middleware.ts

import { auth } from '@/auth';
import {
  authRoutes,
  publicRoutes,
  apiAuthPrefix,
  DEFAULT_SIGNIN_REDIRECT
} from '@/routes';

export default auth((req) => {
  const { nextUrl } = req;
  const isSignedIn = !!req.auth;

  const isApiAuthRoute = nextUrl.pathname.startsWith(apiAuthPrefix);
  const isPublicRoute = publicRoutes.includes(nextUrl.pathname);
  const isAuthRoute = authRoutes.includes(nextUrl.pathname);

  if (isApiAuthRoute || isPublicRoute) {
    return;
  }

  if (isAuthRoute) {
    if (isSignedIn) {
      return Response.redirect(
        new URL(DEFAULT_SIGNIN_REDIRECT, nextUrl).toString()
      );
    }

    return;
  }

  if (!isSignedIn && !isPublicRoute) {
    let callbackUrl = nextUrl.pathname;
    if (nextUrl.search) {
      callbackUrl += nextUrl.search;
    }

    const encodedCallbackUrl = encodeURIComponent(callbackUrl);

    return Response.redirect(
      new URL(
        `/auth/sign-in?callbackUrl=${encodedCallbackUrl}`,
        nextUrl
      ).toString()
    );
  }

  return;
});

export const config = {
  matcher: ['/((?!.+\\.[\\w]+$|_next).*)', '/', '/(api|trpc)(.*)']
};