var NUM_CENTYEAR = 30;
var BUL_TIMECOMPONENT = false;
var BUL_YEARSCROLL = true;
var calendars = [];
var RE_NUM = /^\-?\d+$/;
var calendar_html_fpath = '';

function calendar2(obj_targetm, obj_targetd, obj_targety) {

	// assigning methods
	
	
	this.gen_day = cal_gen_dated2;
	this.gen_month = cal_gen_datem2;
	this.gen_year = cal_gen_datey2;
	
	//this.gen_date = cal_gen_date2;
	this.gen_time = cal_gen_time2;
	this.gen_tsmp = cal_gen_tsmp2;
	this.prs_date = cal_prs_date2;
	this.prs_time = cal_prs_time2;
	this.prs_tsmp = cal_prs_tsmp2;
	this.popup    = cal_popup2;

	// validate input parameters
	/*if (!obj_target)
		return cal_error("Error calling the calendar: no target control specified");
	if (obj_target.value == null)
		return cal_error("Error calling the calendar: parameter specified is not valid target control");
	*/
	
	this.targetm = obj_targetm;
	this.targetd = obj_targetd;
	this.targety = obj_targety;

	this.time_comp = BUL_TIMECOMPONENT;
	this.year_scroll = BUL_YEARSCROLL;
	
	// register in global collections
	this.id = calendars.length;
	calendars[this.id] = this;
}

function cal_popup2 (str_datetime) {
	this.target = new Date();
	
	this.dt_current = this.prs_tsmp(str_datetime ? str_datetime : this.target.value);
	if (!this.dt_current) return;
	
	var obj_calwindow = window.open(
		calendar_html_fpath + 'calendar.html?datetime=' + this.dt_current.valueOf()+ '&id=' + this.id,
		'Calendar', 'width=200,height='+(this.time_comp ? 235 : 210)+
		',status=no,resizable=no,top=200,left=700,dependent=yes,alwaysRaised=yes'
	);
	obj_calwindow.opener = window;
	obj_calwindow.focus();
}

// timestamp generating function
function cal_gen_tsmp2 (dt_datetime) {
	return(this.gen_date(dt_datetime) + ' ' + this.gen_time(dt_datetime));
}

// date generating function
function cal_gen_datem2 (dt_datetime) {
	/*return (
		(dt_datetime.getMonth() < 9 ? '0' : '') + (dt_datetime.getMonth() + 1) + "/"
		+ (dt_datetime.getDate() < 10 ? '0' : '') + dt_datetime.getDate() + "/"
		+ dt_datetime.getFullYear()
	);*/
	return (dt_datetime.getMonth() + 1);
}

// date generating function
function cal_gen_dated2 (dt_datetime) {
	/*return (
		(dt_datetime.getMonth() < 9 ? '0' : '') + (dt_datetime.getMonth() + 1) + "/"
		+ (dt_datetime.getDate() < 10 ? '0' : '') + dt_datetime.getDate() + "/"
		+ dt_datetime.getFullYear()
	);*/
	return (dt_datetime.getDate());
}

// date generating function
function cal_gen_datey2 (dt_datetime) {
	/*return (
		(dt_datetime.getMonth() < 9 ? '0' : '') + (dt_datetime.getMonth() + 1) + "/"
		+ (dt_datetime.getDate() < 10 ? '0' : '') + dt_datetime.getDate() + "/"
		+ dt_datetime.getFullYear()
	);*/
	return (dt_datetime.getFullYear());
}

// time generating function
function cal_gen_time2 (dt_datetime) {
	return (
		(dt_datetime.getHours() < 10 ? '0' : '') + dt_datetime.getHours() + ":"
		+ (dt_datetime.getMinutes() < 10 ? '0' : '') + (dt_datetime.getMinutes()) + ":"
		+ (dt_datetime.getSeconds() < 10 ? '0' : '') + (dt_datetime.getSeconds())
	);
}

// timestamp parsing function
function cal_prs_tsmp2 (str_datetime) {
	// if no parameter specified return current timestamp
	if (!str_datetime)
		return (new Date());

	// if positive integer treat as milliseconds from epoch
	if (RE_NUM.exec(str_datetime))
		return new Date(str_datetime);
		
	// else treat as date in string format
	var arr_datetime = str_datetime.split(' ');
	return this.prs_time(arr_datetime[1], this.prs_date(arr_datetime[0]));
}

