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 'dart:io';
import '../../providers/auth_provider.dart';
import '../../providers/chat_provider.dart';
import '../../providers/data_providers.dart';
import '../../widgets/health_drawer.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 = {};

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

    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();
      }
    });

    return Scaffold(
      drawer: const HealthDrawer(),
      backgroundColor: const Color(0xFFF8F9FC),
      body: SafeArea(
        child: Column(children: [
          // ── 顶部栏 ──
          _buildHeader(user),

          // ── 聊天区域（今日任务已移入对话流第一条消息） ──
          Expanded(child: ChatMessagesView(scrollCtrl: _scrollCtrl, messages: chatState.messages)),

          // ── 底部合并区：智能体栏 + 操作面板 + 输入框（固定高度） ──
          _buildBottomBar(context, selectedAgent),
        ]),
      ),
    );
  }

  // ═════════════════════ 顶部栏 ═════════════════════

  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: CircleAvatar(radius: 20, backgroundColor: const Color(0xFFF0F2FF), backgroundImage: user?.avatarUrl != null ? NetworkImage(user!.avatarUrl!) : null, child: user?.avatarUrl == null ? const Icon(Icons.person, size: 24, color: Color(0xFF8B9CF7)) : null),
        )),
        const SizedBox(width: 10),
        Expanded(child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
          Row(mainAxisSize: MainAxisSize.min, children: [Icon(Icons.smart_toy_outlined, size: 16, color: const Color(0xFF8B9CF7)), const SizedBox(width: 4), Text('AI 健康管家', style: TextStyle(fontSize: 13, fontWeight: FontWeight.w500, color: Colors.grey[600]))]),
          const SizedBox(height: 2),
          Text('${_getGreeting()}，${user?.name ?? '张三'}！', style: const TextStyle(fontSize: 17, fontWeight: FontWeight.bold, color: Color(0xFF1A1A1A))),
        ])),
        Icon(Icons.notifications_none, size: 22, color: Colors.grey[600]),
      ]),
    );
  }

  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（常驻） ═════════════════════

  static final _agentDefs = [
    (ActiveAgent.consultation, '问诊', Icons.chat_bubble_outline),
    (ActiveAgent.health, '记数据', Icons.favorite_border),
    (ActiveAgent.diet, '拍饮食', Icons.restaurant_outlined),
    (ActiveAgent.medication, '药管家', Icons.medication_outlined),
    (ActiveAgent.report, '看报告', Icons.description_outlined),
    (ActiveAgent.exercise, '运动', Icons.directions_run_outlined),
  ];

  Widget _buildAgentBar(ActiveAgent? selected) {
    return Container(
      height: 36,
      padding: const EdgeInsets.symmetric(horizontal: 12),
      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: Container(
              padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
              decoration: BoxDecoration(
                color: isActive ? const Color(0xFF8B9CF7) : Colors.white,
                borderRadius: BorderRadius.circular(16),
                border: Border.all(color: isActive ? const Color(0xFF8B9CF7) : const Color(0xFFE0E0E0)),
              ),
              child: Row(mainAxisSize: MainAxisSize.min, children: [
                Icon(icon, size: 13, color: isActive ? Colors.white : const Color(0xFF666666)),
                const SizedBox(width: 3),
                Text(label, style: TextStyle(fontSize: 11, fontWeight: isActive ? FontWeight.w600 : FontWeight.w500, color: isActive ? Colors.white : const Color(0xFF666666))),
              ]),
            ),
          );
        },
      ),
    );
  }

  // ═════════════════════ 底部合并区：智能体栏 + 操作面板 + 输入框 ═════════════════════

  Widget _buildBottomBar(BuildContext context, ActiveAgent? selectedAgent) {
    return Column(mainAxisSize: MainAxisSize.min, children: [
      // 智能体胶囊栏（常驻，高度36）
      _buildAgentBar(selectedAgent),

      // 图片预览（有选中图片时显示）
      if (_pickedImagePath != null) _buildImagePreview(),

      // 输入框
      _buildCompactInputBar(context),
    ]);
  }

  Widget _buildImagePreview() {
    return Container(
      padding: const EdgeInsets.fromLTRB(12, 8, 12, 4),
      decoration: const BoxDecoration(color: Colors.white, border: Border(top: BorderSide(color: Color(0xFFEEEEEE)))),
      child: Row(children: [
        Stack(children: [
          ClipRRect(
            borderRadius: BorderRadius.circular(8),
            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: Color(0xFF333333), shape: BoxShape.circle), child: const Icon(Icons.close, size: 14, color: Colors.white)),
          )),
        ]),
        const Spacer(),
        Text('点击发送上传图片', style: TextStyle(fontSize: 12, color: Colors.grey[500])),
      ]),
    );
  }

  Widget _buildCompactInputBar(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 8),
      decoration: BoxDecoration(color: Colors.white, border: Border(top: BorderSide(color: const Color(0xFFEEEEEE)))),
      child: Row(children: [
        IconButton(icon: const Icon(Icons.attach_file, size: 24, color: Color(0xFF666666)), onPressed: () => _showAttachmentPicker(context)),
        Expanded(child: TextField(
          controller: _textCtrl,
          style: const TextStyle(fontSize: 15),
          decoration: const InputDecoration(hintText: '输入你想说的...', hintStyle: TextStyle(fontSize: 15, color: Color(0xFFBBBBBB)), contentPadding: EdgeInsets.symmetric(horizontal: 10, vertical: 10), border: InputBorder.none),
          onSubmitted: (_) => _sendMessage(),
        )),
        IconButton(icon: const Icon(Icons.send, size: 24, color: Color(0xFF8B9CF7)), onPressed: _sendMessage),
      ]),
    );
  }

  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);
    }
  }

  void _showAttachmentPicker(BuildContext context) {
    showModalBottomSheet(context: context, builder: (ctx) => SafeArea(child: Wrap(children: [
      ListTile(leading: const Icon(Icons.camera_alt), title: const Text('拍照'), onTap: () { Navigator.pop(ctx); _pickImage(ImageSource.camera); }),
      ListTile(leading: const Icon(Icons.photo_library), title: const Text('从相册选'), onTap: () { Navigator.pop(ctx); _pickImage(ImageSource.gallery); }),
      ListTile(leading: const Icon(Icons.attach_file), 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(() {}); }}),
    ])));
  }

}