/**
 * 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 navLinks = {
		p : 'Prev',
		n : 'Next',
		t : 'Today'
	};
	var _firstDayOfWeek;
	var _firstDate;
	var _lastDate;
	var _selectedDate;

	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="" class="link-prev">&lsaquo; '
					+ 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="" class="link-next">' + navLinks.n
					+ ' &rsaquo;</a>').click(function() {
				jQuery.jcalendar.changeMonth(nextMonth, this, day, month, year);
				return false;
			});
		}

		var todayLink = jQuery('<a href="" class="link-today">' + navLinks.t
				+ '</a>').click(function() {
					day.val(today.getDate());
					jQuery.jcalendar.changeMonth(today, this, day, month, year);
					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];
			headRow.append('<th scope="col" abbr="' + wordday + '" title="'
					+ wordday + '" 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 = ' ';
				} 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());
								return false;
							});

					// 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);

		jQuery('div.jcalendar')
				.html('<table cellspacing="1"></table><div class="jcalendar-links"></div>');
		jQuery('div.jcalendar table').append(headRow, tBody);
		jQuery('div.jcalendar > div.jcalendar-links').append(prevLink,
				todayLink, nextLink);
	};

	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, 1);
			} 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;
		}
	};
}();

jQuery.fn.jcalendar = function(a) {
	this.each(function() {
				var day = $(this).find('select.jcalendar-select-day');
				var month = $(this).find('select.jcalendar-select-month');
				var year = $(this).find('select.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;
};