const fetch = require('isomorphic-unfetch')

class RadioManifest {
  constructor (baseURL, options) {
    this.baseURL = baseURL
    this.options = options

    const radiomanifest = fetch(`${baseURL}/radiomanifest.xml`)
    return radiomanifest
  }

  getShowByName (showName) {

  }

  getStreaming () {

  }

  getSchedule () {

  }

  getShowAtTime () {

  }
}

function getStreaminfoUrl (siteurl) {
  return siteurl + '/streaminfo.json' // XXX: improve this logic
}
function getManifestUrl (siteurl) {
  return siteurl + '/radiomanifest.xml' // XXX: improve this logic
}
function parseRadioManifest (xml) {
  let res = xml.evaluate('/radio-manifest/streaming/source', xml)
  const sources = []
  while (true) {
    const src = res.iterateNext()
    if (src === null) break
    if (!src.hasAttribute('priority')) {
      src.setAttribute('priority', '0')
    } else if (parseInt(src.getAttribute('priority'), 10) < 0) {
      continue
    }
    sources.push(src)
  }
  sources.sort(function cmp (a, b) {
    return parseInt(a.getAttribute('priority', 10)) < parseInt(b.getAttribute('priority', 10))
  })

  res = xml.evaluate('/radio-manifest/schedule', xml)
  const scheduleEl = res.iterateNext()
  let schedule = null
  if (scheduleEl !== null) {
    schedule = scheduleEl.getAttribute('url')
  }

  res = xml.evaluate('/radio-manifest/shows', xml)
  const showsEl = res.iterateNext()
  let shows = null
  if (showsEl !== null) {
    shows = showsEl.getAttribute('src')
  }

  const manifest = new Radio(sources, schedule, shows)
  return manifest
}

function Radio (sources, schedule, shows) {
  this.streaming = new RadioStreaming(sources)
  this.schedule = schedule
  this.shows = shows
  this.name = ''
}

Radio.prototype.getStreaming = function () {
  return this.streaming
}

Radio.prototype.setName = function (name) {
  this.name = name
}

function RadioStreaming (sources) {
  this.sources = sources
}

RadioStreaming.prototype.getOptions = function () {
  return this.sources.map(function (x) {
    return x.getAttribute('name')
  })
}
RadioStreaming.prototype.getSource = function (name) {
  if (name === undefined) {

  }
  const s = this.sources.find(function (x) {
    return x.getAttribute('name') === name
  })
  if (s === undefined) return s
  return s.getAttribute('src')
}

async function get (siteurl, options) {
  let resp = await fetch(getManifestUrl(siteurl))
  let text = await resp.text()

  const parser = new DOMParser()
  const dom = parser.parseFromString(text, 'text/xml')
  const manifest = parseRadioManifest(dom)

  resp = null
  try {
    resp = await fetch(getStreaminfoUrl(siteurl))
    text = await resp.text()

    const data = JSON.parse(text)
    const name = data['icy-name']
    if (name !== undefined) {
      manifest.setName(name)
    }
  } catch (e) {
    if (e instanceof TypeError && e.message.startsWith('NetworkError')) {
      // the fetch has failed
      true
    } else if (e instanceof SyntaxError && e.message.startsWith('JSON.parse')) {
      true
    } else {
      console.error('Error', e)
      throw e
    }
  }

  // XXX: in base alle options fai fetch anche di altra roba
  return manifest
}

function parseM3U (body) {
  body.split('\n').filter((e) => {
    if (e.startsWith('#')) {
      return false
    } else {
      try { new URL(e); return true } catch { return false }
    }
  })
}

module.exports = {
  get: get,
  objs: {
    Radio: Radio,
    RadioStreaming: RadioStreaming
  },
  parsers: {
    M3U: parseM3U,
    radioManifest: parseRadioManifest
  }
}