// lib/screens/restaurant_select_screen.dart

import "package:flutter/material.dart";
import "package:provider/provider.dart";
import "package:geolocator/geolocator.dart";

import "../app/app_state.dart";
import "../models/menu_item.dart";
import "../models/restaurant.dart";
import "../models/service_point.dart";
import "../services/api.dart";
import "../widgets/rescan_button.dart";

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

  @override
  State<RestaurantSelectScreen> createState() => _RestaurantSelectScreenState();
}

class _RestaurantSelectScreenState extends State<RestaurantSelectScreen> {
  late Future<List<Restaurant>> _restaurantsFuture;
  String? _debugLastRaw;
  int? _debugLastStatus;

  // Which restaurant is currently expanded (shows menu)
  int? _expandedBusinessId;

  // Cache for loaded menus and service points
  final Map<int, List<MenuItem>> _menuCache = {};
  final Map<int, List<ServicePoint>> _servicePointCache = {};
  final Map<int, bool> _loadingMenu = {};

  static const String _imageBaseUrl = "https://biz.payfrit.com/uploads";

  @override
  void initState() {
    super.initState();
    _restaurantsFuture = _loadRestaurantsWithLocation();

    // Clear order type when arriving at restaurant select (no beacon = not dine-in)
    // This ensures the table change icon doesn't appear for delivery/takeaway orders
    WidgetsBinding.instance.addPostFrameCallback((_) {
      final appState = context.read<AppState>();
      appState.setOrderType(null);
    });
  }

  Future<List<Restaurant>> _loadRestaurantsWithLocation() async {
    double? lat;
    double? lng;

    // Try to get user location for distance-based sorting
    try {
      final permission = await Geolocator.checkPermission();
      if (permission == LocationPermission.always || permission == LocationPermission.whileInUse) {
        final position = await Geolocator.getCurrentPosition(
          locationSettings: const LocationSettings(
            accuracy: LocationAccuracy.low,
            timeLimit: Duration(seconds: 5),
          ),
        );
        lat = position.latitude;
        lng = position.longitude;
        debugPrint('[RestaurantSelect] Got location: $lat, $lng');
      }
    } catch (e) {
      debugPrint('[RestaurantSelect] Location error (continuing without): $e');
    }

    final raw = await Api.listRestaurantsRaw(lat: lat, lng: lng);
    _debugLastRaw = raw.rawBody;
    _debugLastStatus = raw.statusCode;
    return Api.listRestaurants(lat: lat, lng: lng);
  }

  Future<void> _loadMenuForBusiness(int businessId) async {
    if (_menuCache.containsKey(businessId)) return;
    if (_loadingMenu[businessId] == true) return;

    setState(() => _loadingMenu[businessId] = true);

    try {
      // Load menu items and service points in parallel
      final results = await Future.wait([
        Api.listMenuItems(businessId: businessId),
        Api.listServicePoints(businessId: businessId),
      ]);

      if (mounted) {
        setState(() {
          _menuCache[businessId] = results[0] as List<MenuItem>;
          _servicePointCache[businessId] = results[1] as List<ServicePoint>;
          _loadingMenu[businessId] = false;
        });
      }
    } catch (e) {
      debugPrint('[RestaurantSelect] Error loading menu: $e');
      if (mounted) {
        setState(() => _loadingMenu[businessId] = false);
      }
    }
  }

  void _toggleExpand(Restaurant restaurant) {
    // For delivery/takeaway flow (no beacon), go directly to menu
    // No need to select table - just pick the first service point
    _navigateToMenu(restaurant);
  }

  void _navigateToMenu(Restaurant restaurant) async {
    // Load service points if not cached
    if (!_servicePointCache.containsKey(restaurant.businessId)) {
      try {
        final servicePoints = await Api.listServicePoints(businessId: restaurant.businessId);
        _servicePointCache[restaurant.businessId] = servicePoints;
      } catch (e) {
        debugPrint('[RestaurantSelect] Error loading service points: $e');
      }
    }

    if (!mounted) return;

    // Default to first service point (for delivery/takeaway, table doesn't matter)
    final servicePoints = _servicePointCache[restaurant.businessId];
    final servicePointId = servicePoints?.firstOrNull?.servicePointId ?? 1;

    // Set app state
    final appState = context.read<AppState>();
    appState.setBusinessAndServicePoint(
      restaurant.businessId,
      servicePointId,
      businessName: restaurant.name,
      servicePointName: servicePoints?.firstOrNull?.name,
    );
    Api.setBusinessId(restaurant.businessId);

    // Navigate to full menu browse screen
    Navigator.of(context).pushNamed(
      '/menu_browse',
      arguments: {
        'businessId': restaurant.businessId,
        'servicePointId': servicePointId,
      },
    );
  }

