/**
 * Default values should be changed to fit the current datePicker.
 */
DatePicker.dateFormat="DD MM YYYY";
DatePicker.weekDays = ['s','m','t','w','t','f','s']; 
DatePicker.months = ['January','February','March','April','May','June','Juli','August','September','October','November','December'];
DatePicker.weekStart = 1;
DatePicker.notWorkingDay = [0,6];

/**
 * DatePicker class.
 */
function DatePicker(inpDate,doc){
	doc=doc?doc:document;
	
	this.setDateFormat();
	this.date=inpDate?inpDate:new Date(); // Find the date to set
	
	this.datePicker = doc.createElement("div");
	//this.datePicker.style="z-index:30"
	this.datePicker.className = "datePicker";
	this.datePicker.style.zIndex = 20;
	this.datePicker.setAttribute('style', 'z-index:30')
	
	this.datePicker.onselectstart = function () { return false; }; /* User select off in IE */
	this.datePicker.style.MozUserSelect = "none"; /* User select none in NS */
	
	/***************************************************************************/
	// Append Header
	div = this.datePicker.appendChild(doc.createElement("div"));
	div.className = "header";
	
	table = div.appendChild(doc.createElement("table"));
	table.className = "headerTable";
	table.cellSpacing = 0;
	
	tbody = table.appendChild(doc.createElement("tbody"));
	tr = tbody.appendChild(doc.createElement("tr"));
	
	// Button Back
	td = tr.appendChild(doc.createElement("td"));
	buttonBack = td.appendChild(doc.createElement("button"));
	imgBack = buttonBack.appendChild(doc.createElement("img"));
	imgBack.setAttribute('src',FillFormDatePickerImagesPath+"arrow.left.gif")
	buttonBack.className = "previousButton";
	
	// Header
	td = tr.appendChild(doc.createElement("td"));
	td.className = "labelContainer";
	a = td.appendChild(doc.createElement("a"))
	a.className = "topLabel"
	this.header = a.appendChild(doc.createTextNode("Label"));
	
	// Button Next
	td = tr.appendChild(doc.createElement("td"));
	buttonNext = td.appendChild(doc.createElement("button"));
	imgNext = buttonNext.appendChild(doc.createElement("img"));
	imgNext.setAttribute('src',FillFormDatePickerImagesPath+"arrow.right.gif")
	buttonNext.className = "nextButton";
	
	
	
	/***************************************************************************/
	//Create the table displaying the dates and weekdays
	div = this.datePicker.appendChild(doc.createElement("div"));
	div.className = "grid";
	this.table = div.appendChild(doc.createElement("table"));
	this.table.className = "gridTable";
	this.table.cellSpacing = 0;
	
	var tbody1 = this.table.appendChild(doc.createElement("tbody"));
	var tbody2 = this.table.appendChild(doc.createElement("tbody"));
	
	// Append weekdays table
	tr = tbody1.appendChild(doc.createElement("tr"));
	tr.className = "daysRow";
	for(var j=0;j<7;j++){
		td = tr.appendChild(doc.createElement("td"));
		td.appendChild(doc.createTextNode(""));
		td.className = "";
	}
	tr = tbody1.appendChild(doc.createElement("tr"));
	td = tr.appendChild(doc.createElement( "td" ));
	td.className= "upperLine";
	td.colSpan = 7;
	
	// Append dates table
	for(var i=0;i<6;i++){
		tr = tbody2.appendChild(doc.createElement("tr"));
		for(var j=0;j<7;j++){
			td = tr.appendChild(doc.createElement("td"));
			td.appendChild(doc.createTextNode(""));
		}
	}
	
