/**
 * `/sitemap.xml`, from the API's `/slugs` — one request for every published
 * address, instead of paging through each collection.
 *
 * Cached like any page: a record published a minute ago can wait a minute to
 * be listed. If the API is down the answer is a 503 rather than a sitemap
 * with half the site missing from it, which a crawler would believe.
 */
import {
  defineEventHandler,
  getRequestHeaders,
  setResponseHeader,
  setResponseStatus,
} from 'h3';

import { pireonApi } from '../../app/core/api';
import { originFromHeaders } from '../../app/core/origin';
import { buildSitemap } from '../../app/core/sitemap';

export default defineEventHandler(async (event) => {
  const origin = originFromHeaders(getRequestHeaders(event)) ?? '';
  const { data } = await pireonApi.slugs();

  if (!data) {
    setResponseStatus(event, 503);
    setResponseHeader(event, 'Cache-Control', 'no-store');

    return 'Sitemap temporarily unavailable';
  }

  setResponseHeader(event, 'Content-Type', 'application/xml; charset=utf-8');

  return buildSitemap(origin, data);
});