// ===================================================================
// Author: Matt Kruse <matt@mattkruse.com>
// WWW: http://www.mattkruse.com/

var MONTH_NAMES=new Array('January','February','March','April','May','June','July','August','September','October','November','December','Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec');
var DAY_NAMES=new Array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sun','Mon','Tue','Wed','Thu','Fri','Sat');
function LZ(x) {return(x<0||x>9?"":"0")+x}

// ------------------------------------------------------------------
// Utility functions for parsing in getDateFromFormat()
// ------------------------------------------------------------------
function _isInteger(val) {
	var digits="1234567890";
	for (var i=0; i < val.length; i++) {
		if (digits.indexOf(val.charAt(i))==-1) { return false; }
		}
	return true;
	}
function _getInt(str,i,minlength,maxlength) {
	for (var x=maxlength; x>=minlength; x--) {
		var token=str.substring(i,i+x);
		if (token.length < minlength) { return null; }
		if (_isInteger(token)) { return token; }
		}
	return null;
	}
	
// ------------------------------------------------------------------
// getDateFromFormat( date_string , format_string )
//
// This function takes a date string and a format string. It matches
// If the date string matches the format string, it returns the 
// getTime() of the date. If it does not match, it returns 0.
// ------------------------------------------------------------------
function getDateFromFormat(val,format) {
	val=val+"";
	format=format+"";
	var i_val=0;
	var i_format=0;
	var c="";
	var token="";
	var token2="";
	var x,y;
	var now=new Date();

	var year;
	if (now.getYear() >= 100 && now.getYear() <= 500)
	    year = (now.getYear() - 100);
	else
	    year = now.getYear();

	var month=now.getMonth()+1;
	var date=1;
	var hh=now.getHours();
	var mm=now.getMinutes();
	var ss=now.getSeconds();
	var ampm="";
	
	while (i_format < format.length) {
		// Get next token from format string
		c=format.charAt(i_format);
		token="";
		while ((format.charAt(i_format)==c) && (i_format < format.length)) {
			token += format.charAt(i_format++);
			}
		// Extract contents of value based on format token
		if (token=="yyyy" || token=="yy" || token=="y") {
			if (token=="yyyy") { x=4;y=4; }
			if (token=="yy")   { x=2;y=2; }
			if (token=="y")    { x=2;y=4; }
			year=_getInt(val,i_val,x,y);
			if (year==null) { return 0; }
			i_val += year.length;
			if (year.length==2) {
				if (year > 70) { year=1900+(year-0); }
				else { year=2000+(year-0); }
				}
			}
		else if (token=="MMM"||token=="NNN"){
			month=0;
			for (var i=0; i<MONTH_NAMES.length; i++) {
				var month_name=MONTH_NAMES[i];
				if (val.substring(i_val,i_val+month_name.length).toLowerCase()==month_name.toLowerCase()) {
					if (token=="MMM"||(token=="NNN"&&i>11)) {
						month=i+1;
						if (month>12) { month -= 12; }
						i_val += month_name.length;
						break;
						}
					}
				}
			if ((month < 1)||(month>12)){return 0;}
			}
		else if (token=="EE"||token=="E"){
			for (var i=0; i<DAY_NAMES.length; i++) {
				var day_name=DAY_NAMES[i];
				if (val.substring(i_val,i_val+day_name.length).toLowerCase()==day_name.toLowerCase()) {
					i_val += day_name.length;
					break;
					}
				}
			}
		else if (token=="MM"||token=="M") {
			month=_getInt(val,i_val,token.length,2);
			if(month==null||(month<1)||(month>12)){return 0;}
			i_val+=month.length;}
		else if (token=="dd"||token=="d") {
			date=_getInt(val,i_val,token.length,2);
			if(date==null||(date<1)||(date>31)){return 0;}
			i_val+=date.length;}
		else if (token=="hh"||token=="h") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<1)||(hh>12)){return 0;}
			i_val+=hh.length;}
		else if (token=="HH"||token=="H") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<0)||(hh>23)){return 0;}
			i_val+=hh.length;}
		else if (token=="KK"||token=="K") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<0)||(hh>11)){return 0;}
			i_val+=hh.length;}
		else if (token=="kk"||token=="k") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<1)||(hh>24)){return 0;}
			i_val+=hh.length;hh--;}
		else if (token=="mm"||token=="m") {
			mm=_getInt(val,i_val,token.length,2);
			if(mm==null||(mm<0)||(mm>59)){return 0;}
			i_val+=mm.length;}
		else if (token=="ss"||token=="s") {
			ss=_getInt(val,i_val,token.length,2);
			if(ss==null||(ss<0)||(ss>59)){return 0;}
			i_val+=ss.length;}
		else if (token=="a") {
			if (val.substring(i_val,i_val+2).toLowerCase()=="am") {ampm="AM";}
			else if (val.substring(i_val,i_val+2).toLowerCase()=="pm") {ampm="PM";}
			else {return 0;}
			i_val+=2;}
		else {
			if (val.substring(i_val,i_val+token.length)!=token) {return 0;}
			else {i_val+=token.length;}
			}
		}
	// If there are any trailing characters left in the value, it doesn't match
	if (i_val != val.length) { return 0; }
	// Is date valid for month?
	if (month==2) {
		// Check for leap year
		if ( ( (year%4==0)&&(year%100 != 0) ) || (year%400==0) ) { // leap year
			if (date > 29){ return 0; }
			}
		else { if (date > 28) { return 0; } }
		}
	if ((month==4)||(month==6)||(month==9)||(month==11)) {
		if (date > 30) { return 0; }
		}
	// Correct hours value
	if (hh<12 && ampm=="PM") { hh=hh-0+12; }
	else if (hh>11 && ampm=="AM") { hh-=12; }
	var newdate=new Date(year,month-1,date,hh,mm,ss);
	return newdate.getTime();
	}

