// food_controller.dart — حالة تبويب الطعام (تصفح، سلة، تتبّع الطلب)
import 'dart:async';
import 'dart:math';
import 'package:get/get.dart';
import '../../constant/box_name.dart';
import '../../main.dart';
import '../../views/widgets/error_snakbar.dart';
import 'food_models.dart';
import 'food_service.dart';

class FoodController extends GetxController {
  // ── تصفح ──
  bool isLoadingMerchants = false;
  List<FoodMerchant> merchants = [];
  String city = _defaultCityForCountry();

  // ── تفاصيل مطعم ──
  bool isLoadingMenu = false;
  FoodMerchant? selectedMerchant;
  List<FoodMenuCategory> categories = [];

  // ── السلة (مقيّدة بمطعم واحد فقط) ──
  int? cartMerchantId;
  final Map<String, FoodCartLine> _cart = {};
  List<FoodCartLine> get cartLines => _cart.values.toList();
  int get cartItemsCount => _cart.values.fold(0, (sum, l) => sum + l.quantity);
  int get cartTotal => _cart.values.fold(0, (sum, l) => sum + l.lineTotal);

  // ── عرض السعر الحالي ──
  FoodQuote? currentQuote;
  bool isQuoting = false;

  // ── الطلب النشط (تتبّع) ──
  FoodOrder? activeOrder;
  Timer? _statusPollTimer;

  static String _defaultCityForCountry() {
    final country = box.read(BoxName.countryCode);
    switch (country) {
      case 'SY':
        return 'دمشق';
      case 'EG':
        return 'القاهرة';
      default:
        return 'عمان';
    }
  }

  void setCity(String newCity) {
    if (newCity.trim().isEmpty) return;
    city = newCity.trim();
    fetchMerchants();
  }

  Future<void> fetchMerchants({String? category}) async {
    isLoadingMerchants = true;
    update();
    final res = await FoodService.browseMerchants(city: city, category: category);
    isLoadingMerchants = false;
    if (res.success) {
      merchants = res.data ?? [];
    } else {
      merchants = [];
      mySnackbarWarning(res.message);
    }
    update();
  }

  Future<void> searchMerchants(String query) async {
    if (query.trim().length < 2) return;
    isLoadingMerchants = true;
    update();
    final res = await FoodService.searchMerchants(city: city, query: query.trim());
    isLoadingMerchants = false;
    if (res.success) merchants = res.data ?? [];
    update();
  }

  Future<void> openMerchant(int merchantId) async {
    isLoadingMenu = true;
    selectedMerchant = null;
    categories = [];
    update();

    final res = await FoodService.merchantDetails(merchantId);
    isLoadingMenu = false;
    if (res.success && res.data != null) {
      selectedMerchant = res.data!['merchant'] as FoodMerchant;
      categories = res.data!['categories'] as List<FoodMenuCategory>;
    } else {
      mySnackbarWarning(res.message);
    }
    update();
  }

  // ── إدارة السلة ──

  bool addToCart(FoodMenuItem item, {int quantity = 1, Map<int, List<String>>? options}) {
    final line = FoodCartLine(item: item, quantity: quantity, selectedOptions: options ?? {});
    final existing = _cart[line.lineKey];
    if (existing != null) {
      existing.quantity += quantity;
    } else {
      _cart[line.lineKey] = line;
    }
    currentQuote = null; // أي تعديل بالسلة يُبطل العرض الموقّع القديم
    update();
    return true;
  }

  // يُستدعى من صفحة المطعم مع فحص أن السلة إما فارغة أو لنفس المطعم
  bool addToCartForMerchant(int merchantId, FoodMenuItem item,
      {int quantity = 1, Map<int, List<String>>? options}) {
    if (_cart.isNotEmpty && cartMerchantId != null && cartMerchantId != merchantId) {
      mySnackbarWarning(box.read(BoxName.lang) == 'ar'
          ? 'سلتك تحتوي أصنافاً من مطعم آخر. أفرغها أولاً لإضافة من هذا المطعم.'
          : 'Your cart has items from another restaurant. Clear it first.');
      return false;
    }
    cartMerchantId = merchantId;
    return addToCart(item, quantity: quantity, options: options);
  }

  void removeFromCart(String lineKey) {
    _cart.remove(lineKey);
    if (_cart.isEmpty) cartMerchantId = null;
    currentQuote = null;
    update();
  }

  void updateQuantity(String lineKey, int quantity) {
    final line = _cart[lineKey];
    if (line == null) return;
    if (quantity <= 0) {
      removeFromCart(lineKey);
      return;
    }
    line.quantity = quantity;
    currentQuote = null;
    update();
  }

  void clearCart() {
    _cart.clear();
    cartMerchantId = null;
    currentQuote = null;
    update();
  }

