var m_names = new Array("Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec");
var today = new Date();

Date.prototype.daysInMonth = function () {
	return new Date(this.getFullYear(), this.getMonth()+1, 0).getDate()
}

$.datepicker.setDefaults({
	dateFormat: 'dd M yy',
	showOn: 'both', 
	buttonImage: '/shared/images/calendar.gif', 
	buttonImageOnly: true,
	changeMonth: true,
	changeYear: true,
	//minDate: '-5y', 
	maxDate: '+0y',
	//yearRange: '-10:+5',
	gotoCurrents: true,
	showButtonPanel: true,
	constrainInput: true
	
});

function createDate_Today(retType){
	if (!retType) retType = 1;
	
	var retDate = new Date();
	
	var actualMonthNum = retDate.getMonth()+1;
	
	switch(retType){
		case 1:
			return retDate;
			break;
		case 2:
			return retDate.format('yyyy-mm-dd');
			break;
	}
}

function createDate_CalMonth(monthNum, year, start){
	var theDayNum;
	if (start){
		theDayNum = 1;
	} else {
		theDayNum = today.daysInMonth();
	}
	return new Date(year, monthNum, theDayNum);
}

function createDate_CalMonth_Prev(start){
	var thisDate = new Date();
	thisDate.setDate(today.getDate() - today.daysInMonth());
	return createDate_CalMonth(thisDate.getMonth(), thisDate.getFullYear(), start)
}

function createDate_CalYear_Prev(start){
	if (start){
		return(new Date(today.getFullYear()-1,0,1));
	} else {
		return(new Date(today.getFullYear()-1,11,31));
	}
}

function createDate_CalYear_toNow(start){
	if (start){
		return(new Date(today.getFullYear(),0,1));
	} else {
		return today;
	}
}

function createDate_Week_Next(start){
	if (start){
		return today;
	} else {
		var myDate = new Date();
		myDate.setDate(myDate.getDate() + 7);
		return myDate;
	}
}

function setDatePickerDates(selector, type, newDate){
	if (!type) type=1;
	var tmpVal = '';
	var m_today = createDate_Today(2);
	
	switch (type) {
		case 1:				// Use formDefault value if exists else today
			tmpVal = $(selector).attr('formDefault');
			break;
		case 2:				// use today....
			break;
		case 3:				// use the newDate passed in..
			if (newDate) tmpVal = newDate;
			break;
		case 4:				// use the newDate unless its less than today
			if (newDate) tmpVal = newDate;
			if (tmpVal < m_today) tmpVal = m_today;
	}

	if (tmpVal == '') tmpVal = m_today; 

	// expected in yyyy-mm-dd format
	var dateStr = tmpVal.split('-');
	var aDate = dateStr[2] + ' ' + m_names[dateStr[1]-1] + ' ' + dateStr[0];

	$(selector).val(aDate).trigger('change'); 	// Reset start date to today:		
}

/*
* Initialize any datepickers
*/
function instantiateDatepickers(selector, defaultDates){
	if (!selector) selector = '.datepicker'; 
	if (selector == '') selector = '.datepicker'; 

	jQuery(selector).each(function(index, Element)
	{
		var curEle = jQuery(Element);
		curEle.datepicker(eval("(" + curEle.attr('dpOptions') + ")"));
		var aDate;
		// user formdefault as the default date by default
		// if formdate if not used, it would use dpDate instead
		var dateStr = curEle.attr("formdefault");
		if (!dateStr) dateStr = curEle.attr("dpDate");
		if (dateStr) {
			switch (dateStr){
				//if explicitly stated 'today', set default as today
				case 'today': 
					aDate = new Date();
				//if no text given, set default as empty
				case '':
					break;
				//if not using any predefined value, expect the date in format "yyyy-mm-dd"
				default:
					dateStr = dateStr.split('-');
					aDate = new Date(dateStr[0], dateStr[1] - 1, dateStr[2]);
					break;
			}
			if (aDate) curEle.datepicker("setDate", aDate);
		}
		// Remove minimum date set
		curEle.datepicker("option", "minDate", null);
	});
	/*
	//This is used to enforce to enforce the datepicker set minDate and maxDate

	jQuery(selector).blur(function(e){
		
		var thisEle = jQuery(e.currentTarget);
		// only runs if it has a date in it
		var curDate = thisEle.datepicker("getDate");
		//alert(curDate.format("dd/mm/yyyy"));
		//alert(thisEle.attr("id"));
		
		if (curDate){
			// checks if it is a valid date
			var isValid = true;
			var maxDate = thisEle.datepicker("options", "maxDate");
			var minDate = thisEle.datepicker("options", "minDate");
			if (maxDate) if (maxDate < curDate) isValid = false;
			if (minDate) if (minDate > curDate) isValid = false;
			// if invalid: select the inputbox, focus on it, select all the text and show a message stating the valid range of date
			if (!isValid){
				e.focus();
				e.select();
				if (minDate && maxDate) alert("Please select a date between " + minDate.format("dd mmm yyyy") + " and " + maxDate.format("dd mmm yyyy"));
				else if (minDate) alert("Please select a date between no less than" + minDate.format("dd mmm yyyy"));
				else if (maxDate) alert("Please select a date between no greater than" + maxDate.format("dd mmm yyyy"));
			}
		}
	});
	*/
	/*
	if (defaultDates){
		var aDate;
		for (thisOptn in defaultDates){
			aDate = defaultDates[thisOptn][1].getDate() + ' ' + m_names[defaultDates[thisOptn][1].getMonth()] + ' ' + defaultDates[thisOptn][1].getFullYear();
			jQuery("#" + defaultDates[thisOptn][0]).datepicker().val(aDate).trigger('change');
		}
	} 
	*/
}