// ------------------------------------------------------------------
// parseDate( date_string [, prefer_euro_format] )
//
// This function takes a date string and tries to match it to a
// number of possible date formats to get the value. It will try to
// match against the following international formats, in this order:
// y-M-d   MMM d, y   MMM d,y   y-MMM-d   d-MMM-y  MMM d
// M/d/y   M-d-y      M.d.y     MMM-d     M/d      M-d
// d/M/y   d-M-y      d.M.y     d-MMM     d/M      d-M
// A second argument may be passed to instruct the method to search
// for formats like d/M/y (european format) before M/d/y (American).
// Returns a Date object or null if no patterns match.
// ------------------------------------------------------------------
function parseDate(val) {
	var preferEuro=(arguments.length==2)?arguments[1]:false;
	generalFormats=new Array('MMM d, y','MMM d,y','d-MMM-y','y-M-d','y-MMM-d','MMM d');
	monthFirst=new Array('M/d/y','M-d-y','M.d.y','MMM-d','M/d','M-d');
	dateFirst =new Array('d/M/y','d-M-y','d.M.y','d-MMM','d/M','d-M');
	var checkList=new Array('generalFormats',preferEuro?'dateFirst':'monthFirst',preferEuro?'monthFirst':'dateFirst');
	var d=null;
	for (var i=0; i<checkList.length; i++) {
		var l=window[checkList[i]];
		for (var j=0; j<l.length; j++) {
			d=getDateFromFormat(val,l[j]);
			if (d!=0) { return new Date(d); }
			}
		}
	return null;
}

var bBusy = false;

function calcExpiry(s,e,m,y,d) {

	if (bBusy) { return; }

	bBusy = true;

	var startDate = parseDate($get(s).value);

	// exit if a date is invalid
	if (startDate == null) {
		$get(e).value = "";
		bBusy = false;
		calcStartOrExpiry(s,e,m,y,d);
	} else {

		var leaseMnths = (m != null)? parseInt($get(m).value) : 0;
		var leaseYrs = (y != null)? parseInt($get(y).value) : 0;
		var leaseDays  = (d != null)? parseInt($get(d).value) : 0;

