import React, { useCallback, useEffect, useMemo, useRef, useState } from 'react';
import { Outlet, useNavigate, useLocation } from 'react-router-dom';
import { Layout, Menu, Button, Avatar, Dropdown, Drawer, Grid } from 'antd';
import {
  DashboardOutlined,
  TeamOutlined,
  HomeOutlined,
  SwapOutlined,
  DollarOutlined,
  FileTextOutlined,
  LogoutOutlined,
  UserOutlined,
  MenuFoldOutlined,
  MenuUnfoldOutlined,
  AppstoreOutlined,
  AuditOutlined,
  SettingOutlined,
  WalletOutlined,
  ReadOutlined,
  TagsOutlined,
  FileProtectOutlined,
  CalendarOutlined,
  SafetyOutlined,
  KeyOutlined,
  CheckCircleOutlined,
  LaptopOutlined,
  BellOutlined,
  ApiOutlined,
} from '@ant-design/icons';
import { usePermission } from '../hooks/usePermission';
import NotificationBell from '../components/NotificationBell';

const { Header, Sider, Content } = Layout;

interface MenuItemType {
  key: string;
  icon: React.ReactNode;
  label: string;
  permission?: string;
  children?: MenuItemType[];
}

const allMenuItems: MenuItemType[] = [
  {
    key: '/dashboard',
    icon: <DashboardOutlined />,
    label: '数据面板',
    permission: 'dashboard:view',
  },
  {
    key: 'dorm-group',
    icon: <HomeOutlined />,
    label: '宿舍运营',
    permission: 'room:view',
    children: [
      { key: '/room-visual', icon: <AppstoreOutlined />, label: '宿舍总览', permission: 'room:view' },
      { key: '/rooms', icon: <HomeOutlined />, label: '宿舍管理', permission: 'room:view' },
      { key: '/occupancies', icon: <SwapOutlined />, label: '入住管理', permission: 'occupancy:view' },
    ],
  },
  {
    key: 'student-group',
    icon: <TeamOutlined />,
    label: '学员管理',
    permission: 'student:view',
    children: [
      { key: '/students', icon: <TeamOutlined />, label: '学生管理', permission: 'student:view' },
      { key: '/classes', icon: <TeamOutlined />, label: '班级管理', permission: 'class:view' },
      { key: '/attendance', icon: <CheckCircleOutlined />, label: '考勤管理', permission: 'attendance:view' },
    ],
  },
  {
    key: 'academic-group',
    icon: <CalendarOutlined />,
    label: '教务管理',
    permission: 'schedule:view',
    children: [
      { key: '/schedules', icon: <CalendarOutlined />, label: '排课管理', permission: 'schedule:view' },
      { key: '/teacher-workspace', icon: <LaptopOutlined />, label: '教师工作台', permission: 'class:view' },
    ],
  },
  {
    key: 'classroom-group',
    icon: <ReadOutlined />,
    label: '教室管理',
    permission: 'classroom:view',
    children: [
      { key: '/classroom-schedule', icon: <CalendarOutlined />, label: '排期总览', permission: 'classroom:view' },
      { key: '/classrooms', icon: <ReadOutlined />, label: '教室列表', permission: 'classroom:view' },
      { key: '/classroom-rentals', icon: <FileProtectOutlined />, label: '租赁订单', permission: 'rental:view' },
      { key: '/tenants', icon: <TagsOutlined />, label: '租赁方', permission: 'tenant:view' },
    ],
  },
  {
    key: 'finance-group',
    icon: <DollarOutlined />,
    label: '财务管理',
    permission: 'expense:view',
    children: [
      { key: '/expenses', icon: <DollarOutlined />, label: '费用录入', permission: 'expense:view' },
      { key: '/deposits', icon: <WalletOutlined />, label: '押金管理', permission: 'deposit:view' },
      { key: '/bills', icon: <FileTextOutlined />, label: '账单管理', permission: 'bill:view' },
    ],
  },
  {
    key: 'system-group',
    icon: <SettingOutlined />,
    label: '系统管理',
    permission: 'log:view',
    children: [
      { key: '/notifications', icon: <BellOutlined />, label: '通知中心', permission: 'notification:view' },
      { key: '/operation-logs', icon: <AuditOutlined />, label: '操作日志', permission: 'log:view' },
      { key: '/roles', icon: <SafetyOutlined />, label: '角色管理', permission: 'role:view' },
      { key: '/permissions', icon: <KeyOutlined />, label: '权限一览', permission: 'role:view' },
      { key: '/integration-config', icon: <ApiOutlined />, label: '钉钉集成配置', permission: 'integration:read' },
      { key: '/users', icon: <SettingOutlined />, label: '账号管理', permission: 'user:view' },
    ],
  },
];

const MainLayout: React.FC = () => {
  const [collapsed, setCollapsed] = useState(false);
  const [drawerOpen, setDrawerOpen] = useState(false);
  const [openKeys, setOpenKeys] = useState<string[]>([]);
  const prevPathname = useRef('');
  const navigate = useNavigate();
  const location = useLocation();
  const user = useMemo(() => JSON.parse(localStorage.getItem('user') || '{}'), []);
  const { hasPermission } = usePermission();

  const screens = Grid.useBreakpoint();
  const isMobile = !screens.sm;                          // < 576px (仅 xs)
  const isTablet = (screens.sm || screens.md) && !screens.lg; // 576-991px
  const isDesktop = !!screens.lg;                        // >= 992px

