebase_performance.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_mobx/flutter_mobx.dart';
import 'package:flutter_secure_storage/flutter_secure_storage.dart';
import 'package:frosty/apis/base_api_client.dart' show ApiException;
import 'package:frosty/apis/bttv_api.dart';
import 'package:frosty/apis/dio_client.dart';
import 'package:frosty/apis/ffz_api.dart';
import 'package:frosty/apis/seventv_api.dart';
import 'package:frosty/apis/twitch_api.dart';
import 'package:frosty/apis/twitch_auth_interceptor.dart';
import 'package:frosty/apis/twitch_gql_api.dart';
import 'package:frosty/apis/unauthorized_interceptor.dart';
import 'package:frosty/cache_manager.dart';
import 'package:frosty/constants.dart';
import 'package:frosty/firebase_options.dart';
import 'package:frosty/screens/channel/channel.dart';
import 'package:frosty/screens/home/home.dart';
import 'package:frosty/screens/onboarding/onboarding_intro.dart';
import 'package:frosty/screens/settings/stores/auth_store.dart';
import 'package:frosty/screens/settings/stores/settings_store.dart';
import 'package:frosty/stores/global_assets_store.dart';
import 'package:frosty/theme.dart';
import 'package:frosty/utils.dart';
import 'package:frosty/widgets/alert_message.dart';
import 'package:mobx/mobx.dart';
import 'package:provider/provider.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:url_launcher/url_launcher.dart';
import 'package:web_socket_channel/web_socket_channel.dart';

/// Errors that are expected on a mobile client — transient network/I/O, plugin
/// teardown races, and image fetch failures — and therefore shouldn't be
/// reported to Crashlytics as fatal crashes (which would tank the crash-free
/// metric and bucket unrelated errors together under the global handlers).
///
/// This is a last-resort net. The layers that own these errors already record
/// them non-fatally with precise reasons (e.g. base_api_client, the IRC
/// websocket handlers); this only catches what escapes that local handling.
bool _isNonFatalError(Object error) {
  return error is SocketException ||
      error is HttpException ||
      error is WebSocketChannelException ||
      error is ApiException ||
      error is MissingPluginException ||
      error is NetworkImageLoadException ||
      (error is DioException && error.type != DioExceptionType.badResponse);
}

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  CustomCacheManager.removeOrphanedCacheFiles();

  await Firebase.initializeApp(options: DefaultFirebaseOptions.currentPlatform);

  // Route uncaught framework errors to Crashlytics. Non-crashing UI errors
  // (layout overflows, image-load failures) and other expected transient
  // failures are recorded as non-fatal so they don't inflate the crash count.
  FlutterError.onError = (details) {
    // Run the cheap type checks first; only fall back to the diagnostics string
    // (RenderFlex overflow has no typed signal) when those miss.
    final isNonFatal =
        _isNonFatalError(details.exception) ||
        details.exceptionAsString().contains('overflowed');
    if (isNonFatal) {
      FirebaseCrashlytics.instance.recordFlutterError(details);
    } else {
      FirebaseCrashlytics.instance.recordFlutterFatalError(details);
    }
  };

  // Pass uncaught asynchronous errors to Crashlytics. Expected transient errors
  // are recorded non-fatally; everything else stays fatal. The reason gives the
  // grouping engine a real signal so distinct errors don't collapse into one
  // catch-all issue under this handler frame.
  PlatformDispatcher.instance.onError = (error, stack) {
    FirebaseCrashlytics.instance.recordError(
      error,
      stack,
      reason: error.runtimeType.toString(),
      fatal: !_isNonFatalError(error),
    );
    return true;
  };

  final prefs = await SharedPreferences.getInstance();

  // One-time migration: the quality preference used to be stored under a
  // single global key, which meant a saved 1080p60 from one channel could
  // pin another channel to a variant it doesn't serve. Remove the legacy
  // key; new writes go under per-channel keys.
  await prefs.remove(kLegacyLastStreamQualityKey);

  final firstRun = prefs.getBool('first_run') ?? true;

