RSS Feed Fetcher - RSS - trigger module

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import * as wmill from "https://deno.land/x/windmill@v1.85.0/mod.ts";
import { parse } from "https://deno.land/x/xml/mod.ts";

type Rss = {
  url: string;
};
export async function main(rss_feed: Rss) {
  const rss_feed_url = rss_feed.url;
  let feedStates = (await wmill.getInternalState()) || {};
  const newestItem: Date = new Date(feedStates[rss_feed_url] || 0);

  const items = await fetch(rss_feed_url)
    .then((response) => response.text())
    .then((str) => parse(str))
    .then((feed) => {
      let items = [];
      if (feed["rss"]) {
        items = rss2_items(feed);
      } else if (feed["feed"]) {
        items = atom_items(feed);
      }
      const new_items = items.filter((item) => item.pubDate > newestItem);
      return new_items;
    });

  if (items.length > 0) {
    let newState = (await wmill.getInternalState()) || {};
    const dates = items.map((item) => item.pubDate);
    newState[rss_feed_url] = new Date(Math.max(...dates));
    await wmill.setInternalState(newState);
  }

  return items.reverse();
}

function rss2_items(feed) {
  var items = feed["rss"]["channel"]["item"] || [];
  if (items.length === "undefined") {
    // Single entry
    items = [items];
  }
  return items.map((item) => ({
    title: item.title,
    link: item.link,
    pubDate: new Date(item.pubDate),
  }));
}

function atom_items(feed) {
  var items = feed["feed"]["entry"] || [];
  if (items.length === "undefined") {
    // Single entry
    items = [items];
  }
  return items.map((item) => ({
    title: typeof item.title === "string" ? item.title : item.title["#text"],
    link:
      item.link instanceof Array ? item.link[0]["@href"] : item.link["@href"],
    pubDate: new Date(item.updated),
  }));
}