import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:image_picker/image_picker.dart';
import '../../core/navigation_provider.dart';

final dietProvider = NotifierProvider<DietNotifier, DietState>(DietNotifier.new);

class DietState {
  final String? imagePath;
  final List<FoodItem> foods;
  final String mealType;
  final bool isAnalyzing;
  final int? healthScore;

  DietState({
    this.imagePath,
    this.foods = const [],
    this.mealType = 'lunch',
    this.isAnalyzing = false,
    this.healthScore,
  });

  DietState copyWith({
    String? imagePath,
    List<FoodItem>? foods,
    String? mealType,
    bool? isAnalyzing,
    int? healthScore,
  }) {
    return DietState(
      imagePath: imagePath ?? this.imagePath,
      foods: foods ?? this.foods,
      mealType: mealType ?? this.mealType,
      isAnalyzing: isAnalyzing ?? this.isAnalyzing,
      healthScore: healthScore ?? this.healthScore,
    );
  }
}

class FoodItem {
  final String id;
  String name;
  int calories;
  bool selected;

  FoodItem({
    required this.id,
    required this.name,
    required this.calories,
    this.selected = true,
  });
}

class DietNotifier extends Notifier<DietState> {
  @override
  DietState build() => DietState();

  void setImage(String path) {
    state = state.copyWith(imagePath: path);
  }

  void analyzeImage() async {
    state = state.copyWith(isAnalyzing: true);
    await Future.delayed(const Duration(seconds: 2));
    final mockFoods = [
      FoodItem(id: '1', name: '米饭', calories: 150),
      FoodItem(id: '2', name: '番茄炒蛋', calories: 200),
      FoodItem(id: '3', name: '红烧肉', calories: 350),
      FoodItem(id: '4', name: '青菜', calories: 50),
    ];
    state = state.copyWith(foods: mockFoods, isAnalyzing: false, healthScore: 3);
  }

  void updateFoodName(String id, String name) {
    final foods = state.foods.map((f) => f.id == id ? FoodItem(id: f.id, name: name, calories: f.calories, selected: f.selected) : f).toList();
    state = state.copyWith(foods: foods);
  }

  void updateFoodCalories(String id, int calories) {
    final foods = state.foods.map((f) => f.id == id ? FoodItem(id: f.id, name: f.name, calories: calories, selected: f.selected) : f).toList();
    state = state.copyWith(foods: foods);
  }

  void toggleFood(String id) {
    final foods = state.foods.map((f) => f.id == id ? FoodItem(id: f.id, name: f.name, calories: f.calories, selected: !f.selected) : f).toList();
    state = state.copyWith(foods: foods);
  }

  void addFood() {
    final newId = '${DateTime.now().millisecondsSinceEpoch}';
    final foods = [...state.foods, FoodItem(id: newId, name: '新食物', calories: 100)];
    state = state.copyWith(foods: foods);
  }

  void removeFood(String id) {
    final foods = state.foods.where((f) => f.id != id).toList();
    state = state.copyWith(foods: foods);
  }

  void setMealType(String type) {
    state = state.copyWith(mealType: type);
  }

  void reset() {
    state = DietState();
  }
}

class DietCapturePage extends ConsumerWidget {
  const DietCapturePage({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final state = ref.watch(dietProvider);

    return Scaffold(
      appBar: AppBar(
        title: const Text('拍饮食'),
        centerTitle: true,
      ),
      body: state.imagePath == null ? _buildCaptureView(context, ref) : _buildResultView(context, ref),
    );
  }

