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
///
/// Tab 0: 全部（用户通知，不过滤类型）
/// Tab 1: 系统（type=SYSTEM）
/// Tab 2: 公告（独立接口 /api/v1/announcements）
/// Tab 3: 活动（type=ACTIVITY）
///
/// 注意：通知和公告是两套独立的后端接口，标记已读/全部已读
/// 需要根据当前 Tab 调用对应的接口。
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> _items = [];
  bool _isLoading = false;
  String? _error;

  // 当前是公告 Tab（index=2），需要使用公告 API
  bool get _isAnnouncementsTab => _tabController.index == 2;

  // 按 Tab index 对应的通知类型过滤（仅对通知 Tab 有效）
  static const _tabTypeFilter = <int, NotificationType?>{
    0: null,
    1: NotificationType.system,
    2: null, // 公告 Tab，类型无意义
    3: NotificationType.activity,
  };

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

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

  // ── 数据加载 ──────────────────────────────────────────────────────────────

  Future<void> _load() async {
    setState(() {
      _isLoading = true;
      _error = null;
    });
    try {
      final List<NotificationItem> result;
      if (_isAnnouncementsTab) {
        // Tab 2：公告，使用独立的公告接口
        final resp = await _notificationService.getAnnouncements(page: 1, limit: 50);
        result = resp.notifications;
      } else {
        // Tab 0/1/3：用户通知
        final resp = await _notificationService.getNotifications(
          type: _tabTypeFilter[_tabController.index],
          page: 1,
          limit: 50,
        );
        result = resp.notifications;
      }
      if (mounted) setState(() { _items = result; _isLoading = false; });
    } catch (e) {
      if (mounted) setState(() { _error = e.toString(); _isLoading = false; });
    }
  }

  // ── 操作 ──────────────────────────────────────────────────────────────────

  Future<void> _markAllAsRead() async {
    final bool success;
    if (_isAnnouncementsTab) {
      success = await _notificationService.markAllAnnouncementsAsRead();
    } else {
      // 通知全部已读（后端有 PUT /api/v1/notifications/read-all）
      success = await _notificationService.markAllNotificationsAsRead();
    }
    if (success) {
      NotificationBadgeManager().clearCount();
      _load();
    }
  }

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

  void _openDetail(NotificationItem item) {
    _markAsRead(item);
    // 传递 NotificationItem 让详情页直接渲染，无需二次请求
    Navigator.pushNamed(context, '/message/detail', arguments: item);
  }

  // ── Build ─────────────────────────────────────────────────────────────────

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        automaticallyImplyLeading: false,
        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,
          isScrollable: true,
          tabAlignment: TabAlignment.start,
          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()
              : _items.isEmpty
                  ? EmptyState.noMessages(context)
                  : RefreshIndicator(
                      onRefresh: _load,
                      child: ListView.separated(
                        padding: const EdgeInsets.symmetric(vertical: 8),
                        itemCount: _items.length,
                        separatorBuilder: (_, __) => const Divider(indent: 76),
                        itemBuilder: (_, i) => _buildItem(_items[i]),
                      ),
                    ),
    );
  }

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

  Widget _buildItem(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(context, 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: () => _openDetail(item),
    );
  }

  // ── 工具方法 ──────────────────────────────────────────────────────────────

  String _formatTime(BuildContext context, DateTime time) {
    final now = DateTime.now();
    final diff = now.difference(time);
    if (diff.inMinutes < 1) return context.t('time.justNow');
    if (diff.inMinutes < 60) return context.t('time.minutesAgo').replaceAll('{n}', '${diff.inMinutes}');
    if (diff.inHours < 24) return context.t('time.hoursAgo').replaceAll('{n}', '${diff.inHours}');
    if (diff.inDays < 7) return context.t('time.daysAgo').replaceAll('{n}', '${diff.inDays}');
    return '${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;
    }
  }
}