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_theme.dart';
import '../../core/navigation_provider.dart';
import '../../providers/data_providers.dart';
import '../../services/in_app_notification_service.dart';

class NotificationCenterPage extends ConsumerStatefulWidget {
  const NotificationCenterPage({super.key});

  @override
  ConsumerState<NotificationCenterPage> createState() =>
      _NotificationCenterPageState();
}

class _NotificationCenterPageState
    extends ConsumerState<NotificationCenterPage> {
  InAppNotificationHistory? _history;
  bool _loading = true;
  bool _markingAll = false;
  String? _error;

  InAppNotificationService get _service =>
      ref.read(inAppNotificationServiceProvider);

  @override
  void initState() {
    super.initState();
    Future.microtask(_load);
  }

  Future<void> _load() async {
    if (mounted) {
      setState(() {
        _loading = true;
        _error = null;
      });
    }
    try {
      final history = await _service.getHistory();
      if (!mounted) return;
      setState(() {
        _history = history;
        _loading = false;
      });
      ref.invalidate(notificationUnreadCountProvider);
    } catch (error) {
      if (mounted) {
        setState(() {
          _error = '$error';
          _loading = false;
        });
      }
    }
  }

  Future<void> _open(InAppNotification item) async {
    if (!item.isRead) {
      await _service.acknowledge(item.id);
      if (!mounted) return;
      setState(() {
        final current = _history;
        if (current == null) return;
        _history = InAppNotificationHistory(
          unreadCount: (current.unreadCount - 1).clamp(0, current.unreadCount),
          items: current.items
              .map(
                (value) =>
                    value.id == item.id ? value.copyWith(isRead: true) : value,
              )
              .toList(),
        );
      });
      ref.invalidate(notificationUnreadCountProvider);
    }

    if (!mounted || item.actionType == null) return;
    switch (item.actionType) {
      case 'medication':
        pushRoute(ref, 'medCheckIn', params: {'id': item.actionTargetId ?? ''});
        return;
      case 'exercise':
        pushRoute(ref, 'exercisePlan');
        return;
      case 'health':
        pushRoute(ref, 'trend', params: {'type': item.actionTargetId ?? ''});
        return;
      case 'report':
        final reportId = item.actionTargetId;
        if (reportId != null && reportId.isNotEmpty) {
          pushRoute(ref, 'aiAnalysis', params: {'id': reportId});
        }
        return;
    }
  }

  Future<void> _markAllRead() async {
    if (_markingAll || (_history?.unreadCount ?? 0) == 0) return;
    setState(() => _markingAll = true);
    try {
      await _service.markAllRead();
      if (!mounted) return;
      final current = _history;
      if (current != null) {
        setState(
          () => _history = InAppNotificationHistory(
            unreadCount: 0,
            items: current.items
                .map((item) => item.copyWith(isRead: true))
                .toList(),
          ),
        );
      }
      ref.invalidate(notificationUnreadCountProvider);
    } finally {
      if (mounted) setState(() => _markingAll = false);
    }
  }

  Future<void> _delete(InAppNotification item) async {
    try {
      await _service.delete(item.id);
      if (!mounted) return;
      final current = _history;
      if (current != null) {
        setState(
          () => _history = InAppNotificationHistory(
            unreadCount: item.isRead
                ? current.unreadCount
                : (current.unreadCount - 1).clamp(0, current.unreadCount),
            items: current.items.where((value) => value.id != item.id).toList(),
          ),
        );
      }
      ref.invalidate(notificationUnreadCountProvider);
    } catch (_) {
      if (mounted) await _load();
    }
  }

  @override
  Widget build(BuildContext context) {
    final items = _history?.items ?? const <InAppNotification>[];
    final unread = _history?.unreadCount ?? 0;