  Widget _buildCaptureView(BuildContext context, WidgetRef ref) {
    return Center(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          Container(
            width: 180,
            height: 180,
            decoration: BoxDecoration(
              color: const Color(0xFFF2FAF9),
              borderRadius: BorderRadius.circular(90),
              border: Border.all(color: const Color(0xFF14B8A6), width: 2),
            ),
            child: const Icon(Icons.camera_alt, size: 48, color: Color(0xFF14B8A6)),
          ),
          const SizedBox(height: 24),
          const Text('拍摄或上传您的餐食照片', style: TextStyle(fontSize: 18, fontWeight: FontWeight.w500)),
          const SizedBox(height: 8),
          const Text('AI将识别食物并分析营养成分', style: TextStyle(fontSize: 14, color: Color(0xFF999999))),
          const SizedBox(height: 40),
          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              _captureBtn(context, ref, Icons.camera_alt, '拍照', ImageSource.camera),
              const SizedBox(width: 24),
              _captureBtn(context, ref, Icons.photo_library, '相册', ImageSource.gallery),
            ],
          ),
        ],
      ),
    );
  }

  Widget _captureBtn(BuildContext context, WidgetRef ref, IconData icon, String label, ImageSource source) {
    return Column(
      children: [
        Container(
          width: 80,
          height: 80,
          decoration: BoxDecoration(
            color: const Color(0xFFFEFEFF),
            borderRadius: BorderRadius.circular(20),
            boxShadow: [BoxShadow(color: const Color(0xFF14B8A6).withAlpha(20), blurRadius: 8, offset: const Offset(0, 2))],
          ),
          child: IconButton(
            icon: Icon(icon, size: 32, color: const Color(0xFF14B8A6)),
            onPressed: () => _pickImage(context, ref, source),
          ),
        ),
        const SizedBox(height: 8),
        Text(label, style: const TextStyle(fontSize: 14, color: Color(0xFF666666))),
      ],
    );
  }

  Future<void> _pickImage(BuildContext context, WidgetRef ref, ImageSource source) async {
    final picker = ImagePicker();
    final picked = await picker.pickImage(source: source, imageQuality: 85);
    if (picked != null) {
      ref.read(dietProvider.notifier).setImage(picked.path);
      ref.read(dietProvider.notifier).analyzeImage();
    }
  }

  Widget _buildResultView(BuildContext context, WidgetRef ref) {
    final state = ref.watch(dietProvider);
    final totalCalories = state.foods.where((f) => f.selected).fold(0, (sum, f) => sum + f.calories);

    return SingleChildScrollView(
      padding: const EdgeInsets.all(16),
      child: Column(children: [
        _buildImagePreview(state.imagePath!),
        const SizedBox(height: 20),
        _buildMealSelector(context, ref),
        const SizedBox(height: 20),
        if (state.isAnalyzing) _buildAnalyzingIndicator() else _buildFoodList(context, ref),
        if (!state.isAnalyzing && state.foods.isNotEmpty) ...[
          const SizedBox(height: 20),
          _buildNutritionSummary(totalCalories),
          const SizedBox(height: 20),
          _buildHealthScore(state.healthScore ?? 0),
          const SizedBox(height: 30),
          _buildSubmitButton(context, ref),
        ],
      ]),
    );
  }

  Widget _buildImagePreview(String path) {
    return Container(
      height: 200,
      decoration: BoxDecoration(
        color: const Color(0xFFF5F5F5),
        borderRadius: BorderRadius.circular(20),
        image: DecorationImage(image: FileImage(File(path)), fit: BoxFit.cover),
      ),
    );
  }

  Widget _buildMealSelector(BuildContext context, WidgetRef ref) {
    final state = ref.watch(dietProvider);
    final meals = [
      {'type': 'breakfast', 'label': '早餐', 'icon': '🌅'},
      {'type': 'lunch', 'label': '午餐', 'icon': '☀️'},
      {'type': 'dinner', 'label': '晚餐', 'icon': '🌙'},
      {'type': 'snack', 'label': '加餐', 'icon': '🍪'},
    ];

