/* eslint-disable */
// @ts-ignore
function getLen(v) {
  return Math.sqrt(v.x * v.x + v.y * v.y)
}
function dot(v1, v2) {
  return v1.x * v2.x + v1.y * v2.y
}
function getAngle(v1, v2) {
  var mr = getLen(v1) * getLen(v2)
  if (mr === 0) return 0
  var r = dot(v1, v2) / mr
  if (r > 1) r = 1
  return Math.acos(r)
}
function cross(v1, v2) {
  return v1.x * v2.y - v2.x * v1.y
}
function getRotateAngle(v1, v2) {
  var angle = getAngle(v1, v2)
  if (cross(v1, v2) > 0) {
    angle *= -1
  }
  return angle * 180 / Math.PI
}
function _swipeDirection(x1, x2, y1, y2) {
  if (Math.abs(x1 - x2) >= Math.abs(y1 - y2)) {
    return x1 - x2 > 0 ? 'Left' : 'Right'
  } else {
    return y1 - y2 > 0 ? 'Up' : 'Down'
  }
}
// 实现setTimeout功能
var setTimeout = function(callback, interval, instance) { 
  var now = Date.now
  var stime = now()
  var loop = function() {
    if (now() - stime >= interval) {
      callback()
    } else {
      instance.requestAnimationFrame(loop)
    }
  }
  instance.requestAnimationFrame(loop)
}
var start = function(event, ownerInstance) {
  var instance = event.instance;
  var State = instance.getState()
  if(!State._init) {
    State.preV = {x: null, y: null}
    State.pinchStartLen = null
    State.zoom = 1
    State.isDoubleTap = false
    State.delta = null
    State.last = null
    State.now = null
    State.x1 = State.x2 = State.y1 = State.y2 = null
    State.preTapPosition = {x: null, y: null}
    // 控制定时器
    State._cancelLongTap = function() {
      State.longTapTimeout = false
    }
    State._cancelSingleTap = function() {
      State.singleTapTimeout = false
    }
    State._tapTimeout = function() {
      State.tapTimeout = false
    }
    State._swipeTimeout = function() {
      State.swipeTimeout = false
    }
    State._init = true // 表示已经初始化完成
  }
  State.tapTimeout = true
  State.singleTapTimeout = true
  State.longTapTimeout = true
  State.swipeTimeout = true
  State.now = Date.now()
  State.x1 = event.touches[0].pageX
  State.y1 = event.touches[0].pageY
  State.delta = State.now - (State.last || State.now)
  // 触发 touchStart 事件
  ownerInstance.triggerEvent('touchStart', event)
  if (State.preTapPosition.x !== null) {
    State.isDoubleTap = (State.delta > 0 &&
      State.delta <= 250 &&
      Math.abs(State.preTapPosition.x - State.x1) < 30 &&
      Math.abs(State.preTapPosition.y - State.y1) < 30)
    if (State.isDoubleTap) {
      State._cancelSingleTap()
    }
  }
  State.preTapPosition.x = State.x1
  State.preTapPosition.y = State.y1
  State.last = State.now
  var preV = State.preV
  var len = event.touches.length
  if (len > 1) {
    State._cancelLongTap()
    State._cancelSingleTap()
    var v = {x: event.touches[1].pageX - State.x1, y: event.touches[1].pageY - State.y1}
    preV.x = v.x
    preV.y = v.y
    State.pinchStartLen = getLen(preV)
    // 触发 multipointStart 多指点按 事件
    ownerInstance.triggerEvent('multipointStart', event)
  }
  State._preventTap = false
  setTimeout(function () {
    // 触发 longTap（长按） 事件
    if(State.longTapTimeout) {
      ownerInstance.triggerEvent('longTap', event)
      State._preventTap = true
      State.longTapTimeout = true
    }
  }, 750, instance)

