dojo.provide("dijit._editor.selection");

// FIXME:
//		all of these methods branch internally for IE. This is probably
//		sub-optimal in terms of runtime performance. We should investigate the
//		size difference for differentiating at definition time.

dojo.mixin(dijit._editor.selection, {
	getType: function(){
		// summary:
		//		Get the selection type (like dojo.doc.select.type in IE).
		if(dojo.isIE){
			return dojo.doc.selection.type.toLowerCase();
		}else{
			var stype = "text";

			// Check if the actual selection is a CONTROL (IMG, TABLE, HR, etc...).
			var oSel;
			try{
				oSel = dojo.global.getSelection();
			}catch(e){ /*squelch*/ }

			if(oSel && oSel.rangeCount == 1){
				var oRange = oSel.getRangeAt(0);
				if(	(oRange.startContainer == oRange.endContainer) &&
					((oRange.endOffset - oRange.startOffset) == 1) &&
					(oRange.startContainer.nodeType != 3 /* text node*/)
				){
					stype = "control";
				}
			}
			return stype; //String
		}
	},

	getSelectedText: function(){
		// summary:
		//		Return the text (no html tags) included in the current selection or null if no text is selected
		if(dojo.isIE){
			if(dijit._editor.selection.getType() == 'control'){
				return null;
			}
			return dojo.doc.selection.createRange().text;
		}else{
			var selection = dojo.global.getSelection();
			if(selection){
				return selection.toString(); //String
			}
		}
		return '';
	},

	getSelectedHtml: function(){
		// summary:
		//		Return the html text of the current selection or null if unavailable
		if(dojo.isIE){
			if(dijit._editor.selection.getType() == 'control'){
				return null;
			}
			return dojo.doc.selection.createRange().htmlText;
		}else{
			var selection = dojo.global.getSelection();
			if(selection && selection.rangeCount){
				var i;
				var html = "";
				for(i = 0; i < selection.rangeCount; i++){
					//Handle selections spanning ranges, such as Opera
					var frag = selection.getRangeAt(i).cloneContents();
					var div = dojo.doc.createElement("div");
					div.appendChild(frag);
					html += div.innerHTML;
				}
				return html; //String
			}
			return null;
		}
	},

	getSelectedElement: function(){
		// summary:
		//		Retrieves the selected element (if any), just in the case that
		//		a single element (object like and image or a table) is
		//		selected.
		if(dijit._editor.selection.getType() == "control"){
			if(dojo.isIE){
				var range = dojo.doc.selection.createRange();
				if(range && range.item){
					return dojo.doc.selection.createRange().item(0);
				}
			}else{
				var selection = dojo.global.getSelection();
				return selection.anchorNode.childNodes[ selection.anchorOffset ];
			}
		}
		return null;
	},

	getParentElement: function(){
		// summary:
		//		Get the parent element of the current selection
		if(dijit._editor.selection.getType() == "control"){
			var p = this.getSelectedElement();
			if(p){ return p.parentNode; }
		}else{
			if(dojo.isIE){
				var r = dojo.doc.selection.createRange();
				r.collapse(true);
				return r.parentElement();
			}else{
				var selection = dojo.global.getSelection();
				if(selection){
					var node = selection.anchorNode;
					while(node && (node.nodeType != 1)){ // not an element
						node = node.parentNode;
					}
					return node;
				}
			}
		}
		return null;
	},

	hasAncestorElement: function(/*String*/tagName /* ... */){
		// summary:
		// 		Check whether current selection has a  parent element which is
		// 		of type tagName (or one of the other specified tagName)
		// tagName: String
		//		The tag name to determine if it has an ancestor of.
		return this.getAncestorElement.apply(this, arguments) != null; //Boolean
	},

	getAncestorElement: function(/*String*/tagName /* ... */){
		// summary:
		//		Return the parent element of the current selection which is of
		//		type tagName (or one of the other specified tagName)
		// tagName: String
		//		The tag name to determine if it has an ancestor of.
		var node = this.getSelectedElement() || this.getParentElement();
		return this.getParentOfType(node, arguments); //DOMNode
	},

	isTag: function(/*DomNode*/ node, /*String[]*/ tags){
		// summary:
		//		Function to determine if a node is one of an array of tags.
		// node:
		//		The node to inspect.
		// tags:
		//		An array of tag name strings to check to see if the node matches.
		if(node && node.tagName){
			var _nlc = node.tagName.toLowerCase();
			for(var i=0; i<tags.length; i++){
				var _tlc = String(tags[i]).toLowerCase();
				if(_nlc == _tlc){
					return _tlc; // String
				}
			}
		}
		return "";
	},

	getParentOfType: function(/*DomNode*/ node, /*String[]*/ tags){
		// summary:
		//		Function to locate a parent node that matches one of a set of tags
		// node:
		//		The node to inspect.
		// tags:
		//		An array of tag name strings to check to see if the node matches.
		while(node){
			if(this.isTag(node, tags).length){
				return node; // DOMNode
			}
			node = node.parentNode;
		}
		return null;
	},

