trails/apps/journal/app/routes/api.auth.register.ts

import { data } from "react-router";
import type { Route } from "./+types/api.auth.register";
import { startRegistration, finishRegistration, createSession } from "~/lib/auth.server";

export async function action({ request }: Route.ActionArgs) {
  const body = await request.json();
  const { step, email, username, response, challenge, userId } = body;

  try {
    if (step === "start") {
      const result = await startRegistration(email, username);
      return data({ step: "challenge", options: result.options, userId: result.userId });
    }

    if (step === "finish") {
      const newUserId = await finishRegistration(userId, email, username, response, challenge);
      const cookie = await createSession(newUserId, request);
      return data({ step: "done" }, { headers: { "Set-Cookie": cookie } });
    }

    return data({ error: "Invalid step" }, { status: 400 });
  } catch (e) {
    return data({ error: (e as Error).message }, { status: 400 });
  }
}