/**
 * jCalendar 0.5
 *
 * Some code based on jQuery Date Picker (http://kelvinluck.com/assets/jquery/datePicker/)
 *
 * Copyright (c) 2007 Theodore Serbinski (http://tedserbinski.com)
 * Dual licensed under the MIT (MIT-LICENSE.txt)
 * and GPL (GPL-LICENSE.txt) licenses.
 */
jQuery.jcalendar = function() {
	var months = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
	var days = ['S', 'M', 'Tu', 'W', 'Th', 'F', 'S'];
	var fulldays = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
	var navLinks = {p:'Prev', n:'Next', t:'Current'};
	var navLinkTitles = {p:'Previous Month', n:'Next Month', t:'Back to list of recent entries'};
	var _firstDayOfWeek;
	var _firstDate;
	var _lastDate;
	var _selectedDate;

	var onRedraw, onHoverOver, onHoverOut, onClick;
	var datepopup, datepopupTextField;
	
	var _drawCalendar = function(dateIn, a, day, month, year) {
		var today = new Date();
		var d;
		if (dateIn == undefined) {
			// start from this month.
			d = new Date(today.getFullYear(), today.getMonth(), 1);
			year.val(today.getFullYear());
			month.val(today.getMonth()+1);
			day.val(today.getDate());
		}
		else {
			// start from the passed in date
			d = dateIn;
			d.setDate(1);
		}
		
		// check that date is within allowed limits
		if ((d.getMonth() < _firstDate.getMonth() && d.getFullYear() == _firstDate.getFullYear()) || d.getFullYear() < _firstDate.getFullYear()) {
			d = new Date(_firstDate.getFullYear(), _firstDate.getMonth(), 1);
		}
		else if ((d.getMonth() > _lastDate.getMonth() && d.getFullYear() == _lastDate.getFullYear()) || d.getFullYear() > _lastDate.getFullYear()) {
			d = new Date(_lastDate.getFullYear(), _lastDate.getMonth(), 1);
		}
		
		var firstMonth = true;
		var firstDate = _firstDate.getDate();
		
		// create prev and next links
		if (!(d.getMonth() == _firstDate.getMonth() && d.getFullYear() == _firstDate.getFullYear())) {
			// not in first display month so show a previous link
			firstMonth = false;
			var lastMonth = d.getMonth() == 0 ? new Date(d.getFullYear()-1, 11, 1) : new Date(d.getFullYear(), d.getMonth()-1, 1);
			var prevLink = jQuery('<a href="" title="'+ navLinkTitles.p +'" class="link-prev"><span class="go">&lsaquo;</span> '+ navLinks.p +'</a>').click(function() {
				jQuery.jcalendar.changeMonth(lastMonth, this, day, month, year);
				return false;
			});
		}
		
		var finalMonth = true;
		var lastDate = _lastDate.getDate();
		
		if (!(d.getMonth() == _lastDate.getMonth() && d.getFullYear() == _lastDate.getFullYear())) {
			// in the last month - no next link
			finalMonth = false;
			var nextMonth = new Date(d.getFullYear(), d.getMonth()+1, 1);
			var nextLink = jQuery('<a href="" title="'+ navLinkTitles.n +'" class="link-next">'+ navLinks.n +' <span class="go">&rsaquo;</span></a>').click(function() {
				jQuery.jcalendar.changeMonth(nextMonth, this, day, month, year);
				return false;
			});
		}
		
		var todayLink = jQuery('<a href="" title="'+ navLinkTitles.t +'" class="link-today">'+ navLinks.t +'</a>').click(function() {
			location.href=location.pathname;
			return false;
		});
		
