/**
 * EventUtils.js
 *
 * Released under LGPL License.
 * Copyright (c) 1999-2017 Ephox Corp. All rights reserved
 *
 * License: http://www.tinymce.com/license
 * Contributing: http://www.tinymce.com/contributing
 */

/*jshint loopfunc:true*/
/*eslint no-loop-func:0 */

/**
 * This class wraps the browsers native event logic with more convenient methods.
 *
 * @class tinymce.dom.EventUtils
 */
define(
  'tinymce.core.dom.EventUtils',
  [
    'global!document',
    'global!window',
    'tinymce.core.Env',
    'tinymce.core.util.Delay'
  ],
  function (document, window, Env, Delay) {
    "use strict";

    var eventExpandoPrefix = "mce-data-";
    var mouseEventRe = /^(?:mouse|contextmenu)|click/;
    var deprecated = {
      keyLocation: 1, layerX: 1, layerY: 1, returnValue: 1,
      webkitMovementX: 1, webkitMovementY: 1, keyIdentifier: 1
    };

    // Checks if it is our own isDefaultPrevented function
    var hasIsDefaultPrevented = function (event) {
      return event.isDefaultPrevented === returnTrue || event.isDefaultPrevented === returnFalse;
    };

    // Dummy function that gets replaced on the delegation state functions
    var returnFalse = function () {
      return false;
    };

    // Dummy function that gets replaced on the delegation state functions
    var returnTrue = function () {
      return true;
    };

    /**
     * Binds a native event to a callback on the speified target.
     */
    function addEvent(target, name, callback, capture) {
      if (target.addEventListener) {
        target.addEventListener(name, callback, capture || false);
      } else if (target.attachEvent) {
        target.attachEvent('on' + name, callback);
      }
    }

    /**
     * Unbinds a native event callback on the specified target.
     */
    function removeEvent(target, name, callback, capture) {
      if (target.removeEventListener) {
        target.removeEventListener(name, callback, capture || false);
      } else if (target.detachEvent) {
        target.detachEvent('on' + name, callback);
      }
    }

    /**
     * Gets the event target based on shadow dom properties like path and deepPath.
     */
    function getTargetFromShadowDom(event, defaultTarget) {
      var path, target = defaultTarget;

      // When target element is inside Shadow DOM we need to take first element from path
      // otherwise we'll get Shadow Root parent, not actual target element

      // Normalize target for WebComponents v0 implementation (in Chrome)
      path = event.path;
      if (path && path.length > 0) {
        target = path[0];
      }

      // Normalize target for WebComponents v1 implementation (standard)
      if (event.deepPath) {
        path = event.deepPath();
        if (path && path.length > 0) {
          target = path[0];
        }
      }

      return target;
    }

    /**
     * Normalizes a native event object or just adds the event specific methods on a custom event.
     */
    function fix(originalEvent, data) {
      var name, event = data || {}, undef;

      // Copy all properties from the original event
      for (name in originalEvent) {
        // layerX/layerY is deprecated in Chrome and produces a warning
        if (!deprecated[name]) {
          event[name] = originalEvent[name];
        }
      }

      // Normalize target IE uses srcElement
      if (!event.target) {
        event.target = event.srcElement || document;
      }

      // Experimental shadow dom support
      if (Env.experimentalShadowDom) {
        event.target = getTargetFromShadowDom(originalEvent, event.target);
      }

      // Calculate pageX/Y if missing and clientX/Y available
      if (originalEvent && mouseEventRe.test(originalEvent.type) && originalEvent.pageX === undef && originalEvent.clientX !== undef) {
        var eventDoc = event.target.ownerDocument || document;
        var doc = eventDoc.documentElement;
        var body = eventDoc.body;

        event.pageX = originalEvent.clientX + (doc && doc.scrollLeft || body && body.scrollLeft || 0) -
          (doc && doc.clientLeft || body && body.clientLeft || 0);

        event.pageY = originalEvent.clientY + (doc && doc.scrollTop || body && body.scrollTop || 0) -
          (doc && doc.clientTop || body && body.clientTop || 0);
      }

      // Add preventDefault method
      event.preventDefault = function () {
        event.isDefaultPrevented = returnTrue;