	collapse: function(/*Boolean*/beginning){
		// summary:
		//		Function to collapse (clear), the current selection
		// beginning: Boolean
		//		Boolean to indicate whether to collapse the cursor to the beginning of the selection or end.
		if(window.getSelection){
			var selection = dojo.global.getSelection();
			if(selection.removeAllRanges){ // Mozilla
				if(beginning){
					selection.collapseToStart();
				}else{
					selection.collapseToEnd();
				}
			}else{ // Safari
				// pulled from WebCore/ecma/kjs_window.cpp, line 2536
				selection.collapse(beginning);
			}
		}else if(dojo.isIE){ // IE
			var range = dojo.doc.selection.createRange();
			range.collapse(beginning);
			range.select();
		}
	},

	remove: function(){
		// summary:
		//		Function to delete the currently selected content from the document.
		var sel = dojo.doc.selection;
		if(dojo.isIE){
			if(sel.type.toLowerCase() != "none"){
				sel.clear();
			}
			return sel; //Selection
		}else{
			sel = dojo.global.getSelection();
			sel.deleteFromDocument();
			return sel; //Selection
		}
	},

	selectElementChildren: function(/*DomNode*/element,/*Boolean?*/nochangefocus){
		// summary:
		//		clear previous selection and select the content of the node
		//		(excluding the node itself)
		// element: DOMNode
		//		The element you wish to select the children content of.
		// nochangefocus: Boolean
		//		Boolean to indicate if the foxus should change or not.
		var win = dojo.global;
		var doc = dojo.doc;
		var range;
		element = dojo.byId(element);
		if(doc.selection && dojo.isIE && dojo.body().createTextRange){ // IE
			range = element.ownerDocument.body.createTextRange();
			range.moveToElementText(element);
			if(!nochangefocus){
				try{
					range.select(); // IE throws an exception here if the widget is hidden.  See #5439
				}catch(e){ /* squelch */}
			}
		}else if(win.getSelection){
			var selection = dojo.global.getSelection();
			if(dojo.isOpera){
				//Opera's selectAllChildren doesn't seem to work right
				//against <body> nodes and possibly others ... so
				//we use the W3C range API
				if(selection.rangeCount){
					range = selection.getRangeAt(0);
				}else{
					range = doc.createRange();
				}
				range.setStart(element, 0);
				range.setEnd(element,(element.nodeType == 3)?element.length:element.childNodes.length);
				selection.addRange(range);
			}else{
				selection.selectAllChildren(element);
			}
		}
	},

	selectElement: function(/*DomNode*/element,/*Boolean?*/nochangefocus){
		// summary:
		//		clear previous selection and select element (including all its children)
		// element:  DOMNode
		//		The element to select.
		// nochangefocus: Boolean
		//		Boolean indicating if the focus should be changed.  IE only.
		var range;
		var doc = dojo.doc;
		var win = dojo.global;
		element = dojo.byId(element);
		if(dojo.isIE && dojo.body().createTextRange){
			try{
				range = dojo.body().createControlRange();
				range.addElement(element);
				if(!nochangefocus){
					range.select();
				}
			}catch(e){
				this.selectElementChildren(element,nochangefocus);
			}
		}else if(dojo.global.getSelection){
			var selection = win.getSelection();
			range = doc.createRange();
			if(selection.removeAllRanges){ // Mozilla
				// FIXME: does this work on Safari?
				if(dojo.isOpera){
					//Opera works if you use the current range on
					//the selection if present.
					if(selection.getRangeAt(0)){
						range = selection.getRangeAt(0);
					}
				}
				range.selectNode(element);
				selection.removeAllRanges();
				selection.addRange(range);
			}
		}
	},

	inSelection: function(node){
		// summary:
		//		This function determines if 'node' is
		//		in the current selection.
		// tags:
		//		public
		if(node){
			var newRange;
			var doc = dojo.doc;
			var range;

			if(dojo.global.getSelection){
				//WC3
				var sel = dojo.global.getSelection();
				if(sel && sel.rangeCount > 0){
					range = sel.getRangeAt(0);
				}
				if(range && range.compareBoundaryPoints && doc.createRange){
					try{
						newRange = doc.createRange();
						newRange.setStart(node, 0);
						if(range.compareBoundaryPoints(range.START_TO_END, newRange) === 1){
							return true;
						}
					}catch(e){ /* squelch */}
				}
			}else if(doc.selection){
				// Probably IE, so we can't use the range object as the pseudo
				// range doesn't implement the boundry checking, we have to 
				// use IE specific crud.
				range = doc.selection.createRange();
				try{
					newRange = node.ownerDocument.body.createControlRange();
					if(newRange){
						newRange.addElement(node);
					}
				}catch(e1){
					try{
						newRange = node.ownerDocument.body.createTextRange();
						newRange.moveToElementText(node);
					}catch(e2){/* squelch */}
				}
				if(range && newRange){
					// We can finally compare similar to W3C
					if(range.compareEndPoints("EndToStart", newRange) === 1){
						return true;
					}
				}
			}
		}
		return false; // boolean
	}

});
