define([
	"require",
	"dojo/_base/array", // array.forEach array.indexOf array.map
	"dojo/aspect",
	"dojo/_base/declare", // declare
	"dojo/Deferred", // Deferred
	"dojo/dom", // dom.isDescendant
	"dojo/dom-class", // domClass.add domClass.contains
	"dojo/dom-geometry", // domGeometry.position
	"dojo/dom-style", // domStyle.set
	"dojo/_base/fx", // fx.fadeIn fx.fadeOut
	"dojo/i18n", // i18n.getLocalization
	"dojo/keys",
	"dojo/_base/lang", // lang.mixin lang.hitch
	"dojo/on",
	"dojo/ready",
	"dojo/sniff", // has("ie") has("opera") has("dijit-legacy-requires")
	"dojo/window", // winUtils.getBox, winUtils.get
	"dojo/dnd/Moveable", // Moveable
	"dojo/dnd/TimedMoveable", // TimedMoveable
	"./focus",
	"./_base/manager", // manager.defaultDuration
	"./_Widget",
	"./_TemplatedMixin",
	"./_CssStateMixin",
	"./form/_FormMixin",
	"./_DialogMixin",
	"./DialogUnderlay",
	"./layout/ContentPane",
	"./layout/utils",
	"dojo/text!./templates/Dialog.html",
	"./a11yclick",	// template uses ondijitclick
	"dojo/i18n!./nls/common"
], function(require, array, aspect, declare, Deferred,
			dom, domClass, domGeometry, domStyle, fx, i18n, keys, lang, on, ready, has, winUtils,
			Moveable, TimedMoveable, focus, manager, _Widget, _TemplatedMixin, _CssStateMixin, _FormMixin, _DialogMixin,
			DialogUnderlay, ContentPane, utils, template){

	// module:
	//		dijit/Dialog

	var resolvedDeferred = new Deferred();
	resolvedDeferred.resolve(true);

	var _DialogBase = declare("dijit._DialogBase" + (has("dojo-bidi") ? "_NoBidi" : ""), [_TemplatedMixin, _FormMixin, _DialogMixin, _CssStateMixin], {
		templateString: template,

		baseClass: "dijitDialog",

		cssStateNodes: {
			closeButtonNode: "dijitDialogCloseIcon"
		},

		// Map widget attributes to DOMNode attributes.
		_setTitleAttr: { node: "titleNode", type: "innerHTML" },

		// open: [readonly] Boolean
		//		True if Dialog is currently displayed on screen.
		open: false,

		// duration: Integer
		//		The time in milliseconds it takes the dialog to fade in and out
		duration: manager.defaultDuration,

		// refocus: Boolean
		//		A Toggle to modify the default focus behavior of a Dialog, which
		//		is to re-focus the element which had focus before being opened.
		//		False will disable refocusing. Default: true
		refocus: true,

		// autofocus: Boolean
		//		A Toggle to modify the default focus behavior of a Dialog, which
		//		is to focus on the first dialog element after opening the dialog.
		//		False will disable autofocusing. Default: true
		autofocus: true,

		// _firstFocusItem: [private readonly] DomNode
		//		The pointer to the first focusable node in the dialog.
		//		Set by `dijit/_DialogMixin._getFocusItems()`.
		_firstFocusItem: null,

		// _lastFocusItem: [private readonly] DomNode
		//		The pointer to which node has focus prior to our dialog.
		//		Set by `dijit/_DialogMixin._getFocusItems()`.
		_lastFocusItem: null,

		// draggable: Boolean
		//		Toggles the movable aspect of the Dialog. If true, Dialog
		//		can be dragged by it's title. If false it will remain centered
		//		in the viewport.
		draggable: true,
		_setDraggableAttr: function(/*Boolean*/ val){
			// Avoid _WidgetBase behavior of copying draggable attribute to this.domNode,
			// as that prevents text select on modern browsers (#14452)
			this._set("draggable", val);
		},

		// maxRatio: Number
		//		Maximum size to allow the dialog to expand to, relative to viewport size
		maxRatio: 0.9,