	/***************************************************************************/
	// events 
	var dp = this; // event hook to this date object
	this.table.onclick = function(e){
		e=e==null?doc.parentWindow.event:e;
		
		var el = e.target != null ? e.target : e.srcElement;
		while(el.nodeType != 1)
			el = el.parentNode;
		while(el!=null && el.tagName && el.tagName.toLowerCase()!="td")
			el= el.parentNode;
		
		if( el == null || el.tagName == null || el.tagName.toLowerCase() !="td")
			return;
		
		var d = new Date( dp.date );
		var n = Number( el.firstChild.data );
		if(isNaN(n) || n<=0 || n==null)
			return;
		d.setDate(n);
		dp.setDate(d);
		dp.returnDate();
	}
	
	buttonNext.onclick = function(){
		dp.setDate(new Date(dp.date.getFullYear(),dp.date.getMonth()+1,dp.date.getDate()))
	}
	
	buttonBack.onclick = function(){
		dp.setDate(new Date(dp.date.getFullYear(),dp.date.getMonth()-1,dp.date.getDate()))
	}
	
	this.datePicker.onkeydown = function (e){
		e=e==null?doc.parentWindow.event:e;
		var kc = e.keyCode!=null ? e.keyCode : e.charCode;
		
		if(kc==13||kc==32){
			if ( typeof this.onchange == "function" ) this.onchange();
			dp.returnDate();
			return false;
		}
		
		if(kc<37||kc>40) return true;
		
		var d = new Date(dp.date).valueOf();
		if(kc==37) //left
			d-=24*60*60*1000;
		else if(kc==39) //right
			d+=24*60*60*1000;
		else if(kc==38) //up
			d-=7*24*60*60*1000;
		else if(kc==40) //down
			d+=7*24*60*60*1000;
		dp.setDate(new Date( d ));
		return false;
	}
	/***************************************************************************/
	this.setDate(inpDate);
	return this;
}

/**
 * Getters
 */
DatePicker.prototype.getDOMElement = function(){ return this.datePicker;}
DatePicker.prototype.getDate = function(){return eval(this.dateFormat);};

/**
 * Show and hide the datePicker, when it is shown the focus is set, and 
 * when it is hidden it is blurred.
 */
DatePicker.prototype.show = function(){
	this.datePicker.style.visibility="visible";
	this.datePicker.focus();
}
DatePicker.prototype.hide = function(){
	this.datePicker.style.visibility="hidden";
}

/**
 * Return date calls the onchnge event set by the caller.
 */
DatePicker.prototype.returnDate = function(){
	if ( typeof this.onchange == "function" ) this.onchange();
};

/**
 * The default onchange function is set to do nothing, the calling programm 
 * chould implement this funciton.
 */
DatePicker.prototype.onchange = function () {};
DatePicker.prototype.onblur = function () {};

/**
 * Function used to check if a value is in an array.
 */
Array.prototype.contains = function(val){
	for(var i=0;i<this.length;i++){
		if(this[i]==val)
			return true;
	}
	return false;
}

/**
 * This function is used to set and show the date in the DatePicker. 
 */
DatePicker.prototype.setDate = function(inpDate){
	this.date=inpDate?inpDate:(this.date?this.date:new Date()); // Find the date to set
	tmpDate=new Date(this.date.getFullYear(), this.date.getMonth()); // Get the first day of this month
	today = new Date();
	
	dayNr=tmpDate.getDay();
	day=0;
	
	// Set month and year
	this.header.data = this.date.getFullYear()+" "+DatePicker.months[this.date.getMonth()];
	
	// Set weekDays
	for(var j=0;j<7;j++){
		this.table.tBodies[0].rows[0].cells[j].firstChild.data
			= DatePicker.weekDays[(j+DatePicker.weekStart) % 7];
	}
	// Set dates
	var rows = this.table.tBodies[1].rows;
	for(var i=0;i<6;i++){
		for(var j=0;j<7;j++){
			cell=rows[i].cells[j];
			tmpDate.setDate(day+1);
			if((dayNr==((j+DatePicker.weekStart) % 7) || day) && day<31 && this.date.getMonth() == tmpDate.getMonth()){
				cell.firstChild.data=++day;
				cell.className = (DatePicker.notWorkingDay.contains((j+DatePicker.weekStart) % 7)?"red ":"")
					+(sameDay(this.date,tmpDate)?"selected ":"")
					+(sameDay(today,tmpDate)?"today":"");
			}else{
				cell.firstChild.data=String.fromCharCode( 160 );
				cell.className = "";
			}
		}
	}
}

