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

import { Lang } from "@/constants/languages"
import { env } from "@/env/server"
import { internalServerError } from "@/server/errors/next"

import { signIn } from "@/auth"

export async function GET(
  request: NextRequest,
  context: { params: { lang: Lang } }
) {
  let redirectHeaders: Headers | undefined = undefined
  let redirectTo: string

  const returnUrl = request.headers.get("x-returnurl")
  const isMFA = request.headers.get("x-mfa-login")

  if (returnUrl) {
    // Seamless login request from Current web
    redirectTo = returnUrl
  } else {
    // Normal login request from New web
    redirectTo =
      request.cookies.get("redirectTo")?.value || // Cookie gets set by authRequired middleware
      request.nextUrl.searchParams.get("redirectTo") ||
      "/"

    // Make relative URL to absolute URL
    if (redirectTo.startsWith("/")) {
      if (!env.PUBLIC_URL) {
        throw internalServerError("No value for env.PUBLIC_URL")
      }
      redirectTo = new URL(redirectTo, env.PUBLIC_URL).href
    }

    // Clean up cookie from authRequired middleware
    redirectHeaders = new Headers()
    redirectHeaders.append(
      "set-cookie",
      "redirectTo=; Expires=Thu, 01 Jan 1970 00:00:00 UTC; Path=/; HttpOnly; SameSite=Lax"
    )

    try {
      // Initiate the seamless login flow
      let redirectUrlValue
      switch (context.params.lang) {
        case Lang.da:
          redirectUrlValue = env.SEAMLESS_LOGIN_DA
          break
        case Lang.de:
          redirectUrlValue = env.SEAMLESS_LOGIN_DE
          break
        case Lang.en:
          redirectUrlValue = env.SEAMLESS_LOGIN_EN
          break
        case Lang.fi:
          redirectUrlValue = env.SEAMLESS_LOGIN_FI
          break
        case Lang.no:
          redirectUrlValue = env.SEAMLESS_LOGIN_NO
          break
        case Lang.sv:
          redirectUrlValue = env.SEAMLESS_LOGIN_SV
          break
      }
      const redirectUrl = new URL(redirectUrlValue)
      redirectUrl.searchParams.set("returnurl", redirectTo)
      redirectTo = redirectUrl.toString()
    } catch (e) {
      console.error(
        "Unable to create URL for seamless login, proceeding without it."
      )
      console.error(e)
    }
  }

  try {
    /**
     * Passing `redirect: false` to `signIn` will return the URL instead of
     * automatically redirecting to it inside of `signIn`.
     * https://github.com/nextauthjs/next-auth/blob/3c035ec/packages/next-auth/src/lib/actions.ts#L76
     */
    console.log({ login_NEXTAUTH_URL: process.env.NEXTAUTH_URL })
    console.log({ login_env: process.env })

    console.log({ login_redirectTo: redirectTo })
    const params = isMFA
      ? {
          ui_locales: context.params.lang,
          scope: ["profile_update", "openid", "profile"].join(" "),
          /**
           * The below acr value is required as for New Web same Curity Client is used for MFA
           * while in current web it is being setup using different Curity Client
           */
          acr_values:
            "urn:se:curity:authentication:otp-authenticator:OTP-Authenticator_web",
          for_origin: env.PUBLIC_URL ? env.PUBLIC_URL : "",
        }
      : {
          ui_locales: context.params.lang,
          scope: ["openid", "profile"].join(" "),
          /**
           * The `acr_values` param is used to make Curity display the proper login
           * page for Scandic. Without the parameter Curity presents some choices
           * to the user which we do not want.
           */
          acr_values: "acr",
          /**
           * The `for_origin` param is used to make Curity email login functionality working.
           * Without the parameter Curity gives Internal Error issue for login with Email link.
           */
          for_origin: env.PUBLIC_URL ? env.PUBLIC_URL : "",
        }
    const redirectUrl = await signIn(
      "curity",
      {
        redirectTo,
        redirect: false,
      },
      params
    )

    if (redirectUrl) {
      // Remove nonce for User to be able to login via Magic Link, but normal login fails as nonce becomes absent in the token response
      // if (redirectUrl.indexOf("nonce") != -1) {
      //   redirectUrl = redirectUrl.replace(/nonce=.*&code_challenge=/gi, "&code_challenge=");
      //   redirectUrl = redirectUrl.replace(/&nonce=.*/gi, "");
      // }
      return NextResponse.redirect(redirectUrl, {
        headers: redirectHeaders,
      })
    }
  } catch (error) {
    if (error instanceof AuthError) {
      console.error({ signInAuthError: error })
    } else {
      console.error({ signInError: error })
    }
  }

  return internalServerError()
}