import { NextResponse } from 'next/server';

export async function GET(request) {
    const forwardedHost = request.headers.get('x-forwarded-host');
    const protocol = request.headers.get('x-forwarded-proto') || 'https';
    const host = forwardedHost ? `${protocol}://${forwardedHost}` : request.nextUrl.origin;
    return new NextResponse(
        `User-agent: *` + `\n` + 
        `Disallow: /admin` + `\n` + 
        `Disallow: /private` + `\n` + 
        `Sitemap: ${host}/sitemap.xml`,
        { headers: { 'Content-Type': 'text/plain' } }
    );
}