import 'dart:convert';
import 'dart:io';
import 'package:dio/dio.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:image_picker/image_picker.dart';
import '../../core/navigation_provider.dart';
import '../../core/app_colors.dart';
import '../../core/app_theme.dart';
import '../../providers/auth_provider.dart';
import '../../utils/sse_handler.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;
  final String? errorMessage;
  final String? commentary;

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

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

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

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

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

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

  Future<void> analyzeImage() async {
    state = state.copyWith(isAnalyzing: true, errorMessage: null);
    try {
      final api = ref.read(apiClientProvider);
      final path = state.imagePath!;
      debugPrint('[DietDebug] analyzeImage using: $path');
      final imageFile = File(path);

      final formData = FormData.fromMap({
        'images': await MultipartFile.fromFile(
          imageFile.path,
          filename: imageFile.path.split('/').last,
        ),
      });
      final res = await api.dio.post('/api/ai/analyze-food-image', data: formData);
      final data = res.data;
      if (data['code'] != 0) {
        state = state.copyWith(isAnalyzing: false, errorMessage: data['message'] ?? '识别失败');
        return;
      }

      final raw = data['data'] as String? ?? '[]';
      final foods = _parseFoodItems(raw);
      state = state.copyWith(foods: foods, isAnalyzing: false, healthScore: foods.isNotEmpty ? 3 : null);
      if (foods.isNotEmpty) _fetchCommentary(foods);
    } catch (e) {
      state = state.copyWith(isAnalyzing: false, errorMessage: '识别失败，请重试');
    }
  }

  Future<void> _fetchCommentary(List<FoodItem> foods) async {
    try {
      final api = ref.read(apiClientProvider);
      final token = await api.accessToken;
      if (token == null) return;
      final names = foods.map((f) => '${f.name}(${f.portion},${f.calories}kcal)').join('、');
      final stream = SseHandler.connect(
        agentType: 'default',
        message: '我刚才吃了这些：$names。请结合我的健康档案，给我简短的饮食评价和建议（50字以内）。',
        token: token,
      );
      String text = '';
      await for (final event in stream) {
        if (event['action'] == 'answer') text += (event['data'] as String?) ?? '';
        if (event['action'] == 'status') {
          if (text.isNotEmpty) state = state.copyWith(commentary: text.trim());
        }
      }
    } catch (e) {
      debugPrint('[Diet] 获取饮食点评失败: $e');
    }
  }

  List<FoodItem> _parseFoodItems(String raw) {
    var json = raw.trim();
    if (json.startsWith('```')) {
      final start = json.indexOf('\n');
      if (start != -1) json = json.substring(start + 1);
      final end = json.lastIndexOf('```');
      if (end != -1) json = json.substring(0, end);
      json = json.trim();
    }
    try {
      final list = jsonDecode(json) as List;
      return list.asMap().entries.map((e) {
        final item = e.value as Map<String, dynamic>;
        return FoodItem(
          id: 'food_${DateTime.now().millisecondsSinceEpoch}_${e.key}',
          name: item['name']?.toString() ?? '未知食物',
          portion: item['portion']?.toString() ?? '',
          calories: (item['calories'] as num?)?.toInt() ?? 0,
          selected: true,
        );
      }).toList();
    } catch (_) {
      return [
        FoodItem(
          id: 'food_${DateTime.now().millisecondsSinceEpoch}',
          name: '识别结果（手动编辑）',
          portion: raw.length > 50 ? raw.substring(0, 50) : raw,
          calories: 0,
          selected: true,
        ),
      ];
    }
  }

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

  void updateFoodPortion(String id, String portion) {
    final foods = state.foods.map((f) => f.id == id ? FoodItem(id: f.id, name: f.name, portion: portion, 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, portion: f.portion, 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, portion: f.portion, 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', portion: '', 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();
  }

