import { listPosts } from '~~/server/utils/posts'
import { getSiteData } from '~~/server/utils/site'

const escape = (s: string) =>
  s.replace(/&/g, '&')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')

export default defineEventHandler(async (event) => {
  const base = useRuntimeConfig().public.siteUrl.replace(/\/+$/, '')
  const posts = (await listPosts()).filter((p) => !p.draft).slice(0, 30)
  const site = await getSiteData()

  const items = posts
    .map(
      (post) => `    <item>
      <title>${escape(post.title)}</title>
      <link>${base}/blog/${post.slug}</link>
      <guid isPermaLink="true">${base}/blog/${post.slug}</guid>
      <pubDate>${new Date(post.date).toUTCString()}</pubDate>
      <description>${escape(post.description)}</description>
${post.tags.map((t) => `      <category>${escape(t)}</category>`).join('\n')}
    </item>`,
    )
    .join('\n')

  const xml = `<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
  <channel>
    <title>${escape(site.domain)}</title>
    <link>${base}</link>
    <description>${escape(site.description)}</description>
    <language>en</language>
    <lastBuildDate>${new Date().toUTCString()}</lastBuildDate>
    <atom:link href="${base}/rss.xml" rel="self" type="application/rss+xml"/>
${items}
  </channel>
</rss>`

  setHeader(event, 'content-type', 'application/rss+xml; charset=utf-8')
  setHeader(event, 'cache-control', 'public, max-age=600')
  return xml
})