// if two digit year input dates after this year considered 20 century.
var NUM_CENTYEAR = 30;
// is time input control required by default
var BUL_TIMECOMPONENT = false;
// are year scrolling buttons required by default
var BUL_YEARSCROLL = true;
var calendars = [];
var RE_NUM = /^\-?\d+$/;

function calendarInt(obj_target, obj_dateFormat, obj_timeFormat) {

	// assing methods
	this.gen_date = cal_gen_date1;
	this.gen_time = cal_gen_time1;
	this.gen_tsmp = cal_gen_tsmp1;
	this.prs_date = cal_prs_date1;
	this.prs_time = cal_prs_time1;
	
	this.prs_tsmp = cal_prs_tsmp1;
	this.cal_validate = cal_validate1; 

	
	this.popup    = cal_popup1;

	// 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 tardet control");
	this.target = obj_target;
    this.dateFormat = obj_dateFormat;
    this.timeFormat = obj_timeFormat;
	this.time_comp = BUL_TIMECOMPONENT;
	this.year_scroll = BUL_YEARSCROLL;

	// register in global collections
	this.id = calendars.length;
	calendars[this.id] = this;
}

function cal_popup1 (str_datetime) {
	this.dt_current = this.prs_tsmp(str_datetime ? str_datetime : this.target.value);
	if (!this.dt_current){return;}

	var obj_calwindow = window.open(
		'/js/calendar.jsp?datetime=' + this.dt_current.valueOf()+ '&id=' + this.id,
		'Calendar', 'width=200,height='+(this.time_comp ? 215 : 190)+
		',status=no,resizable=no,top=200,left=200,dependent=yes,alwaysRaised=yes'
	);
	obj_calwindow.opener = window;
	obj_calwindow.focus();
}

// timestamp generating function
function cal_gen_tsmp1 (dt_datetime) {
	return(this.gen_date(dt_datetime) + ' ' + this.gen_time(dt_datetime));
}

// date generating function
function cal_gen_date1 (dt_datetime) {
    return formatDate(dt_datetime, this.dateFormat);
}
// time generating function
function cal_gen_time1 (dt_datetime) {
    return formatDate(dt_datetime, this.timeFormat);
}

//
// timestamp parsing function
//      * use jsp when submitting calendar fields
//      * use date parameter if it is in correct format
//
function cal_validate1 (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 tmpDate = new Date();
    if (this.time_comp) {
        tmpDate.setTime(getDateFromFormat(str_datetime,this.dateFormat + " " + this.timeFormat));
    }
    else {
        tmpDate.setTime(getDateFromFormat(str_datetime,this.dateFormat));
    }
    if (tmpDate.getTime() == 0) {
      return cal_error("Invalid date format " + this.dateFormat + " " + this.timeFormat);
    }
    return tmpDate;
}


//
// timestamp parsing function 
//      * use in calendar control
//      * use date parameter if it is in correct format
//      * otherwise set date to today 
// 
function cal_prs_tsmp1 (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
    return this.prs_date(str_datetime);
}

//
// date parsing function 
//      * use in calendar control
//      * use date parameter if it is in correct format
//      * otherwise set date to today 
// 
function cal_prs_date1 (str_date) {
	if (!str_date) return null;
   var tmpDate = new Date();
   var timeComponent = getDateFromFormat(str_date,this.dateFormat + " " + this.timeFormat);
   if (this.time_comp && timeComponent > 0) {
        	    tmpDate.setTime(timeComponent);
   }  else {
        var dateComponent = getDateFromFormat(str_date,this.dateFormat);
        if (dateComponent > 0 ) {
           tmpDate.setTime(dateComponent);
        }
    }
    return tmpDate;
}

//
// time parsing function 
//      * use in calendar control
//      * use time parameter if it is in correct format
//      * otherwise set date to today 
// 
function cal_prs_time1 (str_time, dt_date) {
	if (!dt_date) return null;
    var tmpDate = new Date();
    tmpDate = dt_date;
    if (str_time!='') {
        tmpDate.setTime(getDateFromFormat(formatDate(dt_date, "dd.MM.yyyy") + " " + str_time, "dd.MM.yyyy " + this.timeFormat));
    }
    if (tmpDate.getTime() == 0) {
        return cal_error("Invalid date format");        
    }
    return tmpDate;
}

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