Component({
  options: {
    addGlobalClass: true,
    pureDataPattern: /^_/,
    multipleSlots: true
  },
  properties: {
    vtabs: {type: Array, value: []},
    tabBarClass: {type: String, value: ''},
    activeClass: {type: String, value: ''},
    tabBarLineColor: {type: String, value: '#07c160'},
    tabBarInactiveTextColor: {type: String, value: '#000000'},
    tabBarActiveTextColor: {type: String, value: '#07c160'},
    tabBarInactiveBgColor: {type: String, value: '#eeeeee'},
    tabBarActiveBgColor: {type: String, value: '#ffffff'},
    activeTab: {type: Number, value: 0},
    animation: {type: Boolean, value: true}
  },
  data: {
    currentView: 0,
    contentScrollTop: 0,
    _heightRecords: [],
    _contentHeight: {}
  },
  observers: {
    activeTab: function activeTab(_activeTab) {
      this.scrollTabBar(_activeTab)
    }
  },
  relations: {
    '../vtabs-content/vtabs-content': {
      type: 'child',
      linked: function linked(target) {
        const _this = this

        target.calcHeight(function (rect) {
          _this.data._contentHeight[target.data.tabIndex] = rect.height
          if (_this._calcHeightTimer) {
            clearTimeout(_this._calcHeightTimer)
          }
          _this._calcHeightTimer = setTimeout(function () {
            _this.calcHeight()
          }, 100)
        })
      },
      unlinked: function unlinked(target) {
        delete this.data._contentHeight[target.data.tabIndex]
      }
    }
  },
  lifetimes: {
    attached: function attached() {}
  },
  methods: {
    calcHeight: function calcHeight() {
      const length = this.data.vtabs.length
      const _contentHeight = this.data._contentHeight
      const _heightRecords = []
      let temp = 0
      for (let i = 0; i < length; i++) {
        _heightRecords[i] = temp + (_contentHeight[i] || 0)
        temp = _heightRecords[i]
      }
      this.data._heightRecords = _heightRecords
    },
    scrollTabBar: function scrollTabBar(index) {
      const len = this.data.vtabs.length
      if (len === 0) return
      let currentView = index < 6 ? 0 : index - 5
      if (currentView >= len) currentView = len - 1
      this.setData({currentView})
    },
    handleTabClick: function handleTabClick(e) {
      const _heightRecords = this.data._heightRecords
      const index = e.currentTarget.dataset.index
      const contentScrollTop = _heightRecords[index - 1] || 0
      this.triggerEvent('tabclick', {index})
      this.setData({
        activeTab: index,
        contentScrollTop
      })
    },
    handleContentScroll: function handleContentScroll(e) {
      const _heightRecords = this.data._heightRecords
      if (_heightRecords.length === 0) return
      const length = this.data.vtabs.length
      const scrollTop = e.detail.scrollTop
      let index = 0
      if (scrollTop >= _heightRecords[0]) {
        for (let i = 1; i < length; i++) {
          if (scrollTop >= _heightRecords[i - 1] && scrollTop < _heightRecords[i]) {
            index = i
            break
          }
        }
      }
      if (index !== this.data.activeTab) {
        this.triggerEvent('change', {index})
        this.setData({activeTab: index})
      }
    }
  }
})