middleware.ts

// * middleware works on the edge

import authConfig from "./auth.config";
import NextAuth from "next-auth";
import {
  publicRoutes,
  authRoutes,
  apiAuthPrefix,
  DEFAULT_LOGIN_REDIRECT,
} from "./route";
const { auth } = NextAuth(authConfig);

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

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

  // order of if condition matters here
  if (isApiAuthRoute) {
    return null;
  }

  if (isAuthRoute) {
    if (isLoggedIn) {
      return Response.redirect(new URL(DEFAULT_LOGIN_REDIRECT, nextUrl));
    } else {
      return null;
    }
  }

  if (!isLoggedIn && !isPublicRoute) {
    // this is done to redirect to the same page after login
    let callbackUrl = nextUrl.pathname;
    if (nextUrl.search) {
      callbackUrl += nextUrl.search;
    }

    const encodedCallbackUrl = encodeURIComponent(callbackUrl);

    return Response.redirect(
      new URL(`/auth/login?callbackUrl=${encodedCallbackUrl}`, nextUrl)
    );
  }
  return null;
});

// Optionally, don't invoke Middleware on some paths
export const config = {
  matcher: ["/((?!.+\\.[\\w]+$|_next).*)", "/", "/(api|trpc)(.*)"],
};