/* MarcGrabanski.com */

/* Pop-Up Calendar Built from Scratch by Marc Grabanski */

/* Small modifications by Josef Hjorth, 2007 */

var popUpCal = {
	selectedMonth: new Date().getMonth(), // 0-11
	selectedYear: new Date().getFullYear(), // 4-digit year
	selectedDay: new Date().getDate(),
	calendarId: 'calendarDiv',
	inputClass: 'calendarSelectDate',
	
	init: function () {
		var x = getElementsByClass(popUpCal.inputClass, document, 'input');
		var y = document.getElementById(popUpCal.calendarId);
		// set the calendar position based on the input position
		for (var i=0; i<x.length; i++) {
			x[i].onfocus = function () {
				popUpCal.selectedMonth = new Date().getMonth();
				popUpCal.selectedYear = new Date().getFullYear();
				setPos(this, y); // setPos(targetObj,moveObj)
				y.style.display = 'block';
				popUpCal.drawCalendar(this); 
				popUpCal.setupLinks(this);
			}

		}
	},
	
	drawCalendar: function (inputObj) {
		
		var html = '';
		html = '<a id="closeCalender">Close Calendar</a>';
		html += '<table cellpadding="0" cellspacing="0" id="linksTable"><tr>';
		html += '	<td><a id="prevMonth"><< Föreg.</a></td>';
		html += '	<td><a id="nextMonth">Nästa >></a></td>';
		html += '</tr></table>';
		html += '<table id="calendar" cellpadding="0" cellspacing="0"><tr>';
		html += '<th colspan="7" class="calendarHeader"><a>'+getMonthName(popUpCal.selectedMonth)+' '+popUpCal.selectedYear+'</a></th>';
		html += '</tr><tr class="weekDaysTitleRow">';
		var weekDays = new Array('S','M','T','O','T','F','L');
		for (var j=0; j<weekDays.length; j++) {
			html += '<td>'+weekDays[j]+'</td>';
		}
		
		var daysInMonth = getDaysInMonth(popUpCal.selectedYear, popUpCal.selectedMonth);
		var startDay = getFirstDayofMonth(popUpCal.selectedYear, popUpCal.selectedMonth);
		var numRows = 0;
		var printDate = 1;
		if (startDay != 7) {
			numRows = Math.ceil(((startDay+1)+(daysInMonth))/7); // calculate the number of rows to generate
		}
		
		// calculate number of days before calendar starts
		if (startDay != 7) {
			var noPrintDays = startDay + 1; 
		} else {
			var noPrintDays = 0; // if sunday print right away	
		}
		var today = new Date().getDate();
		var thisMonth = new Date().getMonth();
		var thisYear = new Date().getFullYear();
		// create calendar rows
		for (var e=0; e<numRows; e++) {
			html += '<tr class="weekDaysRow">';
			// create calendar days
			for (var f=0; f<7; f++) {
				if ( (printDate == today) 
					 && (popUpCal.selectedYear == thisYear) 
					 && (popUpCal.selectedMonth == thisMonth) 
					 && (noPrintDays == 0)) {
					html += '<td id="today" class="weekDaysCell">';
				} else {
					html += '<td class="weekDaysCell">';
				}
				if (noPrintDays == 0) {
					if (printDate <= daysInMonth) {
						html += '<a>'+printDate+'</a>';
					}
					printDate++;
				}
				html += '</td>';
				if(noPrintDays > 0) noPrintDays--;
			}
			html += '</tr>';
		}
		html += '</table>';
		
		// add calendar to element to calendar Div
		var calendarDiv = document.getElementById(popUpCal.calendarId);
		calendarDiv.innerHTML = html;
		
