website/src/app/(payload)/admin/[[...segments]]/page.tsx

import configPromise from '@payload-config'
import { RootPage, generatePageMetadata } from '@payloadcms/next/views'
import { headers as getHeaders } from 'next/headers'
import { notFound, redirect } from 'next/navigation'
import { executeAuthStrategies, getPayload } from 'payload'
// @ts-expect-error generated by Payload admin import map generator
import { importMap } from '../importMap.js'
import { AdminHome } from '../_components/admin-home'
import { AdminLoginForm } from '../_components/admin-login-form'

type AdminPageProps = {
  params: Promise<{ segments?: string[] }>
  searchParams: Promise<{ [key: string]: string | string[] | undefined }>
}

async function getAdminSegments(params: AdminPageProps['params']) {
  const value = await params
  return Array.isArray(value.segments) ? value.segments.filter(Boolean) : []
}

async function getAdminUser() {
  const [config, headers] = await Promise.all([configPromise, getHeaders()])
  const payload = await getPayload({
    config,
    importMap,
  })
  const { user } = await executeAuthStrategies({
    headers,
    payload,
  })

  return user
}

export async function generateMetadata({ params, searchParams }: AdminPageProps) {
  const segments = await getAdminSegments(params)

  if (segments[0] === 'forgot') notFound()

  return generatePageMetadata({
    config: configPromise,
    params: Promise.resolve({ segments }),
    searchParams: searchParams as Promise<{ [key: string]: string | string[] }>,
  })
}

export default async function PayloadAdminPage({ params, searchParams }: AdminPageProps) {
  const segments = await getAdminSegments(params)
  const resolvedSearchParams = await searchParams

  if (segments[0] === 'forgot') notFound()

  if (segments.length === 1 && segments[0] === 'login') {
    if (await getAdminUser()) redirect('/admin')

    return <AdminLoginForm />
  }

  if (segments.length === 0) {
    const user = await getAdminUser()
    if (!user) redirect('/admin/login?redirect=/admin')

    return <AdminHome cacheCleared={resolvedSearchParams.cache === 'cleared'} user={user} />
  }

  return RootPage({
    config: configPromise,
    importMap,
    params: Promise.resolve({ segments }),
    searchParams: Promise.resolve(resolvedSearchParams as { [key: string]: string | string[] }),
  })
}