  Future<bool> refreshQuote() async {
    if (cartMerchantId == null || cartLines.isEmpty) return false;
    isQuoting = true;
    update();

    final res = await FoodService.getQuote(merchantId: cartMerchantId!, lines: cartLines);
    isQuoting = false;
    if (res.success && res.data != null) {
      currentQuote = res.data;
      update();
      return true;
    }
    currentQuote = null;
    mySnackbarWarning(res.message);
    update();
    return false;
  }

  bool _placingOrder = false;
  bool get isPlacingOrder => _placingOrder;

  Future<int?> placeOrder({
    required String deliveryAddress,
    required double deliveryLat,
    required double deliveryLng,
    required String paymentMethod,
    String? customerNote,
  }) async {
    if (currentQuote == null) {
      final ok = await refreshQuote();
      if (!ok || currentQuote == null) return null;
    }

    _placingOrder = true;
    update();

    final res = await FoodService.createOrder(
      quoteToken: currentQuote!.quoteToken,
      clientOrderUuid: _generateUuidV4(),
      deliveryAddress: deliveryAddress,
      deliveryLat: deliveryLat,
      deliveryLng: deliveryLng,
      paymentMethod: paymentMethod,
      customerNote: customerNote,
    );

    _placingOrder = false;
    update();

    if (res.success && res.data != null) {
      clearCart();
      startTrackingOrder(res.data!);
      return res.data;
    }

    mySnackbarWarning(res.message);
    return null;
  }

  // ── تتبّع الطلب (polling — السوكيت ليس مصدر الحقيقة، انظر ملاحظة backend) ──

  void startTrackingOrder(int orderId) {
    _statusPollTimer?.cancel();
    _pollOrderStatus(orderId);
    _statusPollTimer = Timer.periodic(const Duration(seconds: 5), (_) => _pollOrderStatus(orderId));
  }

  Future<void> _pollOrderStatus(int orderId) async {
    final res = await FoodService.getOrderStatus(orderId);
    if (res.success && res.data != null) {
      activeOrder = res.data;
      update();
      if (activeOrder!.status == 'delivered' || foodOrderIsCancelled(activeOrder!.status)) {
        _statusPollTimer?.cancel();
      }
    }
  }

  void stopTracking() {
    _statusPollTimer?.cancel();
    activeOrder = null;
  }

  Future<bool> rateActiveOrder(int rating, {String? comment}) async {
    if (activeOrder == null) return false;
    final res = await FoodService.rateOrder(activeOrder!.id, rating, comment: comment);
    if (res.success) {
      await _pollOrderStatus(activeOrder!.id);
      return true;
    }
    mySnackbarWarning(res.message);
    return false;
  }

  Future<bool> cancelActiveOrder({String? reason}) async {
    if (activeOrder == null) return false;
    final res = await FoodService.cancelOrder(activeOrder!.id, reason: reason);
    if (res.success) {
      await _pollOrderStatus(activeOrder!.id);
      return true;
    }
    mySnackbarWarning(res.message);
    return false;
  }

  static String _generateUuidV4() {
    final rnd = Random.secure();
    final bytes = List<int>.generate(16, (_) => rnd.nextInt(256));
    bytes[6] = (bytes[6] & 0x0f) | 0x40; // version 4
    bytes[8] = (bytes[8] & 0x3f) | 0x80; // variant
    String hex(int start, int end) =>
        bytes.sublist(start, end).map((b) => b.toRadixString(16).padLeft(2, '0')).join();
    return '${hex(0, 4)}-${hex(4, 6)}-${hex(6, 8)}-${hex(8, 10)}-${hex(10, 16)}';
  }

  @override
  void onClose() {
    _statusPollTimer?.cancel();
    super.onClose();
  }
}