import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const ROOT = path.resolve(__dirname, '..');
const DIST = path.join(ROOT, 'dist');

const SITE = 'https://pushkinohistory.ru';
const TITLE = 'История города Пушкино';
const DESC = 'Прошлое, настоящее, будущее города Пушкино.';

const posts = JSON.parse(fs.readFileSync(path.join(ROOT, 'src/content/posts.json'), 'utf8'));

const escapeXml = (s) =>
  String(s)
    .replace(/&/g, '&')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
    .replace(/'/g, '&apos;');

const cdata = (s) => `<![CDATA[${String(s).replace(/]]>/g, ']]]]><![CDATA[>')}]]>`;

const rfc2822 = (s) => {
  const d = new Date(s.replace(' ', 'T') + '+03:00');
  return d.toUTCString();
};

const absoluteImages = (html) =>
  html.replace(/(src|href)="\/uploads\//g, `$1="${SITE}/uploads/`);

const items = posts.map((p) => {
  const html = absoluteImages(p.html);
  const description = p.excerpt
    ? p.excerpt
    : html.replace(/<[^>]+>/g, ' ').replace(/\s+/g, ' ').trim().slice(0, 500);
  const url = `${SITE}/${p.slug}/`;
  return `    <item>
      <title>${escapeXml(p.title)}</title>
      <link>${url}</link>
      <guid isPermaLink="true">${url}</guid>
      <pubDate>${rfc2822(p.date)}</pubDate>
      <dc:creator>${cdata('История города Пушкино')}</dc:creator>
      ${(p.categories || []).map((c) => `<category>${escapeXml(c)}</category>`).join('\n      ')}
      <description>${cdata(description)}</description>
      <content:encoded>${cdata(html)}</content:encoded>
    </item>`;
}).join('\n');

const lastBuild = new Date().toUTCString();

const rss = `<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0"
     xmlns:content="http://purl.org/rss/1.0/modules/content/"
     xmlns:dc="http://purl.org/dc/elements/1.1/"
     xmlns:atom="http://www.w3.org/2005/Atom">
  <channel>
    <title>${escapeXml(TITLE)}</title>
    <link>${SITE}/</link>
    <atom:link href="${SITE}/feed/" rel="self" type="application/rss+xml" />
    <description>${escapeXml(DESC)}</description>
    <language>ru-RU</language>
    <lastBuildDate>${lastBuild}</lastBuildDate>
    <ttl>60</ttl>
${items}
  </channel>
</rss>
`;

fs.mkdirSync(DIST, { recursive: true });
fs.writeFileSync(path.join(DIST, 'feed.xml'), rss);
console.log(`rss: ${posts.length} items → dist/feed.xml`);