		// closable: Boolean
		//		Dialog show [x] icon to close itself, and ESC key will close the dialog.
		closable: true,
		_setClosableAttr: function(val){
			this.closeButtonNode.style.display = val ? "" : "none";
			this._set("closable", val);
		},

		postMixInProperties: function(){
			var _nlsResources = i18n.getLocalization("dijit", "common");
			lang.mixin(this, _nlsResources);
			this.inherited(arguments);
		},

		postCreate: function(){
			domStyle.set(this.domNode, {
				display: "none",
				position: "absolute"
			});
			this.ownerDocumentBody.appendChild(this.domNode);

			this.inherited(arguments);

			aspect.after(this, "onExecute", lang.hitch(this, "hide"), true);
			aspect.after(this, "onCancel", lang.hitch(this, "hide"), true);

			this._modalconnects = [];
		},

		onLoad: function(){
			// summary:
			//		Called when data has been loaded from an href.
			//		Unlike most other callbacks, this function can be connected to (via `dojo.connect`)
			//		but should *not* be overridden.
			// tags:
			//		callback

			// when href is specified we need to reposition the dialog after the data is loaded
			// and find the focusable elements
			this.resize();
			this._position();

			if(this.autofocus && DialogLevelManager.isTop(this)){
				this._getFocusItems();
				focus.focus(this._firstFocusItem);
			}

			this.inherited(arguments);
		},

		focus: function(){
			this._getFocusItems();
			focus.focus(this._firstFocusItem);
		},

		_endDrag: function(){
			// summary:
			//		Called after dragging the Dialog. Saves the position of the dialog in the viewport,
			//		and also adjust position to be fully within the viewport, so user doesn't lose access to handle
			var nodePosition = domGeometry.position(this.domNode),
				viewport = winUtils.getBox(this.ownerDocument);
			nodePosition.y = Math.min(Math.max(nodePosition.y, 0), (viewport.h - nodePosition.h));
			nodePosition.x = Math.min(Math.max(nodePosition.x, 0), (viewport.w - nodePosition.w));
			this._relativePosition = nodePosition;
			this._position();
		},

		_setup: function(){
			// summary:
			//		Stuff we need to do before showing the Dialog for the first
			//		time (but we defer it until right beforehand, for
			//		performance reasons).
			// tags:
			//		private

			var node = this.domNode;

			if(this.titleBar && this.draggable){
				this._moveable = new ((has("ie") == 6) ? TimedMoveable // prevent overload, see #5285
					: Moveable)(node, { handle: this.titleBar });
				aspect.after(this._moveable, "onMoveStop", lang.hitch(this, "_endDrag"), true);
			}else{
				domClass.add(node, "dijitDialogFixed");
			}

			this.underlayAttrs = {
				dialogId: this.id,
				"class": array.map(this["class"].split(/\s/),function(s){
					return s + "_underlay";
				}).join(" "),
				_onKeyDown: lang.hitch(this, "_onKey"),
				ownerDocument: this.ownerDocument
			};
		},

		_size: function(){
			// TODO: remove for 2.0
			this.resize();
		},

		_position: function(){
			// summary:
			//		Position the dialog in the viewport.  If no relative offset
			//		in the viewport has been determined (by dragging, for instance),
			//		center the dialog.  Otherwise, use the Dialog's stored relative offset,
			//		adjusted by the viewport's scroll.
			if(!domClass.contains(this.ownerDocumentBody, "dojoMove")){    // don't do anything if called during auto-scroll
				var node = this.domNode,
					viewport = winUtils.getBox(this.ownerDocument),
					p = this._relativePosition,
					bb = p ? null : domGeometry.position(node),
					l = Math.floor(viewport.l + (p ? p.x : (viewport.w - bb.w) / 2)),
					t = Math.floor(viewport.t + (p ? p.y : (viewport.h - bb.h) / 2))
					;
				domStyle.set(node, {
					left: l + "px",
					top: t + "px"
				});
			}
		},