/*****************************************************************************
 * Sets the parent field and buton of the datepicker, and 
 */
DatePicker.prototype.setParent = function(parentId){
	this.parentButton = document.getElementById(parentId+"Button");
	this.parentField = document.getElementById(parentId);
	
	//this.datePicker.style.top = findPosY(this.parentButton);
	//this.datePicker.style.left = findPosX(this.parentButton)-this.datePicker.offsetWidth;
	
	var dp = this; // event hook
	
	this.parentButton.onclick=function(){
		if(dp.datePicker.style.visibility=="hidden"){
			dp.datePicker.style.top = findPosY(dp.parentButton);
			dp.datePicker.style.left = findPosX(dp.parentButton)-dp.datePicker.offsetWidth;
			hideIntersectElements("select",dp.datePicker);
			dp.show();
		}else{
			dp.parentField.value = dp.getDate();
			dp.hide();
			showElements("select")
			return false;
		}
	}
	
	this.onchange = function () {
		dp.parentField.value = dp.getDate();
		dp.parentButton.focus();
		dp.hide();
		showElements("select")
		return false;
	};
	
	this.onblur = function () {
		dp.parentField.value = dp.getDate();
		dp.parentButton.focus();
		dp.hide();
		showElements("select")
		return false;
	};
}

/*****************************************************************************
 * Parses the date and sets the dateformat
 */
DatePicker.prototype.setDateFormat = function(){
	dateFormat = DatePicker.dateFormat.toUpperCase();
	
	tmpSep = dateFormat.replace(/[YDM]/g,"");
	if(tmpSep.length==2){
		
		dateFormat = dateFormat.match(/YYYY/)
			? dateFormat.replace(/YYYY/,"'+this.date.getFullYear()+'")
			: dateFormat.replace(/YY/,"'+(''+this.date.getFullYear()).slice(-2)+'")
		
		dateFormat = dateFormat.match(/MM/) /* months go from 0-11 therefore +1 */
			? dateFormat.replace(/MM/,"'+('0'+(this.date.getMonth()+1)).slice(-2)+'") 
			: dateFormat.replace(/M/,"'+(this.date.getMonth()+1)+'")
		
		
		dateFormat = dateFormat.match(/DD/)
			? dateFormat.replace(/DD/,"'+('0'+this.date.getDate()).slice(-2)+'")
			: dateFormat.replace(/D/,"'+this.date.getDate()+'")
		
		dateFormat = "'"+dateFormat+"'"
		
	}else{}
	this.dateFormat = dateFormat;
	this.dateSeperator = tmpSep;
}

/*****************************************************************************
 * Creates a datepicker writes it to the document and assings parent handler.
 */
function DatePickerPopup(parent){
	parentField = document.getElementById(parent);
	var thisDate = parentField.value==""?new Date():Date.parse(parentField.value.replace(/[\/-]/g," "));
	var dp = new DatePicker(new Date(thisDate));
	parentField.value = dp.getDate();
	dp.hide();
	dp.setParent(parent);
	
	//bodyNode = dp.parentButton.ownerDocument.getElementsByTagName('body')[0]
	bodyNode = document.getElementsByTagName('body')[0]
	//alert(dp.parentButton.ownerDocument.getElementsByTagName('body')[0])
	//alert(document.getElementsByTagName('body')[0])
	bodyNode.insertBefore(dp.getDOMElement(),bodyNode.firstChild)
}


