/* MarcGrabanski.com v2.4 */
/* Pop-Up Calendar Built from Scratch by Marc Grabanski */
/* Enhanced by Keith Wood (kbwood@iprimus.com.au). */
/* Under the Creative Commons Licence http://creativecommons.org/licenses/by/3.0/
	Share or Remix it but please Attribute the authors. */
var popUpCal = {
	selectedDay: 0,
	selectedMonth: 0, // 0-11
	selectedYear: 0, // 4-digit year
	clearText: 'Clear', // Display text for clear link
	closeText: 'Close', // Display text for close link
	prevText: '<Prev', // Display text for previous month link
	nextText: 'Next>', // Display text for next month link
	currentText: 'Today', // Display text for current month link
	appendText: '', // Display text following the input box, e.g. showing the format
	buttonText: '...', // Text for trigger button
	buttonImage: '', // URL for trigger button image
	buttonImageOnly: false, // True if the image appears alone, false if it appears on a button
	dayNames: ['Su','Mo','Tu','We','Th','Fr','Sa'], // Names of days starting at Sunday
	monthNames: ['January','February','March','April','May','June','July','August','September','October','November','December'], // Names of months
	dateFormat: 'DMY/', // First three are day, month, year in the required order, fourth is the separator, e.g. US would be 'MDY/'
	yearRange: '-10:+10', // Range of years to display in drop-down, either relative to current year (-nn:+nn) or absolute (nnnn:nnnn)
	changeMonth: true, // True if month can be selected directly, false if only prev/next
	changeYear: true, // True if year can be selected directly, false if only prev/next
	firstDay: 0, // The first day of the week, Sun = 0, Mon = 1, ...
	changeFirstDay: true, // True to click on day name to change, false to remain as set
	showOtherMonths: false, // True to show dates in other months, false to leave blank
	minDate: null, // The earliest selectable date, or null for no limit
	maxDate: null, // The latest selectable date, or null for no limit
	speed: 'medium', // Speed of display/closure
	autoPopUp: 'focus', // 'focus' for popup on focus, 'button' for trigger button, or 'both' for either
	closeAtTop: true, // True to have the clear/close at the top, false to have them at the bottom
	hideIfNoPrevNext: true, // True to hide next/previous month links if not applicable, false to just disable them
	customDate: null, // Function that takes a date and returns an array with [0] = true if selectable, false if not,
		// [1] = custom CSS class name(s) or '', e.g. popUpCal.noWeekends
	fieldSettings: null, // Function that takes an input field and returns a set of custom settings for the calendar
	inline: false, // this sets the calendar to always display, use this with customEvent
	customEvent: false, // define an action for the inline calendar

	/* Initialisation. */
	init: function() {
		this.popUpShowing = false;
		this.selectingMonthYear = false;
		this.standalone = false;
		this.lastInput = null;
		this.disabledInputs = [];
		this.calendarDiv = $('<div id="calendar_div"></div>');
		$('body').append(this.calendarDiv);
		$(document).mousedown(popUpCal.checkExternalClick);
	},

	/* Pop-up the calendar in a "dialog" box. */
	showStandalone: function(dateText, prompt, callback, pos) {
		if (!this.standaloneInput) { // internal input field
			this.standaloneInput = $('<input type="text" style="position: absolute; top: -100px;"/>');
			this.standaloneInput.keydown(this.doKeyDown);
			$('body').append(this.standaloneInput);
		}
		this.standaloneInput.val(dateText);
		var windowWidth, windowHeight;
		if (self.innerHeight) { // all except Explorer
			windowWidth = self.innerWidth;
			windowHeight = self.innerHeight;
		} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
			windowWidth = document.documentElement.clientWidth;
			windowHeight = document.documentElement.clientHeight;
		} else if (document.body) { // other Explorers
			windowWidth = document.body.clientWidth;
			windowHeight = document.body.clientHeight;
		} 
		this.pos = pos || ($.blockUI ? [0, 0] : [(windowWidth - 200) / 2,
			(windowHeight - 200) / 2]); // should use actual width/height
		this.prompt = prompt;
		this.customEvent = callback;
		this.standalone = true;
		this.calendarDiv.addClass('calendar_dialog');
		this.showFor(this.standaloneInput[0]);
		if ($.blockUI) $.blockUI(this.calendarDiv, { width: '200px' });
	},