        // Execute preventDefault on the original event object
        if (originalEvent) {
          if (originalEvent.preventDefault) {
            originalEvent.preventDefault();
          } else {
            originalEvent.returnValue = false; // IE
          }
        }
      };

      // Add stopPropagation
      event.stopPropagation = function () {
        event.isPropagationStopped = returnTrue;

        // Execute stopPropagation on the original event object
        if (originalEvent) {
          if (originalEvent.stopPropagation) {
            originalEvent.stopPropagation();
          } else {
            originalEvent.cancelBubble = true; // IE
          }
        }
      };

      // Add stopImmediatePropagation
      event.stopImmediatePropagation = function () {
        event.isImmediatePropagationStopped = returnTrue;
        event.stopPropagation();
      };

      // Add event delegation states
      if (hasIsDefaultPrevented(event) === false) {
        event.isDefaultPrevented = returnFalse;
        event.isPropagationStopped = returnFalse;
        event.isImmediatePropagationStopped = returnFalse;
      }

      // Add missing metaKey for IE 8
      if (typeof event.metaKey == 'undefined') {
        event.metaKey = false;
      }

      return event;
    }

    /**
     * Bind a DOMContentLoaded event across browsers and executes the callback once the page DOM is initialized.
     * It will also set/check the domLoaded state of the event_utils instance so ready isn't called multiple times.
     */
    function bindOnReady(win, callback, eventUtils) {
      var doc = win.document, event = { type: 'ready' };

      if (eventUtils.domLoaded) {
        callback(event);
        return;
      }

      function isDocReady() {
        // Check complete or interactive state if there is a body
        // element on some iframes IE 8 will produce a null body
        return doc.readyState === "complete" || (doc.readyState === "interactive" && doc.body);
      }

      // Gets called when the DOM is ready
      function readyHandler() {
        if (!eventUtils.domLoaded) {
          eventUtils.domLoaded = true;
          callback(event);
        }
      }

      function waitForDomLoaded() {
        if (isDocReady()) {
          removeEvent(doc, "readystatechange", waitForDomLoaded);
          readyHandler();
        }
      }

      function tryScroll() {
        try {
          // If IE is used, use the trick by Diego Perini licensed under MIT by request to the author.
          // http://javascript.nwbox.com/IEContentLoaded/
          doc.documentElement.doScroll("left");
        } catch (ex) {
          Delay.setTimeout(tryScroll);
          return;
        }

        readyHandler();
      }

      // Use W3C method (exclude IE 9,10 - readyState "interactive" became valid only in IE 11)
      if (doc.addEventListener && !(Env.ie && Env.ie < 11)) {
        if (isDocReady()) {
          readyHandler();
        } else {
          addEvent(win, 'DOMContentLoaded', readyHandler);
        }
      } else {
        // Use IE method
        addEvent(doc, "readystatechange", waitForDomLoaded);

        // Wait until we can scroll, when we can the DOM is initialized
        if (doc.documentElement.doScroll && win.self === win.top) {
          tryScroll();
        }
      }

      // Fallback if any of the above methods should fail for some odd reason
      addEvent(win, 'load', readyHandler);
    }

    /**
     * This class enables you to bind/unbind native events to elements and normalize it's behavior across browsers.
     */
    function EventUtils() {
      var self = this, events = {}, count, expando, hasFocusIn, hasMouseEnterLeave, mouseEnterLeave;

      expando = eventExpandoPrefix + (+new Date()).toString(32);
      hasMouseEnterLeave = "onmouseenter" in document.documentElement;
      hasFocusIn = "onfocusin" in document.documentElement;
      mouseEnterLeave = { mouseenter: 'mouseover', mouseleave: 'mouseout' };
      count = 1;

      // State if the DOMContentLoaded was executed or not
      self.domLoaded = false;
      self.events = events;

      /**
       * Executes all event handler callbacks for a specific event.
       *
       * @private
       * @param {Event} evt Event object.
       * @param {String} id Expando id value to look for.
       */
      function executeHandlers(evt, id) {
        var callbackList, i, l, callback, container = events[id];

        callbackList = container && container[evt.type];
        if (callbackList) {
          for (i = 0, l = callbackList.length; i < l; i++) {
            callback = callbackList[i];

            // Check if callback exists might be removed if a unbind is called inside the callback
            if (callback && callback.func.call(callback.scope, evt) === false) {
              evt.preventDefault();
            }