		// if no length specifed, allow an expiry to remain
		if (leaseYrs == 0 && leaseMnths == 0 && leaseDays == 0) { bBusy = false; return; }

		var expiryDay = parseInt((startDate.getDate())+leaseDays-1);
		var expiryMonths = parseInt((startDate.getMonth()+1)+leaseMnths);
		
		var expiryYears = parseInt(startDate.getFullYear()+leaseYrs);
		
		
		// if we need to move months into the next year...
		if (expiryMonths > 12) {
			expiryYears += 1;
			expiryMonths -= 12;
		}
		
		// if we need to jump back to the month before
		if (expiryDay == 0) {
			expiryMonths -= 1;
			if (expiryMonths == 0) {
				expiryMonths = 12;
				expiryYears -= 1;
			}
			expiryDay = getLastDay(expiryMonths, expiryYears)
		}
		
		if (expiryDay > getLastDay(expiryMonths, expiryYears)) {
            expiryDay -= getLastDay(expiryMonths, expiryYears);
            expiryMonths += 1;
            
	        if (expiryMonths > 12) {
		        expiryYears += 1;
		        expiryMonths -= 12;
            }
	    }
		
		if (expiryDay < 10) expiryDay = "0" + expiryDay;

		$get(e).value = expiryDay + "-" + getMonth(expiryMonths) + "-" + expiryYears;

	}

	bBusy = false;

}

function addTimeSpan(dUse, d1, m1, y1) {

    if (dUse == null) { return; }

    var targetDay = parseInt(dUse.getDate()+d1);
	var targetMonths = parseInt(dUse.getMonth()+1+m1);
	var targetYears = parseInt(dUse.getFullYear()+y1);

	// if we need to move months into the next year...
	if (targetMonths > 12) {
		targetYears += 1;
		targetMonths -= 12;
	}
	else if (targetMonths < 1) {
		targetYears -= 1;
		targetMonths += 12;
	}

	// if we need to jump back to the month before
	if (targetDay > getLastDay(targetMonths, targetYears)) {
		targetDay -= getLastDay(targetMonths, targetYears);
		targetMonths += 1;
        if (targetMonths > 12) {
	        targetYears += 1;
	        targetMonths -= 12;
        }
	}
	else if (targetDay < 1) {
		targetMonths -= 1;
        if (targetMonths < 1) {
		    targetYears -= 1;
		    targetMonths += 12;
        }
		targetDay += getLastDay(targetMonths, targetYears);
	}

    if (targetDay < 10) {
    	return "0" + targetDay + "-" + getMonth(targetMonths) + "-" + targetYears;
    }
    else {
    	return targetDay + "-" + getMonth(targetMonths) + "-" + targetYears;
    }

}

function calcStartOrExpiry(s,e,m,y,da) {

	if (bBusy) return;

	var d1 = parseDate($get(s).value);
	var d2 = parseDate($get(e).value);

	var y1 = parseInt($get(y).value);
	var m1 = (m != null)? parseInt($get(m).value): 0;
	var da1 = (da != null)? parseInt($get(da).value): 0;

	bBusy = true;

	if (isNaN(y1)) y1 = 0;
	if (isNaN(m1)) m1 = 0;
	if (isNaN(da1)) da1 = 0;

    // if no length specifed, allow an expiry to remain
	if (y1 == 0 && m1 == 0 && da1 == 0) { bBusy = false; return; }

	var dUse;
	var FACTOR;
	
	// if not start or end then start is today
	if (d1 == null && d2 == null) d1 = new Date();
	
	if (d1 == null) {
		dUse = d2;
		FACTOR = -1;
	} else {
		FACTOR = 1;
		dUse = d1;
	}

	var targetDay = parseInt(dUse.getDate()+(da1 * FACTOR)-1);
	var targetMonths = parseInt(dUse.getMonth()+1+(m1 * FACTOR));
	var targetYears = parseInt(dUse.getFullYear()+(y1 * FACTOR));

