let _ = {
  MIN_LIMIT: 48, // Min size of zone
  DECIMAL_PLACES: 4 // Hotzone positioning decimal point limit number of digits
}

/**
 * Get a power result of 10 for the power of the constant
 * @return {Number}
 */
_.getMultiple = (decimalPlaces = _.DECIMAL_PLACES) => {
  return Math.pow(10, decimalPlaces)
}

/**
 * Limit decimal places
 * @param  {Number} num
 * @return {Number}
 */
_.decimalPoint = (val = 0) => {
  return Math.round(val * _.getMultiple()) / _.getMultiple() || 0
}

/**
 * Get element width and height
 * @param  {Object} elem
 * @return {Object}
 */
_.getOffset = (elem = {}) => ({
  width: elem.clientWidth || 0,
  height: elem.clientHeight || 0
})

/**
 * Get pageX
 * @param  {Object} e
 * @return {Number}
 */
_.getPageX = (e) => ('pageX' in e) ? e.pageX : e.touches[0].pageX

/**
 * Get pageY
 * @param  {Object} e
 * @return {Number}
 */
_.getPageY = (e) => ('pageY' in e) ? e.pageY : e.touches[0].pageY

/**
 * Gets the abscissa value of the mouse click relative to the target node
 * @param  {Object} e
 * @param  {Object} container
 * @return {Number}
 */
_.getDistanceX = (e, container) =>
  _.getPageX(e) - (container.getBoundingClientRect().left + window.pageXOffset)

/**
 * Gets the ordinate value of the mouse click relative to the target node
 * @param  {Object} e
 * @param  {Object} container
 * @return {Number}
 */
_.getDistanceY = (e, container) =>
  _.getPageY(e) - (container.getBoundingClientRect().top + window.pageYOffset)

/**
 * Treatment of boundary conditions when changing the size of the hotzone
 * @param {Object} itemInfo
 * @param {Object} styleInfo
 * @param {Object} container
 */
_.dealEdgeValue = (itemInfo, styleInfo, container) => {
  if (styleInfo.hasOwnProperty('left') && styleInfo.left < 0) {
    styleInfo.left = 0
    styleInfo.width = itemInfo.width + itemInfo.left
  }

  if (styleInfo.hasOwnProperty('top') && styleInfo.top < 0) {
    styleInfo.top = 0
    styleInfo.height = itemInfo.height + itemInfo.top
  }

  if (!styleInfo.hasOwnProperty('left') && styleInfo.hasOwnProperty('width')) {
    if (itemInfo.left + styleInfo.width > container.width) {
      styleInfo.width = container.width - itemInfo.left
    }
  }

  if (!styleInfo.hasOwnProperty('top') && styleInfo.hasOwnProperty('height')) {
    if (itemInfo.top + styleInfo.height > container.height) {
      styleInfo.height = container.height - itemInfo.top
    }
  }

  return Object.assign(itemInfo, styleInfo)
}

/**
 * Handle different drag points, capital letters mean: T-top，L-left，C-center，R-right，B-bottom
 * @param  {Object} itemInfo
 * @param  {Number} moveX
 * @param  {Number} moveY
 * @return {Object}
 */
_.dealTL = (itemInfo, moveX, moveY, minLimit = _.MIN_LIMIT) => {
  let styleInfo = {}
  let width = itemInfo.width - moveX
  let height = itemInfo.height - moveY

  if (width >= Math.min(minLimit, itemInfo.width)) {
    Object.assign(styleInfo, {
      width,
      left: itemInfo.left + moveX
    })
  }

  if (height >= Math.min(minLimit, itemInfo.height)) {
    Object.assign(styleInfo, {
      height,
      top: itemInfo.top + moveY
    })
  }

  return styleInfo
}

_.dealTC = (itemInfo, moveX, moveY, minLimit = _.MIN_LIMIT) => {
  let styleInfo = {}
  let height = itemInfo.height - moveY

  if (height >= Math.min(minLimit, itemInfo.height)) {
    styleInfo = {
      height,
      top: itemInfo.top + moveY
    }
  }

  return styleInfo
}

_.dealTR = (itemInfo, moveX, moveY, minLimit = _.MIN_LIMIT) => {
  let styleInfo = {}
  let width = itemInfo.width + moveX
  let height = itemInfo.height - moveY

  if (width >= Math.min(minLimit, itemInfo.width)) {
    Object.assign(styleInfo, {
      width
    })
  }

  if (height >= Math.min(minLimit, itemInfo.height)) {
    Object.assign(styleInfo, {
      height,
      top: itemInfo.top + moveY
    })
  }

  return styleInfo
}

_.dealCL = (itemInfo, moveX, moveY, minLimit = _.MIN_LIMIT) => {
  let styleInfo = {}
  let width = itemInfo.width - moveX

