Component({
  behaviors: [],
  options: {
    addGlobalClass: true,
    pureDataPattern: /^_/
  },
  properties: {
    duration: {
      type: Number,
      value: 500
    },
    easingFunction: {
      type: String,
      value: 'default'
    },
    loop: {
      type: Boolean,
      value: false,
    },
    videoList: {
      type: Array,
      value: [],
      observer: function observer(...args) {
        const newVal = args.length > 0 && args[0] !== undefined ? args[0] : []
        console.log(newVal)
        this._videoListChanged(newVal)
      }
    }
  },
  data: {
    nextQueue: [],
    prevQueue: [],
    curQueue: [],
    circular: false,
    _last: 1,
    _change: -1,
    _invalidUp: 0,
    _invalidDown: 0,
    _videoContexts: []
  },
  lifetimes: {
    attached() {
      this.data._videoContexts = [
        wx.createVideoContext('video_0', this), wx.createVideoContext('video_1', this), wx.createVideoContext('video_2', this)]
    },
  },
  methods: {
    _videoListChanged(newVal) {
      const _this = this
      const data = this.data
      newVal.forEach(function (item) {
        data.nextQueue.push(item)
      })
      if (data.curQueue.length === 0) {
        this.setData({
          curQueue: data.nextQueue.splice(0, 3)
        }, function () {
          _this.playCurrent(0)
        })
      }
    },

    animationfinish(e) {
      const _data = this.data
      const _last = _data._last
      const _change = _data._change
      const curQueue = _data.curQueue
      const prevQueue = _data.prevQueue
      const nextQueue = _data.nextQueue
      const current = e.detail.current
      const diff = current - _last
      if (diff === 0) return
      this.data._last = current
      this.playCurrent(current)
      this.triggerEvent('change', {activeId: curQueue[current].id})
      const direction = diff === 1 || diff === -2 ? 'up' : 'down'
      if (direction === 'up') {
        console.log(this.data)
        if (this.data._invalidDown === 0) {
          const change = (_change + 1) % 3
          const add = nextQueue.shift()
          const remove = curQueue[change]
          if (add) {
            prevQueue.push(remove)
            curQueue[change] = add
            this.data._change = change
          } else {
            this.data._invalidUp += 1
          }
        } else {
          this.data._invalidDown -= 1
        }
      }
      if (direction === 'down') {
        if (this.data._invalidUp === 0) {
          const _change2 = _change
          const _remove = curQueue[_change2]
          const _add = prevQueue.pop()
          if (_add) {
            curQueue[_change2] = _add
            nextQueue.unshift(_remove)
            this.data._change = (_change2 - 1 + 3) % 3
          } else {
            this.data._invalidDown += 1
          }
        } else {
          this.data._invalidUp -= 1
        }
      }
      let circular = true
      if (nextQueue.length === 0 && current !== 0) {
        circular = false
      }
      if (prevQueue.length === 0 && current !== 2) {
        circular = false
      }
      this.setData({
        curQueue,
        circular
      })
    },

    playCurrent(current) {
      this.data._videoContexts.forEach(function (ctx, index) {
        if (index !== current) {
          ctx.pause()
        } else {
          ctx.play()
        }
      })
    },
    onPlay: function onPlay(e) {
      this.trigger(e, 'play')
    },
    onPause: function onPause(e) {
      this.trigger(e, 'pause')
    },
    onEnded: function onEnded(e) {
      this.trigger(e, 'ended')
    },
    onError: function onError(e) {
      this.trigger(e, 'error')
    },
    onTimeUpdate: function onTimeUpdate(e) {
      this.trigger(e, 'timeupdate')
    },
    onWaiting: function onWaiting(e) {
      this.trigger(e, 'wait')
    },
    onProgress: function onProgress(e) {
      this.trigger(e, 'progress')
    },
    onLoadedMetaData: function onLoadedMetaData(e) {
      this.trigger(e, 'loadedmetadata')
    },
    trigger: function trigger(e, type, ...args) {
      const ext = args.length > 2 && args[2] !== undefined ? args[2] : {}

      const detail = e.detail
      const activeId = e.target.dataset.id
      this.triggerEvent(
        type, Object.assign(Object.assign(Object.assign({}, detail), {activeId}), ext)
      )
    }
  },
})