// Sitemap — hand-rolled static endpoint (no @astrojs/sitemap dependency; our URL
// set is fully known at build time). /admin is intentionally excluded.
import { getCollection } from 'astro:content';
import { PAGE_FIRST, PAGE_REST } from '../lib/news.js';

// Chunk sizes are imported from lib/news.js — the same values the
// /news/[...page] route slices with, so the page count here cannot drift.
const newsPageCount = (n) => (n <= PAGE_FIRST ? 1 : 1 + Math.ceil((n - PAGE_FIRST) / PAGE_REST));

export async function GET(context) {
  const site = context.site; // always set in astro.config.mjs
  const news = (await getCollection('news', ({ data }) => !data.draft))
    .sort((a, b) => b.data.date.valueOf() - a.data.date.valueOf());
  const pages = await getCollection('pages');

  // Static pages come from the actual route files, so a new src/pages/*.astro
  // can never be forgotten here. 404 is excluded; /admin (subdirectory) is
  // intentionally unlisted. Go-live note: /login and /dashboard are mock
  // pages — filter them out before robots.txt stops disallowing everything.
  const staticPages = Object.keys(import.meta.glob('./*.astro'))
    .map((p) => p.slice(1, -'.astro'.length))
    .filter((p) => p !== '/404')
    .map((p) => (p === '/index' ? '/' : p))
    .sort();
  const urls = [
    ...staticPages, '/news',
    ...Array.from({ length: newsPageCount(news.length) - 1 }, (_, i) => `/news/${i + 2}`),
    ...pages.map((p) => `/pages/${p.id}`),
  ].map((path) => `  <url><loc>${new URL(path, site).href}</loc></url>`);
  const articles = news.map(
    (p) => `  <url><loc>${new URL(`/news/${p.id}`, site).href}</loc><lastmod>${p.data.date.toISOString().slice(0, 10)}</lastmod></url>`,
  );

  const xml = `<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
${[...urls, ...articles].join('\n')}
</urlset>
`;
  return new Response(xml, { headers: { 'Content-Type': 'application/xml; charset=utf-8' } });
}