var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

// import Core from './core';
import { polymerWrap, closest } from './helpers/dom/element';
import { isWebComponentSupportedNatively } from './helpers/feature';
import { stopImmediatePropagation as _stopImmediatePropagation } from './helpers/dom/event';

/**
 * Counter which tracks unregistered listeners (useful for detecting memory leaks).
 *
 * @type {Number}
 */
var listenersCounter = 0;

/**
 * Event DOM manager for internal use in Handsontable.
 *
 * @class EventManager
 * @util
 */

var EventManager = function () {
  /**
   * @param {Object} [context=null]
   * @private
   */
  function EventManager() {
    var context = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : null;

    _classCallCheck(this, EventManager);

    this.context = context || this;

    if (!this.context.eventListeners) {
      this.context.eventListeners = [];
    }
  }

  /**
   * Register specified listener (`eventName`) to the element.
   *
   * @param {Element} element Target element.
   * @param {String} eventName Event name.
   * @param {Function} callback Function which will be called after event occur.
   * @returns {Function} Returns function which you can easily call to remove that event
   */


  _createClass(EventManager, [{
    key: 'addEventListener',
    value: function addEventListener(element, eventName, callback) {
      var _this = this;

      var context = this.context;

      function callbackProxy(event) {
        event = extendEvent(context, event);

        callback.call(this, event);
      }
      this.context.eventListeners.push({
        element: element,
        event: eventName,
        callback: callback,
        callbackProxy: callbackProxy
      });

      if (window.addEventListener) {
        element.addEventListener(eventName, callbackProxy, false);
      } else {
        element.attachEvent('on' + eventName, callbackProxy);
      }
      listenersCounter++;

      return function () {
        _this.removeEventListener(element, eventName, callback);
      };
    }

    /**
     * Remove the event listener previously registered.
     *
     * @param {Element} element Target element.
     * @param {String} eventName Event name.
     * @param {Function} callback Function to remove from the event target. It must be the same as during registration listener.
     */

  }, {
    key: 'removeEventListener',
    value: function removeEventListener(element, eventName, callback) {
      var len = this.context.eventListeners.length;
      var tmpEvent = void 0;

      while (len--) {
        tmpEvent = this.context.eventListeners[len];

        if (tmpEvent.event == eventName && tmpEvent.element == element) {
          if (callback && callback != tmpEvent.callback) {
            /* eslint-disable no-continue */
            continue;
          }
          this.context.eventListeners.splice(len, 1);

          if (tmpEvent.element.removeEventListener) {
            tmpEvent.element.removeEventListener(tmpEvent.event, tmpEvent.callbackProxy, false);
          } else {
            tmpEvent.element.detachEvent('on' + tmpEvent.event, tmpEvent.callbackProxy);
          }
          listenersCounter--;
        }
      }
    }

    /**
     * Clear all previously registered events.
     *
     * @private
     * @since 0.15.0-beta3
     */

  }, {
    key: 'clearEvents',
    value: function clearEvents() {
      if (!this.context) {
        return;
      }
      var len = this.context.eventListeners.length;

      while (len--) {
        var event = this.context.eventListeners[len];

        if (event) {
          this.removeEventListener(event.element, event.event, event.callback);
        }
      }
    }

    /**
     * Clear all previously registered events.
     */

  }, {
    key: 'clear',
    value: function clear() {
      this.clearEvents();
    }

    /**
     * Destroy instance of EventManager.
     */

  }, {
    key: 'destroy',
    value: function destroy() {
      this.clearEvents();
      this.context = null;
    }

    /**
     * Trigger event at the specified target element.
     *
     * @param {Element} element Target element.
     * @param {String} eventName Event name.
     */

  }, {
    key: 'fireEvent',
    value: function fireEvent(element, eventName) {
      var options = {
        bubbles: true,
        cancelable: eventName !== 'mousemove',
        view: window,
        detail: 0,
        screenX: 0,
        screenY: 0,
        clientX: 1,
        clientY: 1,
        ctrlKey: false,
        altKey: false,
        shiftKey: false,
        metaKey: false,
        button: 0,
        relatedTarget: undefined
      };
      var event;

      if (document.createEvent) {
        event = document.createEvent('MouseEvents');
        event.initMouseEvent(eventName, options.bubbles, options.cancelable, options.view, options.detail, options.screenX, options.screenY, options.clientX, options.clientY, options.ctrlKey, options.altKey, options.shiftKey, options.metaKey, options.button, options.relatedTarget || document.body.parentNode);
      } else {
        event = document.createEventObject();
      }

      if (element.dispatchEvent) {
        element.dispatchEvent(event);
      } else {
        element.fireEvent('on' + eventName, event);
      }
    }
  }]);

  return EventManager;
}();

/**
 * @param {Object} context
 * @param {Event} event
 * @private
 * @returns {*}
 */


function extendEvent(context, event) {
  var componentName = 'HOT-TABLE';
  var isHotTableSpotted = void 0;
  var fromElement = void 0;
  var realTarget = void 0;
  var target = void 0;
  var len = void 0;
  var nativeStopImmediatePropagation = void 0;

  event.isTargetWebComponent = false;
  event.realTarget = event.target;

  nativeStopImmediatePropagation = event.stopImmediatePropagation;
  event.stopImmediatePropagation = function () {
    nativeStopImmediatePropagation.apply(this);
    _stopImmediatePropagation(this);
  };

  if (!EventManager.isHotTableEnv) {
    return event;
  }
  event = polymerWrap(event);
  len = event.path ? event.path.length : 0;

  while (len--) {
    if (event.path[len].nodeName === componentName) {
      isHotTableSpotted = true;
    } else if (isHotTableSpotted && event.path[len].shadowRoot) {
      target = event.path[len];

      break;
    }
    if (len === 0 && !target) {
      target = event.path[len];
    }
  }
  if (!target) {
    target = event.target;
  }
  event.isTargetWebComponent = true;

  if (isWebComponentSupportedNatively()) {
    event.realTarget = event.srcElement || event.toElement;
  } else if (context instanceof Core || context instanceof Walkontable) {
    // Polymer doesn't support `event.target` property properly we must emulate it ourselves
    if (context instanceof Core) {
      fromElement = context.view ? context.view.wt.wtTable.TABLE : null;
    } else if (context instanceof Walkontable) {
      // .wtHider
      fromElement = context.wtTable.TABLE.parentNode.parentNode;
    }
    realTarget = closest(event.target, [componentName], fromElement);

    if (realTarget) {
      event.realTarget = fromElement.querySelector(componentName) || event.target;
    } else {
      event.realTarget = event.target;
    }
  }

  Object.defineProperty(event, 'target', {
    get: function get() {
      return polymerWrap(target);
    },

    enumerable: true,
    configurable: true
  });

  return event;
}

export default EventManager;

export function getListenersCounter() {
  return listenersCounter;
};