import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:image_picker/image_picker.dart';
import 'package:file_picker/file_picker.dart';
import 'package:shadcn_ui/shadcn_ui.dart';
import '../../core/app_colors.dart';
import '../../core/app_theme.dart';
import '../../core/navigation_provider.dart';
import '../../providers/auth_provider.dart';
import '../../providers/chat_provider.dart';
import '../../providers/data_providers.dart';
import '../../widgets/health_drawer.dart';
import '../diet/diet_capture_page.dart';
import 'widgets/chat_messages_view.dart';

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

class _HomePageState extends ConsumerState<HomePage> {
  final _textCtrl = TextEditingController();
  final _scrollCtrl = ScrollController();
  String? _pickedImagePath;
  final Set<ActiveAgent> _welcomedAgents = {};
  final _focusNode = FocusNode();
  int _lastMsgCount = 0;

  @override void initState() { super.initState(); }
  @override void dispose() { _textCtrl.dispose(); _scrollCtrl.dispose(); _focusNode.dispose(); super.dispose(); }

  void _sendMessage() {
    final text = _textCtrl.text.trim();
    final imagePath = _pickedImagePath;
    if (text.isEmpty && imagePath == null) return;
    _textCtrl.clear();
    _focusNode.unfocus();
    setState(() => _pickedImagePath = null);
    if (imagePath != null) {
      ref.read(chatProvider.notifier).sendImage(imagePath, text);
    } else {
      ref.read(chatProvider.notifier).sendMessage(text);
    }
  }

  @override Widget build(BuildContext context) {
    final chatState = ref.watch(chatProvider);
    final auth = ref.watch(authProvider);
    final user = auth.user;

    ref.listen(cameraActionProvider, (prev, next) {
      if (next == 'camera') { _pickImage(ImageSource.camera); ref.read(cameraActionProvider.notifier).clear(); }
      else if (next == 'gallery') { _pickImage(ImageSource.gallery); ref.read(cameraActionProvider.notifier).clear(); }
    });
    ref.listen(dietActionProvider, (prev, next) {
      if (next == 'pickFoodCamera') { _pickFoodImage(ImageSource.camera); ref.read(dietActionProvider.notifier).clear(); }
      else if (next == 'pickFoodGallery') { _pickFoodImage(ImageSource.gallery); ref.read(dietActionProvider.notifier).clear(); }
    });

    final currentCount = chatState.messages.length;
    if (currentCount > _lastMsgCount) {
      WidgetsBinding.instance.addPostFrameCallback((_) {
        if (_scrollCtrl.hasClients) {
          _scrollCtrl.jumpTo(_scrollCtrl.position.maxScrollExtent);
        }
      });
    }
    _lastMsgCount = currentCount;

    return Scaffold(
      drawer: const HealthDrawer(),
      body: Container(
        decoration: const BoxDecoration(gradient: AppColors.bgGradient),
        child: SafeArea(
        child: Column(children: [
          _buildHeader(user),
          Expanded(child: ChatMessagesView(scrollCtrl: _scrollCtrl, messages: chatState.messages)),
          _buildBottomBar(context),
        ]),
      ),
      ),
    );
  }

  // ═══════ 顶部栏 — 透明背景，与页面渐变无缝衔接 ═══════
  Widget _buildHeader(dynamic user) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
      child: Row(children: [
        Builder(builder: (ctx) => GestureDetector(
          onTap: () => Scaffold.of(ctx).openDrawer(),
          child: const Padding(
            padding: EdgeInsets.all(8),
            child: Icon(LucideIcons.menu, size: 22, color: AppColors.primary),
          ),
        )),
        const SizedBox(width: 12),
        Expanded(child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
          const Text('AI 健康管家', style: TextStyle(fontSize: 13, color: AppColors.textHint)),
          Text('${_getGreeting()}，${(user?.name != null && user!.name!.isNotEmpty) ? user.name : '用户'}！',
            style: const TextStyle(fontSize: 18, fontWeight: FontWeight.w600, color: AppColors.textPrimary)),
        ])),
        GestureDetector(
          onTap: () => pushRoute(ref, 'notificationPrefs'),
          child: const Icon(LucideIcons.bell, size: 22, color: AppColors.textSecondary),
        ),
      ]),
    );
  }

