// @author Rico Sonntag
//
// Hilfsfunktionen zur Auswertung von Datumseingaben (mittels jscalendar)

// Funktion liefert 'true' wenn ein Datumswert vor dem aktuellen Datum (lst_date) liegt
function GetDateStatus(act_date, lst_date)
{
	var actYear = act_date.getFullYear();
	var lstYear = lst_date.getFullYear();

	if (actYear < lstYear)
		return true;
	else
	{
		if (actYear == lstYear)
		{
			var actMonth = act_date.getMonth();
			var lstMonth = lst_date.getMonth();

			if (actMonth < lstMonth)
				return true;
			else
			{
				if (actMonth == lstMonth)
				{
					var actDay = act_date.getDate();
					var lstDay = lst_date.getDate();

					if (actDay < lstDay)
						return true;
				}
			}
		}

		return false;
	}
}

//--------------------------------------------------------------------------
//
//--------------------------------------------------------------------------
function SetupCalendar(Name)
{
	if (document.getElementById(Name))
	{
		var today    = new Date();
		var thisYear = today.getFullYear();

		Calendar.setup(
			{
				inputField  : Name,
				ifFormat    : "%d.%m.%Y",
				button      : Name + "Button",
				weekNumbers : false,
				range       : [thisYear, thisYear + 10], // Jahre immer ab dem Aktuellen

				// alle Werte vor dem heutigen Tag deaktivieren
				dateStatusFunc : function(date) { return GetDateStatus(date, new Date()); }
			}
		);
	}
}

function setBackDate(interval){
	var fieldValue = document.getElementById("Anreisetag").value;
	
	var dateData = fieldValue.split('.');
	var oldDate = new Date(dateData[2], dateData[1]-1, dateData[0]);
	
	var intervalInMs = interval * 86400;	
	var newTs = (oldDate.getTime()/1000) + intervalInMs;
	var newDate = new Date(newTs*1000);
	
	var newDay = newDate.getDate();
	var newMonth = newDate.getMonth() + 1;
	var newYear = newDate.getFullYear();
	if(newDay.toString().length < 2){
		newDay = '0' + newDay;
	}
	if(newMonth.toString().length < 2){
		newMonth = '0' + newMonth;
	}

	document.getElementById("Abreisetag").value = newDay+'.'+newMonth+'.'+newYear;	
}