import { urlsetXml, type Entry } from '@/lib/sitemap';
import { geographySlugsForSitemap } from '@/lib/queries/geography';
import { SITE_URL } from '@/lib/site';
import { toDate } from '@/lib/format';

export const dynamic = 'force-dynamic';

/**
 * Sitemap chunk for geography routes: /countries, /compare and one /country/<slug> per geography that has
 * epidemiology observations. Static segment, so it takes precedence over /sitemap/[id] without touching it.
 */
export async function GET() {
  const now = new Date();
  const geos = await geographySlugsForSitemap();
  const entries: Entry[] = [
    { url: `${SITE_URL}/countries`, lastModified: geos.map((g) => toDate(g.updated_at)).filter((d): d is Date => !!d).sort((a, b) => b.getTime() - a.getTime())[0] ?? now, changeFrequency: 'weekly', priority: 0.7 },
    { url: `${SITE_URL}/compare`, lastModified: now, changeFrequency: 'weekly', priority: 0.5 },
    ...geos.map((g) => ({ url: `${SITE_URL}/country/${g.slug}`, lastModified: toDate(g.updated_at) ?? now, changeFrequency: 'weekly' as const, priority: 0.7 })),
  ];
  return new Response(urlsetXml(entries), { headers: { 'Content-Type': 'application/xml; charset=utf-8', 'Cache-Control': 'public, max-age=3600' } });
}