  // 按 permission 过滤菜单
  const filterByPermission = (items: MenuItemType[]): MenuItemType[] => {
    return items
      .map((item) => {
        if (item.children) {
          const kids = filterByPermission(item.children);
          if (kids.length === 0) return null;
          return { ...item, children: kids };
        }
        if (!item.permission) return item;
        return hasPermission(item.permission) ? item : null;
      })
      .filter(Boolean) as MenuItemType[];
  };

  const menuItems = useMemo(() => filterByPermission(allMenuItems), [hasPermission]);

  const handleLogout = useCallback(() => {
    localStorage.removeItem('token');
    localStorage.removeItem('user');
    localStorage.removeItem('permissions');
    navigate('/login');
  }, [navigate]);

  const handleMenuClick = useCallback((key: string) => {
    navigate(key);
    if (isMobile) setDrawerOpen(false);
  }, [navigate, isMobile]);

  const findSelectedKeys = (items: MenuItemType[], pathname: string): string[] => {
    for (const item of items) {
      if (item.key === pathname) return [item.key];
      if (item.children) {
        const found = findSelectedKeys(item.children, pathname);
        if (found.length > 0) return found;
      }
    }
    return [pathname];
  };

  const findOpenKeys = (items: MenuItemType[], pathname: string): string[] => {
    for (const item of items) {
      if (item.children) {
        if (item.children.some((c) => c.key === pathname || (c.children && c.children.some((gc) => gc.key === pathname)))) {
          return [item.key];
        }
      }
    }
    return [];
  };

  const selectedKeys = useMemo(() => findSelectedKeys(menuItems, location.pathname), [menuItems, location.pathname]);
  // 路径变化时同步展开的菜单（不干扰用户手动展开/收起）
  useEffect(() => {
    if (location.pathname !== prevPathname.current) {
      prevPathname.current = location.pathname;
      setOpenKeys(findOpenKeys(menuItems, location.pathname));
    }
  }, [location.pathname, menuItems]);

  const handleOpenChange = useCallback((keys: string[]) => {
    // 只保留最新打开的一个子菜单
    const latestKey = keys[keys.length - 1];
    setOpenKeys(latestKey ? [latestKey] : []);
  }, []);



  const transformToMenuItems = (items: MenuItemType[]): any[] => {
    return items.map((item) => ({
      key: item.key,
      icon: item.icon,
      label: item.label,
      children: item.children ? transformToMenuItems(item.children) : undefined,
    }));
  };
  const menuContent = useMemo(() => (
    <Menu
      theme="light"
      mode="inline"
      selectedKeys={selectedKeys}
      openKeys={openKeys}
      onOpenChange={handleOpenChange}
      items={transformToMenuItems(menuItems)}
      onClick={({ key }) => handleMenuClick(key)}
      style={{ border: 'none' }}
    />
  ), [selectedKeys, openKeys, menuItems, handleMenuClick]);

  return (
    <Layout style={{ minHeight: '100vh' }}>
      {!isMobile && (
        <Sider
          trigger={null}
          collapsible
          collapsed={isTablet ? true : collapsed}
          theme="light"
          style={{ background: '#fff', borderRight: '1px solid #e5e5e7' }}
        >
          <div
            style={{
              height: 64,
              display: 'flex',
              alignItems: 'center',
              justifyContent: 'center',
              color: '#1d1d1f',
              fontSize: (isTablet || collapsed) ? 16 : 17,
              fontWeight: 600,
              borderBottom: '1px solid #e5e5e7',
            }}
          >
            {(isTablet || collapsed) ? '恭' : '恭学教育基地'}
          </div>
          {menuContent}
        </Sider>
      )}
      {isMobile && (
        <Drawer
          placement="left"
          open={drawerOpen}
          onClose={() => setDrawerOpen(false)}
          size={240}
          styles={{ body: { padding: 0 } }}
          title="恭学教育基地"
        >
          {menuContent}
        </Drawer>
      )}
      <Layout style={{ background: '#f5f5f7' }}>
        <Header
          style={{
            padding: '0 16px',
            background: '#fff',
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'space-between',
            borderBottom: '1px solid #e5e5e7',
            boxShadow: 'none',
          }}
        >
          <Button
            type="text"
            aria-label={isMobile || isTablet ? '打开菜单' : collapsed ? '展开侧边栏' : '收起侧边栏'}
            icon={
              isMobile || isTablet ? (
                <MenuUnfoldOutlined />
              ) : collapsed ? (
                <MenuUnfoldOutlined />
              ) : (
                <MenuFoldOutlined />
              )
            }
            onClick={() => (isMobile || isTablet ? setDrawerOpen(true) : setCollapsed(!collapsed))}
          />
          <div style={{ display: 'flex', alignItems: 'center', gap: 16 }}>
            <NotificationBell />
            <Dropdown
              menu={{
                items: [
                  {
                    key: 'logout',
                    icon: <LogoutOutlined />,
                    label: '退出登录',
                    onClick: handleLogout,
                  },
                ],
              }}
            >
              <div
                role="button"
                tabIndex={0}
                aria-label="用户菜单"
                style={{ cursor: 'pointer', display: 'flex', alignItems: 'center', gap: 8 }}
              >
                <Avatar icon={<UserOutlined />} />
                {isDesktop && <span>{user.name || user.username || '用户'}</span>}
              </div>
            </Dropdown>
          </div>
        </Header>
        <Content
          style={{
            margin: isMobile ? 12 : isTablet ? 16 : 24,
            padding: isMobile ? 12 : isTablet ? 16 : 24,
            background: '#fff',
            borderRadius: 12,
          }}
        >
          <Outlet />
        </Content>
      </Layout>
    </Layout>
  );
};

export default MainLayout;