define([
	"dojo/_base/kernel",
	"dojo/_base/array",
	"dojo/_base/connect",
	"dojo/_base/declare",
	"dojo/_base/lang",
	"dojo/_base/window",
	"dojo/_base/Deferred",
	"dojo/dom",
	"dojo/dom-class",
	"dojo/dom-construct",
	"dojo/on",
	"dojo/ready",
	"dijit/registry",
	"./ProgressIndicator",
	"./TransitionEvent",
	"./viewRegistry"
], function(dojo, array, connect, declare, lang, win, Deferred, dom, domClass, domConstruct, on, ready, registry, ProgressIndicator, TransitionEvent, viewRegistry){

	// module:
	//		dojox/mobile/ViewController

	var Controller = declare("dojox.mobile.ViewController", null, {
		// summary:
		//		A singleton class that controls view transition.
		// description:
		//		This class listens to the "startTransition" events and performs
		//		view transitions. If the transition destination is an external
		//		view specified with the url parameter, the view content is
		//		retrieved and parsed to create a new target view.

		// dataHandlerClass: Object
		//		The data handler class used to load external views,
		//		by default "dojox/mobile/dh/DataHandler"
		//		(see the Data Handlers page in the reference documentation).
		dataHandlerClass: "dojox/mobile/dh/DataHandler",
		// dataSourceClass: Object
		//		The data source class used to load external views,
		//		by default "dojox/mobile/dh/UrlDataSource"
		//		(see the Data Handlers page in the reference documentation).
		dataSourceClass: "dojox/mobile/dh/UrlDataSource",
		// fileTypeMapClass: Object
		//		The file type map class used to load external views,
		//		by default "dojox/mobile/dh/SuffixFileTypeMap"
		//		(see the Data Handlers page in the reference documentation).
		fileTypeMapClass: "dojox/mobile/dh/SuffixFileTypeMap",

		constructor: function(){
			// summary:
			//		Creates a new instance of the class.
			// tags:
			//		private
			this.viewMap = {};
			ready(lang.hitch(this, function(){
				on(win.body(), "startTransition", lang.hitch(this, "onStartTransition"));
			}));
		},

		findTransitionViews: function(/*String*/moveTo){
			// summary:
			//		Parses the moveTo argument and determines a starting view and a destination view.
			// returns: Array
			//		An array containing the currently showing view, the destination view
			//		and the transition parameters, or an empty array if the moveTo argument
			//		could not be parsed. 
			if(!moveTo){ return []; }
			// removes a leading hash mark (#) and params if exists
			// ex. "#bar&myParam=0003" -> "bar"
			moveTo.match(/^#?([^&?]+)(.*)/);
			var params = RegExp.$2;
			var view = registry.byId(RegExp.$1);
			if(!view){ return []; }
			for(var v = view.getParent(); v; v = v.getParent()){ // search for the topmost invisible parent node
				if(v.isVisible && !v.isVisible()){
					var sv = view.getShowingView();
					if(sv && sv.id !== view.id){
						view.show();
					}
					view = v;
				}
			}
			return [view.getShowingView(), view, params]; // fromView, toView, params
		},

		openExternalView: function(/*Object*/ transOpts, /*DomNode*/ target){
			// summary:
			//		Loads an external view and performs a transition to it.
			// returns: dojo/_base/Deferred
			//		Deferred object that resolves when the external view is
			//		ready and a transition starts. Note that it resolves before
			//		the transition is complete.
			// description:
			//		This method loads external view content through the
			//		dojox/mobile data handlers, creates a new View instance with
			//		the loaded content, and performs a view transition to the
			//		new view. The external view content can be specified with
			//		the url property of transOpts. The new view is created under
			//		a DOM node specified by target.
			//
			// example:
			//		This example loads view1.html, creates a new view under
			//		`<body>`, and performs a transition to the new view with the
			//		slide animation.
			//		
			//	|	var vc = ViewController.getInstance();
			//	|	vc.openExternalView({
			//	|	    url: "view1.html", 
			//	|	    transition: "slide"
			//	|	}, win.body());
			//
			//
			// example:
			//		If you want to perform a view transition without animation,
			//		you can give transition:"none" to transOpts.
			//
			//	|	var vc = ViewController.getInstance();
			//	|	vc.openExternalView({
			//	|	    url: "view1.html", 
			//	|	    transition: "none"
			//	|	}, win.body());
			//
			// example:
			//		If you want to dynamically create an external view, but do
			//		not want to perform a view transition to it, you can give noTransition:true to transOpts.
			//		This may be useful when you want to preload external views before the user starts using them.
			//
			//	|	var vc = ViewController.getInstance();
			//	|	vc.openExternalView({
			//	|	    url: "view1.html", 
			//	|	    noTransition: true
			//	|	}, win.body());
			//
			// example:
			//		To do something when the external view is ready:
			//
			//	|	var vc = ViewController.getInstance();
			//	|	Deferred.when(vc.openExternalView({...}, win.body()), function(){
			//	|	    doSomething();
			//	|	});

