import 'dart:io';
import 'dart:async';
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 '../../services/in_app_notification_service.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();
  final _focusNode = FocusNode();
  String? _pickedImagePath;
  int _lastMsgCount = 0;
  Timer? _notificationTimer;
  bool _checkingNotifications = false;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) => _checkNotifications());
    _notificationTimer = Timer.periodic(
      const Duration(seconds: 30),
      (_) => _checkNotifications(),
    );
  }

  @override
  void dispose() {
    _notificationTimer?.cancel();
    _textCtrl.dispose();
    _scrollCtrl.dispose();
    _focusNode.dispose();
    super.dispose();
  }

  Future<void> _checkNotifications() async {
    if (!mounted || _checkingNotifications) return;
    if (!ref.read(authProvider).isLoggedIn) return;
    _checkingNotifications = true;
    try {
      final service = InAppNotificationService(ref.read(apiClientProvider));
      final notifications = await service.getPending();
      for (final notification in notifications) {
        if (!mounted) return;
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            behavior: SnackBarBehavior.floating,
            duration: const Duration(seconds: 5),
            content: Row(
              children: [
                Icon(
                  notification.type == 'ExerciseReminder'
                      ? Icons.directions_run_outlined
                      : Icons.medication_outlined,
                  color: Colors.white,
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(notification.title,
                          style: const TextStyle(fontWeight: FontWeight.w700)),
                      Text(notification.message),
                    ],
                  ),
                ),
              ],
            ),
          ),
        );
        await service.acknowledge(notification.id);
      }
    } catch (_) {
      // App 内提醒失败不阻断主页使用，下次轮询会重试。
    } finally {
      _checkingNotifications = false;
    }
  }

  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: AppBackground(
        safeArea: true,
        child: Column(
          children: [
            _buildHeader(user),
            Expanded(
              child: ChatMessagesView(
                scrollCtrl: _scrollCtrl,
                messages: chatState.messages,
              ),
            ),
            _buildBottomBar(context),
          ],
        ),
      ),
    );
  }

  Widget _buildHeader(dynamic user) {
    final name = (user?.name != null && user!.name!.isNotEmpty)
        ? user.name
        : '用户';
    return Container(
      padding: const EdgeInsets.fromLTRB(14, 10, 14, 10),
      decoration: BoxDecoration(
        color: Colors.white.withValues(alpha: 0.34),
        border: Border(
          bottom: BorderSide(color: Colors.white.withValues(alpha: 0.62)),
        ),
        boxShadow: [
          BoxShadow(
            color: const Color(0xFF101828).withValues(alpha: 0.025),
            blurRadius: 16,
            offset: const Offset(0, 6),
          ),
        ],
      ),
      child: Row(
        children: [
          Builder(
            builder: (ctx) {
              return _HeaderIconButton(
                icon: LucideIcons.menu,
                onTap: () => Scaffold.of(ctx).openDrawer(),
              );
            },
          ),
          const SizedBox(width: 12),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                const Text(
                  'AI 健康管家',
                  style: TextStyle(
                    fontSize: 12,
                    fontWeight: FontWeight.w600,
                    color: AppColors.textHint,
                  ),
                ),
                const SizedBox(height: 2),
                Text(
                  '${_getGreeting()}，$name',
                  style: const TextStyle(
                    fontSize: 18,
                    fontWeight: FontWeight.w800,
                    color: AppColors.textPrimary,
                  ),
                ),
              ],
            ),
          ),
          _HeaderIconButton(
            icon: LucideIcons.bell,
            onTap: () => pushRoute(ref, 'notificationPrefs'),
          ),
        ],
      ),
    );
  }

  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';
  }

  static final _agentDefs = [
    (ActiveAgent.consultation, 'AI问诊', LucideIcons.messageCircle),
    (ActiveAgent.health, '记数据', LucideIcons.heartPulse),
    (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.activity),
  ];

