/*----------------------------------------------------------
	AMAN_RedSYS(R) - Fileinfo:
	$Author: mhosse $
	$HeadURL: file:///var/svn/redsys/trunk/kernel/system/javascripts/suggestions.js $
	$Revision: 3964 $
	$Date: 2008-12-08 17:52:35 +0100 (Mon, 08 Dec 2008) $

	Copyright (c) AMAN Media GmbH 1997 - 2008
	http://www.aman.de | http://www.redsys.de

---------------------------------------------------------*/

/**
 * An autosuggest textbox control.
 * @class
 * @scope public
 */
function AutoSuggestControl(oTextbox /*:HTMLInputElement*/, 
		oProvider /*:SuggestionProvider*/) {

	/**
	 * The currently selected suggestions.
	 * @scope private
	 */   
	this.cur /*:int*/ = -1;

	/**
	 * The dropdown list layer.
	 * @scope private
	 */
	this.layer = null;

	/**
	 * Suggestion provider for the autosuggest feature.
	 * @scope private.
	 */
	this.provider /*:SuggestionProvider*/ = oProvider;

	/**
	 * The textbox to capture.
	 * @scope private
	 */
	this.textbox /*:HTMLInputElement*/ = oTextbox;

	//initialize the control
	this.init();

}

/**
 * Autosuggests one or more suggestions for what the user has typed.
 * If no suggestions are passed in, then no autosuggest occurs.
 * @scope private
 * @param aSuggestions An array of suggestion strings.
 * @param bTypeAhead If the control should provide a type ahead suggestion.
 */
AutoSuggestControl.prototype.autosuggest = function (aSuggestions /*:Array*/,
		bTypeAhead /*:boolean*/) {

	//make sure there's at least one suggestion
	if (aSuggestions.length > 0) {
		if (bTypeAhead) {
			this.typeAhead(aSuggestions[0]);
		}

		this.showSuggestions(aSuggestions);
	} else {
		this.hideSuggestions();
	}
};

/**
 * Creates the dropdown layer to display multiple suggestions.
 * @scope private
 */
AutoSuggestControl.prototype.createDropDown = function () {

	var oThis = this;

	//create the layer and assign styles
	this.layer = document.createElement("div");
	this.layer.className = "suggestions";
	this.layer.style.visibility = "hidden";
	if (this.textbox.offsetWidth == 0)
		this.layer.style.width = this.textbox.style.width;
	else
		this.layer.style.width = this.textbox.offsetWidth;

	//when the user clicks on the a suggestion, get the text (innerHTML)
	//and place it into a textbox
	this.layer.onmousedown = 
		this.layer.onmouseup = 
			this.layer.onmouseover = function (oEvent) {
		oEvent = oEvent || window.event;
		oTarget = oEvent.target || oEvent.srcElement;

		if (oEvent.type == "mousedown") {
			oThis.textbox.value = oTarget.firstChild.nodeValue;
			oThis.hideSuggestions();
		} else if (oEvent.type == "mouseover") {
			oThis.highlightSuggestion(oTarget);
		} else {
			oThis.textbox.focus();
		}
	};


	document.body.appendChild(this.layer);
};




/**
 * Gets the left coordinate of the textbox.
 * @scope private
 * @return The left coordinate of the textbox in pixels.
 */
AutoSuggestControl.prototype.getLeft = function () /*:int*/ {

	var oNode = this.textbox;
	var iLeft = 0;

	while(oNode.tagName != "BODY") {
		iLeft += oNode.offsetLeft;
		oNode = oNode.offsetParent;        
	}

	return iLeft;
};

/**
 * Gets the top coordinate of the textbox.
 * @scope private
 * @return The top coordinate of the textbox in pixels.
 */
AutoSuggestControl.prototype.getTop = function () /*:int*/ {

	var oNode = this.textbox;
	var iTop = 0;

	while(oNode.tagName != "BODY") {
		iTop += oNode.offsetTop;
		oNode = oNode.offsetParent;
	}


	return iTop;
};

/**
 * Handles three keydown events.
 * @scope private
 * @param oEvent The event object for the keydown event.
 */
AutoSuggestControl.prototype.handleKeyDown = function (oEvent /*:Event*/) {

	switch(oEvent.keyCode) {
	case 38: //up arrow
		this.previousSuggestion();
		break;
	case 40: //down arrow 
		this.nextSuggestion();
		break;
	case 13: //enter
		this.hideSuggestions();
		break;
	}