  if (width >= Math.min(minLimit, itemInfo.width)) {
    Object.assign(styleInfo, {
      width,
      left: itemInfo.left + moveX
    })
  }

  return styleInfo
}

_.dealCR = (itemInfo, moveX, moveY, minLimit = _.MIN_LIMIT) => {
  let styleInfo = {}
  let width = itemInfo.width + moveX

  if (width >= Math.min(minLimit, itemInfo.width)) {
    Object.assign(styleInfo, {
      width
    })
  }

  return styleInfo
}

_.dealBL = (itemInfo, moveX, moveY, minLimit = _.MIN_LIMIT) => {
  let styleInfo = {}
  let width = itemInfo.width - moveX
  let height = itemInfo.height + moveY

  if (width >= Math.min(minLimit, itemInfo.width)) {
    Object.assign(styleInfo, {
      width,
      left: itemInfo.left + moveX
    })
  }

  if (height >= Math.min(minLimit, itemInfo.height)) {
    Object.assign(styleInfo, {
      height
    })
  }

  return styleInfo
}

_.dealBC = (itemInfo, moveX, moveY, minLimit = _.MIN_LIMIT) => {
  let styleInfo = {}
  let height = itemInfo.height + moveY

  if (height >= Math.min(minLimit, itemInfo.height)) {
    Object.assign(styleInfo, {
      height
    })
  }

  return styleInfo
}

_.dealBR = (itemInfo, moveX, moveY, minLimit = _.MIN_LIMIT) => {
  let styleInfo = {}
  let width = itemInfo.width + moveX
  let height = itemInfo.height + moveY

  if (width >= Math.min(minLimit, itemInfo.width)) {
    Object.assign(styleInfo, {
      width
    })
  }

  if (height >= Math.min(minLimit, itemInfo.height)) {
    Object.assign(styleInfo, {
      height
    })
  }

  return styleInfo
}

let addItem = {
  bind: function (el, binding, vnode) {
    const MIN_LIMIT = _.MIN_LIMIT
    // 拖拽添加
    // el.addEventListener('mousedown', handleMouseDown)

    function handleMouseDown (e) {
      e && e.preventDefault()

      let itemInfo = {
        top: _.getDistanceY(e, el),
        left: _.getDistanceX(e, el),
        width: 0,
        height: 0
      }
      let container = _.getOffset(el)

      // Only used once at the beginning of init
      let setting = {
        topPer: _.decimalPoint(itemInfo.top / container.height),
        leftPer: _.decimalPoint(itemInfo.left / container.width),
        widthPer: 0,
        heightPer: 0
      }
      let preX = _.getPageX(e)
      let preY = _.getPageY(e)

      vnode.context.addhotZoneItem(setting)

      window.addEventListener('mousemove', handleChange)
      window.addEventListener('mouseup', handleMouseUp)

      function handleChange (e) {
        e && e.preventDefault()

        let moveX = _.getPageX(e) - preX
        let moveY = _.getPageY(e) - preY
        preX = _.getPageX(e)
        preY = _.getPageY(e)

        // Not consider the direction of movement first, consider only the lower right drag point
        let minLimit = 0
        let styleInfo = _.dealBR(itemInfo, moveX, moveY, minLimit)

        // Boundary value processing
        itemInfo = _.dealEdgeValue(itemInfo, styleInfo, container)

        Object.assign(el.lastElementChild.style, {
          top: `${itemInfo.top}px`,
          left: `${itemInfo.left}px`,
          width: `${itemInfo.width}px`,
          height: `${itemInfo.height}px`
        })
      }

      function handleMouseUp () {
        let perInfo = {
          topPer: _.decimalPoint(itemInfo.top / container.height),
          leftPer: _.decimalPoint(itemInfo.left / container.width),
          widthPer: _.decimalPoint(itemInfo.width / container.width),
          heightPer: _.decimalPoint(itemInfo.height / container.height)
        }

        if (vnode.context.isOverRange()) {
          vnode.context.overRange()
        } else if (container.height < MIN_LIMIT && itemInfo.width > MIN_LIMIT) {
          vnode.context.changeItem(Object.assign(perInfo, {
            topPer: 0,
            heightPer: 1
          }))
        } else if (container.width < MIN_LIMIT && itemInfo.height > MIN_LIMIT) {
          vnode.context.changeItem(Object.assign(perInfo, {
            leftper: 0,
            widthPer: 1
          }))
        } else if (itemInfo.width > MIN_LIMIT && itemInfo.height > MIN_LIMIT) {
          vnode.context.changeItem(perInfo)
        } else {
          vnode.context.eraseItem()
        }

        window.removeEventListener('mousemove', handleChange)
        window.removeEventListener('mouseup', handleMouseUp)
      }
    }

    el.$destroy = () => el.removeEventListener('mousedown', handleMouseDown)
  },
  unbind: function (el) {
    el.$destroy()
  }
}

let changeSize = {
  bind: function (el, binding, vnode) {

    el.addEventListener('mousedown', handleMouseDown)

    function handleMouseDown (e) {
      let pointer = e.target.dataset.pointer
      if (!pointer) {
        return
      }

      e && e.stopPropagation()

      let zone = el.parentNode
      let setting = vnode.context.setting
      let container = _.getOffset(zone.parentNode)
      let itemInfo = {
        width: _.getOffset(zone).width || 0,
        height: _.getOffset(zone).height || 0,
        top: setting.topPer * container.height || 0,
        left: setting.leftPer * container.width || 0
      }
      let preX = _.getPageX(e)
      let preY = _.getPageY(e)
      let flag