  if (!instance.getDataset()['propagation']) return false
}
var move = function(event, ownerInstance) {
  var instance = event.instance;
  var State = instance.getState()
  var preV = State.preV
  var len = event.touches.length
  var currentX = event.touches[0].pageX
  var currentY = event.touches[0].pageY
  State.isDoubleTap = false
  if (len > 1) {
    var sCurrentX = event.touches[1].pageX
    var sCurrentY = event.touches[1].pageY
    var v = {x: event.touches[1].pageX - currentX, y: event.touches[1].pageY - currentY}
    if (preV.x !== null) {
      if (State.pinchStartLen > 0) {
        event.zoom = getLen(v) / State.pinchStartLen
        // 触发 pinch 事件
        ownerInstance.triggerEvent('pinch', event)
      }
      event.angle = getRotateAngle(v, preV)
      // 触发 rotate 事件
      ownerInstance.triggerEvent('rotate', event)
    }
    preV.x = v.x
    preV.y = v.y
    if (State.x2 !== null && State.sx2 !== null) {
      event.deltaX = (currentX - State.x2 + sCurrentX - State.sx2) / 2
      event.deltaY = (currentY - State.y2 + sCurrentY - State.sy2) / 2
    } else {
      event.deltaX = 0
      event.deltaY = 0
    }
    // 触发 twoFingerPressMove 事件
    ownerInstance.triggerEvent('twoFingerPressMove', event)
    State.sx2 = sCurrentX
    State.sy2 = sCurrentY
  } else {
    if (State.x2 !== null) {
      event.deltaX = currentX - State.x2
      event.deltaY = currentY - State.y2
      // move事件中添加对当前触摸点到初始触摸点的判断，
      // 如果曾经大于过某个距离(比如10),就认为是移动到某个地方又移回来，应该不再触发tap事件才对。
      var movedX = Math.abs(State.x1 - State.x2)
      var movedY = Math.abs(State.y1 - State.y2)
      if (movedX > 10 || movedY > 10) {
        State._preventTap = true
      }
    } else {
      event.deltaX = 0
      event.deltaY = 0
    }
    // 触发 pressMove 单指点按移动 事件
    ownerInstance.triggerEvent('pressMove', event)
  }
  // 触发 touchMove 移动事件
  ownerInstance.triggerEvent('touchMove', event)
  State._cancelLongTap()
  State.x2 = currentX
  State.y2 = currentY
  // if (len > 1) {
  //   // event.preventDefault()
  // }
  if (!instance.getDataset()['propagation']) return false
}
var end = function(event, ownerInstance) {
  var instance = event.instance;
  var State = instance.getState()
  State._cancelLongTap()
  if (event.touches.length < 2) {
    // 触发 multipointEnd 多指点按结束 事件
    ownerInstance.triggerEvent('multipointEnd', event)
    State.sx2 = State.sy2 = null
  }
  // swipe 
  if ((State.x2 && Math.abs(State.x1 - State.x2) > 30) ||
    (State.y2 && Math.abs(State.y1 - State.y2) > 30)) {
    event.direction = _swipeDirection(State.x1, State.x2, State.y1, State.y2)
    setTimeout(function () {
      if(State.swipeTimeout) {
        // 触发 swipe 滑动 上下左右 事件
        ownerInstance.triggerEvent('swipe', event)
        State.swipeTimeout = true
      }
    }, 0, instance)
  } else {
    setTimeout(function () {
      if(State.tapTimeout) {
        if (!State._preventTap) {
          // 触发 tap 事件
          ownerInstance.triggerEvent('tap', event)
        }
        // trigger double tap immediately
        if (State.isDoubleTap) {
          // 触发 doubleTap 事件
          ownerInstance.triggerEvent('doubleTap', event)
          State.isDoubleTap = false
        }
        State.tapTimeout = true
      }
    }, 0, instance)
    if (!State.isDoubleTap) {
      if (instance.getDataset()['requirefailure']) { // requireFailure
        setTimeout(function () {
          if(State.singleTapTimeout) {
            // 触发 singleTap 事件
            ownerInstance.triggerEvent('singleTap', event)
            State.singleTapTimeout = true
          }
        }, 250, instance)
      } else {
        ownerInstance.triggerEvent('singleTap', event)
        State.singleTapTimeout = true
      }
    }
  }
  // 触发 touchEnd 事件
  ownerInstance.triggerEvent('touchEnd', event)
  State.preV.x = 0
  State.preV.y = 0
  State.zoom = 1
  State.pinchStartLen = null
  State.x1 = State.x2 = null
  State.y1 = State.y2 = null

  if (!instance.getDataset()['propagation']) return false
}
var cancel = function(event, ownerInstance) {
  var instance = event.instance;
  var State = instance.getState()
  State._cancelLongTap()
  State._cancelSingleTap()
  State._tapTimeout()
  State._swipeTimeout()
  // 触发 touchCancel 事件
  ownerInstance.triggerEvent('touchCancel', event)

  if (!instance.getDataset()['propagation']) return false
}
module.exports = {
  start: start,
  move: move,
  end: end,
  cancel: cancel
}