	/* Pop-up the calendar for a given input field. */
	showFor: function(target) {
		var input = (target.nodeName && target.nodeName.toLowerCase() == 'input' ? target : this);
		if (input.nodeName.toLowerCase() != 'input') { // find from button/image trigger
			input = $('../input', input)[0];
		}
		if (popUpCal.lastInput == input) { // already here
			return;
		}
		for (var i = 0; i < popUpCal.disabledInputs.length; i++) {  // check not disabled
			if (popUpCal.disabledInputs[i] == input) {
				return;
			}
		}
		popUpCal.input = $(input);
		popUpCal.hideCalendar('');
		popUpCal.lastInput = input;
		popUpCal.setDateFromField();
		if (!popUpCal.pos) { // position below input
			popUpCal.pos = popUpCal.findPos(input);
			popUpCal.pos[1] += input.offsetHeight;
		}
		popUpCal.calendarDiv.css('position', (popUpCal.standalone && $.blockUI ? 'static' : 'absolute')).
			css('left', popUpCal.pos[0] + 'px').css('top', popUpCal.pos[1] + 'px');
		popUpCal.pos = null;
		$.extend(popUpCal, (popUpCal.fieldSettings ? popUpCal.fieldSettings(input) : {}));
		popUpCal.showCalendar();
	},

	/* Handle keystrokes. */
	doKeyDown: function(e) {
		if (popUpCal.popUpShowing) {
			switch (e.keyCode) {
				case 9:  popUpCal.hideCalendar(''); break; // hide on tab out
				case 13: popUpCal.selectDate(); break; // select the value on enter
				case 27: popUpCal.hideCalendar(popUpCal.speed); break; // hide on escape
				case 33: popUpCal.adjustDate(-1, (e.ctrlKey ? 'Y' : 'M')); break; // previous month/year on page up/+ ctrl
				case 34: popUpCal.adjustDate(+1, (e.ctrlKey ? 'Y' : 'M')); break; // next month/year on page down/+ ctrl
				case 35: if (e.ctrlKey) popUpCal.clearDate(); break; // clear on ctrl+end
				case 36: if (e.ctrlKey) popUpCal.gotoToday(); break; // current on ctrl+home
				case 37: if (e.ctrlKey) popUpCal.adjustDate(-1, 'D'); break; // -1 day on ctrl+left
				case 38: if (e.ctrlKey) popUpCal.adjustDate(-7, 'D'); break; // -1 week on ctrl+up
				case 39: if (e.ctrlKey) popUpCal.adjustDate(+1, 'D'); break; // +1 day on ctrl+right
				case 40: if (e.ctrlKey) popUpCal.adjustDate(+7, 'D'); break; // +1 week on ctrl+down
			}
		}
		else if (e.keyCode == 36 && e.ctrlKey) { // display the calendar on ctrl+home
			popUpCal.showFor(this);
		}
	},

	/* Filter entered characters. */
	doKeyPress: function(e) {
		var chr = String.fromCharCode(e.charCode == undefined ? e.keyCode : e.charCode);
		return (chr < ' ' || chr == popUpCal.dateFormat.charAt(3) || (chr >= '0' && chr <= '9')); // only allow numbers and separator
	},

	/* Attach the calendar to an input field. */
	connectCalendar: function(target) {
		var $input = $(target);
		$input.after('<span class="calendar_append">' + this.appendText + '</span>');
		if (this.autoPopUp == 'focus' || this.autoPopUp == 'both') { // pop-up calendar when in the marked fields
			$input.focus(this.showFor);
		}
		if (this.autoPopUp == 'button' || this.autoPopUp == 'both') { // pop-up calendar when button clicked
			$input.wrap('<span class="calendar_wrap"></span>').
				after(this.buttonImageOnly ? '<img class="calendar_trigger" src="' +
				this.buttonImage + '" alt="' + this.buttonText + '" title="' + this.buttonText + '"/>' :
				'<button type="button" class="calendar_trigger">' + (this.buttonImage != '' ?
				'<img src="' + this.buttonImage + '" alt="' + this.buttonText + '" title="' + this.buttonText + '"/>' :
				this.buttonText) + '</button>');
			$((this.buttonImageOnly ? 'img' : 'button') + '.calendar_trigger', $input.parent('span')).click(this.showFor);
		}
		$input.keydown(this.doKeyDown).keypress(this.doKeyPress);
	},

