import { Suspense, lazy } from 'react'
import { BrowserRouter, Navigate, Route, Routes, useLocation } from 'react-router-dom'
import { ConfigProvider, App as AntdApp, Spin } from 'antd'
import zhCN from 'antd/locale/zh_CN'
import { AuthProvider } from './store/auth'
import { useAuth } from './store/authContext'
import MainLayout from './layouts/MainLayout'
import Login from './pages/Login'
import type { ReactNode } from 'react'

// 路由级懒加载：把原先 1.6MB 的首屏单包按页面拆分。
// Login 与 MainLayout 保持同步加载——它们是未登录用户和登录后首帧的必经路径，
// 懒加载只会凭空多一次往返。
const Dashboard = lazy(() => import('./pages/Dashboard'))
const OpenApiDocs = lazy(() => import('./pages/OpenApiDocs'))
const ApiDebugger = lazy(() => import('./pages/ApiDebugger'))
const Delivery = lazy(() => import('./pages/Delivery'))
const MerchantCenter = lazy(() => import('./pages/MerchantCenter'))
const MerchantRecharge = lazy(() => import('./pages/MerchantRecharge'))
const AlertSettings = lazy(() => import('./pages/AlertSettings'))
const PlatformMerchants = lazy(() => import('./pages/PlatformMerchants'))
const PlatformOrders = lazy(() => import('./pages/PlatformOrders'))
const PlatformProducts = lazy(() => import('./pages/PlatformProducts'))
const PlatformUsers = lazy(() => import('./pages/PlatformUsers'))
const PlatformRock = lazy(() => import('./pages/PlatformRock'))

// RouteFallback 是懒加载页面与权限校验的统一占位，避免切换时白屏。
function RouteFallback() {
  return <div style={{ textAlign: 'center', padding: '100px 0' }}><Spin size="large" /></div>
}

function PrivateRoute({ children }: { children: ReactNode }) {
  const { token } = useAuth()
  if (!token) return <Navigate to="/login" replace />
  return <>{children}</>
}

function AdminRoute({ children }: { children: ReactNode }) {
  const { isAdmin } = useAuth()
  if (!isAdmin) return <Navigate to="/" replace />
  return <>{children}</>
}

const tabPermissions: Record<string, string> = {
  products: 'products:manage',
  orders: 'orders:manage',
  wallet: 'wallet:ledger',
  api: 'api:manage',
  callbacks: 'callbacks:manage',
  members: 'members:manage',
}

function MerchantPermissionRoute({ permission, children }: { permission?: string; children: ReactNode }) {
  const { isAdmin, merchantLoading, merchantPermissions } = useAuth()
  if (isAdmin || !permission) return <>{children}</>
  if (merchantLoading) {
    return <RouteFallback />
  }
  return merchantPermissions.includes(permission) ? <>{children}</> : <Navigate to="/" replace />
}

function MerchantCenterRoute() {
  const location = useLocation()
  const requestedTab = new URLSearchParams(location.search).get('tab') || 'products'
  const tab = requestedTab in tabPermissions ? requestedTab : 'products'
  return (
    <MerchantPermissionRoute permission={tabPermissions[tab]}>
      <MerchantCenter />
    </MerchantPermissionRoute>
  )
}

function AppRoutes() {
  return (
    <Routes>
      <Route path="/login" element={<Login />} />
      <Route path="/delivery/:channel/:orderNo" element={<Delivery />} />
      <Route
        path="/"
        element={
          <PrivateRoute>
            <MainLayout />
          </PrivateRoute>
        }
      >
        <Route index element={<Dashboard />} />
        <Route path="merchant-center" element={<MerchantCenterRoute />} />
        <Route path="merchant-products" element={<MerchantPermissionRoute permission="products:manage"><MerchantCenter fixedTab="products" title="商品列表" /></MerchantPermissionRoute>} />
        <Route path="merchant-orders" element={<MerchantPermissionRoute permission="orders:manage"><MerchantCenter fixedTab="orders" title="发货订单" /></MerchantPermissionRoute>} />
        <Route path="merchant-wallet" element={<MerchantPermissionRoute permission="wallet:ledger"><MerchantCenter fixedTab="wallet" title="积分明细" /></MerchantPermissionRoute>} />
        <Route path="merchant-recharge" element={<MerchantPermissionRoute permission="wallet:view"><MerchantRecharge /></MerchantPermissionRoute>} />
        <Route path="merchant-alert-settings" element={<MerchantPermissionRoute permission="recharge:manage"><AlertSettings /></MerchantPermissionRoute>} />
        <Route path="merchant-members" element={<MerchantPermissionRoute permission="members:manage"><MerchantCenter fixedTab="members" title="成员" /></MerchantPermissionRoute>} />
        <Route path="merchant-callbacks" element={<MerchantPermissionRoute permission="callbacks:manage"><MerchantCenter fixedTab="callbacks" title="回调" /></MerchantPermissionRoute>} />
        <Route path="merchant-api-keys" element={<MerchantPermissionRoute permission="api:manage"><MerchantCenter fixedTab="api" title="API 密钥" /></MerchantPermissionRoute>} />
        <Route
          path="platform-orders"
          element={
            <AdminRoute>
              <PlatformOrders />
            </AdminRoute>
          }
        />
        <Route
          path="platform-merchants"
          element={
            <AdminRoute>
              <PlatformMerchants />
            </AdminRoute>
          }
        />
        <Route
          path="platform-products"
          element={
            <AdminRoute>
              <PlatformProducts />
            </AdminRoute>
          }
        />
        <Route
          path="platform-rock"
          element={
            <AdminRoute>
              <PlatformRock />
            </AdminRoute>
          }
        />
        <Route path="platform-users" element={<AdminRoute><PlatformUsers /></AdminRoute>} />
        <Route path="open-api" element={<MerchantPermissionRoute permission="api:manage"><OpenApiDocs /></MerchantPermissionRoute>} />
        <Route
          path="api-debug"
          element={
            <AdminRoute>
              <ApiDebugger />
            </AdminRoute>
          }
        />
      </Route>
      <Route path="*" element={<Navigate to="/" replace />} />
    </Routes>
  )
}

export default function App() {
  return (
    <ConfigProvider
      locale={zhCN}
      theme={{
        token: {
          colorPrimary: '#2563eb',
          colorInfo: '#2563eb',
          colorSuccess: '#16a34a',
          colorWarning: '#d97706',
          colorError: '#dc2626',
          borderRadius: 8,
          fontFamily: `-apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif`,
        },
        components: {
          Card: {
            paddingLG: 20,
            borderRadiusLG: 10,
          },
          Table: {
            headerBg: '#f8fafc',
            headerColor: '#475569',
            headerSplitColor: 'transparent',
            rowHoverBg: '#f1f5f9',
          },
          Button: {
            fontWeight: 600,
            borderRadius: 6,
          },
          Tag: {
            borderRadiusSM: 4,
          },
        },
      }}
    >
      <AntdApp>
        <AuthProvider>
          <BrowserRouter>
            <Suspense fallback={<RouteFallback />}>
              <AppRoutes />
            </Suspense>
          </BrowserRouter>
        </AuthProvider>
      </AntdApp>
    </ConfigProvider>
  )
}