		// close button link
		document.getElementById('closeCalender').onclick = function () {
			calendarDiv.style.display = 'none';
		}
		// setup next and previous links
		document.getElementById('prevMonth').onclick = function () {
			popUpCal.selectedMonth--;
			if (popUpCal.selectedMonth < 0) {
				popUpCal.selectedMonth = 11;
				popUpCal.selectedYear--;
			}
			popUpCal.drawCalendar(inputObj); 
			popUpCal.setupLinks(inputObj);
		}
		document.getElementById('nextMonth').onclick = function () {
			popUpCal.selectedMonth++;
			if (popUpCal.selectedMonth > 11) {
				popUpCal.selectedMonth = 0;
				popUpCal.selectedYear++;
			}
			popUpCal.drawCalendar(inputObj); 
			popUpCal.setupLinks(inputObj);
		}
		
	}, // end drawCalendar function
	
	setupLinks: function (inputObj) {
		// set up link events on calendar table
		var y = document.getElementById('calendar');
		var x = y.getElementsByTagName('a');
		for (var i=0; i<x.length; i++) {
			x[i].onmouseover = function () {
				this.parentNode.className = 'weekDaysCellOver';
			}
			x[i].onmouseout = function () {
				this.parentNode.className = 'weekDaysCell';
			}
			x[i].onclick = function () {
				document.getElementById(popUpCal.calendarId).style.display = 'none';
				popUpCal.selectedDay = this.innerHTML;
				inputObj.value = formatDate(popUpCal.selectedDay, popUpCal.selectedMonth, popUpCal.selectedYear);		
			}
		}
	}
	
}
// Add calendar event that has wide browser support
if ( typeof window.addEventListener != "undefined" )
	window.addEventListener( "load", popUpCal.init, false );
else if ( typeof window.attachEvent != "undefined" )
	window.attachEvent( "onload", popUpCal.init );
else {
	if ( window.onload != null ) {
		var oldOnload = window.onload;
		window.onload = function ( e ) {
			oldOnload( e );
			popUpCal.init();
		};
	}
	else
		window.onload = popUpCal.init;
}

/* Functions Dealing with Dates */

function formatDate(Day, Month, Year) {
	var numMonth = "0123456789";
	if (numMonth.indexOf(Day.charAt(0)) == -1) 
	{
		Month = getMonthNumber(Month);
		Day = '';
	}
	
	Month++; // adjust javascript month
	if (Month <10) Month = '0'+Month; // add a zero if less than 10
	if (Day < 10) Day = '0'+Day; // add a zero if less than 10
	var dateString = Year+'-'+Month;
	if(Day.length!=1)
		dateString += '-' + Day;
	return dateString;
}

function getMonthName(month) {
	var monthNames = new Array('Januari','Februari','Mars','April','Maj','Juni','Juli','Augusti','September','Oktober','November','December');
	return monthNames[month];
}

function getMonthNumber(month) {
	var monthNumber = new Array('0','1','2','3','4','5','6','7','8','9','10','11');
	return monthNumber[month];
}

function getDayName(day) {
	var dayNames = new Array('Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday')
	return dayNames[day];
}

function getDaysInMonth(year, month) {
	return 32 - new Date(year, month, 32).getDate();
}

function getFirstDayofMonth(year, month) {
	var day;
	day = new Date(year, month, 0).getDay();
	return day;
}

/* Common Scripts */

function getElementsByClass(searchClass,node,tag) {
	var classElements = new Array();
	if ( node == null ) node = document;
	if ( tag == null ) tag = '*';
	var els = node.getElementsByTagName(tag);
	var elsLen = els.length;
	var pattern = new RegExp("(^|\\s)"+searchClass+"(\\s|$)");
	for (i = 0, j = 0; i < elsLen; i++) {
		if ( pattern.test(els[i].className) ) {
			classElements[j] = els[i];
			j++;
		}
	}
	return classElements;
}

/* Position Functions */

function setPos(targetObj,moveObj) {
	var coors = findPos(targetObj);
	moveObj.style.position = 'absolute';
	moveObj.style.top = coors[1]+20 + 'px';
	moveObj.style.left = coors[0] + 'px';
}

function findPos(obj) {
	var curleft = curtop = 0;
	if (obj.offsetParent) {
		curleft = obj.offsetLeft
		curtop = obj.offsetTop
		while (obj = obj.offsetParent) {
			curleft += obj.offsetLeft
			curtop += obj.offsetTop
		}
	}
	return [curleft,curtop];
}