			var d = new Deferred();
			var id = this.viewMap[transOpts.url];
			if(id){
				transOpts.moveTo = id;
				if(transOpts.noTransition){
					registry.byId(id).hide();
				}else{
					new TransitionEvent(win.body(), transOpts).dispatch();
				}
				d.resolve(true);
				return d;
			}

			// if a fixed bottom bar exists, a new view should be placed before it.
			var refNode = null;
			for(var i = target.childNodes.length - 1; i >= 0; i--){
				var c = target.childNodes[i];
				if(c.nodeType === 1){
					var fixed = c.getAttribute("fixed") // TODO: Remove the non-HTML5-compliant attribute in 2.0
						|| c.getAttribute("data-mobile-fixed")
						|| (registry.byNode(c) && registry.byNode(c).fixed);
					if(fixed === "bottom"){
						refNode = c;
						break;
					}
				}
			}

			var dh = transOpts.dataHandlerClass || this.dataHandlerClass;
			var ds = transOpts.dataSourceClass || this.dataSourceClass;
			var ft = transOpts.fileTypeMapClass || this.fileTypeMapClass;
			require([dh, ds, ft], lang.hitch(this, function(DataHandler, DataSource, FileTypeMap){
				var handler = new DataHandler(new DataSource(transOpts.data || transOpts.url), target, refNode);
				var contentType = transOpts.contentType || FileTypeMap.getContentType(transOpts.url) || "html";
				handler.processData(contentType, lang.hitch(this, function(id){
					if(id){
						this.viewMap[transOpts.url] = transOpts.moveTo = id;
						if(transOpts.noTransition){
							registry.byId(id).hide();
						}else{
							new TransitionEvent(win.body(), transOpts).dispatch();
						}
						d.resolve(true);
					}else{
						d.reject("Failed to load "+transOpts.url);
					}
				}));
			}));
			return d;
		},

		onStartTransition: function(evt){
			// summary:
			//		A handler that performs view transition.
			evt.preventDefault();
			if(!evt.detail){ return; }
			var detail = evt.detail;
			if(!detail.moveTo && !detail.href && !detail.url && !detail.scene){ return; }

			if(detail.url && !detail.moveTo){
				var urlTarget = detail.urlTarget;
				var w = registry.byId(urlTarget);
				var target = w && w.containerNode || dom.byId(urlTarget);
				if(!target){
					w = viewRegistry.getEnclosingView(evt.target);
					target = w && w.domNode.parentNode || win.body();
				}
				var src = registry.getEnclosingWidget(evt.target);
				if(src && src.callback){
					detail.context = src;
					detail.method = src.callback;
				}
				this.openExternalView(detail, target);
				return;
			}else if(detail.href){
				if(detail.hrefTarget && detail.hrefTarget != "_self"){
					win.global.open(detail.href, detail.hrefTarget);
				}else{
					var view; // find top level visible view
					for(var v = viewRegistry.getEnclosingView(evt.target); v; v = viewRegistry.getParentView(v)){
						view = v;
					}
					if(view){
						view.performTransition(null, detail.transitionDir, detail.transition, evt.target, function(){location.href = detail.href;});
					}
				}
				return;
			}else if(detail.scene){
				connect.publish("/dojox/mobile/app/pushScene", [detail.scene]);
				return;
			}

			var arr = this.findTransitionViews(detail.moveTo),
				fromView = arr[0],
				toView = arr[1],
				params = arr[2];
			if(!location.hash && !detail.hashchange){
				viewRegistry.initialView = fromView;
			}
			if(detail.moveTo && toView){
				detail.moveTo = (detail.moveTo.charAt(0) === '#' ? '#' + toView.id : toView.id) + params;
			}
			if(!fromView || (detail.moveTo && fromView === registry.byId(detail.moveTo.replace(/^#?([^&?]+).*/, "$1")))){ return; }
			src = registry.getEnclosingWidget(evt.target);
			if(src && src.callback){
				detail.context = src;
				detail.method = src.callback;
			}
			fromView.performTransition(detail);
		}
	});
	Controller._instance = new Controller(); // singleton
	Controller.getInstance = function(){
		return Controller._instance;
	};
	return Controller;
});

