define([
	"dojo/_base/array", // array.indexOf
	"dojo/_base/declare", // declare
	"dojo/dom", // dom.isDescendant domClass.replace
	"dojo/dom-attr",
	"dojo/dom-class", // domClass.replace
	"dojo/_base/lang", // lang.hitch
	"dojo/mouse", // mouse.enter, mouse.leave
	"dojo/on",
	"dojo/window",
	"./a11yclick",
	"./registry",
	"./_Widget",
	"./_CssStateMixin",
	"./_KeyNavContainer",
	"./_TemplatedMixin"
], function(array, declare, dom, domAttr, domClass, lang, mouse, on, winUtils, a11yclick,
			registry, _Widget, _CssStateMixin, _KeyNavContainer, _TemplatedMixin){

	// module:
	//		dijit/_MenuBase

	return declare("dijit._MenuBase", [_Widget, _TemplatedMixin, _KeyNavContainer, _CssStateMixin], {
		// summary:
		//		Abstract base class for Menu and MenuBar.
		//		Subclass should implement _onUpArrow(), _onDownArrow(), _onLeftArrow(), and _onRightArrow().

		// selected: dijit/MenuItem
		//		Currently selected (a.k.a. highlighted) MenuItem, or null if no MenuItem is selected.
		//		If a submenu is open, will be set to MenuItem that displayed the submenu.   OTOH, if
		//		this Menu is in passive mode (i.e. hasn't been clicked yet), will be null, because
		//		"selected" is not merely "hovered".
		selected: null,
		_setSelectedAttr: function(item){
			if(this.selected != item){
				if(this.selected){
					this.selected._setSelected(false);
					this._onChildDeselect(this.selected);
				}
				if(item){
					item._setSelected(true);
				}
				this._set("selected", item);
			}
		},

		// activated: [readonly] Boolean
		//		This Menu has been clicked (mouse or via space/arrow key) or opened as a submenu,
		//		so mere mouseover will open submenus.  Focusing a menu via TAB does NOT automatically make it active
		//		since TAB is a navigation operation and not a selection one.
		//		For Windows apps, pressing the ALT key focuses the menubar menus (similar to TAB navigation) but the
		//		menu is not active (ie no dropdown) until an item is clicked.
		activated: false,
		_setActivatedAttr: function(val){
			domClass.toggle(this.domNode, "dijitMenuActive", val);
			domClass.toggle(this.domNode, "dijitMenuPassive", !val);
			this._set("activated", val);
		},

		// parentMenu: [readonly] Widget
		//		pointer to menu that displayed me
		parentMenu: null,

		// popupDelay: Integer
		//		After a menu has been activated (by clicking on it etc.), number of milliseconds before hovering
		//		(without clicking) another MenuItem causes that MenuItem's popup to automatically open.
		popupDelay: 500,

		// passivePopupDelay: Integer
		//		For a passive (unclicked) Menu, number of milliseconds before hovering (without clicking) will cause
		//		the popup to open.  Default is Infinity, meaning you need to click the menu to open it.
		passivePopupDelay: Infinity,

		// autoFocus: Boolean
		//		A toggle to control whether or not a Menu gets focused when opened as a drop down from a MenuBar
		//		or DropDownButton/ComboButton.   Note though that it always get focused when opened via the keyboard.
		autoFocus: false,

		childSelector: function(/*DOMNode*/ node){
			// summary:
			//		Selector (passed to on.selector()) used to identify MenuItem child widgets, but exclude inert children
			//		like MenuSeparator.  If subclass overrides to a string (ex: "> *"), the subclass must require dojo/query.
			// tags:
			//		protected

			var widget = registry.byNode(node);
			return node.parentNode == this.containerNode && widget && widget.focus;
		},

		postCreate: function(){
			var self = this,
				matches = typeof this.childSelector == "string" ? this.childSelector : lang.hitch(this, "childSelector");
			this.own(
				on(this.containerNode, on.selector(matches, mouse.enter), function(){
					self.onItemHover(registry.byNode(this));
				}),
				on(this.containerNode, on.selector(matches, mouse.leave), function(){
					self.onItemUnhover(registry.byNode(this));
				}),
				on(this.containerNode, on.selector(matches, a11yclick), function(evt){
					self.onItemClick(registry.byNode(this), evt);
					evt.stopPropagation();
					evt.preventDefault();
				})
			);
			this.inherited(arguments);
		},

		onKeyboardSearch: function(/*MenuItem*/ item, /*Event*/ evt, /*String*/ searchString, /*Number*/ numMatches){
			// summary:
			//		Attach point for notification about when a menu item has been searched for
			//		via the keyboard search mechanism.
			// tags:
			//		protected
			this.inherited(arguments);
			if(!!item && (numMatches == -1 || (!!item.popup && numMatches == 1))){
				this.onItemClick(item, evt);
			}
		},

