import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:shadcn_ui/shadcn_ui.dart';
import '../core/app_colors.dart';
import '../core/app_design_tokens.dart';
import '../core/elder_mode_scope.dart';
import '../core/app_module_visuals.dart';
import '../core/navigation_provider.dart';
import '../providers/auth_provider.dart';
import '../providers/chat_provider.dart';
import '../providers/conversation_history_provider.dart';
import 'app_toast.dart';
import 'authenticated_network_image.dart';
import '../providers/data_providers.dart';
import 'drawer_shell.dart';

class HealthDrawer extends ConsumerWidget {
  const HealthDrawer({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    return DrawerShell(
      widthFactor: 0.9,
      showBackground: false,
      child: CustomScrollView(
        physics: const BouncingScrollPhysics(),
        slivers: [
          const SliverToBoxAdapter(child: _DrawerHeroConsumer()),
          SliverToBoxAdapter(
            child: Container(
              padding: const EdgeInsets.fromLTRB(14, 10, 14, 18),
              decoration: const BoxDecoration(
                color: Colors.white,
                borderRadius: BorderRadius.vertical(top: Radius.circular(28)),
              ),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  _NavigationSection(ref: ref),
                  const SizedBox(height: 22),
                  _HistorySection(ref: ref),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}

class _DrawerHeroConsumer extends ConsumerWidget {
  const _DrawerHeroConsumer();

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final user = ref.watch(authProvider.select((state) => state.user));
    final latestHealth = ref.watch(latestHealthProvider);
    return _DrawerHero(user: user, latestHealth: latestHealth, ref: ref);
  }
}

class _DrawerHero extends StatelessWidget {
  final dynamic user;
  final AsyncValue<Map<String, dynamic>> latestHealth;
  final WidgetRef ref;

  const _DrawerHero({
    required this.user,
    required this.latestHealth,
    required this.ref,
  });

  @override
  Widget build(BuildContext context) {
    final topPadding = MediaQuery.paddingOf(context).top;
    return Stack(
      children: [
        Positioned.fill(
          child: Image.asset(
            'assets/branding/drawer_background_v2.png',
            fit: BoxFit.cover,
            alignment: Alignment.topLeft,
          ),
        ),
        Positioned.fill(
          child: DecoratedBox(
            decoration: BoxDecoration(
              gradient: LinearGradient(
                begin: Alignment.topCenter,
                end: Alignment.bottomCenter,
                colors: [
                  Colors.white.withValues(alpha: 0.06),
                  Colors.white.withValues(alpha: 0.18),
                  Colors.white.withValues(alpha: 0.78),
                ],
                stops: const [0.0, 0.58, 1.0],
              ),
            ),
          ),
        ),
        Padding(
          padding: EdgeInsets.fromLTRB(16, topPadding + 16, 16, 12),
          child: Column(
            children: [
              _AccountHeader(user: user, ref: ref),
              const SizedBox(height: 16),
              _HealthDashboard(latestHealth: latestHealth, ref: ref),
            ],
          ),
        ),
      ],
    );
  }
}

class _AccountHeader extends StatelessWidget {
  final dynamic user;
  final WidgetRef ref;
  const _AccountHeader({required this.user, required this.ref});

  @override
  Widget build(BuildContext context) {
    final name = (user?.name?.toString().isNotEmpty ?? false)
        ? user.name.toString()
        : '未设置昵称';
    final phone = (user?.phone?.toString().isNotEmpty ?? false)
        ? user.phone.toString()
        : '未登录';