    return Column(children: [
      const Text('选择餐次', style: TextStyle(fontSize: 14, color: Color(0xFF666666))),
      const SizedBox(height: 12),
      Row(children: meals.map((meal) {
        final isSelected = state.mealType == meal['type'];
        return Expanded(
          child: Padding(
            padding: const EdgeInsets.symmetric(horizontal: 4),
            child: ElevatedButton(
              onPressed: () => ref.read(dietProvider.notifier).setMealType(meal['type']!),
              child: Column(children: [
                Text(meal['icon']!, style: const TextStyle(fontSize: 20)),
                const SizedBox(height: 4),
                Text(meal['label']!, style: TextStyle(fontSize: 12, color: isSelected ? Colors.white : const Color(0xFF14B8A6))),
              ]),
              style: ElevatedButton.styleFrom(
                backgroundColor: isSelected ? const Color(0xFF14B8A6) : const Color(0xFFF2FAF9),
                foregroundColor: isSelected ? Colors.white : const Color(0xFF14B8A6),
                elevation: 0,
                shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
                padding: const EdgeInsets.symmetric(vertical: 12),
              ),
            ),
          ),
        );
      }).toList()),
    ]);
  }

  Widget _buildAnalyzingIndicator() {
    return Center(
      child: Column(children: [
        Container(
          width: 60,
          height: 60,
          padding: const EdgeInsets.all(12),
          decoration: BoxDecoration(
            color: const Color(0xFFE6FAF6),
            borderRadius: BorderRadius.circular(30),
          ),
          child: const CircularProgressIndicator(strokeWidth: 3, color: Color(0xFF14B8A6)),
        ),
        const SizedBox(height: 16),
        const Text('AI 正在识别食物...', style: TextStyle(fontSize: 16, color: Color(0xFF666666))),
      ]),
    );
  }

  Widget _buildFoodList(BuildContext context, WidgetRef ref) {
    final state = ref.watch(dietProvider);

    return Container(
      decoration: BoxDecoration(
        color: const Color(0xFFFEFEFF),
        borderRadius: BorderRadius.circular(20),
        border: Border.all(color: const Color(0xFFD4EDE8), width: 1.5),
      ),
      child: Column(children: [
        Padding(
          padding: const EdgeInsets.all(16),
          child: Row(children: [
            const Text('🍽️', style: TextStyle(fontSize: 20)),
            const SizedBox(width: 8),
            const Text('识别结果', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600)),
            const Spacer(),
            IconButton(
              icon: const Icon(Icons.add, size: 20, color: Color(0xFF14B8A6)),
              onPressed: () => ref.read(dietProvider.notifier).addFood(),
            ),
          ]),
        ),
        ...state.foods.map((food) => _buildFoodItem(context, ref, food)),
      ]),
    );
  }

  Widget _buildFoodItem(BuildContext context, WidgetRef ref, FoodItem food) {
    return Container(
      margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
      padding: const EdgeInsets.all(12),
      decoration: BoxDecoration(
        color: food.selected ? const Color(0xFFF2FAF9) : const Color(0xFFF5F5F5),
        borderRadius: BorderRadius.circular(16),
      ),
      child: Row(children: [
        Checkbox(
          value: food.selected,
          onChanged: (v) => ref.read(dietProvider.notifier).toggleFood(food.id),
          activeColor: const Color(0xFF14B8A6),
        ),
        const SizedBox(width: 8),
        Expanded(
          child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
            TextField(
              decoration: const InputDecoration(border: InputBorder.none, hintText: '食物名称'),
              controller: TextEditingController(text: food.name),
              onChanged: (v) => ref.read(dietProvider.notifier).updateFoodName(food.id, v),
              style: const TextStyle(fontSize: 16),
            ),
            Row(children: [
              const Text('热量：', style: TextStyle(fontSize: 12, color: Color(0xFF999999))),
              SizedBox(
                width: 60,
                child: TextField(
                  decoration: const InputDecoration(border: InputBorder.none, hintText: '0'),
                  controller: TextEditingController(text: food.calories.toString()),
                  keyboardType: TextInputType.number,
                  onChanged: (v) => ref.read(dietProvider.notifier).updateFoodCalories(food.id, int.tryParse(v) ?? 0),
                  style: TextStyle(fontSize: 12, color: const Color(0xFF14B8A6)),
                ),
              ),
              const Text('kcal', style: TextStyle(fontSize: 12, color: Color(0xFF999999))),
            ]),
          ]),
        ),
        IconButton(
          icon: const Icon(Icons.delete, size: 18, color: Color(0xFFCCCCCC)),
          onPressed: () => ref.read(dietProvider.notifier).removeFood(food.id),
        ),
      ]),
    );
  }

