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_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();

  @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();
    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;
    final selectedAgent = ref.watch(selectedAgentProvider);
    final theme = ShadTheme.of(context);

    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(); }
    });

    return Scaffold(
      drawer: const HealthDrawer(),
      backgroundColor: theme.colorScheme.background,
      body: SafeArea(
        child: Column(children: [
          _buildHeader(user, theme),
          Expanded(child: ChatMessagesView(scrollCtrl: _scrollCtrl, messages: chatState.messages)),
          _buildBottomBar(context, selectedAgent, theme),
        ]),
      ),
    );
  }

  // ═══════ 顶部栏 ═══════
  Widget _buildHeader(dynamic user, ShadThemeData theme) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: AppTheme.sLg, vertical: 10),
      decoration: BoxDecoration(
        color: theme.colorScheme.card,
        border: Border(bottom: BorderSide(color: theme.colorScheme.border, width: 0.5)),
      ),
      child: Row(children: [
        Builder(builder: (ctx) => GestureDetector(
          onTap: () => Scaffold.of(ctx).openDrawer(),
          child: CircleAvatar(
            radius: 20,
            backgroundColor: AppTheme.primaryLight,
            backgroundImage: user?.avatarUrl != null ? NetworkImage(user!.avatarUrl!) : null,
            child: user?.avatarUrl == null ? const Icon(Icons.person, size: 28, color: AppTheme.primary) : null,
          ),
        )),
        const SizedBox(width: 10),
        Expanded(child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
          Row(mainAxisSize: MainAxisSize.min, children: [
            Icon(LucideIcons.bot, size: 19, color: AppTheme.primary),
            const SizedBox(width: 4),
            Text('AI 健康管家', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w500, color: theme.colorScheme.mutedForeground)),
          ]),
          const SizedBox(height: 2),
          Text('${_getGreeting()}，${(user?.name != null && user!.name!.isNotEmpty) ? user.name : '用户'}！',
            style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold, color: theme.colorScheme.foreground)),
        ])),
        Icon(LucideIcons.bell, size: 25, color: theme.colorScheme.mutedForeground),
      ]),
    );
  }

  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';
  }

  // ═══════ 智能体选择条 ═══════
  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, '看报告', LucideIcons.fileText),
    (ActiveAgent.exercise, '运动', LucideIcons.trendingUp),
  ];

  Widget _buildAgentBar(ActiveAgent? selected, ShadThemeData theme) {
    return Container(
      height: 40,
      padding: const EdgeInsets.symmetric(horizontal: AppTheme.sMd),
      child: ListView.separated(
        scrollDirection: Axis.horizontal,
        itemCount: _agentDefs.length,
        separatorBuilder: (_, i) => const SizedBox(width: 6),
        itemBuilder: (_, i) {
          final (agent, label, icon) = _agentDefs[i];
          final isActive = selected == agent;
          return GestureDetector(
            onTap: () {
              final notifier = ref.read(selectedAgentProvider.notifier);
              if (isActive) {
                notifier.select(null);
              } else {
                notifier.select(agent);
                ref.read(chatProvider.notifier).setAgent(agent);
                if (_welcomedAgents.add(agent)) {
                  ref.read(chatProvider.notifier).insertAgentWelcome(agent);
                }
              }
            },
            child: AnimatedContainer(
              duration: const Duration(milliseconds: 200),
              padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
              decoration: BoxDecoration(
                color: isActive ? AppTheme.primary : theme.colorScheme.card,
                borderRadius: BorderRadius.circular(AppTheme.rPill),
                boxShadow: isActive ? [AppTheme.shadowLight] : null,
              ),
              child: Row(mainAxisSize: MainAxisSize.min, children: [
                Icon(icon, size: 17, color: isActive ? Colors.white : theme.colorScheme.mutedForeground),
                const SizedBox(width: 4),
                Text(label, style: TextStyle(fontSize: 15, fontWeight: isActive ? FontWeight.w600 : FontWeight.w500, color: isActive ? Colors.white : theme.colorScheme.mutedForeground)),
              ]),
            ),
          );
        },
      ),
    );
  }

  // ═══════ 底部区域 ═══════
  Widget _buildBottomBar(BuildContext context, ActiveAgent? selectedAgent, ShadThemeData theme) {
    return Column(mainAxisSize: MainAxisSize.min, children: [
      Container(
        padding: const EdgeInsets.only(top: AppTheme.sSm, bottom: 6),
        child: _buildAgentBar(selectedAgent, theme),
      ),
      if (_pickedImagePath != null) _buildImagePreview(theme),
      _buildCompactInputBar(theme),
    ]);
  }