		_onKey: function(/*Event*/ evt){
			// summary:
			//		Handles the keyboard events for accessibility reasons
			// tags:
			//		private

			if(evt.keyCode == keys.TAB){
				this._getFocusItems();
				var node = evt.target;
				if(this._firstFocusItem == this._lastFocusItem){
					// don't move focus anywhere, but don't allow browser to move focus off of dialog either
					evt.stopPropagation();
					evt.preventDefault();
				}else if(node == this._firstFocusItem && evt.shiftKey){
					// if we are shift-tabbing from first focusable item in dialog, send focus to last item
					focus.focus(this._lastFocusItem);
					evt.stopPropagation();
					evt.preventDefault();
				}else if(node == this._lastFocusItem && !evt.shiftKey){
					// if we are tabbing from last focusable item in dialog, send focus to first item
					focus.focus(this._firstFocusItem);
					evt.stopPropagation();
					evt.preventDefault();
				}
			}else if(this.closable && evt.keyCode == keys.ESCAPE){
				this.onCancel();
				evt.stopPropagation();
				evt.preventDefault();
			}
		},

		show: function(){
			// summary:
			//		Display the dialog
			// returns: dojo/promise/Promise
			//		Promise object that resolves when the display animation is complete

			if(this.open){
				return resolvedDeferred.promise;
			}

			if(!this._started){
				this.startup();
			}

			// first time we show the dialog, there's some initialization stuff to do
			if(!this._alreadyInitialized){
				this._setup();
				this._alreadyInitialized = true;
			}

			if(this._fadeOutDeferred){
				// There's a hide() operation in progress, so cancel it, but still call DialogLevelManager.hide()
				// as though the hide() completed, in preparation for the DialogLevelManager.show() call below.
				this._fadeOutDeferred.cancel();
				DialogLevelManager.hide(this);
			}

			// Recenter Dialog if user scrolls browser.  Connecting to document doesn't work on IE, need to use window.
			// Be sure that event object doesn't get passed to resize() method, because it's expecting an optional
			// {w: ..., h:...} arg.
			var win = winUtils.get(this.ownerDocument);
			this._modalconnects.push(on(win, "scroll", lang.hitch(this, "resize", null)));

			this._modalconnects.push(on(this.domNode, "keydown", lang.hitch(this, "_onKey")));

			domStyle.set(this.domNode, {
				opacity: 0,
				display: ""
			});

			this._set("open", true);
			this._onShow(); // lazy load trigger

			this.resize();
			this._position();

			// fade-in Animation object, setup below
			var fadeIn;

			this._fadeInDeferred = new Deferred(lang.hitch(this, function(){
				fadeIn.stop();
				delete this._fadeInDeferred;
			}));

			// If delay is 0, code below will delete this._fadeInDeferred instantly, so grab promise while we can.
			var promise = this._fadeInDeferred.promise;

			fadeIn = fx.fadeIn({
				node: this.domNode,
				duration: this.duration,
				beforeBegin: lang.hitch(this, function(){
					DialogLevelManager.show(this, this.underlayAttrs);
				}),
				onEnd: lang.hitch(this, function(){
					if(this.autofocus && DialogLevelManager.isTop(this)){
						// find focusable items each time dialog is shown since if dialog contains a widget the
						// first focusable items can change
						this._getFocusItems();
						focus.focus(this._firstFocusItem);
					}
					this._fadeInDeferred.resolve(true);
					delete this._fadeInDeferred;
				})
			}).play();

			return promise;
		},

		hide: function(){
			// summary:
			//		Hide the dialog
			// returns: dojo/promise/Promise
			//		Promise object that resolves when the display animation is complete

			// If we haven't been initialized yet then we aren't showing and we can just return.
			// Likewise if we are already hidden, or are currently fading out.
			if(!this._alreadyInitialized || !this.open){
				return resolvedDeferred.promise;
			}
			if(this._fadeInDeferred){
				this._fadeInDeferred.cancel();
			}

			// fade-in Animation object, setup below
			var fadeOut;

			this._fadeOutDeferred = new Deferred(lang.hitch(this, function(){
				fadeOut.stop();
				delete this._fadeOutDeferred;
			}));