            // Should we stop propagation to immediate listeners
            if (evt.isImmediatePropagationStopped()) {
              return;
            }
          }
        }
      }

      /**
       * Binds a callback to an event on the specified target.
       *
       * @method bind
       * @param {Object} target Target node/window or custom object.
       * @param {String} names Name of the event to bind.
       * @param {function} callback Callback function to execute when the event occurs.
       * @param {Object} scope Scope to call the callback function on, defaults to target.
       * @return {function} Callback function that got bound.
       */
      self.bind = function (target, names, callback, scope) {
        var id, callbackList, i, name, fakeName, nativeHandler, capture, win = window;

        // Native event handler function patches the event and executes the callbacks for the expando
        function defaultNativeHandler(evt) {
          executeHandlers(fix(evt || win.event), id);
        }

        // Don't bind to text nodes or comments
        if (!target || target.nodeType === 3 || target.nodeType === 8) {
          return;
        }

        // Create or get events id for the target
        if (!target[expando]) {
          id = count++;
          target[expando] = id;
          events[id] = {};
        } else {
          id = target[expando];
        }

        // Setup the specified scope or use the target as a default
        scope = scope || target;

        // Split names and bind each event, enables you to bind multiple events with one call
        names = names.split(' ');
        i = names.length;
        while (i--) {
          name = names[i];
          nativeHandler = defaultNativeHandler;
          fakeName = capture = false;

          // Use ready instead of DOMContentLoaded
          if (name === "DOMContentLoaded") {
            name = "ready";
          }

          // DOM is already ready
          if (self.domLoaded && name === "ready" && target.readyState == 'complete') {
            callback.call(scope, fix({ type: name }));
            continue;
          }

          // Handle mouseenter/mouseleaver
          if (!hasMouseEnterLeave) {
            fakeName = mouseEnterLeave[name];

            if (fakeName) {
              nativeHandler = function (evt) {
                var current, related;

                current = evt.currentTarget;
                related = evt.relatedTarget;

                // Check if related is inside the current target if it's not then the event should
                // be ignored since it's a mouseover/mouseout inside the element
                if (related && current.contains) {
                  // Use contains for performance
                  related = current.contains(related);
                } else {
                  while (related && related !== current) {
                    related = related.parentNode;
                  }
                }

                // Fire fake event
                if (!related) {
                  evt = fix(evt || win.event);
                  evt.type = evt.type === 'mouseout' ? 'mouseleave' : 'mouseenter';
                  evt.target = current;
                  executeHandlers(evt, id);
                }
              };
            }
          }

          // Fake bubbling of focusin/focusout
          if (!hasFocusIn && (name === "focusin" || name === "focusout")) {
            capture = true;
            fakeName = name === "focusin" ? "focus" : "blur";
            nativeHandler = function (evt) {
              evt = fix(evt || win.event);
              evt.type = evt.type === 'focus' ? 'focusin' : 'focusout';
              executeHandlers(evt, id);
            };
          }

          // Setup callback list and bind native event
          callbackList = events[id][name];
          if (!callbackList) {
            events[id][name] = callbackList = [{ func: callback, scope: scope }];
            callbackList.fakeName = fakeName;
            callbackList.capture = capture;
            //callbackList.callback = callback;

            // Add the nativeHandler to the callback list so that we can later unbind it
            callbackList.nativeHandler = nativeHandler;

            // Check if the target has native events support

            if (name === "ready") {
              bindOnReady(target, nativeHandler, self);
            } else {
              addEvent(target, fakeName || name, nativeHandler, capture);
            }
          } else {
            if (name === "ready" && self.domLoaded) {
              callback({ type: name });
            } else {
              // If it already has an native handler then just push the callback
              callbackList.push({ func: callback, scope: scope });
            }
          }
        }

        target = callbackList = 0; // Clean memory for IE

        return callback;
      };

      /**
       * Unbinds the specified event by name, name and callback or all events on the target.
       *
       * @method unbind
       * @param {Object} target Target node/window or custom object.
       * @param {String} names Optional event name to unbind.
       * @param {function} callback Optional callback function to unbind.
       * @return {EventUtils} Event utils instance.
       */
      self.unbind = function (target, names, callback) {
        var id, callbackList, i, ci, name, eventMap;