    return Row(
      children: [
        InkWell(
          onTap: () => pushRoute(ref, 'profile'),
          borderRadius: BorderRadius.circular(33),
          child: Container(
            width: 66,
            height: 66,
            decoration: BoxDecoration(
              shape: BoxShape.circle,
              boxShadow: [
                BoxShadow(
                  color: const Color(0xFF7C5CFF).withValues(alpha: 0.16),
                  blurRadius: 20,
                  offset: const Offset(0, 10),
                ),
              ],
            ),
            child: Stack(
              fit: StackFit.expand,
              children: [
                ClipOval(
                  clipBehavior: Clip.antiAlias,
                  child: ColoredBox(
                    color: const Color(0xFFF1F5F9),
                    child: user?.avatarUrl?.toString().isNotEmpty == true
                        ? AuthenticatedNetworkImage(
                            imageUrl: user.avatarUrl.toString(),
                            fit: BoxFit.cover,
                            width: 66,
                            height: 66,
                            errorBuilder: (_, _, _) => const Icon(
                              Icons.person_rounded,
                              color: Color(0xFF94A3B8),
                              size: 34,
                            ),
                          )
                        : const Icon(
                            Icons.person_rounded,
                            color: Color(0xFF94A3B8),
                            size: 34,
                          ),
                  ),
                ),
              ],
            ),
          ),
        ),
        const SizedBox(width: 14),
        Expanded(
          child: InkWell(
            onTap: () => pushRoute(ref, 'profile'),
            borderRadius: BorderRadius.circular(14),
            child: Padding(
              padding: const EdgeInsets.symmetric(vertical: 4),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    name,
                    maxLines: 1,
                    overflow: TextOverflow.ellipsis,
                    style: const TextStyle(
                      fontSize: 22,
                      fontWeight: FontWeight.w700,
                      color: AppColors.textPrimary,
                    ),
                  ),
                  const SizedBox(height: 5),
                  Text(
                    phone,
                    maxLines: 1,
                    overflow: TextOverflow.ellipsis,
                    style: const TextStyle(
                      fontSize: 13,
                      fontWeight: FontWeight.w600,
                      color: AppColors.textSecondary,
                    ),
                  ),
                ],
              ),
            ),
          ),
        ),
        _IconButton(
          icon: Icons.settings_rounded,
          onTap: () => pushRoute(ref, 'settings'),
        ),
      ],
    );
  }
}

class _HealthDashboard extends StatelessWidget {
  final AsyncValue<Map<String, dynamic>> latestHealth;
  final WidgetRef ref;
  const _HealthDashboard({required this.latestHealth, required this.ref});

  @override
  Widget build(BuildContext context) {
    return _Panel(
      title: '健康仪表盘',
      titleColor: Colors.white,
      backgroundPainter: const _HealthDashboardBackgroundPainter(),
      child: latestHealth.when(
        data: (data) => _DashboardMetrics(data: data, ref: ref),
        loading: () => const SizedBox(
          height: 118,
          child: Center(child: CircularProgressIndicator(strokeWidth: 2)),
        ),
        error: (error, stackTrace) =>
            _DashboardMetrics(data: const <String, dynamic>{}, ref: ref),
      ),
    );
  }
}

class _DashboardMetrics extends StatelessWidget {
  final Map<String, dynamic> data;
  final WidgetRef ref;
  const _DashboardMetrics({required this.data, required this.ref});

  @override
  Widget build(BuildContext context) {
    final items = [
      _MetricInfo(
        label: '血压',
        value: _bpText(data['BloodPressure']),
        unit: 'mmHg',
        routeType: 'blood_pressure',
      ),
      _MetricInfo(
        label: '心率',
        value: _metricVal(data['HeartRate']),
        unit: 'bpm',
        routeType: 'heart_rate',
      ),
      _MetricInfo(
        label: '血糖',
        value: _metricVal(data['Glucose']),
        unit: 'mmol/L',
        routeType: 'glucose',
      ),
      _MetricInfo(
        label: '血氧',
        value: _metricVal(data['SpO2']),
        unit: '%',
        routeType: 'spo2',
      ),
    ];