  // Workaround for clearing stored tokens on uninstall.
  // If first time running app, will clear all tokens in the secure storage.
  // Run non-blocking to avoid ANR on slow Android devices (especially Android 14).
  if (firstRun) {
    debugPrint('Clearing secure storage...');
    const storage = FlutterSecureStorage();

    // Don't block - run in background after app starts.
    // This is safe because first run means no active session depends on this data.
    unawaited(
      storage.deleteAll().catchError((e) {
        debugPrint('Error clearing secure storage: $e');
      }),
    );
  }

  await initUtils();

  // With the shared preferences instance, obtain the existing user settings if it exists.
  // If default settings don't exist, use an empty JSON string to use the default values.
  final userSettings = prefs.getString('settings') ?? '{}';

  // Initialize a settings store from the settings JSON string.
  final settingsStore = SettingsStore.fromJson(jsonDecode(userSettings));

  // Disable Firebase collection in debug builds to avoid polluting production data.
  // In release builds, respect the user's preference.
  if (kDebugMode) {
    FirebaseCrashlytics.instance.setCrashlyticsCollectionEnabled(false);
    FirebaseAnalytics.instance.setAnalyticsCollectionEnabled(false);
    FirebasePerformance.instance.setPerformanceCollectionEnabled(false);
  } else {
    final shareEnabled = settingsStore.shareCrashLogsAndAnalytics;
    FirebaseCrashlytics.instance.setCrashlyticsCollectionEnabled(shareEnabled);
    FirebaseAnalytics.instance.setAnalyticsCollectionEnabled(shareEnabled);
    FirebasePerformance.instance.setPerformanceCollectionEnabled(shareEnabled);
  }

  // Create a MobX reaction that will save the settings on disk every time they are changed.
  autorun((_) => prefs.setString('settings', jsonEncode(settingsStore)));

  /// Initialize API services with a common Dio client.
  /// This will prevent every request from creating a new client instance.
  final dioClient = DioClient.createClient();

  // Create API services
  final twitchApiService = TwitchApi(dioClient);
  final bttvApiService = BTTVApi(dioClient);
  final ffzApiService = FFZApi(dioClient);
  final sevenTVApiService = SevenTVApi(dioClient);
  final twitchGqlApiService = TwitchGqlApi(dioClient);

  // Create global assets store (shared cache for global emotes/badges)
  final globalAssetsStore = GlobalAssetsStore(
    twitchApi: twitchApiService,
    bttvApi: bttvApiService,
    ffzApi: ffzApiService,
    sevenTVApi: sevenTVApiService,
  );

  // Create and initialize the authentication store
  final authStore = AuthStore(
    twitchApi: twitchApiService,
    twitchGqlApi: twitchGqlApiService,
  );

  // Add the auth interceptor to the Dio client after AuthStore creation
  dioClient.interceptors.add(TwitchAuthInterceptor(authStore));

  // Add the unauthorized interceptor to catch 401 errors
  dioClient.interceptors.add(UnauthorizedInterceptor(authStore));

  await authStore.init();
  FirebaseCrashlytics.instance.setCustomKey('is_logged_in', authStore.isLoggedIn);
  if (authStore.isLoggedIn && authStore.user.details != null) {
    FirebaseCrashlytics.instance.setUserIdentifier(authStore.user.details!.id);
  }

  runApp(
    MultiProvider(
      providers: [
        Provider<AuthStore>.value(value: authStore),
        Provider<SettingsStore>.value(value: settingsStore),
        Provider<TwitchApi>.value(value: twitchApiService),
        Provider<BTTVApi>.value(value: bttvApiService),
        Provider<FFZApi>.value(value: ffzApiService),
        Provider<SevenTVApi>.value(value: sevenTVApiService),
        Provider<TwitchGqlApi>.value(value: twitchGqlApiService),
        Provider<GlobalAssetsStore>.value(value: globalAssetsStore),
      ],
      child: MyApp(firstRun: firstRun),
    ),
  );
}

