/**
 * Admin 后台 - 路由配置
 *
 * 所有 Admin 页面的路由定义,使用嵌套路由。
 * 挂载路径: /admin/*
 *
 * 全部页面采用 `lazy` 动态导入。
 *
 * 此前这里是 10 个静态 import:App.tsx 引入 adminRoutes 就把
 * Dashboard/Collection/Logs/Eval/Backtest/Settings/Monitoring/
 * DataCompleteness/DataPipeline/PredictionHistory 连同它们的
 * 数据访问层一次性拉进首屏 —— 一个只想看赛程的匿名访客,
 * 要为完整的后台界面付出流量。改为 lazy 后,后台代码只在实际
 * 访问 /admin/* 时才下载。
 *
 * AdminLayout 保持静态引入:它是所有后台页面的公共外壳,
 * 若也 lazy 则会与页面 chunk 形成串行请求(先下载 layout,
 * 再下载页面),反而更慢。
 */

import { lazy, Suspense } from 'react'
import type { ReactNode } from 'react'
import { Navigate } from 'react-router-dom'
import AdminLayout from './AdminLayout'

const Dashboard = lazy(() => import('./pages/Dashboard'))
const CollectionPage = lazy(() => import('./pages/Collection'))
const DataCompletenessPage = lazy(() => import('./pages/DataCompleteness'))
const DataPipelinePage = lazy(() => import('./pages/DataPipeline'))
const PredictionsPage = lazy(() => import('./pages/PredictionHistory'))
const BacktestPage = lazy(() => import('./pages/Backtest'))
const MonitoringPage = lazy(() => import('./pages/Monitoring'))
const SettingsPage = lazy(() => import('./pages/Settings'))
const LogsPage = lazy(() => import('./pages/Logs'))
const EvalPage = lazy(() => import('./pages/EvalPage'))

/**
 * 页面级懒加载的兜底:后台各页共用。
 * 保持极简,避免后台切换时出现大块占位跳动。
 */
function AdminPageFallback() {
  return (
    <div className="flex min-h-[40vh] items-center justify-center">
      <span className="text-xs text-ink-400" role="status" aria-live="polite">
        加载中…
      </span>
    </div>
  )
}

/** 用 Suspense 包住单个后台页面 */
function page(node: ReactNode): ReactNode {
  return <Suspense fallback={<AdminPageFallback />}>{node}</Suspense>
}

export const adminRoutes = [
  {
    path: '/admin',
    element: <AdminLayout />,
    children: [
      { index: true, element: page(<Dashboard />) },
      { path: 'collection', element: page(<CollectionPage />) },
      { path: 'data-completeness', element: page(<DataCompletenessPage />) },
      { path: 'data-pipeline', element: page(<DataPipelinePage />) },
      { path: 'predictions', element: page(<PredictionsPage />) },
      { path: 'backtest', element: page(<BacktestPage />) },
      { path: 'monitoring', element: page(<MonitoringPage />) },
      { path: 'settings', element: page(<SettingsPage />) },
      { path: 'logs', element: page(<LogsPage />) },
      { path: 'eval', element: page(<EvalPage />) },
      { path: '*', element: <Navigate to="/admin" replace /> },
    ],
  },
]

export { adminRoutes as default }