const DEFAULT_OPTIONS = {
  touchStart: function () { },
  touchMove: function () { },
  touchEnd: function () { },
  touchCancel: function () { },
  multipointStart: function () { },
  multipointEnd: function () { },
  tap: function () { },
  doubleTap: function () { },
  longTap: function () { },
  singleTap: function () { },
  rotate: function () { },
  pinch: function () { },
  pressMove: function () { },
  swipe: function () { }
}
export default class MinaTouch {
  constructor(_page, name, option = {}) {
      this.preV = { x: null, y: null };
      this.pinchStartLen = null;
      this.scale = 1;
      this.isDoubleTap = false;

      this.delta = null;
      this.last = null;
      this.now = null;
      this.tapTimeout = null;
      this.singleTapTimeout = null;
      this.longTapTimeout = null;
      this.swipeTimeout = null;
      this.x1 = this.x2 = this.y1 = this.y2 = null;
      this.preTapPosition = { x: null, y: null };

      this.lastZoom = 1;
      this.tempZoom = 1;

      try {
          if (this._checkBeforeCreate(_page, name)) {
              this._name = name
              this._option = { ...DEFAULT_OPTIONS, ...option }
              _page[name] = this
              this._bindFunc(_page)
          }
      } catch (error) {
          console.error(error)
      }
  }
  _checkBeforeCreate(_page, name) {
      if (!_page || !name) {
          throw new Error('MinaTouch实例化时，必须传入page对象和引用名')
      }
      if (_page[name]) {
          throw new Error('MinaTouch实例化error： ' + name + ' 已经存在page中')
      }
      return true
  }
  _bindFunc(_page) {
      let funcNames = ['start', 'move', 'end', 'cancel']
      for (let funcName of funcNames)
          _page[this._name + '.' + funcName] = this[funcName].bind(this)
  }
  start(evt) {
      if (!evt.touches) return;
      this.now = Date.now();
      this.x1 = evt.touches[0].pageX == null ? evt.touches[0].x : evt.touches[0].pageX;
      this.y1 = evt.touches[0].pageY == null ? evt.touches[0].y : evt.touches[0].pageY;
      this.delta = this.now - (this.last || this.now);
      this._option.touchStart(evt);
      if (this.preTapPosition.x !== null) {
          this.isDoubleTap = (this.delta > 0 && this.delta <= 250 && Math.abs(this.preTapPosition.x - this.x1) < 30 && Math.abs(this.preTapPosition.y - this.y1) < 30);
      }
      this.preTapPosition.x = this.x1;
      this.preTapPosition.y = this.y1;
      this.last = this.now;
      let preV = this.preV,
          len = evt.touches.length;
      if (len > 1) {
          this._cancelLongTap();
          this._cancelSingleTap();
          let otx = evt.touches[1].pageX == null ? evt.touches[1].x : evt.touches[1].pageX;
          let oty = evt.touches[1].pageY == null ? evt.touches[1].y : evt.touches[1].pageY;
          let v = { x: otx - this.x1, y: oty - this.y1 };
          preV.x = v.x;
          preV.y = v.y;
          this.pinchStartLen = getLen(preV);
          this._option.multipointStart(evt);
      }
      this.longTapTimeout = setTimeout(function () {
          evt.type = "longTap";
          this._option.longTap(evt);
      }.bind(this), 750);
  }
  move(evt) {
      if (!evt.touches) return;
      let preV = this.preV,
          len = evt.touches.length,
          currentX = evt.touches[0].pageX == null ? evt.touches[0].x : evt.touches[0].pageX,
          currentY = evt.touches[0].pageY == null ? evt.touches[0].y : evt.touches[0].pageY;
      this.isDoubleTap = false;
      if (len > 1) {
          let otx = evt.touches[1].pageX == null ? evt.touches[1].x : evt.touches[1].pageX;
          let oty = evt.touches[1].pageY == null ? evt.touches[1].y : evt.touches[1].pageY;
          let v = { x: otx - currentX, y: oty - currentY };

          if (preV.x !== null) {
              if (this.pinchStartLen > 0) {
                  evt.singleZoom = getLen(v) / this.pinchStartLen;
                  evt.zoom = evt.singleZoom * this.lastZoom;
                  this.tempZoom = evt.zoom;
                  evt.type = "pinch";
                  this._option.pinch(evt);
              }

              evt.angle = getRotateAngle(v, preV);
              evt.type = "rotate";
              this._option.rotate(evt);
          }
          preV.x = v.x;
          preV.y = v.y;
      } else {
          if (this.x2 !== null) {
              evt.deltaX = currentX - this.x2;
              evt.deltaY = currentY - this.y2;