  Widget _buildNutritionSummary(int totalCalories) {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: const Color(0xFFF2FAF9),
        borderRadius: BorderRadius.circular(16),
      ),
      child: Row(children: [
        const Icon(Icons.fireplace, size: 28, color: Color(0xFFFF6B35)),
        const SizedBox(width: 12),
        Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
          const Text('总热量', style: TextStyle(fontSize: 14, color: Color(0xFF666666))),
          Text('$totalCalories kcal', style: const TextStyle(fontSize: 24, fontWeight: FontWeight.w600)),
        ]),
        const Spacer(),
        Column(crossAxisAlignment: CrossAxisAlignment.end, children: [
          const Text('推荐摄入量', style: TextStyle(fontSize: 12, color: Color(0xFF999999))),
          const Text('午餐约 500-700 kcal', style: TextStyle(fontSize: 12, color: Color(0xFF999999))),
        ]),
      ]),
    );
  }

  Widget _buildHealthScore(int score) {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: const Color(0xFFFEFEFF),
        borderRadius: BorderRadius.circular(20),
        border: Border.all(color: const Color(0xFFD4EDE8), width: 1.5),
      ),
      child: Column(children: [
        const Text('🥗 健康评分', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600)),
        const SizedBox(height: 12),
        Row(
          mainAxisAlignment: MainAxisAlignment.center,
          children: List.generate(5, (i) => Icon(
            Icons.star,
            size: 36,
            color: i < score ? const Color(0xFFFFB800) : Colors.grey[200],
          )),
        ),
        const SizedBox(height: 12),
        Text(_getScoreComment(score), style: TextStyle(fontSize: 14, color: _getScoreColor(score))),
      ]),
    );
  }

  String _getScoreComment(int score) {
    switch (score) {
      case 1: return '饮食不太健康，建议多吃蔬菜';
      case 2: return '需要改善，减少油腻食物';
      case 3: return '还不错，继续保持均衡饮食';
      case 4: return '很健康！营养搭配合理';
      case 5: return '非常健康！饮食管理很棒';
      default: return '请完善食物信息';
    }
  }

  Color _getScoreColor(int score) {
    switch (score) {
      case 1: return const Color(0xFFE53935);
      case 2: return const Color(0xFFF9A825);
      case 3: return const Color(0xFF14B8A6);
      case 4: return const Color(0xFF43A047);
      case 5: return const Color(0xFF00C853);
      default: return Colors.grey[400]!;
    }
  }

  Widget _buildSubmitButton(BuildContext context, WidgetRef ref) {
    return SizedBox(
      width: double.infinity,
      child: ElevatedButton(
        onPressed: () {
          ScaffoldMessenger.of(context).showSnackBar(const SnackBar(
            content: Text('饮食记录已保存 ✅'),
            backgroundColor: Color(0xFF14B8A6),
          ));
          popRoute(ref);
        },
        child: const Text('保存记录'),
        style: ElevatedButton.styleFrom(
          backgroundColor: const Color(0xFF14B8A6),
          foregroundColor: Colors.white,
          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(24)),
          padding: const EdgeInsets.symmetric(vertical: 16),
          textStyle: const TextStyle(fontSize: 16),
        ),
      ),
    );
  }
}