		// update the year and month select boxes
		year.val(d.getFullYear());
		month.val(d.getMonth()+1);
		
		var headRow = jQuery("<tr></tr>");
		for (var i=_firstDayOfWeek; i<_firstDayOfWeek+7; i++) {
			var weekday = i%7;
			var wordday = days[weekday];
			var fullday = fulldays[weekday];
			headRow.append('<th scope="col" abbr="'+ wordday +'" title="'+ fullday +'" class="'+ (weekday == 0 || weekday == 6 ? 'weekend' : 'weekday') +'">'+ wordday +'</th>');
		}
		headRow = jQuery("<thead></thead>").append(headRow);
		
		var tBody = jQuery("<tbody></tbody>");
		var lastDay = (new Date(d.getFullYear(), d.getMonth()+1, 0)).getDate();
		var curDay = _firstDayOfWeek - d.getDay();
		if (curDay > 0) curDay -= 7;
		
		var todayDate = today.getDate();
		var thisMonth = d.getMonth() == today.getMonth() && d.getFullYear() == today.getFullYear();
		
		// render calendar
		do {
			var thisRow = jQuery("<tr></tr>");
			for (var i=0; i<7; i++) {
				var weekday = (_firstDayOfWeek + i) % 7;
				var atts = {'class':(weekday == 0 || weekday == 6 ? 'weekend ' : 'weekday ')};
			
				if (curDay < 0 || curDay >= lastDay) {
					dayStr = '&nbsp;';
				}
				else if (firstMonth && curDay < firstDate-1) {
					dayStr = curDay+1;
					atts['class'] += 'inactive';
				}
				else if (finalMonth && curDay > lastDate-1) {
					dayStr = curDay+1;
					atts['class'] += 'inactive';
				}
				else {
					d.setDate(curDay+1);
			
					// attach a click handler to every day to select it if clicked
					// we use the rel attribute to keep track of the day that is being clicked
					dayStr = jQuery('<a href="" rel="'+ d +'">'+ (curDay+1) +'</a>').click(function(e) {
						if (_selectedDate) {
							//_selectedDate.removeClass('selected');
						}
						_selectedDate = jQuery(this);
						//_selectedDate.addClass('selected');
						day.val(new Date(_selectedDate.attr('rel')).getDate());
						if(onClick) { onClick(this); }
						return false;
					}).hover(function() {
						if(onHoverOver) { onHoverOver(this); }
					}, function() {
						if(onHoverOut) { onHoverOut(this); }
					});
			
					// highlight the current selected day
					if (day.val() == d.getDate()) {
						_selectedDate = dayStr;
						//_selectedDate.addClass('selected');
					}
				}
			
				if (thisMonth && curDay+1 == todayDate) {
					atts['class'] += 'today';
				}
				thisRow.append(jQuery("<td></td>").attr(atts).append(dayStr));
				curDay++;
			}
			
			tBody.append(thisRow);
		} while (curDay < lastDay);
		
		var footerRow = jQuery('<tfoot><tr><td colspan="'+days.length+'"><div class="jcalendar-links"></div></td></tr></tfoot>');
		
		jQuery('div.jcalendar').html('<table cellpadding=0 cellspacing=0></table>');
		jQuery('div.jcalendar table').append(headRow, tBody, footerRow);
		jQuery('div.jcalendar div.jcalendar-links').append(nextLink, prevLink, todayLink);
		
		if(onRedraw) { onRedraw(d.getFullYear(), d.getMonth()); }
	}; // End of _drawCalendar

	return {
		show: function(a, day, month, year) {
 			_firstDate = a._startDate;
			_lastDate = a._endDate;
			_firstDayOfWeek = a._firstDayOfWeek;