  Widget _buildAgentBar() {
    return SizedBox(
      height: 42,
      child: ListView.separated(
        scrollDirection: Axis.horizontal,
        padding: const EdgeInsets.symmetric(horizontal: 14),
        itemCount: _agentDefs.length,
        separatorBuilder: (_, _) => const SizedBox(width: 8),
        itemBuilder: (_, i) {
          final (agent, label, icon) = _agentDefs[i];
          final gradient = _agentGradient(agent);
          return GestureDetector(
            onTap: () =>
                ref.read(chatProvider.notifier).triggerAgent(agent, label),
            child: Container(
              padding: const EdgeInsets.symmetric(horizontal: 13, vertical: 9),
              decoration: BoxDecoration(
                color: Colors.white.withValues(alpha: 0.86),
                borderRadius: BorderRadius.circular(999),
                border: Border.all(color: Colors.white, width: 1.2),
                boxShadow: [
                  BoxShadow(
                    color: const Color(0xFF6366F1).withValues(alpha: 0.10),
                    blurRadius: 14,
                    offset: const Offset(0, 7),
                  ),
                ],
              ),
              child: Row(
                mainAxisSize: MainAxisSize.min,
                children: [
                  Container(
                    width: 16,
                    height: 16,
                    decoration: BoxDecoration(
                      gradient: gradient,
                      borderRadius: BorderRadius.circular(6),
                    ),
                    child: Icon(icon, size: 11, color: Colors.white),
                  ),
                  const SizedBox(width: 6),
                  Text(
                    label,
                    style: const TextStyle(
                      fontSize: 14,
                      fontWeight: FontWeight.w700,
                      color: AppColors.textPrimary,
                    ),
                  ),
                ],
              ),
            ),
          );
        },
      ),
    );
  }

  LinearGradient _agentGradient(ActiveAgent agent) {
    return switch (agent) {
      ActiveAgent.consultation => const LinearGradient(
        begin: Alignment.topCenter,
        end: Alignment.bottomCenter,
        colors: [Color(0xFFFFCAD4), Color(0xFFFF9AAE)],
      ),
      ActiveAgent.health => const LinearGradient(
        begin: Alignment.topCenter,
        end: Alignment.bottomCenter,
        colors: [Color(0xFFFFAFBD), Color(0xFFC9FFBF)],
      ),
      ActiveAgent.diet => const LinearGradient(
        begin: Alignment.topCenter,
        end: Alignment.bottomCenter,
        colors: [Color(0xFFF6D365), Color(0xFFFDA085)],
      ),
      ActiveAgent.medication => const LinearGradient(
        begin: Alignment.topCenter,
        end: Alignment.bottomCenter,
        colors: [Color(0xFF89F7FE), Color(0xFF66A6FF)],
      ),
      ActiveAgent.report => const LinearGradient(
        begin: Alignment.topCenter,
        end: Alignment.bottomCenter,
        colors: [Color(0xFFE0C3FC), Color(0xFF8EC5FC)],
      ),
      ActiveAgent.exercise => const LinearGradient(
        begin: Alignment.topCenter,
        end: Alignment.bottomCenter,
        colors: [Color(0xFFB6F2FF), Color(0xFF7DD3FC)],
      ),
      _ => AppColors.primaryGradient,
    };
  }

  Widget _buildBottomBar(BuildContext context) {
    return Container(
      decoration: BoxDecoration(
        color: Colors.white.withValues(alpha: 0.28),
        border: Border(
          top: BorderSide(color: Colors.white.withValues(alpha: 0.62)),
        ),
        boxShadow: [
          BoxShadow(
            color: const Color(0xFF101828).withValues(alpha: 0.045),
            blurRadius: 20,
            offset: const Offset(0, -8),
          ),
        ],
      ),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          const SizedBox(height: 6),
          _buildAgentBar(),
          const SizedBox(height: 6),
          if (_pickedImagePath != null) _buildImagePreview(),
          _buildInputBar(),
        ],
      ),
    );
  }