    return Row(
      children: [
        for (var i = 0; i < items.length; i++) ...[
          Expanded(
            child: _MetricTile(
              info: items[i],
              onTap: () =>
                  pushRoute(ref, 'trend', params: {'type': items[i].routeType}),
            ),
          ),
          if (i != items.length - 1) const SizedBox(width: 6),
        ],
      ],
    );
  }

  static String _bpText(dynamic bp) {
    if (bp is Map) {
      final systolic = bp['systolic'] ?? bp['value'] ?? '--';
      final diastolic = bp['diastolic'];
      if (diastolic == null) return systolic.toString();
      return '$systolic/$diastolic';
    }
    return '--';
  }

  static String _metricVal(dynamic val, {String unit = ''}) {
    if (val == null) return '--';
    dynamic raw = val;
    if (val is Map) raw = val['value'] ?? val['val'] ?? val['data'];
    if (raw == null) return '--';
    final text = raw is num
        ? raw.toStringAsFixed(raw is double ? 1 : 0)
        : raw.toString();
    if (text.isEmpty || text == '--') return '--';
    return unit.isEmpty ? text : '$text $unit';
  }
}

class _MetricTile extends StatelessWidget {
  final _MetricInfo info;
  final VoidCallback onTap;
  const _MetricTile({required this.info, required this.onTap});

  @override
  Widget build(BuildContext context) {
    final elderMode = ElderModeScope.enabledOf(context);
    return InkWell(
      onTap: onTap,
      borderRadius: BorderRadius.circular(18),
      child: Container(
        height: elderMode ? 108 : 100,
        padding: const EdgeInsets.symmetric(horizontal: 5, vertical: 10),
        decoration: BoxDecoration(
          color: Colors.white.withValues(alpha: 0.22),
          borderRadius: BorderRadius.circular(18),
          border: Border.all(color: Colors.white.withValues(alpha: 0.40)),
        ),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            SizedBox(
              height: 32,
              child: FittedBox(
                fit: BoxFit.scaleDown,
                child: Text(
                  info.value,
                  maxLines: 1,
                  textAlign: TextAlign.center,
                  style: const TextStyle(
                    fontSize: 26,
                    fontWeight: FontWeight.w700,
                    color: Colors.white,
                  ),
                ),
              ),
            ),
            if (info.unit != null)
              Text(
                info.unit!,
                style: const TextStyle(
                  fontSize: 12,
                  fontWeight: FontWeight.w600,
                  color: Color(0xE0FFFFFF),
                ),
              ),
            const SizedBox(height: 2),
            Text(
              info.label,
              style: const TextStyle(
                fontSize: 14,
                fontWeight: FontWeight.w600,
                color: Colors.white,
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class _NavigationSection extends StatelessWidget {
  final WidgetRef ref;
  const _NavigationSection({required this.ref});

  @override
  Widget build(BuildContext context) {
    final elderMode = ElderModeScope.enabledOf(context);
    final items = [
      _NavItem(
        icon: LucideIcons.folderHeart,
        title: '档案',
        route: 'healthArchive',
        colors: AppColors.healthGradient.colors,
      ),
      _NavItem(
        icon: LucideIcons.fileText,
        title: '报告',
        route: 'reports',
        colors: AppColors.reportGradient.colors,
      ),
      _NavItem(
        icon: LucideIcons.pill,
        title: '用药',
        route: 'medications',
        colors: AppColors.medicationGradient.colors,
      ),
      _NavItem(
        icon: AppModuleVisuals.diet.icon,
        title: '饮食',
        route: 'dietRecords',
        colors: AppColors.dietGradient.colors,
      ),
      _NavItem(
        icon: LucideIcons.calendarDays,
        title: '日历',
        route: 'calendar',
        colors: const [Color(0xFFC4B5FD), Color(0xFF8B5CF6)],
      ),
      _NavItem(
        icon: LucideIcons.calendarCheck,
        title: '随访',
        route: 'followups',
        colors: const [Color(0xFFFBCFE8), Color(0xFFF9A8D4)],
      ),
      _NavItem(
        icon: AppModuleVisuals.exercise.icon,
        title: '运动',
        route: 'exercisePlan',
        colors: AppColors.exerciseGradient.colors,
      ),
      _NavItem(
        icon: LucideIcons.bluetooth,
        title: '设备',
        route: 'devices',
        colors: AppColors.deviceGradient.colors,
      ),
    ];