  Future<bool> _onWillPop() async {
    final shouldExit = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text("Exit App?"),
        content: const Text("Are you sure you want to exit?"),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(context).pop(false),
            child: const Text("Cancel"),
          ),
          TextButton(
            onPressed: () => Navigator.of(context).pop(true),
            child: const Text("Exit"),
          ),
        ],
      ),
    );
    return shouldExit ?? false;
  }

  @override
  Widget build(BuildContext context) {
    return PopScope(
      canPop: false,
      onPopInvokedWithResult: (didPop, result) async {
        if (didPop) return;
        final shouldExit = await _onWillPop();
        if (shouldExit && context.mounted) {
          Navigator.of(context).pop();
        }
      },
      child: Scaffold(
        backgroundColor: Colors.black,
        appBar: AppBar(
        backgroundColor: Colors.black,
        foregroundColor: Colors.white,
        title: const Text("Nearby Restaurants"),
        elevation: 0,
        actions: const [
          RescanButton(iconColor: Colors.white),
        ],
      ),
      body: FutureBuilder<List<Restaurant>>(
        future: _restaurantsFuture,
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.waiting) {
            return const Center(
              child: CircularProgressIndicator(color: Colors.white),
            );
          }

          if (snapshot.hasError) {
            return _ErrorPane(
              title: "Failed to Load",
              message: snapshot.error.toString(),
              statusCode: _debugLastStatus,
              raw: _debugLastRaw,
              onRetry: () => setState(() => _restaurantsFuture = _loadRestaurantsWithLocation()),
            );
          }

          final restaurants = snapshot.data ?? const <Restaurant>[];
          if (restaurants.isEmpty) {
            return _ErrorPane(
              title: "No Restaurants Found",
              message: "No Payfrit restaurants nearby.",
              statusCode: _debugLastStatus,
              raw: _debugLastRaw,
              onRetry: () => setState(() => _restaurantsFuture = _loadRestaurantsWithLocation()),
            );
          }

          return ListView.builder(
            padding: const EdgeInsets.symmetric(vertical: 8),
            itemCount: restaurants.length,
            itemBuilder: (context, index) {
              final restaurant = restaurants[index];
              final isExpanded = _expandedBusinessId == restaurant.businessId;

              return _RestaurantBar(
                restaurant: restaurant,
                isExpanded: isExpanded,
                onTap: () => _toggleExpand(restaurant),
                menuItems: _menuCache[restaurant.businessId],
                servicePoints: _servicePointCache[restaurant.businessId],
                isLoading: _loadingMenu[restaurant.businessId] == true,
                imageBaseUrl: _imageBaseUrl,
              );
            },
          );
        },
      ),
      ),
    );
  }
}

class _RestaurantBar extends StatelessWidget {
  final Restaurant restaurant;
  final bool isExpanded;
  final VoidCallback onTap;
  final List<MenuItem>? menuItems;
  final List<ServicePoint>? servicePoints;
  final bool isLoading;
  final String imageBaseUrl;

  const _RestaurantBar({
    required this.restaurant,
    required this.isExpanded,
    required this.onTap,
    required this.menuItems,
    required this.servicePoints,
    required this.isLoading,
    required this.imageBaseUrl,
  });

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        // Restaurant card with header image (matches business selector style)
        GestureDetector(
          onTap: onTap,
          child: Container(
            height: 120,
            margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
            decoration: BoxDecoration(
              borderRadius: BorderRadius.circular(16),
              boxShadow: [
                BoxShadow(
                  color: Colors.black.withAlpha(100),
                  blurRadius: 8,
                  offset: const Offset(0, 4),
                ),
              ],
            ),
            child: ClipRRect(
              borderRadius: BorderRadius.circular(16),
              child: Stack(
                children: [
                  // Header image background
                  Positioned.fill(
                    child: Image.network(
                      "$imageBaseUrl/headers/${restaurant.businessId}.png",
                      fit: BoxFit.cover,
                      errorBuilder: (context, error, stackTrace) {
                        return Image.network(
                          "$imageBaseUrl/headers/${restaurant.businessId}.jpg",
                          fit: BoxFit.cover,
                          errorBuilder: (context, error, stackTrace) {
                            // Fallback to logo centered
                            return Container(
                              color: Colors.grey.shade800,
                              child: Center(
                                child: Image.network(
                                  "$imageBaseUrl/logos/${restaurant.businessId}.png",
                                  width: 60,
                                  height: 60,
                                  fit: BoxFit.contain,
                                  errorBuilder: (context, error, stackTrace) {
                                    return Image.network(
                                      "$imageBaseUrl/logos/${restaurant.businessId}.jpg",
                                      width: 60,
                                      height: 60,
                                      fit: BoxFit.contain,
                                      errorBuilder: (context, error, stackTrace) {
                                        return Text(
                                          restaurant.name.isNotEmpty ? restaurant.name[0].toUpperCase() : "?",
                                          style: const TextStyle(
                                            color: Colors.white54,
                                            fontSize: 36,
                                            fontWeight: FontWeight.bold,
                                          ),
                                        );
                                      },
                                    );
                                  },
                                ),
                              ),
                            );
                          },
                        );
                      },
                    ),
                  ),
                  // Gradient overlay
                  Positioned.fill(
                    child: Container(
                      decoration: BoxDecoration(
                        gradient: LinearGradient(
                          begin: Alignment.topCenter,
                          end: Alignment.bottomCenter,
                          colors: [
                            Colors.transparent,
                            Colors.black.withAlpha(180),
                          ],
                        ),
                      ),
                    ),
                  ),
                  // Business name and arrow at bottom
                  Positioned(
                    bottom: 12,
                    left: 16,
                    right: 16,
                    child: Row(
                      children: [
                        Expanded(
                          child: Text(
                            restaurant.name,
                            style: const TextStyle(
                              color: Colors.white,
                              fontSize: 20,
                              fontWeight: FontWeight.bold,
                              shadows: [
                                Shadow(
                                  offset: Offset(0, 1),
                                  blurRadius: 3,
                                  color: Colors.black54,
                                ),
                              ],
                            ),
                          ),
                        ),
                        const Icon(
                          Icons.arrow_forward_ios,
                          color: Colors.white70,
                          size: 20,
                        ),
                      ],
                    ),
                  ),
                ],
              ),
            ),
          ),
        ),

