var cal;
function onSantoLoad()
{	
	
	
	d = new Date();
	
	var c = new CalendarTable( d.getFullYear(), 1, 1 );
	c.setFullSingleYear(d.getFullYear(),true);
	c.draw();
	
	cal = new Calendar();
	
	writeTitle();
}

function nav(_dir)
{
	if(document.location.href.indexOf("?") > 0)
		var url=document.location.href.substring(0,document.location.href.indexOf("?")+1);
	else
		var url=document.location.href+"?";
	
	var nextDate=cal.incrementOrDecrementDate(cal.getTheDate(),_dir);
	url+="giorno="+nextDate.substring(6)+"&";
	url+="mese="+nextDate.substring(4,6)+"&";
	url+="anno="+nextDate.substring(0,4);
	document.location.href=url;
}

function writeTitle()
{
	//Martedì <span>17</span> Aprile
	var obj=document.getElementById("giorno");
	var d=new Date();
	var year=cal.getTheDate().substring(0,4);
	var month=cal.getTheDate().substring(4,6)-1;
	var day=cal.getTheDate().substring(6);
	d.setFullYear(year, month, day);
	//obj.innerHTML=cal.getWeekDay(d)+" <span>"+day+"</span> "+cal.getYearMonth(d);
}


function Calendar()
{

	var giorniNelMese	= {'01':'31', '02':'28', '03':'31', '04':'30', '05':'31', '06':'30', '07':'31', '08':'31', '09':'30', '10':'31', '11':'31', '12':'31' };
	
	this.incrementOrDecrementDate = function( dateString, nDays ){
		
		var sign = Math.abs(nDays)/nDays;

		for ( var i=0; i<Math.abs(nDays); i++ ){
			
			var date = parseInt( dateString );
			
			date = date + (sign*1);
			
			dateString = date + '';
			var mese 	= dateString.substring( 4,6 );
			var giorno 	= dateString.substring( 6   );
			var anno	= dateString.substring( 0,4 );

			if( giorno == '00'){

				if( mese == '01' ){
					mese = '12';
					anno = ( parseInt(anno)-1 ) + '';
				}else{
					mese = ( parseFloat(mese)-1)  + '';
					if(mese.length==1){
						mese = '0'+mese;
					}
				}

				giorno = giorniNelMese[mese];


			}else if( giorno>giorniNelMese[mese] ){

				giorno = '01';

				if( mese == '12' ){
					mese = '01';
					anno = (parseInt(anno)+1) + '';
				}else{
					mese = (parseFloat(mese)+1) + '';
					if(mese.length==1){
						mese = '0'+mese;
					}
				}

			}

			dateString = anno + mese + giorno;

		}
		return dateString;
	}
	
	this.getTheDate = function(){
		var today = getTodayDateString();
		var theDateString = getDateStringFromQueryString();

		if ( !theDateString || theDateString=='')
			return today;
		else
			return theDateString;
	}
	
	this.getWeekDay = function(dateObj)
	{
		var weekday=new Array(7);
		weekday[0]="Domenica";
		weekday[1]="Lunedì";
		weekday[2]="Martedì";
		weekday[3]="Mercoledì";
		weekday[4]="Giovedì";
		weekday[5]="Venerdì";
		weekday[6]="Sabato";
		return weekday[dateObj.getDay()];
	}
	
	this.getYearMonth = function(dateObj)
	{
		var yearmonth=new Array(12);
		yearmonth[0]="Gennaio";
		yearmonth[1]="Febbraio";
		yearmonth[2]="Marzo";
		yearmonth[3]="Aprile";
		yearmonth[4]="Maggio";
		yearmonth[5]="Giugno";
		yearmonth[6]="Luglio";
		yearmonth[7]="Agosto";
		yearmonth[8]="Settembre";
		yearmonth[9]="Ottobre";
		yearmonth[10]="Novembre";
		yearmonth[11]="Dicembre";
		return yearmonth[dateObj.getMonth()];
	}

	function getTodayDateString(){
		var todayObj	= new Date();

		day = todayObj.getUTCDate();
		if ( day<=9 ){ day = '0' + day };

		month = todayObj.getUTCMonth() + 1;
		if ( month<=9 ){ month = '0' + month };
		
		year = todayObj.getFullYear();
		
		return ('' + year + '' + month + '' + day);
	}
	
	function getDateStringFromQueryString() {
		var query = window.location.search.substring(1);
		if( query && query.indexOf('selectmonth=' )==-1 && query.indexOf('=' )!=-1  && query.indexOf('&' )!=-1){
			// link costruito dal calendar
			var vars = query.split("&");
			var ret = '';
			for ( var i=vars.length-1; i>=0; i-- ){
				var pair = vars[i].split("=");
				if(pair[1].length==1){
					ret += '0' + pair[1];
				}else{
					ret += pair[1];
				}
			}
		}else if( query && query.indexOf('selectmonth=' )!=-1){
			// link costruito dal calendar il quale ha chiesto il cambio del mese
			// vado al primo del mese come da specifiche di calendar.cgi
			var month = query.substring( query.indexOf('=')+1 );
			if( month.length==1 ){ month = '0'+month; }
			var ret = today.substring(0,4) + month + '01';
		}
		return ret;
	}
}