  Future<void> saveRecord() async {
    final selectedFoods = state.foods.where((f) => f.selected).toList();
    if (selectedFoods.isEmpty) return;

    final api = ref.read(apiClientProvider);
    final mealMap = {'breakfast': 'Breakfast', 'lunch': 'Lunch', 'dinner': 'Dinner', 'snack': 'Snack'};
    final totalCal = selectedFoods.fold<int>(0, (s, f) => s + f.calories);

    await api.post('/api/diet-records', data: {
      'mealType': mealMap[state.mealType] ?? 'Lunch',
      'totalCalories': totalCal,
      'healthScore': state.healthScore ?? 3,
      'recordedAt': DateTime.now().toIso8601String().substring(0, 10),
      'foodItems': selectedFoods.asMap().entries.map((e) => {
        'name': e.value.name,
        'portion': e.value.portion,
        'calories': e.value.calories,
        'sortOrder': e.key,
      }).toList(),
    });
  }
}

class DietCapturePage extends ConsumerStatefulWidget {
  const DietCapturePage({super.key});
  @override ConsumerState<DietCapturePage> createState() => _DietCapturePageState();
}

class _DietCapturePageState extends ConsumerState<DietCapturePage> {
  @override void initState() {
    super.initState();
    // 不 reset — 图片由 home_page 传入，这里只做展示
  }

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

    return Scaffold(
      appBar: AppBar(
        title: const Text('拍饮食'),
        centerTitle: true,
      ),
      body: state.imagePath == null
          ? const Center(child: Text('请从首页拍摄或选择食物照片', style: TextStyle(color: AppColors.textSecondary)))
          : _buildResultView(context, ref),
    );
  }

  // ─────────── 设计常量（与项目整体色调一致）───────────
  static const _kPrimary = AppTheme.primary;      // #6C5CE7
  static const _kPrimaryLight = AppTheme.primaryLight; // #EDEAFF
  static const _kPageBg = AppTheme.bg;            // #F8F9FC
  static const _kSurface = AppTheme.surface;      // white
  static const _kText = AppTheme.text;            // #2D2B32
  static const _kSubText = AppTheme.textSub;      // #8A8892
  static const _kBorder = AppTheme.border;        // #EAEAF0
  static const _kWarning = AppTheme.warning;      // #F5A623

  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 Container(
      color: AppColors.background,
      child: SingleChildScrollView(
        padding: const EdgeInsets.all(16),
        child: Column(children: [
          _buildImagePreview(state.imagePath!),
          const SizedBox(height: 16),
          _buildMealSelector(ref),
          const SizedBox(height: 16),
          if (state.isAnalyzing)
            _buildAnalyzingIndicator(state)
          else ...[
            if (state.foods.isNotEmpty) ...[
              _buildFoodList(ref),
              const SizedBox(height: 16),
              _buildNutritionSummary(totalCalories),
              if (state.commentary != null && state.commentary!.isNotEmpty) ...[
                const SizedBox(height: 16),
                _buildAiCommentary(state.commentary!),
              ],
            ],
            const SizedBox(height: 20),
            _buildSubmitButton(),
            const SizedBox(height: 16),
          ],
        ]),
      ),
    );
  }

  // ─────────── 图片预览 ───────────
  Widget _buildImagePreview(String path) {
    return Center(
      child: ClipRRect(
        borderRadius: BorderRadius.circular(20),
        child: Container(
          height: 200,
          width: MediaQuery.of(context).size.width * 0.75,
          decoration: BoxDecoration(
            image: DecorationImage(image: FileImage(File(path)), fit: BoxFit.cover),
            boxShadow: [BoxShadow(color: Colors.black26, blurRadius: 14, offset: const Offset(0, 4))],
          ),
          foregroundDecoration: const BoxDecoration(
            gradient: LinearGradient(
              colors: [Colors.transparent, Colors.black38],
              begin: Alignment.topCenter,
              end: Alignment.bottomCenter,
            ),
          ),
        ),
      ),
    );
  }

  // ─────────── 餐次选择器 ───────────
  Widget _buildMealSelector(WidgetRef ref) {
    final state = ref.watch(dietProvider);
    final meals = [
      _MealData(Icons.wb_sunny_outlined, '早餐', 'breakfast'),
      _MealData(Icons.wb_cloudy_outlined, '午餐', 'lunch'),
      _MealData(Icons.nightlight_round, '晚餐', 'dinner'),
      _MealData(Icons.local_cafe_outlined, '加餐', 'snack'),
    ];