    return Scaffold(
      backgroundColor: const Color(0xFFF6F8FC),
      appBar: AppBar(
        backgroundColor: Colors.white,
        elevation: 0,
        scrolledUnderElevation: 0.5,
        surfaceTintColor: Colors.transparent,
        leading: IconButton(
          icon: const Icon(Icons.arrow_back, color: AppColors.textPrimary),
          onPressed: () => popRoute(ref),
        ),
        title: const Text(
          '通知中心',
          style: TextStyle(
            fontSize: 19,
            fontWeight: FontWeight.w700,
            color: AppColors.textPrimary,
          ),
        ),
        centerTitle: true,
        actions: [
          if (unread > 0)
            Padding(
              padding: const EdgeInsets.only(right: 4),
              child: TextButton(
                onPressed: _markingAll ? null : _markAllRead,
                style: TextButton.styleFrom(
                  foregroundColor: AppColors.textPrimary,
                  padding: const EdgeInsets.symmetric(horizontal: 10),
                ),
                child: _markingAll
                    ? const SizedBox(
                        width: 16,
                        height: 16,
                        child: CircularProgressIndicator(
                          strokeWidth: 2,
                          color: AppColors.textPrimary,
                        ),
                      )
                    : const Text(
                        '全部已读',
                        style: TextStyle(
                          fontSize: 15,
                          fontWeight: FontWeight.w600,
                        ),
                      ),
              ),
            ),
          IconButton(
            tooltip: '通知设置',
            icon: const Icon(Icons.settings_outlined, color: AppColors.textPrimary),
            onPressed: () => pushRoute(ref, 'notificationPrefs'),
          ),
          const SizedBox(width: 4),
        ],
      ),
      body: RefreshIndicator(
        onRefresh: _load,
        color: const Color(0xFF6366F1),
        child: _buildBody(items, unread),
      ),
    );
  }

  Widget _buildBody(List<InAppNotification> items, int unread) {
    if (_loading) {
      return const Center(child: CircularProgressIndicator());
    }
    if (_error != null) {
      return _MessageState(
        icon: LucideIcons.wifiOff,
        title: '通知加载失败',
        message: '请检查网络连接后重试',
        buttonText: '重新加载',
        onPressed: _load,
      );
    }
    if (items.isEmpty) {
      return const _MessageState(
        icon: LucideIcons.bellOff,
        title: '暂时没有通知',
        message: '用药、运动、健康指标和报告消息会显示在这里',
      );
    }

    final today = <InAppNotification>[];
    final earlier = <InAppNotification>[];
    final now = DateTime.now();
    for (final item in items) {
      final local = item.createdAt.toLocal();
      final isToday =
          local.year == now.year &&
          local.month == now.month &&
          local.day == now.day;
      (isToday ? today : earlier).add(item);
    }

    return ListView(
      physics: const AlwaysScrollableScrollPhysics(),
      padding: const EdgeInsets.fromLTRB(16, 8, 16, 32),
      children: [
        if (unread > 0) _UnreadHint(unreadCount: unread),
        const SizedBox(height: 4),
        if (today.isNotEmpty) ...[
          const _SectionTitle('今天'),
          const SizedBox(height: 4),
          ...today.map(_buildDismissible),
        ],
        if (earlier.isNotEmpty) ...[
          if (today.isNotEmpty) const SizedBox(height: 12),
          const _SectionTitle('更早'),
          const SizedBox(height: 4),
          ...earlier.map(_buildDismissible),
        ],
      ],
    );
  }

  Widget _buildDismissible(InAppNotification item) => Padding(
    padding: const EdgeInsets.only(bottom: 12),
    child: Dismissible(
      key: ValueKey(item.id),
      direction: DismissDirection.endToStart,
      background: Container(
        alignment: Alignment.centerRight,
        padding: const EdgeInsets.only(right: 26),
        decoration: BoxDecoration(
          gradient: LinearGradient(
            begin: Alignment.centerLeft,
            end: Alignment.centerRight,
            colors: [
              AppColors.error.withValues(alpha: 0.6),
              AppColors.error,
            ],
          ),
          borderRadius: BorderRadius.circular(20),
        ),
        child: const Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(LucideIcons.trash2, color: Colors.white, size: 22),
            SizedBox(width: 8),
            Text(
              '删除',
              style: TextStyle(
                color: Colors.white,
                fontSize: 15,
                fontWeight: FontWeight.w600,
              ),
            ),
          ],
        ),
      ),
      onDismissed: (_) => _delete(item),
      child: _NotificationCard(item: item, onTap: () => _open(item)),
    ),
  );
}

/// 顶部一行精致提示——只在有未读时显示，不抢眼
class _UnreadHint extends StatelessWidget {
  final int unreadCount;
  const _UnreadHint({required this.unreadCount});