    return _LightSection(
      title: '常用功能',
      child: GridView.builder(
        padding: const EdgeInsets.only(top: 3),
        itemCount: items.length,
        shrinkWrap: true,
        physics: const NeverScrollableScrollPhysics(),
        gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
          crossAxisCount: elderMode ? 2 : 4,
          mainAxisExtent: elderMode ? 82 : 82,
          mainAxisSpacing: elderMode ? 10 : 7,
          crossAxisSpacing: elderMode ? 10 : 8,
        ),
        itemBuilder: (context, index) {
          final item = items[index];
          return _NavTile(
            item: item,
            elderMode: elderMode,
            onTap: () => pushRoute(ref, item.route),
          );
        },
      ),
    );
  }
}

class _NavTile extends StatelessWidget {
  final _NavItem item;
  final bool elderMode;
  final VoidCallback onTap;
  const _NavTile({
    required this.item,
    required this.elderMode,
    required this.onTap,
  });

  String get _title => switch (item.route) {
    'healthArchive' => '健康档案',
    'reports' => '报告管理',
    'medications' => '用药管理',
    'dietRecords' => '饮食记录',
    'calendar' => '健康日历',
    'followups' => '复查随访',
    'exercisePlan' => '运动计划',
    'devices' => '蓝牙设备',
    _ => item.title,
  };

  List<Color> get _colors => switch (item.route) {
    'healthArchive' => AppColors.healthGradient.colors,
    'reports' => AppColors.reportGradient.colors,
    'medications' => AppColors.medicationGradient.colors,
    'dietRecords' => AppColors.dietGradient.colors,
    'calendar' => const [AppColors.calendarLight, AppColors.calendar],
    'followups' => const [AppColors.followupLight, AppColors.followup],
    'exercisePlan' => AppColors.exerciseGradient.colors,
    'devices' => AppColors.deviceGradient.colors,
    _ => item.colors,
  };

  @override
  Widget build(BuildContext context) {
    final isDevice = item.route == 'devices';
    if (elderMode) {
      return InkWell(
        onTap: onTap,
        borderRadius: AppRadius.lgBorder,
        child: Container(
          padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 10),
          decoration: BoxDecoration(
            color: const Color(0xFFF8F8FC),
            borderRadius: AppRadius.lgBorder,
            border: Border.all(color: const Color(0xFFE7E8F0)),
          ),
          child: Row(
            children: [
              Container(
                width: 54,
                height: 54,
                decoration: BoxDecoration(
                  color: isDevice ? AppColors.device : null,
                  gradient: isDevice
                      ? null
                      : LinearGradient(
                          begin: Alignment.topLeft,
                          end: Alignment.bottomRight,
                          colors: _colors,
                        ),
                  borderRadius: AppRadius.mdBorder,
                ),
                child: Icon(item.icon, color: Colors.white, size: 29),
              ),
              const SizedBox(width: 10),
              Expanded(
                child: Text(
                  _title,
                  maxLines: 2,
                  overflow: TextOverflow.ellipsis,
                  style: const TextStyle(
                    fontSize: 17,
                    fontWeight: FontWeight.w700,
                    color: AppColors.textPrimary,
                    height: 1.15,
                  ),
                ),
              ),
            ],
          ),
        ),
      );
    }
    return InkWell(
      onTap: onTap,
      borderRadius: AppRadius.mdBorder,
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 2),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.start,
          children: [
            Container(
              width: 48,
              height: 48,
              decoration: BoxDecoration(
                color: isDevice ? AppColors.device : null,
                gradient: isDevice
                    ? null
                    : LinearGradient(
                        begin: Alignment.topLeft,
                        end: Alignment.bottomRight,
                        colors: _colors,
                      ),
                borderRadius: AppRadius.mdBorder,
                border: null,
                boxShadow: [
                  BoxShadow(
                    color: _colors.last.withValues(alpha: 0.10),
                    blurRadius: 6,
                    offset: const Offset(0, 3),
                  ),
                ],
              ),
              child: Icon(item.icon, color: Colors.white, size: 24),
            ),
            const SizedBox(height: 6),
            Text(
              _title,
              maxLines: 1,
              overflow: TextOverflow.ellipsis,
              textAlign: TextAlign.center,
              style: const TextStyle(
                fontSize: 14,
                fontWeight: FontWeight.w600,
                color: AppColors.textPrimary,
                height: 1.1,
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class _LightSection extends StatelessWidget {
  final String title;
  final Widget child;
  final Widget? trailing;

