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

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';

import 'package:adaptive_dialog/adaptive_dialog.dart';
import 'package:collection/collection.dart';
import 'package:file_picker/file_picker.dart';
import 'package:flutter_gen/gen_l10n/l10n.dart';
import 'package:flutter_web_auth_2/flutter_web_auth_2.dart';
import 'package:go_router/go_router.dart';
import 'package:hive_flutter/hive_flutter.dart';
import 'package:matrix/matrix.dart';
import 'package:universal_html/html.dart' as html;

import 'package:fluffychat/config/app_config.dart';
import 'package:fluffychat/pages/homeserver_picker/homeserver_picker_view.dart';
import 'package:fluffychat/pages/homeserver_picker/public_homeserver.dart';
import 'package:fluffychat/utils/platform_infos.dart';
import 'package:fluffychat/widgets/app_lock.dart';
import 'package:fluffychat/widgets/matrix.dart';
import '../../utils/localized_exception_extension.dart';

import 'package:fluffychat/utils/tor_stub.dart'
    if (dart.library.html) 'package:tor_detector_web/tor_detector_web.dart';

class HomeserverPicker extends StatefulWidget {
  const HomeserverPicker({super.key});

  @override
  HomeserverPickerController createState() => HomeserverPickerController();
}

class HomeserverPickerController extends State<HomeserverPicker> {
  bool isLoading = false;
  bool isLoggingIn = false;

  final TextEditingController homeserverController = TextEditingController(
    text: AppConfig.defaultHomeserver,
  );

  String? error;

  bool isTorBrowser = false;

  Future<void> _checkTorBrowser() async {
    if (!kIsWeb) return;

    Hive.openBox('test').then((value) => null).catchError(
      (e, s) async {
        await showOkAlertDialog(
          context: context,
          title: L10n.of(context)!.indexedDbErrorTitle,
          message: L10n.of(context)!.indexedDbErrorLong,
        );
        _checkTorBrowser();
      },
    );

    final isTor = await TorBrowserDetector.isTorBrowser;
    isTorBrowser = isTor;
  }

  String? _lastCheckedUrl;

  /// Starts an analysis of the given homeserver. It uses the current domain and
  /// makes sure that it is prefixed with https. Then it searches for the
  /// well-known information and forwards to the login page depending on the
  /// login type.
  Future<void> checkHomeserverAction([_]) async {
    homeserverController.text =
        homeserverController.text.trim().toLowerCase().replaceAll(' ', '-');
    if (homeserverController.text == _lastCheckedUrl) return;
    _lastCheckedUrl = homeserverController.text;
    setState(() {
      error = _rawLoginTypes = loginFlows = null;
      isLoading = true;
    });

    try {
      var homeserver = Uri.parse(homeserverController.text);
      if (homeserver.scheme.isEmpty) {
        homeserver = Uri.https(homeserverController.text, '');
      }
      final client = Matrix.of(context).getLoginClient();
      final (_, _, loginFlows) = await client.checkHomeserver(homeserver);
      this.loginFlows = loginFlows;
      if (supportsSso) {
        _rawLoginTypes = await client.request(
          RequestType.GET,
          '/client/v3/login',
        );
      }
    } catch (e) {
      setState(() => error = (e).toLocalizedString(context));
    } finally {
      if (mounted) {
        setState(() => isLoading = false);
      }
    }
  }

  List<LoginFlow>? loginFlows;

  bool _supportsFlow(String flowType) =>
      loginFlows?.any((flow) => flow.type == flowType) ?? false;

  bool get supportsSso => _supportsFlow('m.login.sso');

  bool isDefaultPlatform =
      (PlatformInfos.isMobile || PlatformInfos.isWeb || PlatformInfos.isMacOS);

  bool get supportsPasswordLogin => _supportsFlow('m.login.password');