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 4, vertical: 8),
      child: Row(
        children: [
          Container(
            width: 6,
            height: 6,
            decoration: const BoxDecoration(
              color: Color(0xFFEF4444),
              shape: BoxShape.circle,
            ),
          ),
          const SizedBox(width: 8),
          Text(
            '你有 $unreadCount 条未读消息',
            style: const TextStyle(
              fontSize: 13,
              fontWeight: FontWeight.w600,
              color: AppColors.textSecondary,
            ),
          ),
        ],
      ),
    );
  }
}

class _SectionTitle extends StatelessWidget {
  final String text;
  const _SectionTitle(this.text);

  @override
  Widget build(BuildContext context) => Padding(
    padding: const EdgeInsets.fromLTRB(4, 12, 4, 6),
    child: Text(
      text,
      style: const TextStyle(
        fontSize: 13,
        fontWeight: FontWeight.w700,
        color: AppColors.textHint,
        letterSpacing: 0.3,
      ),
    ),
  );
}

class _NotificationCard extends StatelessWidget {
  final InAppNotification item;
  final VoidCallback onTap;

  const _NotificationCard({required this.item, required this.onTap});

  @override
  Widget build(BuildContext context) {
    final visual = _NotificationVisual.of(item);
    return Material(
      color: Colors.white,
      borderRadius: BorderRadius.circular(14),
      child: InkWell(
        onTap: onTap,
        borderRadius: BorderRadius.circular(14),
        child: Container(
          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
          decoration: BoxDecoration(
            color: Colors.white,
            borderRadius: BorderRadius.circular(14),
            border: Border.all(
              color: item.isRead
                  ? const Color(0xFFEEF1F6)
                  : visual.color.withValues(alpha: 0.20),
            ),
            boxShadow: [
              BoxShadow(
                color: const Color(0xFF101828).withValues(alpha: 0.03),
                blurRadius: 8,
                offset: const Offset(0, 2),
              ),
            ],
          ),
          child: Row(
            crossAxisAlignment: CrossAxisAlignment.center,
            children: [
              // 图标
              Stack(
                clipBehavior: Clip.none,
                children: [
                  Container(
                    width: 36,
                    height: 36,
                    decoration: BoxDecoration(
                      color: visual.lightColor,
                      borderRadius: BorderRadius.circular(10),
                    ),
                    child: Icon(visual.icon, size: 18, color: visual.color),
                  ),
                  if (!item.isRead)
                    Positioned(
                      top: -2,
                      right: -2,
                      child: Container(
                        width: 9,
                        height: 9,
                        decoration: BoxDecoration(
                          color: const Color(0xFFEF4444),
                          shape: BoxShape.circle,
                          border: Border.all(color: Colors.white, width: 1.5),
                        ),
                      ),
                    ),
                ],
              ),
              const SizedBox(width: 11),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Row(
                      children: [
                        Expanded(
                          child: Text(
                            item.title,
                            maxLines: 1,
                            overflow: TextOverflow.ellipsis,
                            style: TextStyle(
                              fontSize: 14,
                              fontWeight: item.isRead
                                  ? FontWeight.w600
                                  : FontWeight.w700,
                              color: AppColors.textPrimary,
                              height: 1.3,
                            ),
                          ),
                        ),
                        const SizedBox(width: 6),
                        Text(
                          _formatTime(item.createdAt),
                          style: const TextStyle(
                            fontSize: 11,
                            color: AppColors.textHint,
                          ),
                        ),
                      ],
                    ),
                    const SizedBox(height: 2),
                    Text(
                      item.message,
                      maxLines: 2,
                      overflow: TextOverflow.ellipsis,
                      style: const TextStyle(
                        fontSize: 12,
                        height: 1.45,
                        color: AppColors.textSecondary,
                      ),
                    ),
                  ],
                ),
              ),
              if (item.actionType != null) ...[
                const SizedBox(width: 4),
                const Icon(
                  Icons.chevron_right_rounded,
                  size: 18,
                  color: AppColors.textHint,
                ),
              ],
            ],
          ),
        ),
      ),
    );
  }

