import { listArticles } from '@/lib/engine';

const SITE = 'https://zeropost.ru';

function escapeXml(s = '') {
  return s
    .replace(/&/g, '&')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
    .replace(/'/g, '&apos;');
}

export async function GET() {
  const articles = await listArticles({ limit: 50 });
  const items = articles.map(a => `
    <item>
      <title>${escapeXml(a.title)}</title>
      <link>${SITE}/blog/${a.slug}</link>
      <guid isPermaLink="true">${SITE}/blog/${a.slug}</guid>
      <pubDate>${new Date(a.published_at).toUTCString()}</pubDate>
      <description>${escapeXml(a.excerpt || '')}</description>
      ${(a.tags || []).map(t => `<category>${escapeXml(t)}</category>`).join('')}
    </item>`).join('');

  const xml = `<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
  <channel>
    <title>ZeroPost</title>
    <link>${SITE}</link>
    <description>Блог про практическое применение ИИ</description>
    <language>ru</language>
    <atom:link href="${SITE}/rss.xml" rel="self" type="application/rss+xml"/>
    ${items}
  </channel>
</rss>`;

  return new Response(xml, {
    headers: {
      'Content-Type': 'application/rss+xml; charset=utf-8',
      'Cache-Control': 'public, max-age=600, s-maxage=600',
    },
  });
}