index.js

import logger from '@/logging'
import time from '@/utils/time'

const Cov = {
  on (el, type, func) {
    el.addEventListener(type, func)
  },
  off (el, type, func) {
    el.removeEventListener(type, func)
  }
}

class Audio {
  constructor (src, options = {}) {
    let preload = true
    if (options.preload !== undefined && options.preload === false) {
      preload = false
    }
    this.tmp = {
      src: src,
      options: options
    }
    this.onEnded = function (e) {
      logger.default.info('track ended')
    }
    if (options.onEnded) {
      this.onEnded = options.onEnded
    }
    this.onError = options.onError

    this.state = {
      preload: preload,
      startLoad: false,
      failed: false,
      try: 3,
      tried: 0,
      playing: false,
      paused: false,
      playbackRate: 1.0,
      progress: 0,
      currentTime: 0,
      volume: 0.5,
      duration: 0,
      loaded: '0',
      durationTimerFormat: '00:00',
      currentTimeFormat: '00:00',
      lastTimeFormat: '00:00'
    }
    if (options.volume !== undefined) {
      this.state.volume = options.volume
    }
    this.hook = {
      playState: [],
      loadState: []
    }
    if (preload) {
      this.init(src, options)
    }
  }

  init (src, options = {}) {
    if (!src) throw Error('src must be required')
    this.state.startLoad = true
    if (this.state.tried >= this.state.try) {
      this.state.failed = true
      logger.default.error('Cannot fetch audio', src)
      if (this.onError) {
        this.onError(src)
      }
      return
    }
    this.$Audio = new window.Audio(src)
    Cov.on(this.$Audio, 'error', () => {
      this.state.tried++
      this.init(src, options)
    })
    if (options.autoplay) {
      this.play()
    }
    if (options.rate) {
      this.$Audio.playbackRate = options.rate
    }
    if (options.loop) {
      this.$Audio.loop = true
    }
    if (options.volume) {
      this.setVolume(options.volume)
    }
    this.loadState()
  }

  loadState () {
    if (this.$Audio.readyState >= 2) {
      Cov.on(this.$Audio, 'progress', this.updateLoadState.bind(this))
    } else {
      Cov.on(this.$Audio, 'loadeddata', () => {
        this.loadState()
      })
    }
  }

  updateLoadState (e) {
    if (!this.$Audio) return
    this.hook.loadState.forEach(func => {
      func(this.state)
    })
    this.state.duration = Math.round(this.$Audio.duration * 100) / 100
    this.state.loaded = Math.round(10000 * this.$Audio.buffered.end(0) / this.$Audio.duration) / 100
    this.state.durationTimerFormat = time.parse(this.state.duration)
  }

  updatePlayState (e) {
    this.state.currentTime = Math.round(this.$Audio.currentTime * 100) / 100
    this.state.duration = Math.round(this.$Audio.duration * 100) / 100
    this.state.progress = Math.round(10000 * this.state.currentTime / this.state.duration) / 100

    this.state.durationTimerFormat = time.parse(this.state.duration)
    this.state.currentTimeFormat = time.parse(this.state.currentTime)
    this.state.lastTimeFormat = time.parse(this.state.duration - this.state.currentTime)

    this.hook.playState.forEach(func => {
      func(this.state)
    })
  }

  updateHook (type, func) {
    if (!(type in this.hook)) throw Error('updateHook: type should be playState or loadState')
    this.hook[type].push(func)
  }

  play () {
    if (this.state.startLoad) {
      if (!this.state.playing && this.$Audio.readyState >= 2) {
        logger.default.info('Playing track')
        this.$Audio.play()
        this.state.paused = false
        this.state.playing = true
        Cov.on(this.$Audio, 'timeupdate', this.updatePlayState.bind(this))
        Cov.on(this.$Audio, 'ended', this.onEnded)
      } else {
        Cov.on(this.$Audio, 'loadeddata', () => {
          this.play()
        })
      }
    } else {
      this.init(this.tmp.src, this.tmp.options)
      Cov.on(this.$Audio, 'loadeddata', () => {
        this.play()
      })
    }
  }

  destroyed () {
    this.$Audio.pause()
    Cov.off(this.$Audio, 'timeupdate', this.updatePlayState)
    Cov.off(this.$Audio, 'progress', this.updateLoadState)
    Cov.off(this.$Audio, 'ended', this.onEnded)
    this.$Audio.remove()
  }

  pause () {
    logger.default.info('Pausing track')
    this.$Audio.pause()
    this.state.paused = true
    this.state.playing = false
    this.$Audio.removeEventListener('timeupdate', this.updatePlayState)
  }

  setVolume (number) {
    if (number > -0.01 && number <= 1) {
      this.state.volume = Math.round(number * 100) / 100
      this.$Audio.volume = this.state.volume
    }
  }

  setTime (time) {
    if (time < 0 && time > this.state.duration) {
      return false
    }
    this.$Audio.currentTime = time
  }
}

export default Audio