import { escapeHtml } from './html.js'
import { siteName, siteUrl } from './site.config.js'

export const toSitemapDate = (iso) => (iso ? iso.slice(0, 10) : '')

const toRssDate = (iso) => {
  if (!iso) return ''
  const date = new Date(iso)
  return Number.isNaN(date.valueOf()) ? '' : date.toUTCString()
}

export const renderFeed = (items) => {
  const lastBuild = toRssDate(items.find((item) => item.date)?.date) || new Date().toUTCString()
  const itemXml = items
    .map((item) => {
      const loc = `${siteUrl}/${item.dir}/${item.name}/`
      const description = item.description
      const pubDate = toRssDate(item.date)
      return `<item>
      <title>${escapeHtml(item.title)}</title>
      <link>${escapeHtml(loc)}</link>
      <guid isPermaLink="true">${escapeHtml(loc)}</guid>
      ${pubDate ? `<pubDate>${escapeHtml(pubDate)}</pubDate>` : ''}
      <category>${escapeHtml(item.dir)}</category>
      ${description ? `<description>${escapeHtml(description)}</description>` : ''}
    </item>`
    })
    .join('\n    ')

  return `<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
  <channel>
    <title>${escapeHtml(siteName)}</title>
    <link>${escapeHtml(`${siteUrl}/`)}</link>
    <description>${escapeHtml(`Notes and posts from ${siteName}`)}</description>
    <language>en-US</language>
    <atom:link href="${escapeHtml(`${siteUrl}/feed.xml`)}" rel="self" type="application/rss+xml"/>
    <lastBuildDate>${escapeHtml(lastBuild)}</lastBuildDate>
    ${itemXml}
  </channel>
</rss>
`
}

export const renderSitemap = (urls) => `<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
${urls
  .map(({ loc, lastmod }) => {
    const modified = lastmod ? `\n    <lastmod>${escapeHtml(lastmod)}</lastmod>` : ''
    return `  <url>
    <loc>${escapeHtml(loc)}</loc>${modified}
  </url>`
  })
  .join('\n')}
</urlset>
`