	// if we need to move months into the next year...
	if (targetMonths > 12) {
		targetYears += 1;
		targetMonths -= 12;
	}

	// if we need to jump back to the month before
	if (targetDay == 0) {
		targetMonths -= 1;
		if (targetMonths == 0) {
			targetMonths = 12;
			targetYears -= 1;
		}
		targetDay = getLastDay(targetMonths, targetYears)
	}
	
	if (targetDay > getLastDay(targetMonths, targetYears)) {
        targetDay -= getLastDay(targetMonths, targetYears);
        targetMonths += 1;
        
	    if (targetMonths > 12) {
		    targetYears += 1;
		    targetMonths -= 12;
        }
	}
	
	if (targetDay < 10) targetDay = "0" + targetDay;

	if (FACTOR == -1) {
		$get(s).value = targetDay + "-" + getMonth(targetMonths) + "-" + targetYears;
	} else {
		$get(e).value = targetDay + "-" + getMonth(targetMonths) + "-" + targetYears;
	}

	bBusy = false;
}

function getLastDay(month, year) {

	var day = 31;

	// Is date valid for month?
	if (month==2) {
		// Check for leap year
		if ( ( (year%4==0)&&(year%100 != 0) ) || (year%400==0) ) { // leap year
			day = 29;
		} else {
			day = 28;
		}
	} else if ((month==4)||(month==6)||(month==9)||(month==11)) {
		day = 30;
	}

	return day;
}

// ------------------------------------------------------------------
// isDate ( date_string, format_string )
// Returns true if date string matches format of format string and
// is a valid date. Else returns false.
// It is recommended that you trim whitespace around the value before
// passing it to this function, as whitespace is NOT ignored!
// ------------------------------------------------------------------
//function isDate(val,format) {
//	var date=getDateFromFormat(val,format);
//	if (date==0) { return false; }
//	return true;
//	}

// -------------------------------------------------------------------
// compareDates(date1,date1format,date2,date2format)
//   Compare two date strings to see which is greater.
//   Returns:
//   1 if date1 is greater than date2
//   0 if date2 is greater than date1 of if they are the same
//  -1 if either of the dates is in an invalid format
// -------------------------------------------------------------------
//function compareDates(date1,dateformat1,date2,dateformat2) {
//	var d1=getDateFromFormat(date1,dateformat1);
//	var d2=getDateFromFormat(date2,dateformat2);
//	if (d1==0 || d2==0) {
//		return -1;
//		}
//	else if (d1 > d2) {
//		return 1;
//		}
//	return 0;
//	}

// ------------------------------------------------------------------
// formatDate (date_object, format)
// Returns a date in the output format specified.
// The format string uses the same abbreviations as in getDateFromFormat()
// ------------------------------------------------------------------
//function formatDate(date,format) {
//	format=format+"";
//	var result="";
//	var i_format=0;
//	var c="";
//	var token="";
//	var y=date.getYear()+"";
//	var M=date.getMonth()+1;
//	var d=date.getDate();
//	var E=date.getDay();
//	var H=date.getHours();
//	var m=date.getMinutes();
//	var s=date.getSeconds();
//	var yyyy,yy,MMM,MM,dd,hh,h,mm,ss,ampm,HH,H,KK,K,kk,k;
//	// Convert real date parts into formatted versions
//	var value=new Object();
//	if (y.length < 4) {y=""+(y-0+1900);}
//	value["y"]=""+y;
//	value["yyyy"]=y;
//	value["yy"]=y.substring(2,4);
//	value["M"]=M;
//	value["MM"]=LZ(M);
//	value["MMM"]=MONTH_NAMES[M-1];
//	value["NNN"]=MONTH_NAMES[M+11];
//	value["d"]=d;
//	value["dd"]=LZ(d);
//	value["E"]=DAY_NAMES[E+7];
//	value["EE"]=DAY_NAMES[E];
//	value["H"]=H;
//	value["HH"]=LZ(H);
//	if (H==0){value["h"]=12;}
//	else if (H>12){value["h"]=H-12;}
//	else {value["h"]=H;}
//	value["hh"]=LZ(value["h"]);
//	if (H>11){value["K"]=H-12;} else {value["K"]=H;}
//	value["k"]=H+1;
//	value["KK"]=LZ(value["K"]);
//	value["kk"]=LZ(value["k"]);
//	if (H > 11) { value["a"]="PM"; }
//	else { value["a"]="AM"; }
//	value["m"]=m;
//	value["mm"]=LZ(m);
//	value["s"]=s;
//	value["ss"]=LZ(s);
//	while (i_format < format.length) {
//		c=format.charAt(i_format);
//		token="";
//		while ((format.charAt(i_format)==c) && (i_format < format.length)) {
//			token += format.charAt(i_format++);
//			}
//		if (value[token] != null) { result=result + value[token]; }
//		else { result=result + token; }
//		}
//	return result;
//	}
//	