		_keyboardSearchCompare: function(/*dijit/_WidgetBase*/ item, /*String*/ searchString){
			// summary:
			//		Compares the searchString to the widget's text label, returning:
			//		-1: a high priority match and stop searching
			//		 0: no match
			//		 1: a match but keep looking for a higher priority match
			// tags:
			//		private
			if(!!item.shortcutKey){
				// accessKey matches have priority
				return searchString == item.shortcutKey.toLowerCase() ? -1 : 0;
			}
			return this.inherited(arguments) ? 1 : 0; // change return value of -1 to 1 so that searching continues
		},

		onExecute: function(){
			// summary:
			//		Attach point for notification about when a menu item has been executed.
			//		This is an internal mechanism used for Menus to signal to their parent to
			//		close them, because they are about to execute the onClick handler.  In
			//		general developers should not attach to or override this method.
			// tags:
			//		protected
		},

		onCancel: function(/*Boolean*/ /*===== closeAll =====*/){
			// summary:
			//		Attach point for notification about when the user cancels the current menu
			//		This is an internal mechanism used for Menus to signal to their parent to
			//		close them.  In general developers should not attach to or override this method.
			// tags:
			//		protected
		},

		_moveToPopup: function(/*Event*/ evt){
			// summary:
			//		This handles the right arrow key (left arrow key on RTL systems),
			//		which will either open a submenu, or move to the next item in the
			//		ancestor MenuBar
			// tags:
			//		private

			if(this.focusedChild && this.focusedChild.popup && !this.focusedChild.disabled){
				this.onItemClick(this.focusedChild, evt);
			}else{
				var topMenu = this._getTopMenu();
				if(topMenu && topMenu._isMenuBar){
					topMenu.focusNext();
				}
			}
		},

		_onPopupHover: function(/*Event*/ /*===== evt =====*/){
			// summary:
			//		This handler is called when the mouse moves over the popup.
			// tags:
			//		private

			// if the mouse hovers over a menu popup that is in pending-close state,
			// then stop the close operation.
			// This can't be done in onItemHover since some popup targets don't have MenuItems (e.g. ColorPicker)

			// highlight the parent menu item pointing to this popup (in case user temporarily moused over another MenuItem)
			this.set("selected", this.currentPopupItem);

			// cancel the pending close (if there is one) (in case user temporarily moused over another MenuItem)
			this._stopPendingCloseTimer();
		},

		onItemHover: function(/*MenuItem*/ item){
			// summary:
			//		Called when cursor is over a MenuItem.
			// tags:
			//		protected

			// Don't do anything unless user has "activated" the menu by:
			//		1) clicking it
			//		2) opening it from a parent menu (which automatically activates it)

			if(this.activated){
				this.set("selected", item);
				if(item.popup && !item.disabled && !this.hover_timer){
					this.hover_timer = this.defer(function(){
						this._openItemPopup(item);
					}, this.popupDelay);
				}
			}else if(this.passivePopupDelay < Infinity){
				if(this.passive_hover_timer){
					this.passive_hover_timer.remove();
				}
				this.passive_hover_timer = this.defer(function(){
					this.onItemClick(item, {type: "click"});
				}, this.passivePopupDelay);
			}

			this._hoveredChild = item;

			item._set("hovering", true);
		},

		_onChildDeselect: function(item){
			// summary:
			//		Called when a child MenuItem becomes deselected.   Setup timer to close its popup.

			this._stopPopupTimer();

			// Setup timer to close all popups that are open and descendants of this menu.
			// Will be canceled if user quickly moves the mouse over the popup.
			if(this.currentPopupItem == item){
				this._stopPendingCloseTimer();
				this._pendingClose_timer = this.defer(function(){
					this._pendingClose_timer = null;
					this.currentPopupItem = null;
					item._closePopup(); // this calls onClose
				}, this.popupDelay);
			}
		},

		onItemUnhover: function(/*MenuItem*/ item){
			// summary:
			//		Callback fires when mouse exits a MenuItem
			// tags:
			//		protected

			if(this._hoveredChild == item){
				this._hoveredChild = null;
			}

			if(this.passive_hover_timer){
				this.passive_hover_timer.remove();
				this.passive_hover_timer = null;
			}

			item._set("hovering", false);
		},

		_stopPopupTimer: function(){
			// summary:
			//		Cancels the popup timer because the user has stop hovering
			//		on the MenuItem, etc.
			// tags:
			//		private

			if(this.hover_timer){
				this.hover_timer = this.hover_timer.remove();
			}
		},

		_stopPendingCloseTimer: function(){
			// summary:
			//		Cancels the pending-close timer because the close has been preempted
			// tags:
			//		private
			if(this._pendingClose_timer){
				this._pendingClose_timer = this._pendingClose_timer.remove();
			}
		},