	/* Attach an inline calendar to a div. */
	displayInline: function(target) {
		$(target).append('<div id="calendar_inline_div"></div><div style="clear:both"></div>');
		popUpCal.selectedDay = new Date().getDate();
		popUpCal.selectedMonth = new Date().getMonth();
		popUpCal.selectedYear = new Date().getFullYear();
		popUpCal.adjustDate(); 
		popUpCal.showCalendar(); 
	},
	
	/* Enable the input field(s) for entry. */
	enableFor: function(inputs) {
		inputs = (inputs.jquery ? inputs : $(inputs));
		inputs.each(function() {
			this.disabled = false;
			$('../button.calendar_trigger', this).each(function() { this.disabled = false; });
			$('../img.calendar_trigger', this).css('opacity', '1.0');
			var $this = this;
			popUpCal.disabledInputs = $.map(popUpCal.disabledInputs,
				function(value) { return (value == $this ? null : value); }); // delete entry
		});
		return false;
	},

	/* Disable the input field(s) from entry. */
	disableFor: function(inputs) {
		inputs = (inputs.jquery ? inputs : $(inputs));
		inputs.each(function() {
			this.disabled = true;
			$('../button.calendar_trigger', this).each(function() { this.disabled = true; });
			$('../img.calendar_trigger', this).css('opacity', '0.5');
			var $this = this;
			popUpCal.disabledInputs = $.map(popUpCal.disabledInputs,
				function(value) { return (value == $this ? null : value); }); // delete entry
			popUpCal.disabledInputs[popUpCal.disabledInputs.length] = this;
		});
		return false;
	},