			// fire onHide when the promise resolves.
			this._fadeOutDeferred.then(lang.hitch(this, 'onHide'));

			// If delay is 0, code below will delete this._fadeOutDeferred instantly, so grab promise while we can.
			var promise = this._fadeOutDeferred.promise;

			fadeOut = fx.fadeOut({
				node: this.domNode,
				duration: this.duration,
				onEnd: lang.hitch(this, function(){
					this.domNode.style.display = "none";
					DialogLevelManager.hide(this);
					this._fadeOutDeferred.resolve(true);
					delete this._fadeOutDeferred;
				})
			}).play();

			if(this._scrollConnected){
				this._scrollConnected = false;
			}
			var h;
			while(h = this._modalconnects.pop()){
				h.remove();
			}

			if(this._relativePosition){
				delete this._relativePosition;
			}
			this._set("open", false);

			return promise;
		},

		resize: function(dim){
			// summary:
			//		Called with no argument when viewport scrolled or viewport size changed.  Adjusts Dialog as
			//		necessary to keep it visible.
			//
			//		Can also be called with an argument (by dojox/layout/ResizeHandle etc.) to explicitly set the
			//		size of the dialog.
			// dim: Object?
			//		Optional dimension object like {w: 200, h: 300}

			if(this.domNode.style.display != "none"){

				this._checkIfSingleChild();

				if(!dim){
					if(this._shrunk){
						// If we earlier shrunk the dialog to fit in the viewport, reset it to its natural size
						if(this._singleChild){
							if(typeof this._singleChildOriginalStyle != "undefined"){
								this._singleChild.domNode.style.cssText = this._singleChildOriginalStyle;
								delete this._singleChildOriginalStyle;
							}
						}
						array.forEach([this.domNode, this.containerNode, this.titleBar, this.actionBarNode], function(node){
							if(node){	// because titleBar may not be defined
								domStyle.set(node, {
									position: "static",
									width: "auto",
									height: "auto"
								});
							}
						});
						this.domNode.style.position = "absolute";
					}

					// If necessary, shrink Dialog to fit in viewport and have some space around it
					// to indicate that it's a popup.  This will also compensate for possible scrollbars on viewport.
					var viewport = winUtils.getBox(this.ownerDocument);
					viewport.w *= this.maxRatio;
					viewport.h *= this.maxRatio;

					var bb = domGeometry.position(this.domNode);
					if(bb.w >= viewport.w || bb.h >= viewport.h){
						dim = {
							w: Math.min(bb.w, viewport.w),
							h: Math.min(bb.h, viewport.h)
						};
						this._shrunk = true;
					}else{
						this._shrunk = false;
					}
				}

				// Code to run if user has requested an explicit size, or the shrinking code above set an implicit size
				if(dim){
					// Set this.domNode to specified size
					domGeometry.setMarginBox(this.domNode, dim);

					// And then size this.containerNode
					var layoutNodes = [];
					if(this.titleBar){
						layoutNodes.push({domNode: this.titleBar, region: "top"});
					}
					if(this.actionBarNode){
						layoutNodes.push({domNode: this.actionBarNode, region: "bottom"});
					}
					var centerSize = {domNode: this.containerNode, region: "center"};
					layoutNodes.push(centerSize);

					var contentDim = utils.marginBox2contentBox(this.domNode, dim);
					utils.layoutChildren(this.domNode, contentDim, layoutNodes);

					// And then if this.containerNode has a single layout widget child, size it too.
					// Otherwise, make this.containerNode show a scrollbar if it's overflowing.
					if(this._singleChild){
						var cb = utils.marginBox2contentBox(this.containerNode, centerSize);
						// note: if containerNode has padding singleChildSize will have l and t set,
						// but don't pass them to resize() or it will doubly-offset the child
						this._singleChild.resize({w: cb.w, h: cb.h});
						// TODO: save original size for restoring it on another show()?
					}else{
						this.containerNode.style.overflow = "auto";
						this._layoutChildren();		// send resize() event to all child widgets
					}
				}else{
					this._layoutChildren();		// send resize() event to all child widgets
				}

				if(!has("touch") && !dim){
					// If the user has scrolled the viewport then reposition the Dialog.  But don't do it for touch
					// devices, because it will counteract when a keyboard pops up and then the browser auto-scrolls
					// the focused node into view.
					this._position();
				}
			}
		},

