middleware.js

import { createClient } from "@supabase/supabase-js";
import { NextResponse } from "next/server";

const supabase = createClient(
  process.env.NEXT_PUBLIC_SUPABASE_URL,
  process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY
);

function getValidURL(url) {
  if (url.includes("http://") || url.includes("https://")) {
    return url;
  }
  return "https://" + url;
}

export default async function handler(req) {
  if (req.method === "GET") {
    let pathname = req.nextUrl.pathname;
    let parts = pathname.split("/");
    let id = parts[parts.length - 1];

    try {
      const { data, error } = await supabase
        .from("urls")
        .select("original_url")
        .eq("id", id)
        .single();

      if (data && !error) {
        const shortUrl = data.original_url;
        return NextResponse.redirect(getValidURL(shortUrl));
      }
    } catch (error) {
      console.log(error.message);
    }
  }
}