/*****************************************************************************
 * Used to find the position on the page of a given object. 
 */
function findPosX(obj){
	var curleft = 0;
	if (obj.offsetParent){
		while (obj.offsetParent){
			curleft += obj.offsetLeft
			obj = obj.offsetParent;
		}
	}
	else if (obj.x)
		curleft += obj.x;
	return curleft;
}
function findPosY(obj){
	var curtop = 0;
	if (obj.offsetParent)	{
		while (obj.offsetParent){
			curtop += obj.offsetTop
			obj = obj.offsetParent;
		}
	}
	else if (obj.y)
		curtop += obj.y;
	return curtop;
}

/*****************************************************************************
 * Returs true if two dates are the same, even if the time differ. 
 */
function sameDay(date1,date2){
	return (date1.getFullYear()==date2.getFullYear()
		&& date1.getMonth()==date2.getMonth()
		&& date1.getDate()==date2.getDate());
}

/*****************************************************************************
 * Returns true if two elements overlap
 */
function intersects(elem1,elem2){
	top1 = findPosY(elem1);
	left1 = findPosX(elem1);
	bottom1 = top1 + elem1.offsetHeight;
	right1 = left1 + elem1.offsetWidth;
	
	top2 = findPosY(elem2);
	left2 = findPosX(elem2);
	bottom2 = top2 + elem2.offsetHeight;
	right2 = left2 + elem2.offsetWidth;
	
	// Test if elem1's borders overlap elem2
	leftIn = left2<left1 && left1<right2;
	topIn = top2<top1 && top1<bottom2;
	rightIn = left2<right1 && right1<right2;
	bottomIn = top2<bottom1 && bottom1<bottom2;
	
	// Test if elem2's borders overlap elem1
	leftIn2 = left1<left2 && left2<right1;
	topIn2 = top1<top2 && top2<bottom1;
	rightIn2 = left1<right2 && right2<right1;
	bottomIn2 = top2<bottom1 && bottom2<bottom1;
	
	/*
	alert(
		'leftIn = left2<left1 && left1<right2; '+leftIn +' = '+ left2+'<'+left1 +' && '+ left1+'<'+right2
		+'\ntopIn = top2<top1 && top1<bottom2; '+topIn +' = '+ top2+'<'+top1 +' && '+ top1+'<'+bottom2
		+'\nrightIn = left2<right1 && right1<right2; '+rightIn +' = '+ left2+'<'+right1 +' && '+ right1+'<'+right2
		+'\nbottomIn = top2<bottom1 && bottom1<bottom2; '+bottomIn +' = '+ top2+'<'+bottom1 +' && '+ bottom1+'<'+bottom2
	)
	*/
	// Test that the corners og elem1 overlap elem2
	nw = topIn && leftIn;
	ne = topIn && rightIn;
	sw = bottomIn && leftIn;
	se = bottomIn && rightIn;
	
	ns = topIn && bottomIn && leftIn2;
	we = leftIn && rightIn && topIn2;
	/*
	alert(
		'nw = topIn && leftIn; '+nw +'='+ topIn +'&&'+ leftIn
		+'\nne = topIn && rightIn; '+ne +'='+ topIn +'&&'+ rightIn
		+'\nsw = bottomIn && leftIn; '+sw +'='+ bottomIn +'&&'+ leftIn
		+'\nse = bottomIn && rightIn; '+se +'='+ bottomIn +'&&'+ rightIn
	)
	*/
	return nw || ne || sw || se || ns || we;
}

/*****************************************************************************
 * 
 */
function hideIntersectElements(tagName,elem){
	elements = document.getElementsByTagName(tagName);
	for(var i=0;i<elements.length;i++){
		if(intersects(elements[i],elem))
			elements[i].style.visibility = "hidden"
	}
}

function showElements(tagName){
	elements = document.getElementsByTagName(tagName);
	for(var i=0;i<elements.length;i++){
		elements[i].style.visibility = "visible"
	}
}