        // Expanded menu content
        AnimatedCrossFade(
          firstChild: const SizedBox.shrink(),
          secondChild: _buildExpandedContent(context),
          crossFadeState: isExpanded ? CrossFadeState.showSecond : CrossFadeState.showFirst,
          duration: const Duration(milliseconds: 300),
          sizeCurve: Curves.easeInOut,
        ),
      ],
    );
  }

  Widget _buildExpandedContent(BuildContext context) {
    if (isLoading) {
      return Container(
        padding: const EdgeInsets.all(32),
        child: const Center(
          child: CircularProgressIndicator(color: Colors.white),
        ),
      );
    }

    if (menuItems == null || menuItems!.isEmpty) {
      return Container(
        padding: const EdgeInsets.all(24),
        margin: const EdgeInsets.symmetric(horizontal: 12),
        child: const Center(
          child: Text(
            "No menu available",
            style: TextStyle(color: Colors.white70),
          ),
        ),
      );
    }

    // Organize menu items by category
    final itemsByCategory = <int, List<MenuItem>>{};
    for (final item in menuItems!) {
      if (item.isRootItem && item.isActive) {
        itemsByCategory.putIfAbsent(item.categoryId, () => []).add(item);
      }
    }

    // Sort within categories
    for (final list in itemsByCategory.values) {
      list.sort((a, b) => a.sortOrder.compareTo(b.sortOrder));
    }

    final categoryIds = itemsByCategory.keys.toList()..sort();

    return Container(
      margin: const EdgeInsets.symmetric(horizontal: 12),
      decoration: BoxDecoration(
        color: Colors.grey.shade900.withAlpha(200),
        borderRadius: const BorderRadius.only(
          bottomLeft: Radius.circular(12),
          bottomRight: Radius.circular(12),
        ),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          // Service point selector (if multiple)
          if (servicePoints != null && servicePoints!.length > 1)
            Padding(
              padding: const EdgeInsets.fromLTRB(16, 16, 16, 8),
              child: Text(
                "Select a table to order",
                style: TextStyle(
                  color: Colors.white.withAlpha(180),
                  fontSize: 14,
                ),
              ),
            ),

          // Category sections with items
          ...categoryIds.map((categoryId) {
            final items = itemsByCategory[categoryId]!;
            final categoryName = items.first.categoryName;

            return _CategorySection(
              categoryId: categoryId,
              categoryName: categoryName,
              items: items,
              imageBaseUrl: imageBaseUrl,
              restaurant: restaurant,
              servicePoints: servicePoints,
            );
          }),

          const SizedBox(height: 12),
        ],
      ),
    );
  }
}

class _CategorySection extends StatelessWidget {
  final int categoryId;
  final String categoryName;
  final List<MenuItem> items;
  final String imageBaseUrl;
  final Restaurant restaurant;
  final List<ServicePoint>? servicePoints;

  const _CategorySection({
    required this.categoryId,
    required this.categoryName,
    required this.items,
    required this.imageBaseUrl,
    required this.restaurant,
    required this.servicePoints,
  });