/*
* Date Format 1.2.3
* (c) 2007-2009 Steven Levithan <stevenlevithan.com>
* MIT license
*
* Includes enhancements by Scott Trenda <scott.trenda.net>
* and Kris Kowal <cixar.com/~kris.kowal/>
*
* Accepts a date, a mask, or a date and a mask.
* Returns a formatted version of the given date.
* The date defaults to the current date/time.
* The mask defaults to dateFormat.masks.default.
*/

var dateFormat = function () {
	var	token = /d{1,4}|m{1,4}|yy(?:yy)?|([HhMsTt])\1?|[LloSZ]|"[^"]*"|'[^']*'/g,
		timezone = /\b(?:[PMCEA][SDP]T|(?:Pacific|Mountain|Central|Eastern|Atlantic) (?:Standard|Daylight|Prevailing) Time|(?:GMT|UTC)(?:[-+]\d{4})?)\b/g,
		timezoneClip = /[^-+\dA-Z]/g,
		pad = function (val, len) {
			val = String(val);
			len = len || 2;
			while (val.length < len) val = "0" + val;
			return val;
		};

	// Regexes and supporting functions are cached through closure
	return function (date, mask, utc) {
		var dF = dateFormat;

		// You can't provide utc if you skip other args (use the "UTC:" mask prefix)
		if (arguments.length == 1 && Object.prototype.toString.call(date) == "[object String]" && !/\d/.test(date)) {
			mask = date;
			date = undefined;
		}

		// Passing date through Date applies Date.parse, if necessary
		date = date ? new Date(date) : new Date;
		if (isNaN(date)) throw SyntaxError("invalid date");

		mask = String(dF.masks[mask] || mask || dF.masks["default"]);

		// Allow setting the utc argument via the mask
		if (mask.slice(0, 4) == "UTC:") {
			mask = mask.slice(4);
			utc = true;
		}

		var	_ = utc ? "getUTC" : "get",
			d = date[_ + "Date"](),
			D = date[_ + "Day"](),
			m = date[_ + "Month"](),
			y = date[_ + "FullYear"](),
			H = date[_ + "Hours"](),
			M = date[_ + "Minutes"](),
			s = date[_ + "Seconds"](),
			L = date[_ + "Milliseconds"](),
			o = utc ? 0 : date.getTimezoneOffset(),
			flags = {
				d:    d,
				dd:   pad(d),
				ddd:  dF.i18n.dayNames[D],
				dddd: dF.i18n.dayNames[D + 7],
				m:    m + 1,
				mm:   pad(m + 1),
				mmm:  dF.i18n.monthNames[m],
				mmmm: dF.i18n.monthNames[m + 12],
				yy:   String(y).slice(2),
				yyyy: y,
				h:    H % 12 || 12,
				hh:   pad(H % 12 || 12),
				H:    H,
				HH:   pad(H),
				M:    M,
				MM:   pad(M),
				s:    s,
				ss:   pad(s),
				l:    pad(L, 3),
				L:    pad(L > 99 ? Math.round(L / 10) : L),
				t:    H < 12 ? "a"  : "p",
				tt:   H < 12 ? "am" : "pm",
				T:    H < 12 ? "A"  : "P",
				TT:   H < 12 ? "AM" : "PM",
				Z:    utc ? "UTC" : (String(date).match(timezone) || [""]).pop().replace(timezoneClip, ""),
				o:    (o > 0 ? "-" : "+") + pad(Math.floor(Math.abs(o) / 60) * 100 + Math.abs(o) % 60, 4),
				S:    ["th", "st", "nd", "rd"][d % 10 > 3 ? 0 : (d % 100 - d % 10 != 10) * d % 10]
			};

		return mask.replace(token, function ($0) {
			return $0 in flags ? flags[$0] : $0.slice(1, $0.length - 1);
		});
	};
}();

//Some common format strings
dateFormat.masks = {
	"default":      "ddd mmm dd yyyy HH:MM:ss",
	shortDate:      "m/d/yy",
	mediumDate:     "mmm d, yyyy",
	longDate:       "mmmm d, yyyy",
	fullDate:       "dddd, mmmm d, yyyy",
	shortTime:      "h:MM TT",
	mediumTime:     "h:MM:ss TT",
	longTime:       "h:MM:ss TT Z",
	isoDate:        "yyyy-mm-dd",
	isoTime:        "HH:MM:ss",
	isoDateTime:    "yyyy-mm-dd'T'HH:MM:ss",
	isoUtcDateTime: "UTC:yyyy-mm-dd'T'HH:MM:ss'Z'"
};

//Internationalization strings
dateFormat.i18n = {
	dayNames: [
		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
		"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
	],
	monthNames: [
		"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
		"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"
	]
};

//For convenience...
Date.prototype.format = function (mask, utc) {
	return dateFormat(this, mask, utc);
};