};

/**
 * Handles keyup events.
 * @scope private
 * @param oEvent The event object for the keyup event.
 */
AutoSuggestControl.prototype.handleKeyUp = function (oEvent /*:Event*/) {

	var iKeyCode = oEvent.keyCode;

	//for backspace (8) and delete (46), shows suggestions without typeahead
	if (iKeyCode == 8 || iKeyCode == 46) {
		this.provider.requestSuggestions(this, false);

		//make sure not to interfere with non-character keys
	} else if (iKeyCode < 32 || (iKeyCode >= 33 && iKeyCode < 46) || (iKeyCode >= 112 && iKeyCode <= 123)) {
		//ignore
	} else {
		//request suggestions from the suggestion provider with typeahead
		this.provider.requestSuggestions(this, true);
	}
};

/**
 * Hides the suggestion dropdown.
 * @scope private
 */
AutoSuggestControl.prototype.hideSuggestions = function () {
	this.layer.style.visibility = "hidden";
};

/**
 * Highlights the given node in the suggestions dropdown.
 * @scope private
 * @param oSuggestionNode The node representing a suggestion in the dropdown.
 */
AutoSuggestControl.prototype.highlightSuggestion = function (oSuggestionNode) {

	for (var i=0; i < this.layer.childNodes.length; i++) {
		var oNode = this.layer.childNodes[i];
		if (oNode == oSuggestionNode) {
			oNode.className = "current"
		} else if (oNode.className == "current") {
			oNode.className = "";
		}
	}
};

/**
 * Initializes the textbox with event handlers for
 * auto suggest functionality.
 * @scope private
 */
AutoSuggestControl.prototype.init = function () {

	//save a reference to this object
	var oThis = this;

	//assign the onkeyup event handler
	this.textbox.onkeyup = function (oEvent) {

		//check for the proper location of the event object
		if (!oEvent) {
			oEvent = window.event;
		}    

		//call the handleKeyUp() method with the event object
		oThis.handleKeyUp(oEvent);
	};

	//assign onkeydown event handler
	this.textbox.onkeydown = function (oEvent) {

		//check for the proper location of the event object
		if (!oEvent) {
			oEvent = window.event;
		}    

		//call the handleKeyDown() method with the event object
		oThis.handleKeyDown(oEvent);
	};

	//assign onblur event handler (hides suggestions)    
	this.textbox.onblur = function () {
		oThis.hideSuggestions();
	};

	//create the suggestions dropdown
	this.createDropDown();
};

/**
 * Highlights the next suggestion in the dropdown and
 * places the suggestion into the textbox.
 * @scope private
 */
AutoSuggestControl.prototype.nextSuggestion = function () {
	var cSuggestionNodes = this.layer.childNodes;

	if (cSuggestionNodes.length > 0 && this.cur < cSuggestionNodes.length-1) {
		var oNode = cSuggestionNodes[++this.cur];
		this.highlightSuggestion(oNode);
		this.textbox.value = oNode.firstChild.nodeValue; 
	}
};

/**
 * Highlights the previous suggestion in the dropdown and
 * places the suggestion into the textbox.
 * @scope private
 */
AutoSuggestControl.prototype.previousSuggestion = function () {
	var cSuggestionNodes = this.layer.childNodes;

	if (cSuggestionNodes.length > 0 && this.cur > 0) {
		var oNode = cSuggestionNodes[--this.cur];
		this.highlightSuggestion(oNode);
		this.textbox.value = oNode.firstChild.nodeValue;   
	}
};

/**
 * Selects a range of text in the textbox.
 * @scope public
 * @param iStart The start index (base 0) of the selection.
 * @param iLength The number of characters to select.
 */
AutoSuggestControl.prototype.selectRange = function (iStart /*:int*/, iLength /*:int*/) {

	//use text ranges for Internet Explorer
	if (this.textbox.createTextRange) {
		var oRange = this.textbox.createTextRange(); 
		oRange.moveStart("character", iStart); 
		oRange.moveEnd("character", iLength - this.textbox.value.length);      
		oRange.select();

		//use setSelectionRange() for Mozilla
	} else if (this.textbox.setSelectionRange) {
		this.textbox.setSelectionRange(iStart, iLength);
	}     

