import { createClient } from "@/utils/supabase/server";
import { NextResponse } from "next/server";
import { AUTH_ERROR_MESSAGES, AUTH_ROUTES } from "@/features/auth/constants";
import { getAuthErrorMessage } from "@/features/auth/errors";

/**
 * OAuth/??? ?? ?? ??
 */
export async function GET(request: Request) {
  const { searchParams, origin } = new URL(request.url);

  const code = searchParams.get("code");
  const next = searchParams.get("next") ?? AUTH_ROUTES.HOME;
  const error = searchParams.get("error");
  const error_code = searchParams.get("error_code");
  const error_description = searchParams.get("error_description");

  if (error) {
    console.error("Auth callback error parameter:", {
      error,
      error_code,
      error_description,
    });

    let message: string = AUTH_ERROR_MESSAGES.DEFAULT;

    if (error === "access_denied") {
      message = AUTH_ERROR_MESSAGES.OAUTH_ACCESS_DENIED;
    } else if (error === "server_error") {
      message = AUTH_ERROR_MESSAGES.OAUTH_SERVER_ERROR;
    }

    return NextResponse.redirect(
      `${origin}${AUTH_ROUTES.LOGIN}?message=${encodeURIComponent(message)}`,
    );
  }

  if (code) {
    const supabase = await createClient();
    const { error: exchangeError } =
      await supabase.auth.exchangeCodeForSession(code);

    if (!exchangeError) {
      const forwardedHost = request.headers.get("x-forwarded-host");
      const isLocalEnv = process.env.NODE_ENV === "development";

      if (isLocalEnv) {
        return NextResponse.redirect(`${origin}${next}`);
      }

      if (forwardedHost) {
        return NextResponse.redirect(`https://${forwardedHost}${next}`);
      }

      return NextResponse.redirect(`${origin}${next}`);
    }

    console.error("Auth exchange error:", exchangeError.message);
    const message = getAuthErrorMessage(exchangeError);
    return NextResponse.redirect(
      `${origin}${AUTH_ROUTES.LOGIN}?message=${encodeURIComponent(message)}`,
    );
  }

  const errorMessage = encodeURIComponent(
    AUTH_ERROR_MESSAGES.INVALID_AUTH_LINK,
  );
  return NextResponse.redirect(
    `${origin}${AUTH_ROUTES.LOGIN}?message=${errorMessage}`,
  );
}