import 'dart:io';
import 'package:injectable/injectable.dart';
import 'package:mnemo_cards_backend/api/di/injector.dart';
import 'package:mnemo_cards_backend/user/user_manager.dart';
import 'package:shelf/shelf.dart';
import 'package:shelf/shelf_io.dart' as shelf_io;
import 'package:shelf_router/shelf_router.dart';

import 'v2/ads_api_v2.dart';
import 'v2/admin_users_api_v2.dart';
import 'v2/auth_api_v2.dart';
import 'v2/discounts_api_v2.dart';
import 'v2/games_api_v2.dart';
import 'v2/packs_api_v2.dart';
import 'v2/purchases_api_v2.dart';
import 'v2/promocodes_api_v2.dart';
import 'v2/subscriptions_api_v2.dart';
import 'v2/tasks_api_v2.dart';
import 'v2/tests_api_v2.dart';
import 'v2/users_api_v2.dart';
import 'v2/authorize_v2.dart';
import 'v2/jwt_service.dart';
import 'authorize/access_middleware.dart';
import 'package:mnemo_cards_backend/packs/pack_manager.dart';
import 'package:mnemo_cards_backend/statistics/session_tracking_middleware.dart';
import 'package:mnemo_cards_backend/statistics/session_tracker.dart';

@lazySingleton
class MnemoShelf {
  final UserManager userManager;

  MnemoShelf(this.userManager);

  Future<void> initV2(List<String> args) async {
    final addressArg =
        args.indexOf('-a') == -1 ? null : args[args.indexOf('-a') + 1];
    final portArg =
        args.indexOf('-p') == -1 ? null : args[args.indexOf('-p') + 1];
    final address = addressArg ?? InternetAddress.anyIPv4.address;
    final port = int.tryParse(portArg ?? '') ?? 8443;
    final certs = args.contains('--certs')
        ? args[args.indexOf('--certs') + 1]
        : null; // null = HTTP without SSL
    final dualMode =
        args.contains('--dual'); // Запуск HTTP и HTTPS одновременно

    // V2 APIs (new RESTful API with OAuth2/JWT)
    final v2Routers = [
      getIt.get<AuthApiV2>().router,
      getIt.get<PacksApiV2>().router,
      getIt.get<TestsApiV2>().router,
      getIt.get<GamesApiV2>().router,
      getIt.get<PurchasesApiV2>().router,
      getIt.get<AdsApiV2>().router,
      getIt.get<UsersApiV2>().router,
      getIt.get<PromocodesApiV2>().router,
      getIt.get<SubscriptionsApiV2>().router,
      getIt.get<AdminUsersApiV2>().router,
      getIt.get<DiscountsApiV2>().router,
      getIt.get<TasksApiV2>().router,
    ];

    final v2Router = v2Routers.fold<Router>(
      Router(),
      (router, child) => router..mount('/', child),
    );

    // Note: rootRouter is not used because we manually route to v1/v2 handlers
    // for different authentication middleware. Keeping for reference.
    // final rootRouter = Router()
    //   ..mount('/', v1Router) // Legacy v1 APIs
    //   ..mount('/api/v2', v2Router); // New v2 APIs
    // ..mount(
    //   '/swagger',
    //   SwaggerUI('public/open_api.yaml', title: 'Api'),
    // )
    // ..mount('/', createStaticHandler('public'));

    // Configure a pipeline with proper CORS configuration
    // Поддерживаем как HTTP (разработка), так и HTTPS (продакшен)
    // Note: allowedOrigins is kept for reference but not used since we allow all origins
    // final allowedOrigins = [
    //   'https://1592725-cf88967.twc1.net',
    //   'https://1592725-cf88967.twc1.net:443',
    //   '5492281-cf88967.twc1.net',
    //   '5492281-cf88967.twc1.net:8443'
    //   'http://localhost:*',
    //   'http://localhost:51717', // для разработки
    //   'http://localhost:3000', // для разработки
    //   'http://localhost:8000', // для разработки
    //   'http://127.0.0.1:8000', // для разработки
    // ];

    final corsConfig = {
      'Access-Control-Allow-Origin': '*', // Разрешаем все домены для гибкости
      'Access-Control-Allow-Methods':
          'GET, POST, PUT, DELETE, PATCH, HEAD, OPTIONS',
      'Access-Control-Allow-Headers':
          'Origin, Content-Type, Accept, Authorization, user_token, request_token, app_version',
      'Access-Control-Expose-Headers': 'Authorization',
      'Access-Control-Max-Age': '86400',
    };

    // Добавляем HSTS только для HTTPS соединений
    if (certs != null) {
      corsConfig['Strict-Transport-Security'] =
          'max-age=31536000; includeSubDomains';
    }