//function calcBreaks(s,r,b,ry,by) {

//	if (bBusy) { return; }

//	var startDate = parseDate($get(s).value);
//	
//	var rentYrs = (ry != null)? parseInt($get(ry).value) : 0;
//	var breakYrs = (by != null)? parseInt($get(by).value) : 0;

//	bBusy = true;

//	// exit if a date is invalid
//	if (startDate == null) {
//		$get(r).innerText = "";
//		$get(b).innerText = "";
//	} else {
//		var today = new Date();
//		var rentYear;
//		var breakYear;
//		var bDone = false; 
//        
//        do
//        {
//            rentYear = parseInt(startDate.getFullYear()+rentYrs);
//            
//            if(rentYear > parseInt(today.getFullYear())){
//                bDone = true;
//            }else{
//                rentYrs += rentYrs;
//            }
//               
//        }
//        while(!bDone && rentYrs > 0);
//        
//        bDone = false;
//        
//        do
//        {
//            breakYear = parseInt(startDate.getFullYear()+breakYrs);
//            
//            if(breakYear > parseInt(today.getFullYear())){
//                bDone = true;
//            }else{
//                breakYrs += breakYrs;
//            }
//                   
//        }
//        while(!bDone && breakYrs > 0);
//        
//		//set new review and break date before startDate is manipulate
//		$get(r).innerText = startDate.getDate() + "-" + getMonth(parseInt(startDate.getMonth()+1)) + "-" + parseInt(startDate.getFullYear()+rentYrs);
//		$get(b).innerText = startDate.getDate() + "-" + getMonth(parseInt(startDate.getMonth()+1)) + "-" + parseInt(startDate.getFullYear()+breakYrs);
//	}

//	bBusy = false;
//}

//function dateDifference(inter, d1, d2) {
//	
//	var INTERVAL = 1;
//	var strResult = "";
//	
//	switch (inter) {
//		case "y":
//			INTERVAL = (1000*60*60*24*365);
//			break;
//		case "m":
//			strResult = ""+((dateDifference("y", d1, d2) * 12)+(d2.getMonth() - d1.getMonth()));
//			// INTERVAL = (1000*60*60*24*30); this is not accurrate enough so we are 
//			// counting the years by 12 and then add the difference in exact month progression 
//			break;
//		case "d":
//			INTERVAL = (1000*60*60*24);
//			break;
//	}
//	
//	var result = (d2-d1)/INTERVAL;

//	if (strResult == "") { strResult = ""+result; }
//    
//	if (strResult.indexOf(".") >=0) {
//	    //if (inter == "y") {
//		//    strResult = Math.round(strResult);
//		//} else {
//		strResult = strResult.substring(0, strResult.indexOf("."));
//		//}
//    }

//    return strResult;
//}