  const _LightSection({
    required this.title,
    required this.child,
    this.trailing,
  });

  @override
  Widget build(BuildContext context) => Column(
    crossAxisAlignment: CrossAxisAlignment.start,
    children: [
      Padding(
        padding: const EdgeInsets.symmetric(horizontal: 2),
        child: Row(
          children: [
            Expanded(
              child: Text(
                title,
                style: const TextStyle(
                  fontSize: 18,
                  fontWeight: FontWeight.w600,
                  color: AppColors.textPrimary,
                ),
              ),
            ),
            ?trailing,
          ],
        ),
      ),
      const SizedBox(height: 8),
      child,
    ],
  );
}

class _Panel extends StatelessWidget {
  final String title;
  final Widget child;
  final CustomPainter? backgroundPainter;
  final Color titleColor;
  const _Panel({
    required this.title,
    required this.child,
    this.backgroundPainter,
    this.titleColor = AppColors.textPrimary,
  });

  @override
  Widget build(BuildContext context) {
    return Container(
      clipBehavior: Clip.antiAlias,
      decoration: BoxDecoration(
        color: backgroundPainter == null ? null : const Color(0xFFBAE6FD),
        gradient: backgroundPainter != null
            ? null
            : LinearGradient(
                begin: Alignment.topLeft,
                end: Alignment.bottomRight,
                colors: [
                  Colors.white.withValues(alpha: 0.92),
                  const Color(0xFFF8F4FF).withValues(alpha: 0.84),
                ],
              ),
        borderRadius: AppRadius.xlBorder,
        boxShadow: AppShadows.soft,
      ),
      child: CustomPaint(
        painter: backgroundPainter,
        child: Padding(
          padding: const EdgeInsets.all(14),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text(
                title,
                style: TextStyle(
                  fontSize: 18,
                  fontWeight: FontWeight.w600,
                  color: titleColor,
                ),
              ),
              const SizedBox(height: 12),
              child,
            ],
          ),
        ),
      ),
    );
  }
}

class _HealthDashboardBackgroundPainter extends CustomPainter {
  const _HealthDashboardBackgroundPainter();

  @override
  void paint(Canvas canvas, Size size) {
    final rect = Offset.zero & size;
    final paint = Paint()
      ..shader = const LinearGradient(
        begin: Alignment.topLeft,
        end: Alignment.bottomRight,
        colors: [Color(0xFF00C6FB), Color(0xFF005BEA)],
      ).createShader(rect);
    canvas.drawRect(rect, paint);
  }

  @override
  bool shouldRepaint(_HealthDashboardBackgroundPainter oldDelegate) => false;
}