	/* Construct and display the calendar. */
	showCalendar: function() {
		this.popUpShowing = true;
		var today = new Date();
		today = new Date(today.getFullYear(), today.getMonth(), today.getDate()); // clear time
		// build the calendar HTML
		var controls = '<div id="calendar_control">' +
			'<a id="calendar_clear" onclick="popUpCal.clearDate();">' + this.clearText + '</a>' +
			'<a id="calendar_close" onclick="popUpCal.hideCalendar(popUpCal.speed);">' +
			this.closeText + '</a></div>';
		var html = (this.prompt ? '<div id="calendar_prompt">' + this.prompt + '</div>' : '') +
			(this.closeAtTop && !this.inline ? controls : '') + '<div id="calendar_links">' +
			(this.canAdjustMonth(-1) ? '<a id="calendar_prev" ' +
			'onclick="popUpCal.adjustDate(-1, \'M\');">' + this.prevText + '</a>' :
			(this.hideIfNoPrevNext ? '' : '<label id="calendar_prev">' + this.prevText + '</label>')) +
			(this.isInRange(today) ? '<a id="calendar_current" ' +
			'onclick="popUpCal.gotoToday();">' + this.currentText + '</a>' : '') +
			(this.canAdjustMonth(+1) ? '<a id="calendar_next" ' +
			'onclick="popUpCal.adjustDate(+1, \'M\');">' + this.nextText + '</a>' :
			(this.hideIfNoPrevNext ? '' : '<label id="calendar_next">' + this.nextText + '</label>')) +
			'</div><div id="calendar_header">';
		if (!this.changeMonth) {
			html += this.monthNames[this.selectedMonth] + '&nbsp;';
		}
		else {
			var inMinYear = (this.minDate && this.minDate.getFullYear() == this.selectedYear);
			var inMaxYear = (this.maxDate && this.maxDate.getFullYear() == this.selectedYear);
			html += '<select id="calendar_newMonth" onchange="popUpCal.selectMonthYear(this, \'M\');" ' +
				'onclick="popUpCal.clickMonthYear();">';
			for (var month = 0; month < 12; month++) {
				if ((!inMinYear || month >= this.minDate.getMonth()) &&
						(!inMaxYear || month <= this.maxDate.getMonth())) {
					html += '<option value="' + month + '"' +
						(month == this.selectedMonth ? ' selected="selected"' : '') +
						'>' + this.monthNames[month] + '</option>';
				}
			}
			html += '</select>';
		}
		if (!this.changeYear) {
			html += this.selectedYear;
		}
		else {
			// determine range of years to display
			var years = this.yearRange.split(':');
			var year = 0;
			var endYear = 0;
			if (years.length != 2) {
				year = this.selectedYear - 10;
				endYear = this.selectedYear + 10;
			}
			else if (years[0].charAt(0) == '+' || years[0].charAt(0) == '-') {
				year = this.selectedYear + parseInt(years[0]);
				endYear = this.selectedYear + parseInt(years[1]);
			}
			else {
				year = parseInt(years[0]);
				endYear = parseInt(years[1]);
			}
			year = (this.minDate ? Math.max(year, this.minDate.getFullYear()) : year);
			endYear = (this.maxDate ? Math.min(endYear, this.maxDate.getFullYear()) : endYear);
			html += '<select id="calendar_newYear" onchange="popUpCal.selectMonthYear(this, \'Y\');" ' +
				'onclick="popUpCal.clickMonthYear();">';
			for (; year <= endYear; year++) {
				html += '<option value="' + year + '"' +
					(year == this.selectedYear ? ' selected="selected"' : '') +
					'>' + year + '</option>';
			}
			html += '</select>';
		}
		html += '</div><table id="calendar" cellpadding="0" cellspacing="0"><thead>' +
			'<tr class="calendar_titleRow">';
		for (var dow = 0; dow < 7; dow++) {
			html += '<td>' + (this.changeFirstDay ? '<a onclick="popUpCal.changeWeekDay(this);">' : '') +
				this.dayNames[(dow + this.firstDay) % 7] + (this.changeFirstDay ? '</a>' : '') + '</td>';
		}
		html += '</tr></thead><tbody>';
		var daysInMonth = this.getDaysInMonth(this.selectedYear, this.selectedMonth);
		this.selectedDay = Math.min(this.selectedDay, daysInMonth);
		var leadDays = (this.getFirstDayOfMonth(this.selectedYear, this.selectedMonth) - this.firstDay + 7) % 7;
		var currentDate = new Date(this.currentYear, this.currentMonth, this.currentDay);
		var selectedDate = new Date(this.selectedYear, this.selectedMonth, this.selectedDay);
		var printDate = new Date(this.selectedYear, this.selectedMonth, 1 - leadDays);
		var numRows = Math.ceil((leadDays + daysInMonth) / 7); // calculate the number of rows to generate
		for (var row = 0; row < numRows; row++) { // create calendar rows
			html += '<tr class="calendar_daysRow">';
			for (var dow = 0; dow < 7; dow++) { // create calendar days
				var customSettings = (this.customDate ? this.customDate(printDate) : [true, '']);
				var otherMonth = (printDate.getMonth() != this.selectedMonth);
				var unselectable = otherMonth || !customSettings[0] ||
					(this.minDate && printDate < this.minDate) ||
					(this.maxDate && printDate > this.maxDate);
				html += '<td class="calendar_daysCell' +
					((dow + this.firstDay + 6) % 7 >= 5 ? ' calendar_weekEndCell' : '') + // highlight weekends
					(otherMonth ? ' calendar_otherMonth' : '') + // highlight days from other months
					(printDate.getTime() == selectedDate.getTime() ? ' calendar_daysCellOver' : '') + // highlight selected day
					(unselectable ? ' calendar_unselectable' : '') +  // highlight unselectable days
					(!otherMonth || this.showOtherMonths ? ' ' + customSettings[1] : '') + '"' + // highlight custom dates
					(printDate.getTime() == currentDate.getTime() ? ' id="calendar_currentDay"' : // highlight current day
					(printDate.getTime() == today.getTime() ? ' id="calendar_today"' : '')) + // highlight today (if different)
					(unselectable ? '' : ' onmouseover="$(this).addClass(\'calendar_daysCellOver\');"' +
					' onmouseout="$(this).removeClass(\'calendar_daysCellOver\');"' +
					' onclick="popUpCal.selectDay(this);")') + '>' + // actions
					(otherMonth ? (this.showOtherMonths ? printDate.getDate() : '&nbsp;') : // display for other months
					(unselectable ? printDate.getDate() : '<a>' + printDate.getDate() + '</a>')) + '</td>'; // display for this month
				printDate.setDate(printDate.getDate() + 1);
			}
			html += '</tr>';
		}
		html += '</tbody></table>' + (this.closeAtTop || this.inline ? '' : controls) +
			'<!--[if lte IE 6.5]><iframe src="javascript:false;" id="calendar_cover"></iframe><![endif]-->';
		// add calendar to element to calendar div
		if (!this.inline) {
			this.calendarDiv.empty().append(html).show(this.speed, this.coverSelects);
			if (this.speed == '') this.coverSelects();
			this.input[0].focus();
		}
		else {
			$('#calendar_inline_div').empty().append(html);
		}
	}, // end showCalendar