	//set focus back to the textbox
	this.textbox.focus();      
}; 

/**
 * Builds the suggestion layer contents, moves it into position,
 * and displays the layer.
 * @scope private
 * @param aSuggestions An array of suggestions for the control.
 */
AutoSuggestControl.prototype.showSuggestions = function (aSuggestions /*:Array*/) {

	var oDiv = null;
	this.layer.innerHTML = "";  //clear contents of the layer

	for (var i=0; i < aSuggestions.length; i++) {
		oDiv = document.createElement("div");
		oDiv.appendChild(document.createTextNode(aSuggestions[i]));
		this.layer.appendChild(oDiv);
	}

	this.layer.style.left = this.getLeft() + "px";
	this.layer.style.top = (this.getTop()+this.textbox.offsetHeight) + "px";
	this.layer.style.width = this.textbox.offsetWidth;
	this.layer.style.visibility = "visible";

};

/**
 * Inserts a suggestion into the textbox, highlighting the 
 * suggested part of the text.
 * @scope private
 * @param sSuggestion The suggestion for the textbox.
 */
AutoSuggestControl.prototype.typeAhead = function (sSuggestion /*:String*/) {

	//check for support of typeahead functionality
	if (this.textbox.createTextRange || this.textbox.setSelectionRange){
		var iLen = this.textbox.value.length; 
		this.textbox.value = sSuggestion; 
		this.selectRange(iLen, sSuggestion.length);
	}
};


function StateSuggestions(options) {

	/**
	 * The available suggestions.
	 * @scope private
	 */   
	this.options = options;

}

/**
 * Request suggestions for the given autosuggest control. 
 * @scope protected
 * @param oAutoSuggestControl The autosuggest control to provide suggestions for.
 */
StateSuggestions.prototype.requestSuggestions = function (oAutoSuggestControl /*:AutoSuggestControl*/,
		bTypeAhead /*:boolean*/) {
	var aSuggestions = [];
	var sTextboxValue = oAutoSuggestControl.textbox.value;

	if (sTextboxValue.length > 0){

		//convert value in textbox to lowercase
		var sTextboxValueLC = sTextboxValue.toLowerCase();

		//search for matching states
		for (var i=0; i < this.options.length; i++) { 

			//convert state name to lowercase
			var sStateLC = this.options[i].toLowerCase();

			//compare the lowercase versions for case-insensitive comparison
			if (sStateLC.indexOf(sTextboxValueLC) == 0) {

				//add a suggestion using what's already in the textbox to begin it                
				aSuggestions.push(sTextboxValue + this.options[i].substring(sTextboxValue.length));
			} 
		}
	}

	//provide suggestions to the control
	oAutoSuggestControl.autosuggest(aSuggestions, bTypeAhead);
};


/**
 * Provides suggestions for state names (USA).
 * @class
 * @scope public
 */
function RemoteStateSuggestions(url) {

	if (typeof XMLHttpRequest != "undefined") {
		this.http = new XMLHttpRequest();
	} else if (typeof ActiveXObject != "undefined") {
		this.http = new ActiveXObject("MSXML2.XmlHttp");
	} else {
		alert("No XMLHttpRequest object available. This functionality will not work.");
	}

	this.url = url;
	if (url.indexOf("?") < 0)
		this.url = url + "?userInput=";
	else
		this.url = url + "&userInput=";
}

/**
 * Request suggestions for the given autosuggest control. 
 * @scope protected
 * @param oAutoSuggestControl The autosuggest control to provide suggestions for.
 */
RemoteStateSuggestions.prototype.requestSuggestions = function (oAutoSuggestControl /*:AutoSuggestControl*/,
		bTypeAhead /*:boolean*/) {

	var oHttp = this.http;

	//if there is already a live request, cancel it
	if (oHttp.readyState != 0) {
		oHttp.abort();
	}                 

	//build the URL
	var sURL = this.url + encodeURIComponent(oAutoSuggestControl.textbox.value);

	//open connection to states.txt file
	oHttp.open("get", sURL , true);
	oHttp.onreadystatechange = function () {
		if (oHttp.readyState == 4) {
			//evaluate the returned text JavaScript (an array)
			var aSuggestions = eval(oHttp.responseText);

			//provide suggestions to the control
			oAutoSuggestControl.autosuggest(aSuggestions, bTypeAhead);        
		}    
	};
	oHttp.send(null);


};