// =================================================================
// validationDate.
//	
//	
//	
//	
//	
// =================================================================

function validationDateClass(){
	
	this.error = false;
	this.errorMsg = null;
	
	var daysInMonth = new Array(12);
	daysInMonth[1] = 31;
	daysInMonth[2] = 29; // must programmatically check this
	daysInMonth[3] = 31;
	daysInMonth[4] = 30;
	daysInMonth[5] = 31;
	daysInMonth[6] = 30;
	daysInMonth[7] = 31;
	daysInMonth[8] = 31;
	daysInMonth[9] = 30;
	daysInMonth[10] = 31;
	daysInMonth[11] = 30;
	daysInMonth[12] = 31;
	
	this.setError = function (msg,errorObject){
	
		this.error = true;
		this.errorMsg = msg;
		errorObject.addError(this.errorMsg);
	}
	
	this.checkDate = function (day, month, year , errorObject){

		if (isEmpty(year)) {
			this.setError("Please enter a Year.",errorObject);
			return false;
		}
		if (isEmpty(month)) {
			this.setError("Please enter a Month.",errorObject);
			return false;
		}
		if (isEmpty(day)) {
			this.setError("Please enter a Day of the month.",errorObject);
			return false;
		}
	
		if ((day == 31) && ((month == 2) || (month == 4) || (month == 6) || (month == 9) || (month == 11))) {
			this.setError("Please enter a valid Day and Month combination.",errorObject);
			return false;
		}
	
		if (day == 30 && month == 2) {
			this.setError("Please enter a valid Day and Month combination.",errorObject);
			return false;
		}
		// Leap year...
		if (day == 29 && month == 2) {
			if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)) {
				return true;
			}
			else {
				this.setError("Please enter a valid Day and Month combination.",errorObject);
				return false;
			}
		}	
		if (!this.isInYear4DigitFormat(year+"")) {
			this.setError("Year must be a 4 digit numeric value.",errorObject);
			return false;
		}
		return true;
	}
	
	this.daysInFebruary = function(year){
		// February has 29 days in any year evenly divisible by four,
		// EXCEPT for centurial years which are not also divisible by 400.
		return (((year % 4 == 0) && ((!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28);
	}
		
	this.isInDayFormat = function(value){
		if (!isIntegerInRange(value, 1, 31)) {
			return false;
		}
		return true;
	}
	
	this.isInMonthFormat = function(value){
		if (!isIntegerInRange(value, 1, 12)) {
			return false;
		}
		return true;
	}
	
	// this function expects year to be four digits
	this.isInYear4DigitFormat = function(value){
		return isIntegerOfLength(value, 4);
	}
	
	
	this.isValidDayMonth = function(day, month){
		var intMonth = parseInt(month, 10);
		var intDay = parseInt(day, 10);
		// catch invalid days, except for February
		if ((intDay > daysInMonth[intMonth])) {
			return false;
		}
		else {
			return true;
		}
	}
	
	
	
	this.isDateInFuture = function(day, month, year ){
		var inFuture = false;
		var d = new Date();
		var currentDay = d.getDate();
		var currentMonth = d.getMonth() + 1;
		var currentYear = d.getFullYear();
		
		var dayValue = parseInt(day, 10);
		var monthValue = parseInt(month, 10);
		var yearValue = parseInt(year, 10);
		
		if (yearValue > currentYear) {
			inFuture = true;
		}
		else {
			if ((yearValue == currentYear) && (monthValue > currentMonth)) {
				inFuture = true;
			}
			else {
				if ((yearValue == currentYear) && (monthValue == currentMonth) &&
				(dayValue > currentDay)) {
					inFuture = true;
				}
			}
		}		
		// if date is not in future, return false
		if (!inFuture) {
			return false;
		}		
		return true;
	}
	
	this.isYearInFuture = function (value){
		var d = new Date();
		var currentYear = d.getFullYear();
		var yearValue = parseInt(value, 10);
		
		if (yearValue > currentYear) {
			return true;
		}
		return false;
	}
	
	
	
	// =================================================================
	// Private functions below
	// =================================================================
	
	function isEmpty(s){
		return ((s == null) || (s.length == 0));
	}
	
	function isIntegerOfLength(value, requiredLength){
		if (!isInteger(value)) {
			return false;
		}
		if (value.length != requiredLength) {
			return false;
		}
		return true;
	}
	
	
	function isInteger(s){
		var i;
		var inputLen = s.length;
		if (inputLen == 0) {
			return false;
		}
		for (i = 0; i < inputLen; i++) {
			// Check that current character is number.
			var c = s.charAt(i);
			if (!isDigit(c)) {
				return false;
			}
		}
		// All characters are numbers.
		return true;
	}

	function isDigit(c)
	{
		return ((c >= "0") && (c <= "9"));
	}
	
	
}
var validationDate = new validationDateClass();
//tests
//validationDate.checkDate("31","2","2000",error) 
//error.display();