import { type NextRequest, NextResponse } from "next/server"
import { AuthError } from "next-auth"

import { Lang } from "@scandic-hotels/common/constants/language"
import { logger } from "@scandic-hotels/common/logger"
import { isValidLang } from "@scandic-hotels/common/utils/languages"

import { env } from "@/env/server"
import { internalServerError } from "@/server/errors/next"
import { getPublicURL } from "@/server/utils"

import { signOut } from "@/auth"

export async function GET(
  request: NextRequest,
  context: RouteContext<"/[lang]/logout">
) {
  const publicURL = getPublicURL(request)
  const params = await context.params
  const lang = isValidLang(params.lang) ? params.lang : Lang.en

  let redirectTo: string = ""

  logger.debug(
    `[logout] source: ${request.headers.get("x-logout-source") || "normal"}`
  )

  const redirectToSearchParamValue =
    request.nextUrl.searchParams.get("redirectTo")
  const redirectToFallback = `/${lang}`

  redirectTo = redirectToSearchParamValue || redirectToFallback

  // Make relative URL to absolute URL
  if (redirectTo.startsWith("/")) {
    logger.debug(`[logout] make redirectTo absolute, from ${redirectTo}`)
    redirectTo = new URL(redirectTo, publicURL).href
    logger.debug(`[logout] make redirectTo absolute, to ${redirectTo}`)
  }

  try {
    redirectTo = `${env.CURITY_ISSUER_USER}/authn/authenticate/logout?redirect_uri=${encodeURIComponent(redirectTo)}`
    logger.debug(`[logout] final redirectUrl: ${redirectTo}`)

    /**
     * Passing `redirect: false` to `signOut` will return a result object
     * instead of automatically redirecting inside of `signOut`.
     * https://github.com/nextauthjs/next-auth/blob/3c035ec/packages/next-auth/src/lib/actions.ts#L104
     */
    const redirectUrlObj = await signOut({
      redirectTo,
      redirect: false,
    })

    if (redirectUrlObj) {
      logger.debug(`[logout] redirecting to: ${redirectUrlObj.redirect}`)
      return NextResponse.redirect(redirectUrlObj.redirect)
    } else {
      logger.error(`[logout] missing redirectUrlObj reponse from signOut()`)
    }
  } catch (error) {
    if (error instanceof AuthError) {
      logger.error("signOutAuthError", { signOutAuthError: error })
    } else {
      logger.error("signOutError", { signOutError: error })
    }
  }

  return internalServerError()
}