// Simulates the Mopidy JSON-RPC WebSocket API.

const TRACKS = [
  {
    uri: 'mock:track:1',
    name: 'Ocean Drive',
    artists: [{ name: 'Duke Dumont' }],
    album: { name: 'Ocean Drive', images: [] },
    length: 232000,
  },
  {
    uri: 'mock:track:2',
    name: 'Feel It Still',
    artists: [{ name: 'Portugal. The Man' }],
    album: { name: 'Woodstock', images: [] },
    length: 178000,
  },
  {
    uri: 'mock:track:3',
    name: 'Sailing',
    artists: [{ name: 'Christopher Cross' }],
    album: { name: 'Christopher Cross', images: [] },
    length: 261000,
  },
  {
    uri: 'mock:track:4',
    name: 'Beyond the Sea',
    artists: [{ name: 'Bobby Darin' }],
    album: { name: 'That\'s All', images: [] },
    length: 185000,
  },
  {
    uri: 'mock:track:5',
    name: 'Into the Mystic',
    artists: [{ name: 'Van Morrison' }],
    album: { name: 'Moondance', images: [] },
    length: 215000,
  },
]

const RADIO_STATIONS = [
  { uri: 'http://stream.swr3.de/swr3/mp3-128/stream.mp3',  name: 'SWR3' },
  { uri: 'http://ndr.de/ndr1welle-nord-128.mp3',           name: 'NDR 1 Welle Nord' },
  { uri: 'http://live-bauhaus.radiobt.de/bauhaus/mp3-128', name: 'Radio Bauhaus' },
]

export function createMopidyMock() {
  let state = 'playing'
  let currentIndex = 0
  let position = 0
  let positionTimer = null

  const listeners = {}

  function emit(event, data) {
    if (listeners[event]) listeners[event].forEach(fn => fn(data))
  }

  function startTimer() {
    if (positionTimer) return
    positionTimer = setInterval(() => {
      if (state === 'playing') {
        position += 1000
        const track = TRACKS[currentIndex]
        if (position >= track.length) {
          currentIndex = (currentIndex + 1) % TRACKS.length
          position = 0
          emit('event:trackPlaybackStarted', { tl_track: { track: TRACKS[currentIndex] } })
        }
      }
    }, 1000)
  }

  startTimer()

  async function call(method, params = {}) {
    await new Promise(r => setTimeout(r, 15))

    switch (method) {
      case 'playback.get_current_track':
        return TRACKS[currentIndex]

      case 'playback.get_state':
        return state

      case 'playback.get_time_position':
        return position

      case 'playback.play':
        state = 'playing'
        emit('event:playbackStateChanged', { new_state: 'playing' })
        return null

      case 'playback.pause':
        state = 'paused'
        emit('event:playbackStateChanged', { new_state: 'paused' })
        return null

      case 'playback.stop':
        state = 'stopped'
        position = 0
        emit('event:playbackStateChanged', { new_state: 'stopped' })
        return null

      case 'playback.next':
        currentIndex = (currentIndex + 1) % TRACKS.length
        position = 0
        state = 'playing'
        emit('event:trackPlaybackStarted', { tl_track: { track: TRACKS[currentIndex] } })
        return null

      case 'playback.previous':
        currentIndex = (currentIndex - 1 + TRACKS.length) % TRACKS.length
        position = 0
        state = 'playing'
        emit('event:trackPlaybackStarted', { tl_track: { track: TRACKS[currentIndex] } })
        return null

      case 'playback.seek':
        position = params.time_position || 0
        return null

      case 'tracklist.get_tracks':
        return TRACKS

      case 'library.browse':
        return TRACKS.map(t => ({ uri: t.uri, name: t.name, type: 'track' }))

      case 'library.search':
        return [{ tracks: TRACKS }]

      default:
        return null
    }
  }

  return {
    call,
    on(event, fn) {
      if (!listeners[event]) listeners[event] = []
      listeners[event].push(fn)
    },
    off(event, fn) {
      if (listeners[event]) listeners[event] = listeners[event].filter(l => l !== fn)
    },
    getTracks: () => TRACKS,
    getRadioStations: () => RADIO_STATIONS,
  }
}