import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';

import '../../providers/auth_provider.dart';
import '../../utils/i10n.dart';
import '../../utils/permissions.dart';
import '../../utils/responsive.dart';

/// 管理中心页（底部导航第 4 个 tab）：各管理模块入口。
///
/// 模块可见性由 [SessionPermissions] 统一驱动，与 [router.dart] 的路由可达性
/// 保持一致：
/// - 用户管理：所有已登录账号可见（数据范围由后端按会话权限收敛）；
/// - 渠道商管理：管理员 + 渠道商可见，代理商不可见；
/// - 其余模块（设备/激活码/公司介绍/滚动字幕）对所有账号可见。
class AdminHubPage extends ConsumerWidget {
  const AdminHubPage({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final t = AppLocalizations.of(context);
    // 注：按需求「设备分组」整合进设备管理功能（设备详情/设备列表内可改分组），
    // 「应用管理」移除以简化管理页。故网格不再单列这两项。
    final scheme = Theme.of(context).colorScheme;
    final user = ref.watch(authProvider).user;
    // 菜单可见性与路由可达性由同一套 SessionPermissions 谓词驱动：
    // - 用户管理：所有已登录账号（各角色看自己范围内用户）；
    // - 渠道商管理：管理员 + 渠道商（代理商不可见，路由层亦会拦截其深链）。
    final showUserManagement = SessionPermissions.canViewUserManagement(user);
    final showChannelManagement =
        SessionPermissions.canViewChannelManagement(user);

    final items = [
      _MenuItem(
        title: t.deviceManagement,
        icon: Icons.devices_outlined,
        color: scheme.primary,
        route: '/admin/device',
      ),
      _MenuItem(
        title: t.activationCode,
        icon: Icons.vpn_key_outlined,
        color: Colors.amber,
        route: '/admin/activation',
      ),
      if (showUserManagement)
        _MenuItem(
          title: t.userManagement,
          icon: Icons.people_outlined,
          color: scheme.outline,
          route: '/admin/sys/user',
        ),
      _MenuItem(
        title: t.companyIntro,
        icon: Icons.business_outlined,
        color: Colors.teal,
        route: '/admin/intro/store-list',
      ),
      _MenuItem(
        title: t.marqueeManagement,
        icon: Icons.subtitles_outlined,
        color: Colors.deepPurple,
        route: '/admin/marquee',
      ),
      if (showChannelManagement)
        _MenuItem(
          title: t.channelManagement,
          icon: Icons.account_tree_outlined,
          color: Colors.blue,
          route: '/admin/channel',
        ),
    ];

    return Scaffold(
      appBar: AppBar(title: Text(t.admin)),
      body: GridView.builder(
        padding: const EdgeInsets.all(16),
        gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
          crossAxisCount: context.responsive.gridCount(minTileWidth: 300),
          mainAxisSpacing: 12,
          crossAxisSpacing: 12,
          childAspectRatio: 1.2,
        ),
        itemCount: items.length,
        itemBuilder: (context, index) {
          final item = items[index];
          return Card(
            child: InkWell(
              onTap: () => context.push(item.route),
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Icon(item.icon, size: 40, color: item.color),
                  const SizedBox(height: 8),
                  Text(
                    item.title,
                    style: Theme.of(context).textTheme.titleMedium,
                  ),
                ],
              ),
            ),
          );
        },
      ),
    );
  }
}

class _MenuItem {
  const _MenuItem({
    required this.title,
    required this.icon,
    required this.color,
    required this.route,
  });

  final String title;
  final IconData icon;
  final Color color;
  final String route;
}