  String _getGreeting() {
    final hour = DateTime.now().hour;
    if (hour < 9) return '早上好';
    if (hour < 12) return '上午好';
    if (hour < 18) return '下午好';
    return '晚上好';
  }

  // ═══════ 智能体胶囊 ═══════
  static final _agentDefs = [
    (ActiveAgent.consultation, '问诊', LucideIcons.messageCircle),
    (ActiveAgent.health, '记数据', LucideIcons.heart),
    (ActiveAgent.diet, '拍饮食', LucideIcons.utensils),
    (ActiveAgent.medication, '药管家', LucideIcons.pill),
    (ActiveAgent.report, '报告分析', LucideIcons.fileText),
    (ActiveAgent.exercise, '运动', LucideIcons.trendingUp),
  ];

  Widget _buildAgentBar() {
    return SizedBox(
      height: 32,
      child: ListView.separated(
        scrollDirection: Axis.horizontal,
        padding: const EdgeInsets.symmetric(horizontal: 16),
        itemCount: _agentDefs.length,
        separatorBuilder: (_, i) => const SizedBox(width: 8),
        itemBuilder: (_, i) {
          final (agent, label, icon) = _agentDefs[i];
          return GestureDetector(
            onTap: () => ref.read(chatProvider.notifier).triggerAgent(agent, label),
            child: Container(
              padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 8),
              decoration: BoxDecoration(
                color: Colors.white,
                borderRadius: BorderRadius.circular(18),
                boxShadow: AppColors.cardShadowLight,
              ),
              child: Row(mainAxisSize: MainAxisSize.min, children: [
                Icon(icon, size: 17, color: AppColors.textPrimary),
                const SizedBox(width: 5),
                Text(label, style: const TextStyle(fontSize: 15, fontWeight: FontWeight.w600, color: AppColors.textPrimary)),
              ]),
            ),
          );
        },
      ),
    );
  }

  // ═══════ 底部输入区 ═══════
  Widget _buildBottomBar(BuildContext context) {
    return Column(mainAxisSize: MainAxisSize.min, children: [
      Container(padding: const EdgeInsets.only(top: 4, bottom: 4), child: _buildAgentBar()),
      if (_pickedImagePath != null) _buildImagePreview(),
      _buildInputBar(),
    ]);
  }

  Widget _buildImagePreview() {
    return Container(
      padding: const EdgeInsets.fromLTRB(12, 8, 12, 4),
      color: AppColors.cardInner,
      child: Row(children: [
        ClipRRect(
          borderRadius: BorderRadius.circular(8),
          child: Image.file(File(_pickedImagePath!), width: 48, height: 48, fit: BoxFit.cover),
        ),
        const SizedBox(width: 10),
        const Text('点击发送图片', style: TextStyle(fontSize: 14, color: AppColors.textSecondary)),
        const Spacer(),
        GestureDetector(
          onTap: () => setState(() => _pickedImagePath = null),
          child: const Icon(Icons.close, size: 20, color: AppColors.textHint),
        ),
      ]),
    );
  }