// date parsing function
function cal_prs_date2 (str_date) {

	var arr_date = str_date.split('/');

	if (arr_date.length != 3) return alert ("Invalid date format: '" + str_date + "'.\nFormat accepted is dd-mm-yyyy.");
	if (!arr_date[1]) return alert ("Invalid date format: '" + str_date + "'.\nNo day of month value can be found.");
	if (!RE_NUM.exec(arr_date[1])) return alert ("Invalid day of month value: '" + arr_date[1] + "'.\nAllowed values are unsigned integers.");
	if (!arr_date[0]) return alert ("Invalid date format: '" + str_date + "'.\nNo month value can be found.");
	if (!RE_NUM.exec(arr_date[0])) return alert ("Invalid month value: '" + arr_date[0] + "'.\nAllowed values are unsigned integers.");
	if (!arr_date[2]) return alert ("Invalid date format: '" + str_date + "'.\nNo year value can be found.");
	if (!RE_NUM.exec(arr_date[2])) return alert ("Invalid year value: '" + arr_date[2] + "'.\nAllowed values are unsigned integers.");

	var dt_date = new Date();
	dt_date.setDate(1);

	if (arr_date[0] < 1 || arr_date[0] > 12) return alert ("Invalid month value: '" + arr_date[0] + "'.\nAllowed range is 01-12.");
	dt_date.setMonth(arr_date[0]-1);
	 
	if (arr_date[2] < 100) arr_date[2] = Number(arr_date[2]) + (arr_date[2] < NUM_CENTYEAR ? 2000 : 1900);
	dt_date.setFullYear(arr_date[2]);

	var dt_numdays = new Date(arr_date[2], arr_date[0], 0);
	dt_date.setDate(arr_date[1]);
	if (dt_date.getMonth() != (arr_date[0]-1)) return alert ("Invalid day of month value: '" + arr_date[1] + "'.\nAllowed range is 01-"+dt_numdays.getDate()+".");

	return (dt_date)
}

// time parsing function
function cal_prs_time2 (str_time, dt_date) {

	if (!dt_date) return null;
	var arr_time = String(str_time ? str_time : '').split(':');

	if (!arr_time[0]) dt_date.setHours(0);
	else if (RE_NUM.exec(arr_time[0])) 
		if (arr_time[0] < 24) dt_date.setHours(arr_time[0]);
		else return cal_error ("Invalid hours value: '" + arr_time[0] + "'.\nAllowed range is 00-23.");
	else return cal_error ("Invalid hours value: '" + arr_time[0] + "'.\nAllowed values are unsigned integers.");
	
	if (!arr_time[1]) dt_date.setMinutes(0);
	else if (RE_NUM.exec(arr_time[1]))
		if (arr_time[1] < 60) dt_date.setMinutes(arr_time[1]);
		else return cal_error ("Invalid minutes value: '" + arr_time[1] + "'.\nAllowed range is 00-59.");
	else return cal_error ("Invalid minutes value: '" + arr_time[1] + "'.\nAllowed values are unsigned integers.");

	if (!arr_time[2]) dt_date.setSeconds(0);
	else if (RE_NUM.exec(arr_time[2]))
		if (arr_time[2] < 60) dt_date.setSeconds(arr_time[2]);
		else return cal_error ("Invalid seconds value: '" + arr_time[2] + "'.\nAllowed range is 00-59.");
	else return cal_error ("Invalid seconds value: '" + arr_time[2] + "'.\nAllowed values are unsigned integers.");

	dt_date.setMilliseconds(0);
	return dt_date;
}

function cal_error (str_message) {
	alert (str_message);
	return null;
}

var dtCh= "-";
var minYear=1900;
var maxYear=2100;
var err = 0;
function isInteger(s){
    var i;
    for (i = 0; i < s.length; i++){
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function stripCharsInBag(s, bag){
    var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++){
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function daysInFebruary (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 );
}
function DaysArray(n) {
    for (var i = 1; i <= n; i++) {
        this[i] = 31
        if (i==4 || i==6 || i==9 || i==11) {this[i] = 30}
        if (i==2) {this[i] = 29}
   }
   return this
}

function isDate(dtStr){
    var m1;
    var m2;
    var m3;
    var daysInMonth = DaysArray(12)
    var pos1=dtStr.indexOf(dtCh)
    var pos2=dtStr.indexOf(dtCh,pos1+1)
    var strYear=dtStr.substring(0,pos1)
    var strMonth=dtStr.substring(pos1+1,pos2)
    var strDay=dtStr.substring(pos2+1)

    strYr=strYear
    if (strDay.charAt(0)=="0" && strDay.length>1) strDay=strDay.substring(1)
    if (strMonth.charAt(0)=="0" && strMonth.length>1) strMonth=strMonth.substring(1)
    for (var i = 1; i <= 3; i++) {
        if (strYr.charAt(0)=="0" && strYr.length>1) strYr=strYr.substring(1)
    }
    month=parseInt(strMonth)
    day=parseInt(strDay)
    year=parseInt(strYr)
    if (pos1==-1 || pos2==-1){
        return false
    }
    if (strMonth.length<1 || month<1 || month>12){
        return false
    }
    if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
        return false
    }
    if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
         return false
    }
    if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
        return false
    }
    return true
}