    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16),
      child: Row(
        children: meals.map((m) {
          final isSelected = state.mealType == m.type;
          return Expanded(
            child: Padding(
              padding: const EdgeInsets.symmetric(horizontal: 4),
              child: GestureDetector(
                onTap: () => ref.read(dietProvider.notifier).setMealType(m.type),
                child: AnimatedContainer(
                  duration: const Duration(milliseconds: 200),
                  padding: const EdgeInsets.symmetric(vertical: 10),
                  decoration: BoxDecoration(
                    color: isSelected ? _kPrimary : _kSurface,
                    borderRadius: BorderRadius.circular(14),
                    border: Border.all(color: isSelected ? _kPrimary : _kBorder),
                    boxShadow: isSelected
                        ? [BoxShadow(color: _kPrimary.withAlpha(30), blurRadius: 6, offset: const Offset(0, 2))]
                        : null,
                  ),
                  child: Column(mainAxisSize: MainAxisSize.min, children: [
                    Icon(m.icon, size: 23, color: isSelected ? AppColors.textOnGradient : _kSubText),
                    const SizedBox(height: 4),
                    Text(m.label, style: TextStyle(fontSize: 15, fontWeight: FontWeight.w600, color: isSelected ? AppColors.textOnGradient : _kSubText)),
                  ]),
                ),
              ),
            ),
          );
        }).toList(),
      ),
    );
  }

  // ─────────── 分析中指示器 ───────────
  Widget _buildAnalyzingIndicator(DietState state) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 40),
      child: Center(
        child: Column(children: [
          SizedBox(
            width: 56, height: 56,
            child: Stack(
              alignment: Alignment.center,
              children: [
                const CircularProgressIndicator(strokeWidth: 3, color: _kPrimary),
                const Icon(Icons.restaurant, size: 25, color: _kPrimary),
              ],
            ),
          ),
          const SizedBox(height: 20),
          const Text('正在识别食物...', style: TextStyle(fontSize: 18, color: _kSubText)),
          if (state.errorMessage != null) ...[
            const SizedBox(height: 8),
            Text(state.errorMessage!, style: const TextStyle(fontSize: 16, color: AppTheme.error), textAlign: TextAlign.center),
          ],
        ]),
      ),
    );
  }

  // ─────────── 食物列表 ───────────
  Widget _buildFoodList(WidgetRef ref) {
    final state = ref.watch(dietProvider);
    final totalCal = state.foods.where((f) => f.selected).fold(0, (s, f) => s + f.calories);

    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16),
      child: Container(
        decoration: BoxDecoration(
          color: _kSurface,
          borderRadius: BorderRadius.circular(16),
          boxShadow: [AppTheme.shadowLight],
        ),
        child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
          Padding(
            padding: const EdgeInsets.fromLTRB(16, 14, 8, 0),
            child: Row(children: [
              Container(
                padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                decoration: BoxDecoration(color: _kPrimaryLight, borderRadius: BorderRadius.circular(8)),
                child: const Text('识别结果', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: _kPrimary)),
              ),
              const Spacer(),
              Container(
                padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
                decoration: BoxDecoration(color: AppColors.warningLight, borderRadius: BorderRadius.circular(8)),
                child: Text('共 $totalCal kcal', style: const TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: _kWarning)),
              ),
              IconButton(
                icon: const Icon(Icons.add_circle_outline, size: 25, color: _kPrimary),
                padding: EdgeInsets.zero,
                constraints: const BoxConstraints(),
                onPressed: () => ref.read(dietProvider.notifier).addFood(),
              ),
            ]),
          ),
          const SizedBox(height: 8),
          ...state.foods.map((food) => _buildFoodItem(ref, food)),
          const SizedBox(height: 12),
        ]),
      ),
    );
  }