		_layoutChildren: function(){
			// Override _ContentPaneResizeMixin._layoutChildren because even when there's just a single layout child
			// widget, sometimes we don't want to size it explicitly (i.e. to pass a dim argument to resize())

			array.forEach(this.getChildren(), function(widget){
				if(widget.resize){
					widget.resize();
				}
			});
		},

		destroy: function(){
			if(this._fadeInDeferred){
				this._fadeInDeferred.cancel();
			}
			if(this._fadeOutDeferred){
				this._fadeOutDeferred.cancel();
			}
			if(this._moveable){
				this._moveable.destroy();
			}
			var h;
			while(h = this._modalconnects.pop()){
				h.remove();
			}

			DialogLevelManager.hide(this);

			this.inherited(arguments);
		}
	});

	if(has("dojo-bidi")){
		_DialogBase = declare("dijit._DialogBase", _DialogBase, {
			_setTitleAttr: function(/*String*/ title){
				this._set("title", title);
				this.titleNode.innerHTML = title;
				this.applyTextDir(this.titleNode);
			},

			_setTextDirAttr: function(textDir){
				if(this._created && this.textDir != textDir){
					this._set("textDir", textDir);
					this.set("title", this.title);
				}
			}
		});
	}

	var Dialog = declare("dijit.Dialog", [ContentPane, _DialogBase], {
		// summary:
		//		A modal dialog Widget.
		// description:
		//		Pops up a modal dialog window, blocking access to the screen
		//		and also graying out the screen Dialog is extended from
		//		ContentPane so it supports all the same parameters (href, etc.).
		// example:
		// |	<div data-dojo-type="dijit/Dialog" data-dojo-props="href: 'test.html'"></div>
		// example:
		// |	var foo = new Dialog({ title: "test dialog", content: "test content" });
		// |	foo.placeAt(win.body());
		// |	foo.startup();
	});
	Dialog._DialogBase = _DialogBase;	// for monkey patching and dojox/widget/DialogSimple

	var DialogLevelManager = Dialog._DialogLevelManager = {
		// summary:
		//		Controls the various active "levels" on the page, starting with the
		//		stuff initially visible on the page (at z-index 0), and then having an entry for
		//		each Dialog shown.

		_beginZIndex: 950,

		show: function(/*dijit/_WidgetBase*/ dialog, /*Object*/ underlayAttrs){
			// summary:
			//		Call right before fade-in animation for new dialog.
			//		Saves current focus, displays/adjusts underlay for new dialog,
			//		and sets the z-index of the dialog itself.
			//
			//		New dialog will be displayed on top of all currently displayed dialogs.
			//
			//		Caller is responsible for setting focus in new dialog after the fade-in
			//		animation completes.

			// Save current focus
			ds[ds.length - 1].focus = focus.curNode;

			// Set z-index a bit above previous dialog
			var zIndex = ds[ds.length - 1].dialog ? ds[ds.length - 1].zIndex + 2 : Dialog._DialogLevelManager._beginZIndex;
			domStyle.set(dialog.domNode, 'zIndex', zIndex);

			// Display the underlay, or if already displayed then adjust for this new dialog
			DialogUnderlay.show(underlayAttrs, zIndex - 1);

			ds.push({dialog: dialog, underlayAttrs: underlayAttrs, zIndex: zIndex});
		},

		hide: function(/*dijit/_WidgetBase*/ dialog){
			// summary:
			//		Called when the specified dialog is hidden/destroyed, after the fade-out
			//		animation ends, in order to reset page focus, fix the underlay, etc.
			//		If the specified dialog isn't open then does nothing.
			//
			//		Caller is responsible for either setting display:none on the dialog domNode,
			//		or calling dijit/popup.hide(), or removing it from the page DOM.

