/**
 * Represents a single show. This show could be defined in the shows.xml file, or could be inferred from the
 * schedule.
 */

class RadioShow {
  constructor(name, description, website, feed, schedule, radio_calendar) {
    this.name = name;
    this.description = description;
    this.website = website;
    this.feed = feed;
    this.schedule = schedule;
    this.radio_calendar = radio_calendar;
  }

  getName() {
    return this.name;
  }
  getWebsite() {
    return this.website;
  }
  getFeed() {
    return this.feed;
  }
  getSchedule() {
    return this.schedule;
  }
}

/**
 * @private
 * @return {Array<RadioShow>}
 */
function parseRadioShows(xml) {
  const doc = xml.cloneNode(true);
  const bookmarks = doc.evaluate(
    "//bookmark",
    doc,
    showsNamespaceResolver,
    XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,
    null,
  );
  const shows = [];
  for (let i = 0; i < bookmarks.snapshotLength; i++) {
    const bm = bookmarks.snapshotItem(i);

    let name = doc.evaluate(
      "./info/metadata/show:name",
      bm,
      showsNamespaceResolver,
      XPathResult.STRING_TYPE,
    ).stringValue;
    if (name === "") {
      name = doc.evaluate(
        "./title",
        bm,
        showsNamespaceResolver,
        XPathResult.STRING_TYPE,
      ).stringValue;
    }
    let website = doc.evaluate(
      "./info/metadata/show:website",
      bm,
      showsNamespaceResolver,
      XPathResult.STRING_TYPE,
    ).stringValue;
    if (website === "") {
      website = bm.getAttribute("href");
    }
    const feed = doc.evaluate(
      "./info/metadata/show:feed",
      bm,
      showsNamespaceResolver,
      XPathResult.STRING_TYPE,
    ).stringValue;
    const schedule = doc.evaluate(
      "./info/metadata/show:schedule",
      bm,
      showsNamespaceResolver,
      XPathResult.STRING_TYPE,
    ).stringValue;
    let description = doc.evaluate(
      "./info/metadata/show:description",
      bm,
      showsNamespaceResolver,
      XPathResult.STRING_TYPE,
    ).stringValue;
    if (description === "") {
      description = doc.evaluate(
        "./desc",
        bm,
        showsNamespaceResolver,
        XPathResult.STRING_TYPE,
      ).stringValue;
    }

    const show = new RadioShow(
      name,
      description || null,
      website || null,
      feed || null,
      schedule || null,
    );
    shows.push(show);
  }

  return shows;
}

async function getShows(manifest) {
  if (manifest.showsURL) {
    let resp = null;
    try {
      resp = await fetch(manifest.showsURL);
    } catch (e) {
      true;
    }
    if (resp !== null) {
      try {
        const text = await resp.text();
        const parser = new DOMParser();
        const showsDom = parser.parseFromString(text, "text/xml");
        return parseRadioShows(showsDom);
      } catch (e) {
        console.error("Error while parsing shows file", e);
        throw e;
      }
    }
  }
}

function showsNamespaceResolver(prefix) {
  const prefixes = {
    show: "https://radiomanifest.degenerazione.xyz/shows/",
  };
  return prefixes[prefix] || null;
}

export default {
  get: getShows,
  parse: parseRadioShows,
  RadioShow: RadioShow,
};