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 '../../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 '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();
  bool _taskCardsExpanded = true;
  String? _pickedImagePath;
  double _lastScrollOffset = 0;
  DateTime? _lastCollapseTime;
  bool _exerciseDone = false;
  final Set<ActiveAgent> _welcomedAgents = {};

  static final _mockFollowUps = [
    {'hospital': '协和医院', 'department': '心内科', 'date': DateTime.now().add(const Duration(days: 2)), 'type': '复查'},
    {'hospital': '人民医院', 'department': '心内科', 'date': DateTime.now().add(const Duration(days: 3)), 'type': '复诊'},
  ];

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

  void _onTextChange() {
    if (_textCtrl.text.isNotEmpty && _taskCardsExpanded) {
      setState(() => _taskCardsExpanded = false);
    }
  }

  void _onScroll() {
    if (!_scrollCtrl.hasClients) return;
    final offset = _scrollCtrl.offset;
    if (offset < _lastScrollOffset && _taskCardsExpanded) {
      final delta = _lastScrollOffset - offset;
      if (delta > 50) {
        final now = DateTime.now();
        if (_lastCollapseTime == null || now.difference(_lastCollapseTime!) > const Duration(seconds: 2)) {
          _lastCollapseTime = now;
          setState(() => _taskCardsExpanded = false);
        }
      }
    }
    _lastScrollOffset = offset;
  }

  void _sendMessage() {
    final text = _textCtrl.text.trim();
    final imagePath = _pickedImagePath;
    if (text.isEmpty && imagePath == null) return;
    _textCtrl.clear();
    setState(() { _taskCardsExpanded = false; _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';
  }

  // ═════════════════════ 今日任务（可折叠/展开） ═════════════════════

  Widget _buildTaskCardsArea() {
    final latestHealth = ref.watch(latestHealthProvider);

    if (_taskCardsExpanded) {
      return latestHealth.when(
        data: (data) => _taskCardContent(data),
        loading: () => _taskCardContent({}),
        error: (_, __) => _taskCardContent({}),
      );
    }

    // 折叠状态：与展开态容器完全相同，只保留标题行
    return GestureDetector(
      onTap: () => setState(() => _taskCardsExpanded = true),
      behavior: HitTestBehavior.opaque,
      child: Container(
        margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 6),
        padding: const EdgeInsets.all(14),
        decoration: BoxDecoration(color: Colors.white, borderRadius: BorderRadius.circular(16), boxShadow: [BoxShadow(color: const Color(0xFF8B9CF7).withAlpha(8), blurRadius: 6, offset: const Offset(0, 1))]),
        child: Row(children: [
          const Text('今日任务', style: TextStyle(fontSize: 15, fontWeight: FontWeight.w600, color: Color(0xFF1A1A1A))),
          const Spacer(),
          const Text('展开 ▾', style: TextStyle(fontSize: 12, color: Color(0xFF8B9CF7))),
        ]),
      ),
    );
  }

  Widget _taskCardContent(Map<String, dynamic> healthData) {
    return Container(
      margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 6),
      padding: const EdgeInsets.all(14),
      decoration: BoxDecoration(color: Colors.white, borderRadius: BorderRadius.circular(16), boxShadow: [BoxShadow(color: const Color(0xFF8B9CF7).withAlpha(8), blurRadius: 6, offset: const Offset(0, 1))]),
      child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
        Row(children: [
          const Text('今日任务', style: TextStyle(fontSize: 15, fontWeight: FontWeight.w600, color: Color(0xFF1A1A1A))),
          const Spacer(),
          GestureDetector(onTap: () => setState(() => _taskCardsExpanded = false), child: Row(mainAxisSize: MainAxisSize.min, children: [
            const Text('收起', style: TextStyle(fontSize: 12, color: Color(0xFF999999))),
            const Text('∧', style: TextStyle(fontSize: 12, color: Color(0xFF999999))),
          ])),
        ]),
        const SizedBox(height: 10),
        ..._getTodayTasks(healthData),
      ]),
    );
  }

  List<Widget> _getTodayTasks(Map<String, dynamic> healthData) {
    final now = DateTime.now();
    final tasks = <Widget>[];

    // 1. 数据摘要卡片（有今日指标数据时显示）
    final summaryParts = <String>[];
    final bp = healthData['BloodPressure'];
    if (bp is Map) {
      final s = bp['systolic'];
      final d = bp['diastolic'];
      if (s != null && d != null) summaryParts.add('血压 $s/$d');
    }
    final hr = healthData['HeartRate'];
    if (hr is int) summaryParts.add('心率 $hr');
    final bs = healthData['BloodSugar'];
    if (bs is num) summaryParts.add('血糖 $bs');
    final bo = healthData['BloodOxygen'];
    if (bo is num) summaryParts.add('血氧 $bo');
    final wt = healthData['Weight'];
    if (wt is num) summaryParts.add('体重 $wt');

    if (summaryParts.isNotEmpty) {
      tasks.add(_summaryCard(summaryParts));
    }

    // 2. 用药提醒（从后端拉取真实数据）
    final reminders = ref.watch(medicationReminderProvider);
    reminders.whenData((meds) {
      for (final m in meds) {
        final name = m['name'] ?? '';
        final dosage = m['dosage'] ?? '';
        final times = (m['timeOfDay'] as List?)?.map((t) => t.toString().substring(0, 5)).join(', ') ?? '';
        final medOverdue = now.hour >= 8;
        tasks.add(_taskRow(
          icon: Icons.medication_rounded,
          label: '$name $dosage ($times)',
          status: 'pending',
          isOverdue: medOverdue,
          onTap: () => _handleMedicationCheck,
        ));
      }
    });