  Widget _buildImagePreview() {
    return Container(
      margin: const EdgeInsets.fromLTRB(14, 8, 14, 0),
      padding: const EdgeInsets.all(10),
      decoration: BoxDecoration(
        color: Colors.white.withValues(alpha: 0.9),
        borderRadius: BorderRadius.circular(14),
        border: Border.all(color: AppColors.borderLight),
      ),
      child: Row(
        children: [
          ClipRRect(
            borderRadius: BorderRadius.circular(10),
            child: Image.file(
              File(_pickedImagePath!),
              width: 48,
              height: 48,
              fit: BoxFit.cover,
            ),
          ),
          const SizedBox(width: 10),
          const Expanded(
            child: Text(
              '点击发送图片',
              style: TextStyle(fontSize: 14, color: AppColors.textSecondary),
            ),
          ),
          GestureDetector(
            onTap: () => setState(() => _pickedImagePath = null),
            child: const Icon(Icons.close, size: 20, color: AppColors.textHint),
          ),
        ],
      ),
    );
  }

  Widget _buildInputBar() {
    return Padding(
      padding: const EdgeInsets.fromLTRB(12, 0, 12, 10),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.end,
        children: [
          _RoundToolButton(
            icon: LucideIcons.plus,
            onTap: () => _showAttachmentPicker(context),
          ),
          const SizedBox(width: 8),
          Expanded(
            child: ConstrainedBox(
              constraints: const BoxConstraints(maxHeight: 118),
              child: TextField(
                controller: _textCtrl,
                focusNode: _focusNode,
                style: const TextStyle(
                  fontSize: 15,
                  color: AppColors.textPrimary,
                ),
                maxLines: null,
                textInputAction: TextInputAction.newline,
                decoration: InputDecoration(
                  hintText: '输入你想说的...',
                  filled: true,
                  fillColor: Colors.white,
                  contentPadding: const EdgeInsets.symmetric(
                    horizontal: 16,
                    vertical: 11,
                  ),
                  border: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(22),
                    borderSide: const BorderSide(color: AppColors.borderLight),
                  ),
                  enabledBorder: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(22),
                    borderSide: const BorderSide(color: AppColors.borderLight),
                  ),
                  focusedBorder: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(22),
                    borderSide: const BorderSide(
                      color: AppColors.auraIndigo,
                      width: 1.2,
                    ),
                  ),
                ),
                onSubmitted: (_) => _sendMessage(),
              ),
            ),
          ),
          const SizedBox(width: 8),
          GestureDetector(
            onTap: _sendMessage,
            child: Container(
              width: 42,
              height: 42,
              margin: EdgeInsets.only(bottom: _pickedImagePath != null ? 0 : 2),
              decoration: BoxDecoration(
                gradient: AppColors.primaryGradient,
                borderRadius: BorderRadius.circular(21),
                boxShadow: AppColors.buttonShadow,
              ),
              child: const Icon(
                LucideIcons.send,
                size: 19,
                color: Colors.white,
              ),
            ),
          ),
        ],
      ),
    );
  }

  void _showAttachmentPicker(BuildContext context) {
    showModalBottomSheet(
      context: context,
      backgroundColor: Colors.white,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
      ),
      builder: (ctx) => SafeArea(
        child: Padding(
          padding: const EdgeInsets.symmetric(vertical: 10),
          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('从相册选择'),
                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');
    }
  }
}

class _HeaderIconButton extends StatelessWidget {
  final IconData icon;
  final VoidCallback onTap;
  const _HeaderIconButton({required this.icon, required this.onTap});

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: onTap,
      child: Container(
        width: 38,
        height: 38,
        decoration: BoxDecoration(
          gradient: AppColors.surfaceGradient,
          borderRadius: BorderRadius.circular(14),
          border: Border.all(color: AppColors.borderLight),
          boxShadow: AppColors.cardShadowLight,
        ),
        child: Icon(icon, size: 20, color: AppColors.textPrimary),
      ),
    );
  }
}

class _RoundToolButton extends StatelessWidget {
  final IconData icon;
  final VoidCallback onTap;
  const _RoundToolButton({required this.icon, required this.onTap});

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: onTap,
      child: Container(
        width: 42,
        height: 42,
        margin: const EdgeInsets.only(bottom: 2),
        decoration: BoxDecoration(
          gradient: AppColors.surfaceGradient,
          borderRadius: BorderRadius.circular(21),
          border: Border.all(color: AppColors.borderLight),
          boxShadow: AppColors.cardShadowLight,
        ),
        child: Icon(icon, size: 21, color: AppColors.primaryDark),
      ),
    );
  }
}