  static String _formatTime(DateTime value) {
    final local = value.toLocal();
    final now = DateTime.now();
    final time =
        '${local.hour.toString().padLeft(2, '0')}:'
        '${local.minute.toString().padLeft(2, '0')}';
    if (local.year == now.year &&
        local.month == now.month &&
        local.day == now.day) {
      return time;
    }
    if (local.year == now.year) return '${local.month}月${local.day}日 $time';
    return '${local.year}年${local.month}月${local.day}日 $time';
  }
}

class _NotificationVisual {
  final IconData icon;
  final Color color;
  final Color lightColor;
  final String label;

  const _NotificationVisual(this.icon, this.color, this.lightColor, this.label);

  factory _NotificationVisual.of(InAppNotification item) {
    switch (item.actionType) {
      case 'exercise':
        return const _NotificationVisual(
          LucideIcons.activity,
          Color(0xFF10B981),
          Color(0xFFD1FAE5),
          '运动',
        );
      case 'health':
        if (item.severity == 'critical') {
          return const _NotificationVisual(
            LucideIcons.triangleAlert,
            Color(0xFFEF4444),
            Color(0xFFFEE2E2),
            '紧急',
          );
        }
        return const _NotificationVisual(
          LucideIcons.heartPulse,
          Color(0xFFF59E0B),
          Color(0xFFFEF3C7),
          '健康',
        );
      case 'report':
        if (item.severity == 'error') {
          return const _NotificationVisual(
            LucideIcons.fileWarning,
            Color(0xFFEF4444),
            Color(0xFFFEE2E2),
            '报告',
          );
        }
        return const _NotificationVisual(
          LucideIcons.fileCheck2,
          Color(0xFF8B5CF6),
          Color(0xFFEDE9FE),
          '报告',
        );
      default:
        return const _NotificationVisual(
          LucideIcons.pill,
          Color(0xFF3B82F6),
          Color(0xFFDBEAFE),
          '用药',
        );
    }
  }
}

class _MessageState extends StatelessWidget {
  final IconData icon;
  final String title;
  final String message;
  final String? buttonText;
  final VoidCallback? onPressed;

  const _MessageState({
    required this.icon,
    required this.title,
    required this.message,
    this.buttonText,
    this.onPressed,
  });

  @override
  Widget build(BuildContext context) => ListView(
    physics: const AlwaysScrollableScrollPhysics(),
    padding: const EdgeInsets.fromLTRB(28, 120, 28, 32),
    children: [
      Container(
        padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 36),
        decoration: BoxDecoration(
          color: Colors.white,
          borderRadius: BorderRadius.circular(24),
          border: Border.all(color: const Color(0xFFE9EEF5)),
          boxShadow: [
            BoxShadow(
              color: const Color(0xFF101828).withValues(alpha: 0.04),
              blurRadius: 14,
              offset: const Offset(0, 4),
            ),
          ],
        ),
        child: Column(
          children: [
            Container(
              width: 72,
              height: 72,
              decoration: BoxDecoration(
                gradient: const LinearGradient(
                  begin: Alignment.topLeft,
                  end: Alignment.bottomRight,
                  colors: [Color(0xFFEEF2FF), Color(0xFFF5F3FF)],
                ),
                borderRadius: BorderRadius.circular(22),
              ),
              child: Icon(icon, size: 32, color: const Color(0xFF6366F1)),
            ),
            const SizedBox(height: 20),
            Text(
              title,
              style: const TextStyle(
                fontSize: 18,
                fontWeight: FontWeight.w800,
                color: AppColors.textPrimary,
              ),
            ),
            const SizedBox(height: 8),
            Text(
              message,
              textAlign: TextAlign.center,
              style: const TextStyle(
                fontSize: 13,
                height: 1.5,
                color: AppColors.textSecondary,
              ),
            ),
            if (buttonText != null) ...[
              const SizedBox(height: 22),
              FilledButton(
                onPressed: onPressed,
                style: FilledButton.styleFrom(
                  backgroundColor: const Color(0xFF6366F1),
                  padding: const EdgeInsets.symmetric(
                    horizontal: 28,
                    vertical: 12,
                  ),
                ),
                child: Text(buttonText!),
              ),
            ],
          ],
        ),
      ),
    ],
  );
}