import 'package:flutter/material.dart';
import '../../../../app/theme/app_colors.dart';
import '../../../../app/theme/app_typography.dart';
import '../../../../app/i18n/app_localizations.dart';
import '../../../../shared/widgets/empty_state.dart';
import '../../../../core/services/notification_service.dart';
import '../../../../core/providers/notification_badge_manager.dart';

/// A8. 消息模块
///
/// 通知 + 公告，分类Tab + 消息详情
/// 接入后端真实 API
class MessagePage extends StatefulWidget {
  const MessagePage({super.key});

  @override
  State<MessagePage> createState() => _MessagePageState();
}

class _MessagePageState extends State<MessagePage>
    with SingleTickerProviderStateMixin {
  late TabController _tabController;
  final NotificationService _notificationService = NotificationService();

  List<NotificationItem> _notifications = [];
  bool _isLoading = false;
  String? _error;
  NotificationType? _currentFilter;

  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 4, vsync: this);
    _tabController.addListener(() {
      if (!_tabController.indexIsChanging) {
        _onTabChanged(_tabController.index);
      }
    });
    _loadNotifications();
  }

  @override
  void dispose() {
    _tabController.dispose();
    super.dispose();
  }

  void _onTabChanged(int index) {
    switch (index) {
      case 0:
        _currentFilter = null;
        break;
      case 1:
        _currentFilter = NotificationType.system;
        break;
      case 2:
        _currentFilter = NotificationType.announcement;
        break;
      case 3:
        _currentFilter = NotificationType.activity;
        break;
    }
    _loadNotifications();
  }

  Future<void> _loadNotifications() async {
    setState(() {
      _isLoading = true;
      _error = null;
    });

    try {
      final response = await _notificationService.getNotifications(
        type: _currentFilter,
      );
      if (mounted) {
        setState(() {
          _notifications = response.notifications;
          _isLoading = false;
        });
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _error = e.toString();
          _isLoading = false;
        });
      }
    }
  }

  Future<void> _markAllAsRead() async {
    final success = await _notificationService.markAllAnnouncementsAsRead();
    if (success) {
      NotificationBadgeManager().clearCount();
      _loadNotifications();
    }
  }

  Future<void> _markAsRead(NotificationItem item) async {
    if (item.isRead) return;
    final success = await _notificationService.markAsRead(item.id);
    if (success) {
      NotificationBadgeManager().decrementCount();
      _loadNotifications();
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(context.t('message.title')),
        actions: [
          TextButton(
            onPressed: _markAllAsRead,
            child: Text(context.t('notification.markAllRead'),
                style: AppTypography.labelSmall.copyWith(color: AppColors.primary)),
          ),
        ],
        bottom: TabBar(
          controller: _tabController,
          tabs: [
            Tab(text: context.t('common.all')),
            Tab(text: context.t('notification.system')),
            Tab(text: context.t('notification.announcement')),
            Tab(text: context.t('notification.activity')),
          ],
        ),
      ),
      body: _isLoading
          ? const Center(child: CircularProgressIndicator())
          : _error != null
              ? _buildErrorView()
              : _notifications.isEmpty
                  ? EmptyState.noMessages()
                  : RefreshIndicator(
                      onRefresh: _loadNotifications,
                      child: ListView.separated(
                        padding: const EdgeInsets.symmetric(vertical: 8),
                        itemCount: _notifications.length,
                        separatorBuilder: (_, __) => const Divider(indent: 76),
                        itemBuilder: (context, index) {
                          return _buildMessageItem(_notifications[index]);
                        },
                      ),
                    ),
    );
  }

  Widget _buildErrorView() {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Text(context.t('notification.loadFailed'),
              style: AppTypography.bodyMedium),
          const SizedBox(height: 16),
          ElevatedButton(
            onPressed: _loadNotifications,
            child: Text(context.t('notification.retry')),
          ),
        ],
      ),
    );
  }

  Widget _buildMessageItem(NotificationItem item) {
    return ListTile(
      contentPadding: const EdgeInsets.symmetric(horizontal: 20, vertical: 4),
      leading: Container(
        width: 44,
        height: 44,
        decoration: BoxDecoration(
          color: _iconColor(item.type).withValues(alpha: 0.1),
          shape: BoxShape.circle,
        ),
        child: Icon(_iconData(item.type), size: 22, color: _iconColor(item.type)),
      ),
      title: Row(
        children: [
          Expanded(
            child: Text(item.title,
                style: AppTypography.labelMedium.copyWith(
                  fontWeight: item.isRead ? FontWeight.w400 : FontWeight.w600,
                )),
          ),
          if (item.publishedAt != null)
            Text(_formatTime(item.publishedAt!), style: AppTypography.caption),
        ],
      ),
      subtitle: Padding(
        padding: const EdgeInsets.only(top: 4),
        child: Text(
          item.content,
          style: AppTypography.bodySmall,
          maxLines: 2,
          overflow: TextOverflow.ellipsis,
        ),
      ),
      trailing: !item.isRead
          ? Container(
              width: 8,
              height: 8,
              decoration: const BoxDecoration(
                color: AppColors.primary,
                shape: BoxShape.circle,
              ),
            )
          : null,
      onTap: () {
        _markAsRead(item);
        Navigator.pushNamed(context, '/message/detail');
      },
    );
  }

  String _formatTime(DateTime time) {
    final now = DateTime.now();
    final diff = now.difference(time);
    if (diff.inMinutes < 1) return '刚刚';
    if (diff.inMinutes < 60) return '${diff.inMinutes}分钟前';
    if (diff.inHours < 24) return '${diff.inHours}小时前';
    if (diff.inDays < 7) return '${diff.inDays}天前';
    return '${time.month}/${time.day}';
  }

  IconData _iconData(NotificationType type) {
    switch (type) {
      case NotificationType.system:
        return Icons.settings_rounded;
      case NotificationType.activity:
        return Icons.swap_horiz_rounded;
      case NotificationType.reward:
        return Icons.card_giftcard_rounded;
      case NotificationType.upgrade:
        return Icons.system_update_rounded;
      case NotificationType.announcement:
        return Icons.campaign_rounded;
    }
  }

  Color _iconColor(NotificationType type) {
    switch (type) {
      case NotificationType.system:
        return AppColors.primary;
      case NotificationType.activity:
        return AppColors.success;
      case NotificationType.reward:
        return AppColors.warning;
      case NotificationType.upgrade:
        return AppColors.info;
      case NotificationType.announcement:
        return AppColors.info;
    }
  }
}