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

  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: onTap,
      borderRadius: BorderRadius.circular(18),
      child: Container(
        width: 42,
        height: 42,
        decoration: BoxDecoration(
          color: Colors.white.withValues(alpha: 0.84),
          borderRadius: BorderRadius.circular(18),
          border: Border.all(color: Colors.white, width: 1.2),
        ),
        child: Icon(icon, size: 22, color: const Color(0xFF475569)),
      ),
    );
  }
}

class _MetricInfo {
  final String label;
  final String value;
  final String? unit;
  final String routeType;
  const _MetricInfo({
    required this.label,
    required this.value,
    this.unit,
    required this.routeType,
  });
}

class _NavItem {
  final IconData icon;
  final String title;
  final String route;
  final List<Color> colors;
  const _NavItem({
    required this.icon,
    required this.title,
    required this.route,
    required this.colors,
  });
}

class _HistorySection extends ConsumerStatefulWidget {
  final WidgetRef ref;
  const _HistorySection({required this.ref});

  static const int _previewCount = 7;

  @override
  ConsumerState<_HistorySection> createState() => _HistorySectionState();
}

class _HistorySectionState extends ConsumerState<_HistorySection> {
  String? _selectedId;
  bool _selecting = false;
  bool _deleting = false;
  bool _expanded = false;
  bool _clearing = false;
  String? _loadingConversationId;

  void _enterSelect(String id) {
    setState(() {
      _selecting = true;
      _selectedId = id;
    });
  }

  void _toggleSelect(String id) {
    setState(() {
      if (_selectedId == id) {
        _selectedId = null;
        _selecting = false;
      } else {
        _selectedId = id;
      }
    });
  }

  void _exitSelect() {
    setState(() {
      _selecting = false;
      _selectedId = null;
    });
  }

  @override
  Widget build(BuildContext context) {
    final async = ref.watch(conversationHistoryProvider);
    final currentConversationId = ref.watch(
      chatProvider.select((state) => state.conversationId),
    );

    return _LightSection(
      title: '对话记录',
      trailing: _buildHeaderAction(context, async),
      child: async.when(
        loading: () => const Padding(
          padding: EdgeInsets.symmetric(vertical: 14),
          child: Center(
            child: SizedBox(
              width: 22,
              height: 22,
              child: CircularProgressIndicator(strokeWidth: 2),
            ),
          ),
        ),
        error: (error, stackTrace) => const Padding(
          padding: EdgeInsets.symmetric(vertical: 14),
          child: Text(
            '加载失败',
            style: TextStyle(fontSize: 13, color: AppColors.textSecondary),
          ),
        ),
        data: (allItems) {
          final list = allItems
              .where((item) => item.id != currentConversationId)
              .toList();
          if (list.isEmpty) {
            return const Padding(
              padding: EdgeInsets.symmetric(vertical: 12),
              child: Text(
                '暂无历史，发起对话后会显示在这里',
                style: TextStyle(fontSize: 13, color: AppColors.textSecondary),
              ),
            );
          }
          final visible = _expanded
              ? list
              : list.take(_HistorySection._previewCount).toList();
          return Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              for (var i = 0; i < visible.length; i++)
                _DrawerHistoryTile(
                  item: visible[i],
                  selecting: _selecting,
                  selected: _selectedId == visible[i].id,
                  loading: _loadingConversationId == visible[i].id,
                  onTap: () => _openConversation(context, visible[i].id),
                  onLongPress: _loadingConversationId == null && !_deleting
                      ? () => _enterSelect(visible[i].id)
                      : null,
                ),
              if (list.length > _HistorySection._previewCount) ...[
                const SizedBox(height: 8),
                Align(
                  alignment: Alignment.centerRight,
                  child: InkWell(
                    onTap: _selecting
                        ? null
                        : () => setState(() => _expanded = !_expanded),
                    borderRadius: BorderRadius.circular(999),
                    child: Padding(
                      padding: const EdgeInsets.symmetric(
                        horizontal: 8,
                        vertical: 6,
                      ),
                      child: Text(
                        _expanded ? '收起' : '显示全部',
                        style: const TextStyle(
                          fontSize: 12,
                          fontWeight: FontWeight.w600,
                          color: AppColors.textSecondary,
                        ),
                      ),
                    ),
                  ),
                ),
              ],
            ],
          );
        },
      ),
    );
  }

