middleware.ts

import NextAuth from "next-auth";

import authConfig from "./auth.config";
import {
  DEFAULT_LOGIN_REDIRECT,
  apiAuthPrefix,
  authRoutes,
  publicRoutes,
} from "@/routes";
import { getUserByUsername } from "./lib/db-functions";
import { BASE_API } from "./lib/utils";

const { auth } = NextAuth(authConfig);

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

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

  if (isApiAuthRoute || nextUrl.pathname.startsWith("/api/users")) {
    return;
  }

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

  if (!isLoggedIn && !isPublicRoute) {
    const pathnames = nextUrl.pathname.split("/");
    if (pathnames.length == 2) {
      const username = pathnames[1];
      const response = await fetch(`${BASE_API}/api/users/${username}`);
      if (response.ok) {
        return;
      }
    }

    let callbackUrl = nextUrl.pathname;
    if (nextUrl.search) {
      callbackUrl += nextUrl.search;
    }

    const encodedCallbackUrl = encodeURIComponent(callbackUrl);

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

  return;
});

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