  Widget _buildFoodItem(WidgetRef ref, FoodItem food) {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 4),
      child: AnimatedContainer(
        duration: const Duration(milliseconds: 200),
        decoration: BoxDecoration(
          color: food.selected ? AppColors.iconBg : AppColors.background,
          borderRadius: BorderRadius.circular(AppTheme.rMd),
          border: Border.all(color: food.selected ? _kPrimary.withAlpha(30) : AppColors.border),
        ),
        child: Padding(
          padding: const EdgeInsets.fromLTRB(12, 10, 6, 10),
          child: Row(children: [
            GestureDetector(
              onTap: () => ref.read(dietProvider.notifier).toggleFood(food.id),
              child: Container(
                width: 22, height: 22,
                decoration: BoxDecoration(
                  shape: BoxShape.circle,
                  color: food.selected ? _kPrimary : AppTheme.surface,
                  border: Border.all(color: food.selected ? _kPrimary : AppColors.border, width: 2),
                ),
                child: food.selected ? const Icon(Icons.check, size: 17, color: AppColors.textOnGradient) : null,
              ),
            ),
            const SizedBox(width: 12),
            Expanded(
              child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
                TextField(
                  controller: TextEditingController(text: food.name),
                  onChanged: (v) => ref.read(dietProvider.notifier).updateFoodName(food.id, v),
                  style: const TextStyle(fontSize: 18, fontWeight: FontWeight.w600, color: _kText),
                  decoration: const InputDecoration(
                    isDense: true,
                    contentPadding: EdgeInsets.zero,
                    border: InputBorder.none,
                  ),
                ),
                const SizedBox(height: 2),
                Row(children: [
                  Expanded(
                    flex: 3,
                    child: TextField(
                      controller: TextEditingController(text: food.portion),
                      onChanged: (v) => ref.read(dietProvider.notifier).updateFoodPortion(food.id, v),
                      style: const TextStyle(fontSize: 15, color: _kSubText),
                      decoration: const InputDecoration(
                        isDense: true,
                        contentPadding: EdgeInsets.zero,
                        border: InputBorder.none,
                        hintText: '份量',
                        hintStyle: TextStyle(fontSize: 15, color: AppTheme.textHint),
                      ),
                    ),
                  ),
                  const SizedBox(width: 8),
                  Expanded(
                    flex: 2,
                    child: TextField(
                      controller: TextEditingController(text: food.calories.toString()),
                      onChanged: (v) => ref.read(dietProvider.notifier).updateFoodCalories(food.id, int.tryParse(v) ?? 0),
                      keyboardType: TextInputType.number,
                      style: const TextStyle(fontSize: 15, fontWeight: FontWeight.w600, color: _kWarning),
                      textAlign: TextAlign.right,
                      decoration: const InputDecoration(
                        isDense: true,
                        contentPadding: EdgeInsets.zero,
                        border: InputBorder.none,
                        hintText: '0',
                        hintStyle: TextStyle(fontSize: 15),
                      ),
                    ),
                  ),
                  const SizedBox(width: 2),
                  const Text('kcal', style: TextStyle(fontSize: 14, color: _kSubText)),
                ]),
              ]),
            ),
            IconButton(
              icon: const Icon(Icons.close, size: 19, color: AppColors.textHint),
              padding: EdgeInsets.zero,
              constraints: const BoxConstraints(),
              onPressed: () => ref.read(dietProvider.notifier).removeFood(food.id),
            ),
          ]),
        ),
      ),
    );
  }