			if(ds[ds.length - 1].dialog == dialog){
				// Removing the top (or only) dialog in the stack, return focus
				// to previous dialog

				ds.pop();

				var pd = ds[ds.length - 1];	// the new active dialog (or the base page itself)

				// Adjust underlay
				if(ds.length == 1){
					// Returning to original page.  Hide the underlay.
					DialogUnderlay.hide();
				}else{
					// Popping back to previous dialog, adjust underlay.
					DialogUnderlay.show(pd.underlayAttrs, pd.zIndex - 1);
				}

				// Adjust focus.
				// TODO: regardless of setting of dialog.refocus, if the exeucte() method set focus somewhere,
				// don't shift focus back to button.  Note that execute() runs at the start of the fade-out but
				// this code runs later, at the end of the fade-out.  Menu has code like this.
				if(dialog.refocus){
					// If we are returning control to a previous dialog but for some reason
					// that dialog didn't have a focused field, set focus to first focusable item.
					// This situation could happen if two dialogs appeared at nearly the same time,
					// since a dialog doesn't set it's focus until the fade-in is finished.
					var focus = pd.focus;
					if(pd.dialog && (!focus || !dom.isDescendant(focus, pd.dialog.domNode))){
						pd.dialog._getFocusItems();
						focus = pd.dialog._firstFocusItem;
					}

					if(focus){
						// Refocus the button that spawned the Dialog.   This will fail in corner cases including
						// page unload on IE, because the dijit/form/Button that launched the Dialog may get destroyed
						// before this code runs.  (#15058)
						try{
							focus.focus();
						}catch(e){
						}
					}
				}
			}else{
				// Removing a dialog out of order (#9944, #10705).
				// Don't need to mess with underlay or z-index or anything.
				var idx = array.indexOf(array.map(ds, function(elem){
					return elem.dialog;
				}), dialog);
				if(idx != -1){
					ds.splice(idx, 1);
				}
			}
		},

		isTop: function(/*dijit/_WidgetBase*/ dialog){
			// summary:
			//		Returns true if specified Dialog is the top in the task
			return ds[ds.length - 1].dialog == dialog;
		}
	};

	// Stack representing the various active "levels" on the page, starting with the
	// stuff initially visible on the page (at z-index 0), and then having an entry for
	// each Dialog shown.
	// Each element in stack has form {
	//		dialog: dialogWidget,
	//		focus: returnFromGetFocus(),
	//		underlayAttrs: attributes to set on underlay (when this widget is active)
	// }
	var ds = Dialog._dialogStack = [
		{dialog: null, focus: null, underlayAttrs: null}    // entry for stuff at z-index: 0
	];

	// If focus was accidentally removed from the dialog, such as if the user clicked a blank
	// area of the screen, or clicked the browser's address bar and then tabbed into the page,
	// then refocus.   Won't do anything if focus was removed because the Dialog was closed, or
	// because a new Dialog popped up on top of the old one, or when focus moves to popups
	focus.watch("curNode", function(attr, oldNode, node){
 		// Note: if no dialogs, ds.length==1 but ds[ds.length-1].dialog is null
		var topDialog = ds[ds.length - 1].dialog;

		// If a node was focused, and there's a Dialog currently showing, and not in the process of fading out...
		// Ignore focus events on other document though because it's likely an Editor inside of the Dialog.
		if(node && topDialog && !topDialog._fadeOutDeferred && node.ownerDocument == topDialog.ownerDocument){
			// If the node that was focused is inside the dialog or in a popup, even a context menu that isn't
			// technically a descendant of the the dialog, don't do anything.
			do{
				if(node == topDialog.domNode || domClass.contains(node, "dijitPopup")){ return; }
			}while(node = node.parentNode);

			// Otherwise, return focus to the dialog.  Use a delay to avoid confusing dijit/focus code's
			// own tracking of focus.
			topDialog.focus();
		}
	});

	// Back compat w/1.6, remove for 2.0
	if(has("dijit-legacy-requires")){
		ready(0, function(){
			var requires = ["dijit/TooltipDialog"];
			require(requires);	// use indirection so modules not rolled into a build
		});
	}

	return Dialog;
});