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        // Category header
        Padding(
          padding: const EdgeInsets.fromLTRB(16, 16, 16, 8),
          child: Text(
            categoryName,
            style: const TextStyle(
              color: Colors.white,
              fontSize: 16,
              fontWeight: FontWeight.bold,
            ),
          ),
        ),
        // Horizontal scroll of items
        SizedBox(
          height: 140,
          child: ListView.builder(
            scrollDirection: Axis.horizontal,
            padding: const EdgeInsets.symmetric(horizontal: 12),
            itemCount: items.length,
            itemBuilder: (context, index) {
              final item = items[index];
              return _MenuItemCard(
                item: item,
                imageBaseUrl: imageBaseUrl,
                onTap: () => _handleItemTap(context, item),
              );
            },
          ),
        ),
      ],
    );
  }

  void _handleItemTap(BuildContext context, MenuItem item) {
    // Default to first service point if available
    final servicePointId = servicePoints?.firstOrNull?.servicePointId ?? 1;

    // Set app state
    final appState = context.read<AppState>();
    appState.setBusinessAndServicePoint(
      restaurant.businessId,
      servicePointId,
      businessName: restaurant.name,
      servicePointName: servicePoints?.firstOrNull?.name,
    );
    Api.setBusinessId(restaurant.businessId);

    // Navigate to full menu browse screen
    Navigator.of(context).pushNamed(
      '/menu_browse',
      arguments: {
        'businessId': restaurant.businessId,
        'servicePointId': servicePointId,
      },
    );
  }
}

class _MenuItemCard extends StatelessWidget {
  final MenuItem item;
  final String imageBaseUrl;
  final VoidCallback onTap;

  const _MenuItemCard({
    required this.item,
    required this.imageBaseUrl,
    required this.onTap,
  });

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: onTap,
      child: Container(
        width: 120,
        margin: const EdgeInsets.symmetric(horizontal: 4),
        decoration: BoxDecoration(
          color: Colors.grey.shade800,
          borderRadius: BorderRadius.circular(10),
        ),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            // Item image
            ClipRRect(
              borderRadius: const BorderRadius.only(
                topLeft: Radius.circular(10),
                topRight: Radius.circular(10),
              ),
              child: SizedBox(
                height: 80,
                width: 120,
                child: Image.network(
                  "$imageBaseUrl/items/${item.itemId}.png",
                  fit: BoxFit.cover,
                  errorBuilder: (context, error, stackTrace) {
                    return Image.network(
                      "$imageBaseUrl/items/${item.itemId}.jpg",
                      fit: BoxFit.cover,
                      errorBuilder: (context, error, stackTrace) {
                        return Container(
                          color: Theme.of(context).colorScheme.primaryContainer,
                          child: Center(
                            child: Icon(
                              Icons.restaurant,
                              color: Theme.of(context).colorScheme.onPrimaryContainer,
                              size: 32,
                            ),
                          ),
                        );
                      },
                    );
                  },
                ),
              ),
            ),
            // Item details
            Expanded(
              child: Padding(
                padding: const EdgeInsets.all(8),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      item.name,
                      style: const TextStyle(
                        color: Colors.white,
                        fontSize: 12,
                        fontWeight: FontWeight.w500,
                      ),
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                    ),
                    const Spacer(),
                    Text(
                      "\$${item.price.toStringAsFixed(2)}",
                      style: TextStyle(
                        color: Theme.of(context).colorScheme.primary,
                        fontSize: 12,
                        fontWeight: FontWeight.bold,
                      ),
                    ),
                  ],
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class _ErrorPane extends StatelessWidget {
  final String title;
  final String message;
  final int? statusCode;
  final String? raw;
  final VoidCallback onRetry;

  const _ErrorPane({
    required this.title,
    required this.message,
    required this.statusCode,
    required this.raw,
    required this.onRetry,
  });

  @override
  Widget build(BuildContext context) {
    return Center(
      child: SingleChildScrollView(
        padding: const EdgeInsets.all(18),
        child: ConstrainedBox(
          constraints: const BoxConstraints(maxWidth: 720),
          child: Card(
            color: Colors.grey.shade900,
            child: Padding(
              padding: const EdgeInsets.all(18),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    title,
                    style: Theme.of(context).textTheme.titleLarge?.copyWith(
                          color: Colors.white,
                        ),
                  ),
                  const SizedBox(height: 10),
                  Text(message, style: const TextStyle(color: Colors.white70)),
                  const SizedBox(height: 14),
                  if (statusCode != null)
                    Text("HTTP: $statusCode", style: const TextStyle(color: Colors.white70)),
                  if (raw != null && raw!.trim().isNotEmpty) ...[
                    const SizedBox(height: 10),
                    const Text("Raw response:", style: TextStyle(color: Colors.white70)),
                    const SizedBox(height: 6),
                    Text(raw!, style: const TextStyle(color: Colors.white54)),
                  ],
                  const SizedBox(height: 14),
                  FilledButton(
                    onPressed: onRetry,
                    child: const Text("Retry"),
                  ),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}