/** 
  * 组合按键
  *@params json keys 监听的按键 
  *@params bool isOrder 按键是否有相应的顺序 
  *@params Function sucFuc 完成按键的回调函数 
  *@params Function cancelFuc 完成按键取消后的回调函数 
  */
 var dqKeys = function (keys, isOrder, sucFuc, cancelFuc) {
    // 函数体 
    return new dqKeys.fn.init(keys, isOrder, sucFuc, cancelFuc);
  }
  dqKeys.fn = dqKeys.prototype = {
    'rightKeys': {}, //监听的按键{key:code},code为按键对应的ascii码  
    'curKeys': [], //当前按下的键 
    'sucFuc': null, //完成按键的回调函数 
    'cancelFuc': null, //完成按键取消后的回调函数 
    'isFinsh': false, //判断是否完成按键 
    'isOrder': false, //按键是否有相应的顺序 
    init: function (keys, isOrder, sucFuc, cancelFuc) {
      this.rightKeys = keys;
      this.sucFuc = sucFuc;
      this.cancelFuc = cancelFuc;
      this.isOrder = isOrder;
 
      return this;
    },
    listenkeys: function () { //监听用户键盘操作         
      var _self = this;
      _self.addListener('keydown', function (oEvent) {
        var oEvent = oEvent || window.event;
        if (!_self.arrayContain(_self.curKeys, oEvent.keyCode)) {
          if (_self.isOrder && _self.getNextKey() == oEvent.keyCode) {
            _self.curKeys.push(oEvent.keyCode);
          } else if (!_self.isOrder) {
            _self.curKeys.push(oEvent.keyCode);
          }
        }
        if (_self.checkResult(_self.rightKeys, _self.curKeys)) {
          if (_self.sucFuc && !_self.isFinsh) {
            _self.sucFuc();
          }
          _self.isFinsh = true;
        }
      });
      _self.addListener('keyup', function (oEvent) {
        var oEvent = oEvent || window.event;
        if (_self.checkResult(_self.rightKeys, _self.curKeys) && _self.isFinsh) {
          //完成按键,又取消的事件 
          if (_self.cancelFuc) {
            _self.cancelFuc();
          }
        }
 
        _self.curKey = _self.remove(_self.curKeys, oEvent.keyCode);
        _self.isFinsh = false;
      });
    },
    arrayContain: function (arr, val) { //判断数组中是否包含某个元素 
      return (arr.indexOf(val) == -1) ? false : true;
    },
    checkResult: function (json, arr) { //判断用户是否按下监听的所有按键 
      for (var i in json) {
        if (arr.indexOf(json[i]) == -1) {
          return false;
        }
      }
      return true;
    },
    remove: function (arr, val) { //从数组中移除某个元素       
      var index = arr.indexOf(val);
      if (index > -1) {
        arr.splice(index, 1);
      }
      return arr;
    },
    getNextKey: function () { //获取下一次按键对应的ascii码 
      for (var i in this.rightKeys) {
        if (this.curKeys.indexOf(this.rightKeys[i]) == -1) {
          return this.rightKeys[i];
        }
      }
      return null;
    },
    addListener: function (ev, fn, bool) { //事件绑定 
      if (document.attachEvent) {
        document.attachEvent('on' + ev, fn);
      } else {
        document.addEventListener(ev, fn, bool);
      }
    }
 
  }
  dqKeys.fn.init.prototype = dqKeys.fn;
  export default dqKeys;