middleware.ts

import authConfig from "./auth.config";
import NextAuth from "next-auth";
import {
  DEFAULT_LOGIN_REDIRECT,
  apiAuthPrefix,
  authRoutes,
  publicRoutes,
} from "./routes";

const { auth } = NextAuth(authConfig);

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

  // next auth server
  const isApiAuthRoutes = nextUrl.pathname.startsWith(apiAuthPrefix);

  const isPublicRoutes = publicRoutes.includes(nextUrl.pathname);

  const isAuthRoute = authRoutes.includes(nextUrl.pathname);

  // next auth server
  if (isApiAuthRoutes) {
    return null;
  }

  // sign-in/log-in page
  if (isAuthRoute) {
    if (isLoggedIn) {
      return Response.redirect(new URL(DEFAULT_LOGIN_REDIRECT, nextUrl));
    }
    return null;
  }

  // protected routes
  if (!isLoggedIn && !isPublicRoutes) {
    return Response.redirect(new URL("/auth/login", nextUrl));
  }

  return null;
});

// this just help to invoke auth , not related to protected routes or public routes
export const config = {
  matcher: ["/((?!.+\\.[\\w]+$|_next).*)", "/", "/(api|trpc)(.*)"],
};