  Widget? _buildHeaderAction(
    BuildContext context,
    AsyncValue<List<ConversationListItem>> async,
  ) {
    if (_selecting && _selectedId != null) {
      return _HistorySelectionBar(
        deleting: _deleting,
        onCancel: _exitSelect,
        onDelete: () => _deleteSelected(context),
      );
    }
    final hasHistory = async.asData?.value.isNotEmpty == true;
    if (!_expanded || !hasHistory) return null;
    return TextButton(
      onPressed: _clearing ? null : () => _confirmClearAll(context),
      style: TextButton.styleFrom(
        foregroundColor: AppColors.error,
        padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
        minimumSize: Size.zero,
        tapTargetSize: MaterialTapTargetSize.shrinkWrap,
      ),
      child: Text(
        _clearing ? '清空中' : '清空全部',
        style: const TextStyle(fontSize: 13, fontWeight: FontWeight.w600),
      ),
    );
  }

  Future<void> _openConversation(BuildContext context, String id) async {
    if (_loadingConversationId != null || _deleting || _clearing) return;
    if (_selecting) {
      _toggleSelect(id);
      return;
    }
    setState(() => _loadingConversationId = id);
    final error = await ref.read(chatProvider.notifier).loadConversation(id);
    if (!mounted) return;
    setState(() => _loadingConversationId = null);
    if (error != null) {
      if (context.mounted) {
        AppToast.show(context, error, type: AppToastType.error);
      }
      return;
    }
    if (context.mounted) Navigator.of(context).maybePop();
  }

  Future<void> _confirmClearAll(BuildContext context) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: const Text('清空全部对话'),
        content: const Text('清空后无法恢复，确定继续吗？'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(dialogContext, false),
            child: const Text('取消'),
          ),
          TextButton(
            onPressed: () => Navigator.pop(dialogContext, true),
            style: TextButton.styleFrom(foregroundColor: AppColors.error),
            child: const Text('清空'),
          ),
        ],
      ),
    );
    if (confirmed != true || !mounted) return;
    setState(() => _clearing = true);
    try {
      final count = await ref
          .read(conversationHistoryProvider.notifier)
          .clearAll();
      if (!context.mounted) return;
      setState(() => _expanded = false);
      AppToast.show(context, '已清空 $count 条对话', type: AppToastType.success);
    } catch (_) {
      if (context.mounted) {
        AppToast.show(context, '清空失败，请稍后重试', type: AppToastType.error);
      }
    } finally {
      if (mounted) setState(() => _clearing = false);
    }
  }

  Future<void> _deleteSelected(BuildContext context) async {
    final id = _selectedId;
    if (id == null || _deleting) return;
    setState(() => _deleting = true);
    try {
      await ref.read(conversationHistoryProvider.notifier).deleteOne(id);
      _exitSelect();
    } catch (_) {
      if (context.mounted) {
        AppToast.show(context, '删除失败，请稍后重试', type: AppToastType.error);
      }
    } finally {
      if (mounted) setState(() => _deleting = false);
    }
  }
}

class _HistorySelectionBar extends StatelessWidget {
  final bool deleting;
  final VoidCallback onCancel;
  final VoidCallback onDelete;

  const _HistorySelectionBar({
    required this.deleting,
    required this.onCancel,
    required this.onDelete,
  });