		_getTopMenu: function(){
			// summary:
			//		Returns the top menu in this chain of Menus
			// tags:
			//		private
			for(var top = this; top.parentMenu; top = top.parentMenu){}
			return top;
		},

		onItemClick: function(/*dijit/_WidgetBase*/ item, /*Event*/ evt){
			// summary:
			//		Handle clicks on an item.
			// tags:
			//		private

			if(this.passive_hover_timer){
				this.passive_hover_timer.remove();
			}

			this.focusChild(item);

			if(item.disabled){
				return false;
			}

			if(item.popup){
				this.set("selected", item);
				this.set("activated", true);
				this._openItemPopup(item, /^key/.test(evt._origType || evt.type));
			}else{
				// before calling user defined handler, close hierarchy of menus
				// and restore focus to place it was when menu was opened
				this.onExecute();

				// user defined handler for click
				item._onClick ? item._onClick(evt) : item.onClick(evt);
			}
		},

		_openItemPopup: function(/*dijit/MenuItem*/ from_item, /*Boolean*/ focus){
			// summary:
			//		Open the popup to the side of/underneath the current menu item, and optionally focus first item
			// tags:
			//		protected

			if(from_item == this.currentPopupItem){
				// Specified popup is already being shown, so just return
				return;
			}
			if(this.currentPopupItem){
				// If another popup is currently shown, then close it
				this._stopPendingCloseTimer();
				this.currentPopupItem._closePopup();
			}
			this._stopPopupTimer();

			var popup = from_item.popup;
			popup.parentMenu = this;

			// detect mouseover of the popup to handle lazy mouse movements that temporarily focus other menu items\c
			this.own(this._mouseoverHandle = on.once(popup.domNode, "mouseover", lang.hitch(this, "_onPopupHover")));

			var self = this;
			from_item._openPopup({
				parent: this,
				orient: this._orient || ["after", "before"],
				onCancel: function(){ // called when the child menu is canceled
					if(focus){
						// put focus back on my node before focused node is hidden
						self.focusChild(from_item);
					}

					// close the submenu (be sure this is done _after_ focus is moved)
					self._cleanUp();
				},
				onExecute: lang.hitch(this, "_cleanUp", true),
				onClose: function(){
					// Remove handler created by onItemHover
					if(self._mouseoverHandle){
						self._mouseoverHandle.remove();
						delete self._mouseoverHandle;
					}
				}
			}, focus);

			this.currentPopupItem = from_item;

			// TODO: focusing a popup should clear tabIndex on Menu (and it's child MenuItems), so that neither
			// TAB nor SHIFT-TAB returns to the menu.  Only ESC or ENTER should return to the menu.
		},

		onOpen: function(/*Event*/ /*===== e =====*/){
			// summary:
			//		Callback when this menu is opened.
			//		This is called by the popup manager as notification that the menu
			//		was opened.
			// tags:
			//		private

			this.isShowingNow = true;
			this.set("activated", true);
		},

		onClose: function(){
			// summary:
			//		Callback when this menu is closed.
			//		This is called by the popup manager as notification that the menu
			//		was closed.
			// tags:
			//		private

			this.set("activated", false);
			this.set("selected", null);
			this.isShowingNow = false;
			this.parentMenu = null;
		},

		_closeChild: function(){
			// summary:
			//		Called when submenu is clicked or focus is lost.  Close hierarchy of menus.
			// tags:
			//		private
			this._stopPopupTimer();

			if(this.currentPopupItem){
				// If focus is on a descendant MenuItem then move focus to me,
				// because IE doesn't like it when you display:none a node with focus,
				// and also so keyboard users don't lose control.
				// Likely, immediately after a user defined onClick handler will move focus somewhere
				// else, like a Dialog.
				if(this.focused){
					domAttr.set(this.selected.focusNode, "tabIndex", this.tabIndex);
					this.selected.focusNode.focus();
				}

				// Close all popups that are open and descendants of this menu
				this.currentPopupItem._closePopup();
				this.currentPopupItem = null;
			}
		},

		_onItemFocus: function(/*MenuItem*/ item){
			// summary:
			//		Called when child of this Menu gets focus from:
			//
			//		1. clicking it
			//		2. tabbing into it
			//		3. being opened by a parent menu.
			//
			//		This is not called just from mouse hover.

			if(this._hoveredChild && this._hoveredChild != item){
				this.onItemUnhover(this._hoveredChild);	// any previous mouse movement is trumped by focus selection
			}
			this.set("selected", item);
		},

		_onBlur: function(){
			// summary:
			//		Called when focus is moved away from this Menu and it's submenus.
			// tags:
			//		protected

			this._cleanUp(true);
			this.inherited(arguments);
		},

		_cleanUp: function(/*Boolean*/ clearSelectedItem){
			// summary:
			//		Called when the user is done with this menu.  Closes hierarchy of menus.
			// tags:
			//		private

			this._closeChild(); // don't call this.onClose since that's incorrect for MenuBar's that never close
			if(typeof this.isShowingNow == 'undefined'){ // non-popup menu doesn't call onClose
				this.set("activated", false);
			}

			if(clearSelectedItem){
				this.set("selected", null);
			}
		}
	});
});