/* places the results of an ajax call either in the innerHTML of a target dom object or
 * call a user defined function optionally passing parameters.
 * */
function ajaxCallback() {
	var serverData=arguments[0];
	var status= arguments[1];    	// these two are a given
	var obj=null; 
	var parameters=null;

	if(arguments.length>2)obj=arguments[2];  // either a proc or an object
	if(arguments.length>3) parameters =arguments[3];


	// if we were passed a callback function then use it
	if (Object.prototype.toString.call(obj) == "[object Function]") {

		if(parameters){

			obj(serverData, parameters);
		}else{
			obj(serverData);
		};
	}else{

		//console.log('Object.prototype.toString.call(obj):'+Object.prototype.toString.call(obj) );
		// put the results in a div
		if(Object.prototype.toString.call(obj)=='[object String]'){
			document.getElementById(obj).innerHTML=serverData;
		}else{
			obj.innerHTML=serverData;
		}
	};   
}




/* can be called with a variable number of params.
 * 
 * either:  
 *     	ajaxPage(url,userSpecifiedCallbackfuntion | domObject{as an object or the string representing the id})  - the domObjects innerHTML will be set to the result of an ajax call
 * 
 *   or
 *   	ajaxPage(url,userSpoecifiedCallbackfuntion,parameterObject) - as above exept the parameter object is passed to the callbackFunction
 *   
 * */
function ajaxPage(){
	/*
	 * for (var i = 0; i < arguments.length; i++) { alert(arguments[i]); }
	 */
	var page=arguments[0];
	var targetId=arguments[1];
	var params=null;
	if(arguments.length==3)params=arguments[2];
	var AJAX = Xhr();
       
	if (AJAX==null) {                               
		alert("Your browser doesn't support AJAX.");                                      
		return false;                                 
	}
	AJAX.onreadystatechange = function() {                     
		if (AJAX.readyState==4 || AJAX.readyState=="complete") {
			if(!params){
				ajaxCallback(AJAX.responseText, AJAX.status,targetId);
			}else if(params){
				// deal with an extra parameter to the function passed as target
				// id
				ajaxCallback(AJAX.responseText, AJAX.status,targetId,params);
			}            
		}                                                       
	}

	//console.log(page);

	//AJAX.open("POST","/",true);
	//AJAX.setRequestHeader("Content-type","application/x-www-form-urlencoded");
	//AJAX.send(page);


	AJAX.open("GET", page, true);                                
	AJAX.send(null);     
}

//function used by the quick reply inline editor to update the db
function quickReplyCallBack(serverData,id){
	document.getElementById('QRE'+id).innerHTML=serverData;  

	/*document.getElementById('QREX'+id).onkeyup = function(evt) {
		evt = evt || window.event;
		while($(this).outerHeight() < this.scrollHeight + parseFloat($(this).css("borderTopWidth")) + parseFloat($(this).css("borderBottomWidth"))) {
			$(this).height($(this).height()+1);
		};

	};*/

}

//function used by the quick reply inline editor to update the db
function quickReply(itemNumber,forumid,threadid,postid){
	if(document.getElementById('QRED'+itemNumber)){
		document.getElementById('QRED'+itemNumber).innerHTML='';
	}
	var newDiv=document.getElementById('QRE'+itemNumber);
	if(newDiv){
		newDiv.parentNode.removeChild(newDiv);
		return;
	}
	newDiv=document.createElement('div');
	newDiv.id='QRE'+itemNumber;

	addClass(newDiv,'quickReply');
	insertAfter(newDiv,document.getElementById('QR'+itemNumber));
	newDiv=$('QRE'+itemNumber);
	ajaxPage("/?page=mz.edit.quick2&fi="+forumid+'&ti='+threadid+'&pi='+postid+'&id='+ itemNumber, quickReplyCallBack ,itemNumber);

}

function addClass(element, classToAdd) {
	var currentClassValue = element.className;

	if (currentClassValue.indexOf(classToAdd) == -1) {
		if ((currentClassValue == null) || (currentClassValue === "")) {
			element.className = classToAdd;
		} else {
			element.className += " " + classToAdd;
		};
	};
}

function insertAfter(newElement,targetElement) {
	//target is what you want it to go after. Look for this elements parent.
	var parent = targetElement.parentNode;

	//if the parents lastchild is the targetElement...
	if(parent.lastchild == targetElement) {
		//add the newElement after the target element.
		parent.appendChild(newElement);
	} else {
		// else the target has siblings, insert the new element between the target and it's next sibling.
		parent.insertBefore(newElement, targetElement.nextSibling);
	};
}

function Xhr(){ /* returns cross-browser XMLHttpRequest, or null if unable */
    try {
        return new XMLHttpRequest();
    }catch(e){}
    try {
        return new ActiveXObject("Msxml3.XMLHTTP");
    }catch(e){}
    try {
        return new ActiveXObject("Msxml2.XMLHTTP.6.0");
    }catch(e){}
    try {
        return new ActiveXObject("Msxml2.XMLHTTP.3.0");
    }catch(e){}
    try {
        return new ActiveXObject("Msxml2.XMLHTTP");
    }catch(e){}
    try {
        return new ActiveXObject("Microsoft.XMLHTTP");
    }catch(e){}
    return null;
}