      // Hide the info displayed by hover
      vnode.context.handlehideZone(true)

      window.addEventListener('mousemove', handleChange)
      window.addEventListener('mouseup', handleMouseUp)

      function handleChange (e) {
        e && e.preventDefault()
        flag = true

        let moveX = _.getPageX(e) - preX
        let moveY = _.getPageY(e) - preY

        preX = _.getPageX(e)
        preY = _.getPageY(e)

        // Handling the situation when different dragging points are selected
        let styleInfo = _[pointer](itemInfo, moveX, moveY)

        // Boundary value processing
        itemInfo = _.dealEdgeValue(itemInfo, styleInfo, container)

        Object.assign(zone.style, {
          top: `${itemInfo.top}px`,
          left: `${itemInfo.left}px`,
          width: `${itemInfo.width}px`,
          height: `${itemInfo.height}px`
        })
      }

      function handleMouseUp () {
        if (flag) {
          flag = false
          let perInfo = {
            topPer: _.decimalPoint(itemInfo.top / container.height),
            leftPer: _.decimalPoint(itemInfo.left / container.width),
            widthPer: _.decimalPoint(itemInfo.width / container.width),
            heightPer: _.decimalPoint(itemInfo.height / container.height)
          }
          vnode.context.changeInfo(perInfo)

          // 兼容数据无变更情况下导致 computed 不更新，数据仍为 px 时 resize 出现的问题
          Object.assign(zone.style, {
            top: `${itemInfo.top}px`,
            left: `${itemInfo.left}px`,
            width: `${itemInfo.width}px`,
            height: `${itemInfo.height}px`
          })
        }
        // Show the info
        vnode.context.handlehideZone(false)

        window.removeEventListener('mousemove', handleChange)
        window.removeEventListener('mouseup', handleMouseUp)
      }
    }

    el.$destroy = () => el.removeEventListener('mousedown', handleMouseDown)
  },
  unbind: function (el) {
    el.$destroy()
  }
}

let dragItem = {
  bind: function (el, binding, vnode) {
    el.addEventListener('mousedown', handleMouseDown)

    function handleMouseDown (e) {
      e && e.stopPropagation()

      let container = _.getOffset(el.parentNode)
      let preX = _.getPageX(e)
      let preY = _.getPageY(e)
      let topPer
      let leftPer
      let flag

      window.addEventListener('mousemove', handleChange)
      window.addEventListener('mouseup', handleMouseUp)

      function handleChange (e) {
        e && e.preventDefault()
        flag = true

        // Hide the info displayed by hover
        vnode.context.handlehideZone(true)

        let setting = vnode.context.setting
        let moveX = _.getPageX(e) - preX
        let moveY = _.getPageY(e) - preY

        setting.topPer = setting.topPer || 0
        setting.leftPer = setting.leftPer || 0
        topPer = _.decimalPoint(moveY / container.height + setting.topPer)
        leftPer = _.decimalPoint(moveX / container.width + setting.leftPer)

        // Hotzone moving boundary processing
        if (topPer < 0) {
          topPer = 0
          moveY = -container.height * setting.topPer
        }

        if (leftPer < 0) {
          leftPer = 0
          moveX = -container.width * setting.leftPer
        }

        if (topPer + setting.heightPer > 1) {
          topPer = 1 - setting.heightPer
          moveY = container.height * (topPer - setting.topPer)
        }

        if (leftPer + setting.widthPer > 1) {
          leftPer = 1 - setting.widthPer
          moveX = container.width * (leftPer - setting.leftPer)
        }

        el.style.transform = `translate(${moveX}px, ${moveY}px)`
      }

      function handleMouseUp () {
        if (flag) {
          flag = false
          el.style.transform = 'translate(0, 0)'
          vnode.context.changeInfo({
            topPer,
            leftPer
          })
        }

        // Show the info
        vnode.context.handlehideZone(false)

        window.removeEventListener('mousemove', handleChange)
        window.removeEventListener('mouseup', handleMouseUp)
      }
    }

    el.$destroy = () => el.removeEventListener('mousedown', handleMouseDown)
  },
  unbind: function (el) {
    el.$destroy()
  }
}

// export default _