    // CORS middleware that handles preflight requests
    Middleware corsMiddleware() {
      return (Handler innerHandler) {
        return (Request request) async {
          // Handle preflight requests
          if (request.method == 'OPTIONS') {
            return Response.ok('', headers: corsConfig);
          }

          // Process the request and add CORS headers to response
          final response = await innerHandler(request);
          return response.change(headers: {
            ...response.headers,
            ...corsConfig,
          });
        };
      };
    }

    final v2Handler = Pipeline()
        .addMiddleware(corsMiddleware())
        .addMiddleware(logRequests(logger: logger('v2')))
        .addMiddleware(
            authorizeV2(getIt.get<UserManager>(), getIt.get<JwtService>()))
        .addMiddleware(accessMiddleware(
            buildAccessService(getIt.get<PackManager>()),
            getIt.get<PackManager>()))
        .addMiddleware(sessionTrackingMiddleware(getIt.get<SessionTracker>()))
        .addHandler(v2Router);

    final rootRouter = Router()
      ..mount('/api/v2', v2Handler)
      ..all('/<ignored|.*>', (Request request) async {
        if (request.method == 'OPTIONS') {
          return Response.ok('', headers: corsConfig);
        }
        return Response.notFound('Not Found', headers: corsConfig);
      });

    final handler = rootRouter.call;

    if (dualMode) {
      // Запуск HTTP и HTTPS серверов одновременно
      await _startDualServers(handler, address, port, certs);
    } else {
      // Обычный запуск одного сервера
      final server = await _createServer(
        handler,
        address,
        port,
        securityContext: certs != null ? getSecurityContext(certs) : null,
        poweredByHeader: null,
        shared: true,
      );

      final protocol = certs != null ? 'https' : 'http';
      print(
          'Serving app at $protocol://${server.address.address}:${server.port}');
      final url = '$protocol://${server.address.address}:${server.port}';
      print('Server listening on $url');

      if (certs != null) {
        print('HTTPS enabled with SSL certificates from: $certs');
        print('Domain: 1592725-cf88967.twc1.net');
      }
    }
  }

  Future<void> _startDualServers(
      Handler handler, Object address, int port, String? certs) async {
    print('🚀 Starting DUAL mode: HTTP + HTTPS servers');

    // HTTP сервер на указанном порту
    final httpServer = await _createServer(
      handler,
      address,
      port,
      securityContext: null, // HTTP без SSL
      poweredByHeader: null,
      shared: true,
    );

    // HTTPS сервер на порту + 1 (например, 8443 -> 8081)
    final httpsPort = port + 1;
    final httpsServer = await _createServer(
      handler,
      address,
      httpsPort,
      securityContext: certs != null ? getSecurityContext(certs) : null,
      poweredByHeader: null,
      shared: true,
    );

    print('✅ Both servers started successfully!');
    print(
        '📡 HTTP server: http://${httpServer.address.address}:${httpServer.port}');
    print(
        '🔒 HTTPS server: https://${httpsServer.address.address}:${httpsServer.port}');

    if (certs != null) {
      print('🔐 HTTPS enabled with SSL certificates from: $certs');
      print('🌐 Domain: 1592725-cf88967.twc1.net');
    }
  }

  SecurityContext getSecurityContext(String path) {
    // Для Let's Encrypt используем fullchain.pem и privkey.pem
    // Для самоподписанных сертификатов используем server.crt и server.key
    String serverCert, key;

    if (path.contains('letsencrypt') || path.contains('/etc/letsencrypt/')) {
      // Let's Encrypt сертификаты
      serverCert = path + '/fullchain.pem';
      key = path + '/privkey.pem';
    } else {
      // Самоподписанные сертификаты
      serverCert = path.startsWith('/')
          ? path + '/server.crt'
          : Platform.script.resolve('$path/server.crt').toFilePath();
      key = path.startsWith('/')
          ? path + '/server.key'
          : Platform.script.resolve('$path/server.key').toFilePath();
    }

    return SecurityContext(withTrustedRoots: false)
      ..useCertificateChain(serverCert)
      ..usePrivateKey(key);
  }

  logger(String tag) => (String msg, bool isError) {
        if (isError) {
          print('[ERROR][$tag] $msg');
        } else {
          print('[$tag] $msg');
        }
      };

  Future<HttpServer> _createServer(
    Handler handler,
    Object address,
    int port, {
    SecurityContext? securityContext,
    int? backlog,
    bool shared = false,
    String? poweredByHeader = 'Dart with package:shelf',
  }) async {
    backlog ??= 0;
    var server = await (securityContext == null
        ? HttpServer.bind(address, port, backlog: backlog, shared: shared)
        : HttpServer.bindSecure(
            address,
            port,
            securityContext,
            backlog: backlog,
            shared: shared,
            requestClientCertificate: true,
          ));
    shelf_io.serveRequests(server, handler, poweredByHeader: poweredByHeader);
    return server;
  }
}