Cloudflare worker

worker.js

export default {
  async fetch(request, env, context) {
        const url = new URL(request.url)
        const end = url.pathname.split('/').pop()
        // check if end is number with regex
        const regex = /\d/g
        const isNumber = regex.test(end)
        if (isNumber && url.pathname.startsWith('/episode/')) {
          // is number search for the new name and redirect
            return await handleRequest(request)
        }
        return request;
    }
}

const getlink = async (number) => {
  const resp = await fetch('https://anchor.fm/s/414d1d4/podcast/rss')
  const data = await resp.text()
  // search all occurence of https://anchor.fm/indiemakers/episodes/.*< in data
  // search all occurence of <title><![CDATA[.*]]></title>
  const regex = /<title><!\[CDATA\[.*\]\]><\/title>/g
  const links = data.match(regex)
  const episodes = links.map(link => link
    .toLowerCase()
    .normalize('NFD')
    .replace(']]></title>', '')
    .replace('<title><![cdata[', '')
    .replace(/[^a-z0-9 ]/gi, '')
    .trim()
    .replace(/ /g, '-')
    .replace(/,/g, '')
    .replace(/'/g, '')
    .toLowerCase(),
  )
  const link = episodes[episodes.length - number]
  const newLink = `https://indiemakers.fr/episode/${link}`
  return newLink
}

async function handleRequest(request) {
    const url = new URL(request.url)
    const end = url.pathname.split('/').pop()
    const endNumb = Number(end)
    console.log('end', endNumb)
    const destinationURL = await getlink(endNumb)
    return Response.redirect(destinationURL, 301)
}