  Widget _buildImagePreview(ShadThemeData theme) {
    return Container(
      padding: const EdgeInsets.fromLTRB(12, 8, 12, 4),
      decoration: BoxDecoration(
        color: theme.colorScheme.card,
        border: Border(top: BorderSide(color: theme.colorScheme.border)),
      ),
      child: Row(children: [
        Stack(children: [
          ClipRRect(
            borderRadius: BorderRadius.circular(AppTheme.rXs),
            child: Image.file(File(_pickedImagePath!), width: 60, height: 60, fit: BoxFit.cover),
          ),
          Positioned(top: -4, right: -4, child: GestureDetector(
            onTap: () => setState(() => _pickedImagePath = null),
            child: Container(
              width: 20, height: 20,
              decoration: const BoxDecoration(color: AppTheme.text, shape: BoxShape.circle),
              child: const Icon(Icons.close, size: 17, color: Colors.white),
            ),
          )),
        ]),
        const Spacer(),
        Text('点击发送上传图片', style: TextStyle(fontSize: 15, color: theme.colorScheme.mutedForeground)),
      ]),
    );
  }

  Widget _buildCompactInputBar(ShadThemeData theme) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: AppTheme.sSm, vertical: AppTheme.sSm),
      decoration: BoxDecoration(
        color: theme.colorScheme.card,
        border: Border(top: BorderSide(color: theme.colorScheme.border)),
      ),
      child: Row(crossAxisAlignment: CrossAxisAlignment.end, children: [
        ShadButton.ghost(
          size: ShadButtonSize.sm,
          leading: Icon(LucideIcons.paperclip, size: 25, color: theme.colorScheme.mutedForeground),
          onPressed: () => _showAttachmentPicker(context, theme),
        ),
        Expanded(
          child: TextField(
            controller: _textCtrl,
            focusNode: _focusNode,
            style: TextStyle(fontSize: 18, color: theme.colorScheme.foreground),
            maxLines: null,
            textInputAction: TextInputAction.newline,
            decoration: InputDecoration(
              hintText: '输入你想说的...',
              hintStyle: TextStyle(fontSize: 18, color: theme.colorScheme.mutedForeground),
              filled: true,
              fillColor: theme.colorScheme.muted,
              contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
              border: OutlineInputBorder(
                borderRadius: BorderRadius.circular(AppTheme.rXl),
                borderSide: BorderSide.none,
              ),
              enabledBorder: OutlineInputBorder(
                borderRadius: BorderRadius.circular(AppTheme.rXl),
                borderSide: BorderSide.none,
              ),
              focusedBorder: OutlineInputBorder(
                borderRadius: BorderRadius.circular(AppTheme.rXl),
                borderSide: BorderSide.none,
              ),
            ),
            onSubmitted: (_) => _sendMessage(),
          ),
        ),
        const SizedBox(width: 4),
        ShadButton(
          size: ShadButtonSize.sm,
          leading: Icon(LucideIcons.send, size: 21, color: theme.colorScheme.primaryForeground),
          onPressed: _sendMessage,
        ),
      ]),
    );
  }

  void _showAttachmentPicker(BuildContext context, ShadThemeData theme) {
    showModalBottomSheet(
      context: context,
      backgroundColor: theme.colorScheme.card,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(AppTheme.rXl)),
      ),
      builder: (ctx) => SafeArea(
        child: Padding(
          padding: const EdgeInsets.symmetric(vertical: AppTheme.sMd),
          child: Wrap(children: [
            ListTile(
              leading: Icon(LucideIcons.camera, color: theme.colorScheme.foreground),
              title: Text('拍照', style: TextStyle(color: theme.colorScheme.foreground)),
              onTap: () { Navigator.pop(ctx); _pickImage(ImageSource.camera); },
            ),
            ListTile(
              leading: Icon(LucideIcons.image, color: theme.colorScheme.foreground),
              title: Text('从相册选', style: TextStyle(color: theme.colorScheme.foreground)),
              onTap: () { Navigator.pop(ctx); _pickImage(ImageSource.gallery); },
            ),
            ListTile(
              leading: Icon(LucideIcons.file, color: theme.colorScheme.foreground),
              title: Text('传文件', style: TextStyle(color: theme.colorScheme.foreground)),
              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 picker = ImagePicker();
    final picked = await picker.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 picker = ImagePicker();
    final picked = await picker.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');
    }
  }
}