let weixinReadyPromise = new Promise((resolve, reject) => {
  if (!window.navigator.userAgent.toLowerCase().includes('micromessenger')) {
    return resolve('other')
  }
  if (!window.wx) { alert('请引入微信相关文件') }
  window.wx.config({
    debug: false,
    appId: '',
    timestamp: 1,
    nonceStr: '',
    signature: '',
    jsApiList: []
  })
  window.wx.ready(async () => {
    await new Promise(res => setTimeout(res, 200)) // 立刻resolve的话，自动播放可能会失败
    resolve('wx')
  })
})

export class PlayInfo {
  src = ''
  startTime = 0
  endTime = 0
  timeUpdate: (e: Event) => void = null
  updateStatus: (status: string) => void = null
}

export class AudioPromiseInner {
  info = new PlayInfo()
  audio: HTMLAudioElement = null
  canPlayPromise: Promise<boolean> = null
  canPlayDefer: Defer = null
  playDefer: Defer = null

  async play(src, startTime = 0, endTime = 0, timeUpdate = f => f, updateStatus = f => f) {
    if (!src) throw new Error('bad audio src: ' + src)
    await weixinReadyPromise
    if (!this.audio) {
      this.audio = new Audio()
      this.audio.addEventListener("canplay", () => this.onCanPlay())
      this.audio.addEventListener("ended", () => this.onEnded())
      this.audio.addEventListener("timeupdate", e => this.onTimeupdate(e))
      for (let e of "abort error stalled suspend waiting".split(' ')) {
        console.log('adding listener: ', e)
        this.audio.addEventListener(e, (...args) => console.log('event: ', ...args, 'for', src))
      }
    }
    if (this.info.src !== src) {
      this.pause('', 'paused')
      if (src) {
        this.audio.src = src
        this.audio.load()
        setTimeout(() => this.onCanPlay(), 500) // redrocket项目read页面直接刷新无法播放单词，定位到onCanPlay未被调用，待进一步诊断
      }
      this.canPlayPromise = new Promise((resolve, reject) => {
        this.canPlayDefer = {resolve, reject}
      })
    }
    Object.assign(this.info, {src, startTime, endTime, timeUpdate, updateStatus})
    console.log(`playing ${this.info.src} from ${startTime} -> ${endTime || ''}`)
    await this.canPlayPromise
    return new Promise((resolve, reject) => { // promise 返回三种状态：ended paused error
      this.playDefer = {resolve, reject}
      this.audio.currentTime = startTime
      let p = this.audio.play()
      p && p.catch && p.catch(err => { // 错误的情况也要让播放返回，低版本iphone不支持catch
        resolve('error')
      })
    })
  }
  pause(src, status = 'paused') {
    if (src && src !== this.info.src)
      return
    this.audio && this.audio.pause()
    this.info.updateStatus && this.info.updateStatus(status)
    if (this.playDefer) {
      this.playDefer.resolve(status)
    }
  }
  onEnded() {
    this.pause('', 'ended')
  }
  onTimeupdate(e) {
    if (this.info.endTime && +e.target.currentTime > this.info.endTime) {
      this.pause('', 'ended')
    }
    this.info.timeUpdate(e)
  }
  onCanPlay() {
    this.canPlayDefer.resolve(true)
  }
}

let singleAudio = new AudioPromiseInner()

export default class AudioPromise {
  info = new PlayInfo()
  constructor(src, timeUpdate = f => f, updateStatus = f => f) {
    Object.assign(this.info, {src, timeUpdate, updateStatus})
  }
  async play(startTime = 0, endTime = 0) {
    return singleAudio.play(this.info.src, startTime, endTime, this.info.timeUpdate, this.info.updateStatus)
  }
  async pause() {
    singleAudio.canPlayPromise && await singleAudio.canPlayPromise
    return singleAudio.pause(this.info.src)
  }
}