          } else {
              evt.deltaX = 0;
              evt.deltaY = 0;
          }
          this._option.pressMove(evt);
      }

      this._option.touchMove(evt);

      this._cancelLongTap();
      this.x2 = currentX;
      this.y2 = currentY;
      if (len > 1) {
          // evt.preventDefault();
      }
  }
  end(evt) {
      if (!evt.changedTouches) return;
      this._cancelLongTap();
      let self = this;
      evt.direction = this._swipeDirection(this.x1, this.x2, this.y1, this.y2); //在结束钩子都加入方向判断，但触发swipe瞬时必须位移大于30
      if (evt.touches.length < 2) {
          this.lastZoom = this.tempZoom;
          this._option.multipointEnd(evt);
      }
      this._option.touchEnd(evt);
      //swipe
      if ((this.x2 && Math.abs(this.x1 - this.x2) > 30) ||
          (this.y2 && Math.abs(this.y1 - this.y2) > 30)) {
          // evt.direction = this._swipeDirection(this.x1, this.x2, this.y1, this.y2);
          this.swipeTimeout = setTimeout(function () {
              evt.type = "swipe";
              self._option.swipe(evt);

          }, 0)
      } else {
          this.tapTimeout = setTimeout(function () {
              evt.type = "tap";
              self._option.tap(evt);
              // trigger double tap immediately
              if (self.isDoubleTap) {
                  evt.type = "doubleTap";
                  self._option.doubleTap(evt);
                  clearTimeout(self.singleTapTimeout);
                  self.isDoubleTap = false;
              }
          }, 0)

          if (!self.isDoubleTap) {
              self.singleTapTimeout = setTimeout(function () {
                  self._option.singleTap(evt);
              }, 250);
          }
      }

      this.preV.x = 0;
      this.preV.y = 0;
      this.scale = 1;
      this.pinchStartLen = null;
      this.x1 = this.x2 = this.y1 = this.y2 = null;
  }
  cancel(evt) {
      clearTimeout(this.singleTapTimeout);
      clearTimeout(this.tapTimeout);
      clearTimeout(this.longTapTimeout);
      clearTimeout(this.swipeTimeout);
      this._option.touchCancel(evt);
  }
  _cancelLongTap() {
      clearTimeout(this.longTapTimeout);
  }

  _cancelSingleTap() {
      clearTimeout(this.singleTapTimeout);
  }

  _swipeDirection(x1, x2, y1, y2) {
      return Math.abs(x1 - x2) >= Math.abs(y1 - y2) ? (x1 - x2 > 0 ? 'Left' : 'Right') : (y1 - y2 > 0 ? 'Up' : 'Down')
  }
  destroy() {
      if (this.singleTapTimeout) clearTimeout(this.singleTapTimeout);
      if (this.tapTimeout) clearTimeout(this.tapTimeout);
      if (this.longTapTimeout) clearTimeout(this.longTapTimeout);
      if (this.swipeTimeout) clearTimeout(this.swipeTimeout);

      this._option.rotate = null;
      this._option.touchStart = null;
      this._option.multipointStart = null;
      this._option.multipointEnd = null;
      this._option.pinch = null;
      this._option.swipe = null;
      this._option.tap = null;
      this._option.doubleTap = null;
      this._option.longTap = null;
      this._option.singleTap = null;
      this._option.pressMove = null;
      this._option.touchMove = null;
      this._option.touchEnd = null;
      this._option.touchCancel = null;

      this.preV = this.pinchStartLen = this.scale = this.isDoubleTap = this.delta = this.last = this.now = this.tapTimeout = this.singleTapTimeout = this.longTapTimeout = this.swipeTimeout = this.x1 = this.x2 = this.y1 = this.y2 = this.preTapPosition = this.rotate = this.touchStart = this.multipointStart = this.multipointEnd = this.pinch = this.swipe = this.tap = this.doubleTap = this.longTap = this.singleTap = this.pressMove = this.touchMove = this.touchEnd = this.touchCancel = null;

      return null;
  }
}

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) {
  let mr = getLen(v1) * getLen(v2);
  if (mr === 0) return 0;
  let 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) {
  let angle = getAngle(v1, v2);
  if (cross(v1, v2) > 0) {
      angle *= -1;
  }

  return angle * 180 / Math.PI;
}