        // Don't bind to text nodes or comments
        if (!target || target.nodeType === 3 || target.nodeType === 8) {
          return self;
        }

        // Unbind event or events if the target has the expando
        id = target[expando];
        if (id) {
          eventMap = events[id];

          // Specific callback
          if (names) {
            names = names.split(' ');
            i = names.length;
            while (i--) {
              name = names[i];
              callbackList = eventMap[name];

              // Unbind the event if it exists in the map
              if (callbackList) {
                // Remove specified callback
                if (callback) {
                  ci = callbackList.length;
                  while (ci--) {
                    if (callbackList[ci].func === callback) {
                      var nativeHandler = callbackList.nativeHandler;
                      var fakeName = callbackList.fakeName, capture = callbackList.capture;

                      // Clone callbackList since unbind inside a callback would otherwise break the handlers loop
                      callbackList = callbackList.slice(0, ci).concat(callbackList.slice(ci + 1));
                      callbackList.nativeHandler = nativeHandler;
                      callbackList.fakeName = fakeName;
                      callbackList.capture = capture;

                      eventMap[name] = callbackList;
                    }
                  }
                }

                // Remove all callbacks if there isn't a specified callback or there is no callbacks left
                if (!callback || callbackList.length === 0) {
                  delete eventMap[name];
                  removeEvent(target, callbackList.fakeName || name, callbackList.nativeHandler, callbackList.capture);
                }
              }
            }
          } else {
            // All events for a specific element
            for (name in eventMap) {
              callbackList = eventMap[name];
              removeEvent(target, callbackList.fakeName || name, callbackList.nativeHandler, callbackList.capture);
            }

            eventMap = {};
          }

          // Check if object is empty, if it isn't then we won't remove the expando map
          for (name in eventMap) {
            return self;
          }

          // Delete event object
          delete events[id];

          // Remove expando from target
          try {
            // IE will fail here since it can't delete properties from window
            delete target[expando];
          } catch (ex) {
            // IE will set it to null
            target[expando] = null;
          }
        }

        return self;
      };

      /**
       * Fires the specified event on the specified target.
       *
       * @method fire
       * @param {Object} target Target node/window or custom object.
       * @param {String} name Event name to fire.
       * @param {Object} args Optional arguments to send to the observers.
       * @return {EventUtils} Event utils instance.
       */
      self.fire = function (target, name, args) {
        var id;

        // Don't bind to text nodes or comments
        if (!target || target.nodeType === 3 || target.nodeType === 8) {
          return self;
        }

        // Build event object by patching the args
        args = fix(null, args);
        args.type = name;
        args.target = target;

        do {
          // Found an expando that means there is listeners to execute
          id = target[expando];
          if (id) {
            executeHandlers(args, id);
          }

          // Walk up the DOM
          target = target.parentNode || target.ownerDocument || target.defaultView || target.parentWindow;
        } while (target && !args.isPropagationStopped());

        return self;
      };

      /**
       * Removes all bound event listeners for the specified target. This will also remove any bound
       * listeners to child nodes within that target.
       *
       * @method clean
       * @param {Object} target Target node/window object.
       * @return {EventUtils} Event utils instance.
       */
      self.clean = function (target) {
        var i, children, unbind = self.unbind;

        // Don't bind to text nodes or comments
        if (!target || target.nodeType === 3 || target.nodeType === 8) {
          return self;
        }

        // Unbind any element on the specified target
        if (target[expando]) {
          unbind(target);
        }

        // Target doesn't have getElementsByTagName it's probably a window object then use it's document to find the children
        if (!target.getElementsByTagName) {
          target = target.document;
        }

        // Remove events from each child element
        if (target && target.getElementsByTagName) {
          unbind(target);

          children = target.getElementsByTagName('*');
          i = children.length;
          while (i--) {
            target = children[i];

            if (target[expando]) {
              unbind(target);
            }
          }
        }

        return self;
      };

      /**
       * Destroys the event object. Call this on IE to remove memory leaks.
       */
      self.destroy = function () {
        events = {};
      };

      // Legacy function for canceling events
      self.cancel = function (e) {
        if (e) {
          e.preventDefault();
          e.stopImmediatePropagation();
        }

        return false;
      };
    }

    EventUtils.Event = new EventUtils();
    EventUtils.Event.bind(window, 'ready', function () { });

    return EventUtils;
  }
);