			// pass in the selected form date if one was set
			var selected;
			if (year.val() > 0 && month.val() > 0 && day.val() > 0) {
			  selected = new Date(year.val(), month.val()-1, day.val());
			}
			else {	
			  selected = null;
			}
			_drawCalendar(selected, a, day, month, year);
		},
		changeMonth: function(d, e, day, month, year) {
			_drawCalendar(d, e, day, month, year);
		},
		/**
		* Function: setLanguageStrings
		*
		* Allows you to localise the calendar by passing in relevant text for the english strings in the plugin.
		*
		* Arguments:
		* days		-	Array, e.g. ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday']
		* months	-	Array, e.g. ['January', 'Febuary', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
		* navLinks	-	Object, e.g. {p:'Prev', n:'Next', c:'Close', b:'Choose date'}
		**/
		setLanguageStrings: function(aDays, aMonths, aNavLinks) {
			days = aDays;
			months = aMonths;
			navLinks = aNavLinks;
		},
		/**
		* Function: setDateWindow
		*
		* Used internally to set the start and end dates for a given date select
		*
		* Arguments:
		* i			-	The id of the INPUT element this date window is for
		* w			-	The date window - an object containing startDate and endDate properties
		*				e.g. {startDate:'24-11-1981', endDate:'25-12-2012}
		**/
		setDateWindow: function(i, w, year) {
			if (w == undefined) w = {};
			if (w.startDate == undefined) {
				// set the minimum browseable date equal to January of the min year in the select box
				// don't get the first option because that is an empty year

				// note we can't do this: year.find('option:eq(1)').val()
				// it doesn't work in 1.0 since find() is destructive
				// so we copy the object to a new var
				i._startDate = new Date($(year).find('option:eq(1)').val(), 0, 1);
			}
			else {
  			dateParts = w.startDate.split('-');
  			i._startDate = new Date(dateParts[2], Number(dateParts[1])-1, Number(dateParts[0]));
			}
			if (w.endDate == undefined) {
			  // set the maximum browseable date equal to December of the max year in the select box

			  // note we can't do this: year.find('option:last').val()
				// it doesn't work in 1.0 since find() is destructive
				// so we copy the object to a new var
				i._endDate = new Date($(year).find('option:last').val(), 11, 31);
			}
			else {
  			dateParts = w.endDate.split('-');
  			i._endDate = new Date(dateParts[2], Number(dateParts[1])-1, Number(dateParts[0]));
			}
			i._firstDayOfWeek = w.firstDayOfWeek == undefined ? 0 : w.firstDayOfWeek;
		},
		setupEvents: function(fnHoverOver, fnHoverOut, fnReDraw, fnOnClick) {
			onClick=fnOnClick;
			onRedraw=fnReDraw;
			onHoverOver=fnHoverOver;
			onHoverOut=fnHoverOut;
		}
	};
}();

jQuery.fn.jcalendar = function(a) {
	//jQuery.jcalendar.jcalXMLurl=arguments.length>1?arguments[1]:'';
	this.each(function() {
		
		var day = $(this).find('select.jcalendar-select-day');
		if(!day) { day = $(this).find('.jcalendar-select-day'); }
		
		var month = $(this).find('select.jcalendar-select-month');
		if(!month) { month = $(this).find('.jcalendar-select-month'); }
		
		var year = $(this).find('select.jcalendar-select-year');
		if(!year) { year = $(this).find('.jcalendar-select-year'); }
		
		$('div.jcalendar-selects').after('<div class="jcalendar"></div>');
		jQuery.jcalendar.setDateWindow(this, a, year);
		jQuery.jcalendar.show(this, day, month, year);
	
		day.change(function() {
			// only if a valid day is selected
			if (this.value > 0) {
				d = new Date(year.val(), month.val()-1, this.value);
				jQuery.jcalendar.changeMonth(d, a, day, month, year);
			}
		});
	
		month.change(function() {
			// only if a valid month is selected
			if (this.value > 0) {
				d = new Date(year.val(), this.value-1, 1);
				jQuery.jcalendar.changeMonth(d, a, day, month, year);
			}
		});
	
		year.change(function() {
			// only if a valid year is selected
			if (this.value > 0) {
				d = new Date(this.value, month.val()-1, 1);
				jQuery.jcalendar.changeMonth(d, a, day, month, year);
			}
		});
	});
	return this;
};