/**
 * 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,
}