	/* Fix IE < 7 select problems. */
	coverSelects: function() {
		if ($.browser.msie) {
			$('#calendar_cover').css({width: popUpCal.calendarDiv[0].offsetWidth + 4,
				height: popUpCal.calendarDiv[0].offsetHeight + 4});
		}
	},
	
	/* Hide the calendar from view. */
	hideCalendar: function(speed) {
		if (this.popUpShowing) {
			this.calendarDiv.hide(speed, this.tidyStandalone);
			if (speed == '') this.tidyStandalone();
			this.popUpShowing = false;
			this.lastInput = null;
			this.prompt = null;
			if (this.standalone && $.blockUI) $.unblockUI();
			this.standalone = false;
		}
	},

	/* Tidy up after a dialog display. */
	tidyStandalone: function() {
		popUpCal.calendarDiv.removeClass('calendar_dialog');
		$('calendar_prompt').remove();
	},

	/* Action for current link. */
	gotoToday: function() {
		var date = new Date();
		popUpCal.selectedDay = date.getDate();
		popUpCal.selectedMonth = date.getMonth();
		popUpCal.selectedYear = date.getFullYear();
		popUpCal.adjustDate();
	},

	/* Action for selecting a new month/year. */
	selectMonthYear: function(select, period) {
		popUpCal.selectingMonthYear = false;
		popUpCal[period == 'M' ? 'selectedMonth' : 'selectedYear'] =
			select.options[select.selectedIndex].value - 0;
		popUpCal.adjustDate();
	},

	/* Restore input focus after not changing month/year. */
	clickMonthYear: function() {
		if (popUpCal.selectingMonthYear && !$.browser.msie) {
			popUpCal.input[0].focus();
		}
		popUpCal.selectingMonthYear = !popUpCal.selectingMonthYear;
	},

	/* Action for changing the first week day. */
	changeWeekDay: function(a) {
		for (var i = 0; i < 7; i++) {
			if (popUpCal.dayNames[i] == a.firstChild.nodeValue) {
				popUpCal.firstDay = i;
				break;
			}
		}
		popUpCal.showCalendar();
	},

	/* Action for selecting a day. */
	selectDay: function(td) {
		popUpCal.selectedDay = $("a", td).html();
		popUpCal.selectDate();
	},

	/* Update the input field with the selected date. */
	selectDate: function(value) {
		this.currentDay = this.selectedDay;
		this.currentMonth = this.selectedMonth;
		this.currentYear = this.selectedYear;
		this.date = (value != null ? value : this.formatDate(this.selectedDay, this.selectedMonth, this.selectedYear));
		if (this.customEvent) {
			this.customEvent();  // trigger it
		} 
		else {
			// set the input field with the date and fire the change event
			this.input.val(this.date);
			this.input.trigger('change');
		}
		if (!this.inline) {
			this.hideCalendar(this.speed);
		}
	},

	/* Erase the input field and hide the calendar. */
	clearDate: function() {
		this.selectDate('');
	},

	/* Close calendar if clicked elsewhere. */
	checkExternalClick: function(event) {
		if (popUpCal.popUpShowing && !(popUpCal.standalone && $.blockUI)) {
			var node = event.target;
			var cal = popUpCal.calendarDiv[0];
			while (node && node != cal && node.className != 'calendar_trigger') {
				node = node.parentNode;
			}
			if (!node) {
				popUpCal.hideCalendar('');
			}
		}
	},

	/* Set as customDate function to prevent selection of weekends. */
	noWeekends: function(date) {
		var day = date.getDay();
		return [(day > 0 && day < 6), ''];
	},

