AstralRinth/apps/frontend/src/middleware/auth.js

const whitelistedParams = ["flow", "error"];

export default defineNuxtRouteMiddleware(async (_to, from) => {
  const config = useRuntimeConfig();
  const auth = await useAuth();

  if (!auth.value.user) {
    const fullPath = from.fullPath;

    const url = new URL(fullPath, config.public.apiBaseUrl);

    const extractedParams = whitelistedParams.reduce((acc, param) => {
      if (url.searchParams.has(param)) {
        acc[param] = url.searchParams.get(param);
        url.searchParams.delete(param);
      }
      return acc;
    }, {});

    const redirectPath = encodeURIComponent(url.pathname + url.search);

    return await navigateTo(
      {
        path: "/auth/sign-in",
        query: {
          redirect: redirectPath,
          ...extractedParams,
        },
      },
      {
        replace: true,
      },
    );
  }
});