import { getCookieDomain } from "@/lib/getDomain";
import { env } from "@/lib/env";
import { NextResponse } from "next/server";
const BASE_URL = env.APP_URL;

export async function GET(req: Request) {
  const url = new URL(req.url);
  const code = url.searchParams.get("code");
  const isHttps = url.protocol === "https:";


  if (!code) {
    return NextResponse.redirect(`${BASE_URL}/login?error=missing_code`);
  }

  const redirectUri = `${BASE_URL}/api/auth/callback`;

  const tokenRes = await fetch(
    `${env.KEYCLOAK_BASE_URL}/realms/${env.KEYCLOAK_REALM}/protocol/openid-connect/token`,
    {
      method: "POST",
      headers: { "Content-Type": "application/x-www-form-urlencoded" },
      body: new URLSearchParams({
        client_id: env.KEYCLOAK_CLIENT_ID,
        client_secret: env.KEYCLOAK_CLIENT_SECRET,
        grant_type: "authorization_code",
        code,
        redirect_uri: redirectUri,
      }),
    }
  );

  const text = await tokenRes.text();
  let data: { access_token?: string; expires_in?: number };
  try {
    data = JSON.parse(text) as typeof data;
  } catch {
    return NextResponse.redirect(`${BASE_URL}/login?error=token_parse`);
  }

  if (!tokenRes.ok || !data.access_token) {
    console.error("token exchange failed", tokenRes.status, text);
    return NextResponse.redirect(`${BASE_URL}/login?error=token_exchange`);
  }

  const res = NextResponse.redirect(`${BASE_URL}/admin/create-news`);

  // Secure cookies are ignored on http:// (e.g. localhost) — browser drops them.
  res.cookies.set("access_token", data.access_token, {
    httpOnly: true,
    secure: isHttps,
    sameSite: "lax",
    path: "/",
    maxAge: data.expires_in,
    ...(BASE_URL ? { BASE_URL } : {}),
  });

  return res;
}