// Navigator key for sleep timer. Allows navigation popping without context.
final navigatorKey = GlobalKey<NavigatorState>();

class MyApp extends StatefulWidget {
  final bool firstRun;

  const MyApp({super.key, this.firstRun = false});

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  final AppLinks _appLinks = AppLinks();
  StreamSubscription<Uri>? _linkSubscription;

  @override
  void initState() {
    super.initState();

    AdvancedInAppReview()
        .setMinDaysBeforeRemind(7)
        .setMinDaysAfterInstall(1)
        .setMinLaunchTimes(5)
        .setMinSecondsBeforeShowDialog(3)
        .monitor();

    _initDeepLinks();
  }

  @override
  Widget build(BuildContext context) {
    return Observer(
      builder: (context) {
        final settingsStore = context.read<SettingsStore>();
        final themes = FrostyThemes(
          colorSchemeSeed: Color(settingsStore.accentColor),
        );

        return MaterialApp(
          title: 'Frosty',
          theme: themes.light,
          darkTheme: themes.dark,
          themeMode: settingsStore.themeType == ThemeType.system
              ? ThemeMode.system
              : settingsStore.themeType == ThemeType.light
              ? ThemeMode.light
              : ThemeMode.dark,
          navigatorObservers: [
            FirebaseAnalyticsObserver(
              analytics: FirebaseAnalytics.instance,
            ),
          ],
          home: widget.firstRun ? const OnboardingIntro() : const Home(),
          navigatorKey: navigatorKey,
        );
      },
    );
  }

  Future<void> _initDeepLinks() async {
    try {
      // Handle links when app is already open
      _linkSubscription = _appLinks.uriLinkStream.listen((uri) {
        handleDeepLink(uri);
      });

      // Handle the initial link if app was opened from a link.
      // Add timeout to prevent indefinite blocking on certain Android lifecycle states.
      final initialLink = await _appLinks.getInitialLink().timeout(
        const Duration(seconds: 3),
        onTimeout: () => null,
      );
      if (initialLink != null) {
        handleDeepLink(initialLink);
      }
    } catch (e) {
      debugPrint('Failed to initialize deep links: $e');
    }
  }

  Future<void> handleDeepLink(Uri uri) async {
    final failureSnackbar = SnackBar(
      content: AlertMessage(
        message: 'Unable to navigate to \'$uri\'',
        centered: false,
        trailingIcon: Icons.open_in_browser_rounded,
        // Fallback, allow user to open URL outside app
        onTrailingIconPressed: () async {
          await launchUrl(
            uri,
            mode: LaunchMode.inAppWebView, // Force browser
          );
        },
      ),
    );

    // Handle channel links
    if (uri.pathSegments.isNotEmpty) {
      final channelName = uri.pathSegments.first;

      try {
        final twitchApi = context.read<TwitchApi>();

        final user = await twitchApi.getUser(userLogin: channelName);

        final route = MaterialPageRoute(
          settings: const RouteSettings(name: VideoChat.routeName),
          builder: (context) => VideoChat(
            userId: user.id,
            userName: user.displayName,
            userLogin: user.login,
          ),
        );

        if (navigatorKey.currentState == null) return;

        WidgetsBinding.instance.addPostFrameCallback(
          (_) => navigatorKey.currentState?.push(route),
        );
      } catch (e) {
        // If we get here, there was most likely an error with the Twitch API call and/or this isn't really a channel link
        debugPrint('Failed to open link $uri due to error: $e');

        if (navigatorKey.currentContext == null) return;
        ScaffoldMessenger.of(
          navigatorKey.currentContext!,
        ).showSnackBar(failureSnackbar);
      }
    }
    // TODO: Here we can implement handlers for other types of links
    else {
      // If we get here, it's a link format that we're unable to handle
      if (navigatorKey.currentContext == null) return;
      ScaffoldMessenger.of(
        navigatorKey.currentContext!,
      ).showSnackBar(failureSnackbar);
    }
  }

  @override
  void dispose() {
    _linkSubscription?.cancel();
    super.dispose();
  }
}