  Widget _buildInputBar() {
    return Container(
      padding: const EdgeInsets.fromLTRB(12, 8, 12, 10),
      child: Row(crossAxisAlignment: CrossAxisAlignment.end, children: [
        GestureDetector(
          onTap: () => _showAttachmentPicker(context),
          child: const Padding(
            padding: EdgeInsets.only(bottom: 10),
            child: Icon(LucideIcons.plus, size: 24, color: AppColors.textSecondary),
          ),
        ),
        const SizedBox(width: 8),
        Expanded(
          child: Container(
            constraints: const BoxConstraints(maxHeight: 120),
            decoration: BoxDecoration(
              color: Colors.white,
              borderRadius: BorderRadius.circular(20),
            ),
            child: TextField(
              controller: _textCtrl,
              focusNode: _focusNode,
              style: const TextStyle(fontSize: 15, color: AppColors.textPrimary),
              maxLines: null,
              textInputAction: TextInputAction.newline,
              decoration: const InputDecoration(
                hintText: '输入你想说的...',
                hintStyle: TextStyle(fontSize: 15, color: AppColors.textHint),
                filled: true, fillColor: Colors.white,
                contentPadding: EdgeInsets.symmetric(horizontal: 16, vertical: 10),
                border: OutlineInputBorder(borderRadius: BorderRadius.all(Radius.circular(20)), borderSide: BorderSide.none),
                enabledBorder: OutlineInputBorder(borderRadius: BorderRadius.all(Radius.circular(20)), borderSide: BorderSide.none),
                focusedBorder: OutlineInputBorder(borderRadius: BorderRadius.all(Radius.circular(20)), borderSide: BorderSide.none),
              ),
              onSubmitted: (_) => _sendMessage(),
            ),
          ),
        ),
        const SizedBox(width: 8),
        GestureDetector(
          onTap: _sendMessage,
          child: Container(
            width: 40, height: 40,
            margin: EdgeInsets.only(bottom: _pickedImagePath != null ? 0 : 4),
            decoration: BoxDecoration(
              gradient: const LinearGradient(
                colors: [AppColors.blueMeasure, AppColors.primary],
                begin: Alignment.topLeft,
                end: Alignment.bottomRight,
              ),
              borderRadius: BorderRadius.circular(20),
            ),
            child: const Icon(LucideIcons.send, size: 20, color: Colors.white),
          ),
        ),
      ]),
    );
  }

  void _showAttachmentPicker(BuildContext context) {
    showModalBottomSheet(
      context: context,
      backgroundColor: Colors.white,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(16)),
      ),
      builder: (ctx) => SafeArea(
        child: Padding(
          padding: const EdgeInsets.symmetric(vertical: 8),
          child: Wrap(children: [
            ListTile(
              leading: const Icon(Icons.camera_alt_outlined, color: AppColors.primary),
              title: const Text('拍照'),
              onTap: () { Navigator.pop(ctx); _pickImage(ImageSource.camera); },
            ),
            ListTile(
              leading: const Icon(Icons.photo_library_outlined, color: AppColors.primary),
              title: const Text('从相册选'),
              onTap: () { Navigator.pop(ctx); _pickImage(ImageSource.gallery); },
            ),
            ListTile(
              leading: const Icon(Icons.file_open_outlined, color: AppColors.primary),
              title: const Text('传文件'),
              onTap: () async {
                Navigator.pop(ctx);
                final result = await FilePicker.platform.pickFiles();
                if (result != null && result.files.isNotEmpty) {
                  _textCtrl.text = '[文件已选择] ${result.files.first.name}';
                  if (mounted) setState(() {});
                }
              },
            ),
          ]),
        ),
      ),
    );
  }

  Future<void> _pickImage(ImageSource source) async {
    final picked = await ImagePicker().pickImage(source: source, imageQuality: 85);
    if (picked != null) {
      final token = await ref.read(apiClientProvider).accessToken;
      if (token == null) return;
      setState(() => _pickedImagePath = picked.path);
    }
  }

  Future<void> _pickFoodImage(ImageSource source) async {
    final picked = await ImagePicker().pickImage(source: source, imageQuality: 80, maxWidth: 1024, maxHeight: 1024);
    if (picked != null && mounted) {
      ref.read(dietProvider.notifier).reset();
      ref.read(dietProvider.notifier).setImage(picked.path);
      ref.read(dietProvider.notifier).analyzeImage();
      pushRoute(ref, 'dietCapture');
    }
  }
}