	/* Format and display the given date. */
	formatDate: function(day, month, year) {
		month++; // adjust javascript month
		var dateString = '';
		for (var i = 0; i < 3; i++) {
			dateString += this.dateFormat.charAt(3) +
				(this.dateFormat.charAt(i) == 'D' ? (day < 10 ? '0' : '') + day :
				(this.dateFormat.charAt(i) == 'M' ? (month < 10 ? '0' : '') + month :
				(this.dateFormat.charAt(i) == 'Y' ? year : '?')));
		}
		return dateString.substring(this.dateFormat.charAt(3) ? 1 : 0);
	},

	/* Parse existing date and initialise calendar. */
	setDateFromField: function() {
		var currentDate = this.input.val().split(this.dateFormat.charAt(3));
		if (currentDate.length == 3) {
			this.currentDay = parseInt(this.trimNumber(currentDate[this.dateFormat.indexOf('D')]));
			this.currentMonth = parseInt(this.trimNumber(currentDate[this.dateFormat.indexOf('M')])) - 1;
			this.currentYear = parseInt(this.trimNumber(currentDate[this.dateFormat.indexOf('Y')]));
		}
		else {
			this.currentDay = new Date().getDate();
			this.currentMonth = new Date().getMonth();
			this.currentYear = new Date().getFullYear();
		}
		this.selectedDay = this.currentDay;
		this.selectedMonth = this.currentMonth;
		this.selectedYear = this.currentYear;
		this.adjustDate(0, 'D', true);
	},

	/* Ensure numbers are not treated as octal. */
	trimNumber: function(value) {
		if (value == '')
			return '';
		while (value.charAt(0) == '0') {
			value = value.substring(1);
		}
		return value;
	},


	/* Adjust one of the date sub-fields. */
	adjustDate: function(offset, period, dontShow) {
		var date = new Date(this.selectedYear + (period == 'Y' ? offset : 0),
			this.selectedMonth + (period == 'M' ? offset : 0),
			this.selectedDay + (period == 'D' ? offset : 0));
		// ensure it is within the bounds set
		date = (this.minDate && date < this.minDate ? this.minDate : date);
		date = (this.maxDate && date > this.maxDate ? this.maxDate : date);
		this.selectedDay = date.getDate();
		this.selectedMonth = date.getMonth();
		this.selectedYear = date.getFullYear();
		if (!dontShow) {
			this.showCalendar();
		}
	},

	/* Find the number of days in a given month. */
	getDaysInMonth: function(year, month) {
		return 32 - new Date(year, month, 32).getDate();
	},

	/* Find the day of the week of the first of a month. */
	getFirstDayOfMonth: function(year, month) {
		return new Date(year, month, 1).getDay();
	},

	/* Determines if we should allow a "next/prev" month display change. */
	canAdjustMonth: function(offset) {
		var date = new Date(this.selectedYear, this.selectedMonth + offset, 1);
		if (offset < 0) {
			date.setDate(this.getDaysInMonth(date.getFullYear(), date.getMonth()));
		}
		return this.isInRange(date);
	},

	/* Is the given date in the accepted range? */
	isInRange: function(date) {
		return ((!this.minDate || date >= this.minDate) && (!this.maxDate || date <= this.maxDate));
	},

	/* Find an object's position on the screen. */
	findPos: function(obj) {
		var curleft = curtop = 0;
		if (obj.offsetParent) {
			curleft = obj.offsetLeft;
			curtop = obj.offsetTop;
			while (obj = obj.offsetParent) {
				var origcurleft = curleft;
				curleft += obj.offsetLeft;
				if (curleft < 0) {
					curleft = origcurleft;
				}
				curtop += obj.offsetTop;
			}
		}
		return [curleft,curtop];
	}
};

/* Attach the calendar to a jQuery selection. */
$.fn.calendar = function(settings) {
	// customise the calendar object
	$.extend(popUpCal, settings || {});
	// attach the calendar to each nominated input element
	return this.each(function() {
		if (this.nodeName.toLowerCase() == 'input') {
			popUpCal.connectCalendar(this);
		} 
		else if (this.nodeName.toLowerCase() == 'div') {
			popUpCal.displayInline(this);
		}
	});
};

/* Initialise the calendar. */
$(document).ready(function() {
   popUpCal.init();
});