middleware.ts

import { NextResponse } from 'next/server';
import type { NextRequest } from 'next/server';
const PUBLIC_FILE = /\.(.*)$/; 

export const getValidSubdomain = (host?: string | null) => {
    let subdomain: string | null = null;
    if (!host && typeof window !== 'undefined') {
      host = window.location.host;
    }
    if(host === 'localhost:3000' || host === 'heliup.xyz') {
        return;
    }
    if (host && host.includes('.')) {
        const parts = host.split('.');
        const candidate = parts[0];
        if (candidate && parts.length > 1 && !['www', 'localhost'].includes(candidate)) {
          subdomain = candidate;
        }
      }
    return subdomain;
  };
export async function middleware(req: NextRequest) {
  const url = req.nextUrl.clone();
  if (PUBLIC_FILE.test(url.pathname) || url.pathname.includes('_next')) return;
  const host = req.headers.get('host');
  const subdomain = getValidSubdomain(host);
  if (subdomain) {
    console.log(`>>> Rewriting: ${url.pathname} to /view-organization/${subdomain}${url.pathname}`);
    url.pathname = `/view-organization/${subdomain}${url.pathname}`;
  }
  return NextResponse.rewrite(url);
}