  Map<String, dynamic>? _rawLoginTypes;

  void ssoLoginAction(String? id) async {
    final redirectUrl = kIsWeb
        ? Uri.parse(html.window.location.href)
            .resolveUri(
              Uri(pathSegments: ['auth.html']),
            )
            .toString()
        : isDefaultPlatform
            ? '${AppConfig.appOpenUrlScheme.toLowerCase()}://login'
            : 'http://localhost:3001//login';

    final url = Matrix.of(context).getLoginClient().homeserver!.replace(
      path: '/_matrix/client/v3/login/sso/redirect${id == null ? '' : '/$id'}',
      queryParameters: {'redirectUrl': redirectUrl},
    );

    final urlScheme = isDefaultPlatform
        ? Uri.parse(redirectUrl).scheme
        : "http://localhost:3001";
    final result = await FlutterWebAuth2.authenticate(
      url: url.toString(),
      callbackUrlScheme: urlScheme,
    );
    final token = Uri.parse(result).queryParameters['loginToken'];
    if (token?.isEmpty ?? false) return;

    setState(() {
      error = null;
      isLoading = isLoggingIn = true;
    });
    try {
      await Matrix.of(context).getLoginClient().login(
            LoginType.mLoginToken,
            token: token,
            initialDeviceDisplayName: PlatformInfos.clientName,
          );
    } catch (e) {
      setState(() {
        error = e.toLocalizedString(context);
      });
    } finally {
      if (mounted) {
        setState(() {
          isLoading = isLoggingIn = false;
        });
      }
    }
  }

  List<IdentityProvider>? get identityProviders {
    final loginTypes = _rawLoginTypes;
    if (loginTypes == null) return null;
    final List? rawProviders =
        loginTypes.tryGetList('flows')?.singleWhereOrNull(
                  (flow) => flow['type'] == AuthenticationTypes.sso,
                )['identity_providers'] ??
            [
              {'id': null},
            ];
    if (rawProviders == null) return null;
    final list =
        rawProviders.map((json) => IdentityProvider.fromJson(json)).toList();
    if (PlatformInfos.isCupertinoStyle) {
      list.sort((a, b) => a.brand == 'apple' ? -1 : 1);
    }
    return list;
  }

  List<PublicHomeserver>? cachedHomeservers;

  Future<List<PublicHomeserver>> loadHomeserverList() async {
    if (cachedHomeservers != null) return cachedHomeservers!;
    final result = await Matrix.of(context)
        .getLoginClient()
        .httpClient
        .get(AppConfig.homeserverList);
    final resultJson = jsonDecode(result.body)['public_servers'] as List;
    final homeserverList =
        resultJson.map((json) => PublicHomeserver.fromJson(json)).toList();
    return cachedHomeservers = homeserverList;
  }

  void login() => context.push(
        '${GoRouter.of(context).routeInformationProvider.value.uri.path}/login',
      );

  @override
  void initState() {
    _checkTorBrowser();
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback(checkHomeserverAction);
  }

  @override
  Widget build(BuildContext context) => HomeserverPickerView(this);

  Future<void> restoreBackup() async {
    final picked = await AppLock.of(context).pauseWhile(
      FilePicker.platform.pickFiles(withData: true),
    );
    final file = picked?.files.firstOrNull;
    if (file == null) return;
    setState(() {
      error = null;
      isLoading = isLoggingIn = true;
    });
    try {
      final client = Matrix.of(context).getLoginClient();
      await client.importDump(String.fromCharCodes(file.bytes!));
      Matrix.of(context).initMatrix();
    } catch (e) {
      setState(() {
        error = e.toLocalizedString(context);
      });
    } finally {
      if (mounted) {
        setState(() {
          isLoading = isLoggingIn = false;
        });
      }
    }
  }
}

class IdentityProvider {
  final String? id;
  final String? name;
  final String? icon;
  final String? brand;

  IdentityProvider({this.id, this.name, this.icon, this.brand});

  factory IdentityProvider.fromJson(Map<String, dynamic> json) =>
      IdentityProvider(
        id: json['id'],
        name: json['name'],
        icon: json['icon'],
        brand: json['brand'],
      );
}