  @override
  Widget build(BuildContext context) {
    return Align(
      alignment: Alignment.centerRight,
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 8),
        decoration: BoxDecoration(
          color: Colors.white,
          borderRadius: BorderRadius.circular(18),
          border: Border.all(color: const Color(0xFFE5E7EB)),
          boxShadow: AppColors.cardShadowLight,
        ),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            _HistoryActionButton(
              icon: Icons.delete_outline_rounded,
              label: deleting ? '删除中' : '删除',
              color: AppColors.error,
              onTap: deleting ? null : onDelete,
            ),
            const SizedBox(width: 8),
            Container(width: 1, height: 22, color: const Color(0xFFE5E7EB)),
            const SizedBox(width: 8),
            _HistoryActionButton(
              icon: Icons.close_rounded,
              label: '取消',
              color: AppColors.textSecondary,
              onTap: onCancel,
            ),
          ],
        ),
      ),
    );
  }
}

class _HistoryActionButton extends StatelessWidget {
  final IconData icon;
  final String label;
  final Color color;
  final VoidCallback? onTap;

  const _HistoryActionButton({
    required this.icon,
    required this.label,
    required this.color,
    required this.onTap,
  });

  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: onTap,
      borderRadius: BorderRadius.circular(12),
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 6),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(
              icon,
              size: 18,
              color: onTap == null ? AppColors.textHint : color,
            ),
            const SizedBox(width: 5),
            Text(
              label,
              style: TextStyle(
                fontSize: 14,
                fontWeight: FontWeight.w600,
                color: onTap == null ? AppColors.textHint : color,
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class _DrawerHistoryTile extends StatelessWidget {
  final ConversationListItem item;
  final bool selecting;
  final bool selected;
  final bool loading;
  final VoidCallback onTap;
  final VoidCallback? onLongPress;
  const _DrawerHistoryTile({
    required this.item,
    required this.selecting,
    required this.selected,
    required this.loading,
    required this.onTap,
    required this.onLongPress,
  });

  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: onTap,
      onLongPress: onLongPress,
      borderRadius: BorderRadius.circular(8),
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 2),
        decoration: selected
            ? BoxDecoration(
                color: const Color(0xFFF1F3F7),
                borderRadius: BorderRadius.circular(8),
              )
            : null,
        child: Column(
          children: [
            Padding(
              padding: const EdgeInsets.symmetric(vertical: 11),
              child: Row(
                children: [
                  Expanded(
                    child: Text(
                      _displaySummary(item),
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                      style: TextStyle(
                        fontSize: 15,
                        fontWeight: FontWeight.w600,
                        color: selected
                            ? AppColors.textSecondary
                            : AppColors.textPrimary,
                        height: 1.2,
                      ),
                    ),
                  ),
                  const SizedBox(width: 10),
                  if (loading)
                    const SizedBox(
                      width: 16,
                      height: 16,
                      child: CircularProgressIndicator(strokeWidth: 2),
                    )
                  else
                    Text(
                      _shortDate(item.updatedAt),
                      style: const TextStyle(
                        fontSize: 13,
                        fontWeight: FontWeight.w700,
                        color: AppColors.textHint,
                      ),
                    ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }

  static String _displayTitle(ConversationListItem item) {
    final s = item.summary?.trim();
    if (s != null && s.isNotEmpty) return s;
    final t = item.title?.trim();
    if (t != null && t.isNotEmpty) return t;
    return '未命名对话';
  }

  static String _displaySummary(ConversationListItem item) {
    final s = item.summary?.trim();
    if (s != null && s.isNotEmpty) return s.replaceAll(RegExp(r'\s+'), ' ');
    return _displayTitle(item);
  }

  static String _shortDate(DateTime time) {
    final now = DateTime.now();
    final local = time.toLocal();
    if (local.year == now.year &&
        local.month == now.month &&
        local.day == now.day) {
      return '今天';
    }
    final yesterday = now.subtract(const Duration(days: 1));
    if (local.year == yesterday.year &&
        local.month == yesterday.month &&
        local.day == yesterday.day) {
      return '昨天';
    }
    return '${local.month}/${local.day}';
  }
}