middleware.ts

import NextAuth from 'next-auth';
import authConfig from '@/auth.config';
import {
    DEFAULT_LOGIN_REDIRECT,
    apiAuthPrefix,
    authRoutes,
    protectedRoutes,
} from '@/routes';

const { auth } = NextAuth(authConfig);

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

    const isApiAuthRoute = nextUrl.pathname.startsWith(apiAuthPrefix);
    const isProtectedRoute = protectedRoutes.some(route => new RegExp(route).test(nextUrl.pathname));
    const isAuthRoute = authRoutes.includes(nextUrl.pathname);

    if (isApiAuthRoute) {
        return undefined;
    }

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

    if (!isLoggedIn && isProtectedRoute) {
        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 undefined;
});

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