  // ─────────── 营养摘要 ───────────
  Widget _buildNutritionSummary(int totalCalories) {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16),
      child: Container(
        padding: const EdgeInsets.all(20),
        decoration: BoxDecoration(
          gradient: AppColors.primaryGradient,
          borderRadius: BorderRadius.circular(16),
          boxShadow: [BoxShadow(color: _kPrimary.withAlpha(40), blurRadius: 10, offset: const Offset(0, 4))],
        ),
        child: Row(children: [
          SizedBox(
            width: 56, height: 56,
            child: Stack(
              alignment: Alignment.center,
              children: [
                SizedBox(
                  width: 56, height: 56,
                  child: CircularProgressIndicator(
                    value: (totalCalories / 700).clamp(0.0, 1.0),
                    strokeWidth: 4,
                    backgroundColor: Colors.white24,
                    color: AppColors.textOnGradient,
                  ),
                ),
                Column(mainAxisSize: MainAxisSize.min, children: [
                  Text('$totalCalories', style: const TextStyle(fontSize: 17, fontWeight: FontWeight.w800, color: AppColors.textOnGradient)),
                  Text('kcal', style: const TextStyle(fontSize: 13, color: AppColors.textOnGradient)),
                ]),
              ],
            ),
          ),
          const SizedBox(width: 16),
          Expanded(
            child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
              const Text('本餐热量', style: TextStyle(fontSize: 17, color: AppColors.textOnGradient)),
              const SizedBox(height: 4),
              Row(children: [
                Expanded(child: _macroBar('碳水', 0.55, AppColors.warningLight)),
                const SizedBox(width: 8),
                Expanded(child: _macroBar('蛋白', 0.25, AppColors.iconBg)),
                const SizedBox(width: 8),
                Expanded(child: _macroBar('脂肪', 0.20, AppColors.errorLight)),
              ]),
            ]),
          ),
        ]),
      ),
    );
  }

  Widget _macroBar(String label, double ratio, Color color) {
    return Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
      Row(children: [
        Container(width: 6, height: 6, decoration: BoxDecoration(color: color, shape: BoxShape.circle)),
        const SizedBox(width: 4),
        Text(label, style: const TextStyle(fontSize: 13, color: AppColors.textOnGradient)),
      ]),
      const SizedBox(height: 3),
      ClipRRect(
        borderRadius: BorderRadius.circular(2),
        child: LinearProgressIndicator(value: ratio, minHeight: 4, backgroundColor: Colors.white24, color: color),
      ),
    ]);
  }

  // ─────────── AI 点评 ───────────
  Widget _buildAiCommentary(String text) {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16),
      child: Container(
        padding: const EdgeInsets.all(16),
        decoration: BoxDecoration(
          gradient: AppColors.gLightPurple,
          borderRadius: BorderRadius.circular(16),
          boxShadow: [BoxShadow(color: AppTheme.primary.withAlpha(20), blurRadius: 12, offset: const Offset(0, 4))],
        ),
        child: Row(crossAxisAlignment: CrossAxisAlignment.start, children: [
          Container(
            width: 36, height: 36,
            decoration: BoxDecoration(
              gradient: AppColors.primaryGradient,
              borderRadius: const BorderRadius.all(Radius.circular(10)),
            ),
            child: const Icon(Icons.auto_awesome, size: 20, color: AppColors.textOnGradient),
          ),
          const SizedBox(width: 12),
          Expanded(child: Text(text, style: const TextStyle(fontSize: 16, color: _kText, height: 1.6))),
        ]),
      ),
    );
  }

  // ─────────── 保存按钮 ───────────
  Widget _buildSubmitButton() {
    return SizedBox(
      width: double.infinity,
      height: 52,
      child: Container(
        decoration: BoxDecoration(
          gradient: AppColors.gPurplePink,
          borderRadius: BorderRadius.circular(14),
          boxShadow: [BoxShadow(color: AppColors.primary.withAlpha(20), blurRadius: 12, offset: const Offset(0, 4))],
        ),
        padding: const EdgeInsets.all(1.5),
        child: Material(
          color: AppTheme.surface,
          borderRadius: BorderRadius.circular(12.5),
          child: InkWell(
            onTap: () async {
              try {
                await ref.read(dietProvider.notifier).saveRecord();
                if (mounted) popRoute(ref);
              } catch (e) { debugPrint('[Diet] 保存记录失败: $e'); }
            },
            borderRadius: BorderRadius.circular(12),
            child: const Row(mainAxisAlignment: MainAxisAlignment.center, children: [
              Icon(Icons.check_circle_outline, size: 22, color: AppColors.primary),
              SizedBox(width: 8),
              Text('保存记录', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: AppColors.primary)),
            ]),
          ),
        ),
      ),
    );
  }
}

class _MealData {
  final IconData icon;
  final String label;
  final String type;
  const _MealData(this.icon, this.label, this.type);
}