import { allPublishedForFeeds } from "@autoscholar/core";
import { db } from "@/lib/server/db";

export const runtime = "nodejs";
export const dynamic = "force-dynamic";
const esc = (s: string) =>
  s.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;").replace(/"/g, "&quot;");

export async function GET() {
  const base = process.env.APP_BASE_URL ?? "http://localhost:8470";
  const rows = await allPublishedForFeeds(db(), 100);
  const updated = rows[0] ? new Date(rows[0].p.updatedAt).toISOString() : new Date().toISOString();
  const entries = rows
    .map(
      (r) =>
        `<entry><title>${esc(r.v.title)}</title><link href="${base}/research/${r.p.slug}"/><id>${base}/research/${r.p.slug}</id><updated>${new Date(r.p.updatedAt).toISOString()}</updated><published>${new Date(r.v.publishedAt).toISOString()}</published><author><name>AutoScholar (AI-generated research)</name></author><summary>${esc(r.v.abstract)}</summary>${r.v.keywords.map((k) => `<category term="${esc(k)}"/>`).join("")}</entry>`,
    )
    .join("");
  const xml = `<?xml version="1.0" encoding="utf-8"?><feed xmlns="http://www.w3.org/2005/Atom"><title>AutoScholar.ai working papers</title><link href="${base}/research"/><link rel="self" href="${base}/feed.atom"/><id>${base}/</id><updated>${updated}</updated>${entries}</feed>`;
  return new Response(xml, {
    headers: {
      "content-type": "application/atom+xml; charset=utf-8",
      "cache-control": "public, max-age=300",
    },
  });
}