    // 无提醒时显示默认用药卡片
    if (tasks.length <= (summaryParts.isNotEmpty ? 1 : 0)) {
      tasks.add(_taskRow(
        icon: Icons.medication_rounded,
        label: '暂无用药提醒',
        status: 'pending',
        onTap: null,
      ));
    }

    // 3. 运动卡片（超时变红）
    final exOverdue = now.hour >= 18 && !_exerciseDone;
    tasks.add(_taskRow(
      icon: Icons.directions_run,
      label: '今日待运动：散步 30 分钟',
      status: _exerciseDone ? 'done' : 'pending',
      isOverdue: exOverdue,
      onTap: _exerciseDone ? null : () => setState(() => _exerciseDone = true),
    ));

    // 4. 测量卡片
    tasks.add(_taskRow(
      icon: Icons.today,
      label: '今日测量：血压',
      status: 'pending',
      onTap: () => _textCtrl.text = '血压 ',
    ));

    // 5. 异常指标
    tasks.addAll(_buildAbnormalRows(healthData));

    // 6. 复查提醒（未来3天内有复查安排时显示）
    final upcomingFollowUps = _mockFollowUps.where((f) {
      final date = f['date'] as DateTime;
      return date.difference(now).inDays <= 3 && date.isAfter(now);
    }).toList();

    if (upcomingFollowUps.isNotEmpty) {
      tasks.add(_followUpCard(upcomingFollowUps.first));
    }

    return tasks;
  }

  List<Widget> _buildAbnormalRows(Map<String, dynamic> healthData) {
    final rows = <Widget>[];
    final bp = healthData['BloodPressure'];
    if (bp is Map) { final s = bp['systolic']; if (s is int && s >= 140) rows.add(_taskRow(icon: Icons.warning_amber_rounded, label: '血压 $s/${bp['diastolic'] ?? '--'} 偏高', status: 'warning', onTap: () => pushRoute(ref, 'trend', params: {'type': 'blood_pressure'}))); }
    return rows;
  }

  Widget _summaryCard(List<String> parts) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 10),
      child: GestureDetector(
        behavior: HitTestBehavior.opaque,
        onTap: () => pushRoute(ref, 'trend'),
        child: Container(
          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
          decoration: BoxDecoration(
            color: const Color(0xFFF1F8E9),
            borderRadius: BorderRadius.circular(10),
          ),
          child: Row(children: [
            const Icon(Icons.check_circle, size: 18, color: Color(0xFF43A047)),
            const SizedBox(width: 10),
            Expanded(child: Text(
              '今日已记录：${parts.join('、')}',
              style: const TextStyle(fontSize: 13, color: Color(0xFF333333)),
            )),
          ]),
        ),
      ),
    );
  }

  Widget _followUpCard(Map<String, dynamic> followUp) {
    final date = followUp['date'] as DateTime;
    final now = DateTime.now();
    final diff = date.difference(now).inDays;
    String dateLabel;
    if (diff == 0) {
      dateLabel = '今天';
    } else if (diff == 1) {
      dateLabel = '明天';
    } else if (diff == 2) {
      dateLabel = '后天';
    } else {
      dateLabel = '$diff天后';
    }

    return _taskRow(
      icon: Icons.event_available,
      label: '📋 $dateLabel ${followUp['hospital']} ${followUp['department']} ${followUp['type']}',
      status: 'pending',
      onTap: () => pushRoute(ref, 'followups'),
    );
  }

  Widget _taskRow({required IconData icon, required String label, required String status, VoidCallback? onTap, bool isOverdue = false}) {
    final colors = {'done': const Color(0xFF43A047), 'warning': const Color(0xFFFF9800), 'pending': const Color(0xFF9E9E9E)};
    final icons = {'done': Icons.check_circle, 'warning': Icons.warning, 'pending': Icons.circle_outlined};
    final effectiveStatus = isOverdue ? 'warning' : status;
    return Padding(
      padding: const EdgeInsets.only(bottom: 10),
      child: GestureDetector(
        behavior: HitTestBehavior.opaque,
        onTap: onTap,
        child: Container(
          padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 6),
          decoration: BoxDecoration(
            color: isOverdue ? const Color(0xFFFFEBEE) : Colors.transparent,
            borderRadius: BorderRadius.circular(8),
          ),
          child: Row(crossAxisAlignment: CrossAxisAlignment.center, children: [
            Container(width: 30, height: 30, decoration: BoxDecoration(color: const Color(0xFFF0F2FF), borderRadius: BorderRadius.circular(8)), child: Icon(icon, size: 15, color: const Color(0xFF8B9CF7))),
            const SizedBox(width: 10), Expanded(child: Text(label, style: const TextStyle(fontSize: 13, color: Color(0xFF333333)))),
            Icon(icons[effectiveStatus], size: 18, color: colors[effectiveStatus] ?? Colors.grey),
          ]),
        ),
      ),
    );
  }

  void _handleMedicationCheck() async {
    await ref.read(medicationServiceProvider).confirm('');
    if (!mounted) return;
    ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('已记录服药 ✅'), backgroundColor: Color(0xFF8B9CF7)));
  }

  // ═════════════════════ 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: (_, __) => 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(() {}); }}),
    ])));
  }

}