function SwatDateEntry(id, use_current_date)
{
	this.id = id;
	this.use_current_date = use_current_date;

	this.year = document.getElementById(id + '_year');
	this.month = document.getElementById(id + '_month');
	this.day = document.getElementById(id + '_day');

	this.calendar = null;
	this.time_entry = null;

	if (this.year)
		YAHOO.util.Event.addListener(this.year, 'change',
			this.handleYearChange, this, true);

	if (this.month)
		YAHOO.util.Event.addListener(this.month, 'change',
			this.handleMonthChange, this, true);

	if (this.day)
		YAHOO.util.Event.addListener(this.day, 'change',
			this.handleDayChange, this, true);

	this.lookup_table = {};
	this.reverse_lookup_table = {};
}

SwatDateEntry.prototype.setSensitivity = function(sensitivity)
{
	var elements = [];

	if (this.year)
		elements.push(this.year);

	if (this.month)
		elements.push(this.month);

	if (this.day)
		elements.push(this.day);

	for (var i = 0; i < elements.length; i++) {
		if (sensitivity) {
			elements[i].disabled = false;
			YAHOO.util.Dom.removeClass(elements[i], 'swat-insensitive');
		} else {
			elements[i].disabled = true;
			YAHOO.util.Dom.addClass(elements[i], 'swat-insensitive');
		}
	}

	if (this.calendar)
		this.calendar.setSensitivity(sensitivity);

	if (this.time_entry)
		this.time_entry.setSensitivity(sensitivity);
}

SwatDateEntry.prototype.handleYearChange = function()
{
	this.update('year');
}

SwatDateEntry.prototype.handleMonthChange = function()
{
	this.update('month');
}

SwatDateEntry.prototype.handleDayChange = function()
{
	this.update('day');
}

SwatDateEntry.prototype.addLookupTable = function(table_name, table)
{
	this.lookup_table[table_name] = table;
	this.reverse_lookup_table[table_name] = {};
	for (var key in table) {
		this.reverse_lookup_table[table_name][table[key]] = key;
	}
}

SwatDateEntry.prototype.lookup = function(table_name, key)
{
	return this.lookup_table[table_name][key];
}

SwatDateEntry.prototype.reverseLookup = function(table_name, key)
{
	return this.reverse_lookup_table[table_name][key];
}

SwatDateEntry.prototype.setCalendar = function(calendar)
{
	if (typeof SwatCalendar != 'undefined' &&
		calendar instanceof SwatCalendar) {
		this.calendar = calendar;
		calendar.date_entry = this;
	}
}

SwatDateEntry.prototype.setTimeEntry = function(time_entry)
{
	if (typeof SwatTimeEntry != 'undefined' &&
		time_entry instanceof SwatTimeEntry) {
		this.time_entry = time_entry;
		time_entry.date_entry = this;
	}
}

/**
 * @deprecated Use setTimeEntry() instead.
 */
SwatDateEntry.prototype.setSwatTime = function(swat_time)
{
	this.setTimeEntry(swat_time);
}

SwatDateEntry.prototype.reset = function(reset_time)
{
	if (this.year)
		this.year.selectedIndex = 0;

	if (this.month)
		this.month.selectedIndex = 0;

	if (this.day)
		this.day.selectedIndex = 0;

	if (this.time_entry && reset_time)
		this.time_entry.reset(false);
}

SwatDateEntry.prototype.setNow = function(set_time)
{
	var now = new Date();

	if (this.year && this.year.selectedIndex == 0) {
		var this_year = this.lookup('year', now.getFullYear());

		if (this_year)
			this.year.selectedIndex = this_year;
		else
			this.year.selectedIndex = 1;
	}

	if (this.month && this.month.selectedIndex == 0) {
		var this_month = this.lookup('month', now.getMonth() + 1);

		if (this_month)
			this.month.selectedIndex = this_month;
		else
			this.month.selectedIndex = 1;
	}

	if (this.day && this.day.selectedIndex == 0) {
		var this_day = this.lookup('day', now.getDate());
		if (this_day)
			this.day.selectedIndex = this_day;
		else
			this.day.selectedIndex = 1;
	}

	if (this.time_entry && set_time)
		this.time_entry.setNow(false);
}

SwatDateEntry.prototype.setDefault = function(set_time)
{
	var now = new Date();

	if (this.year && this.year.selectedIndex == 0) {
		/*
		 * Default to this year if it exists in the options. This behaviour
		 * is somewhat different from the others, but just makes common sense.
		 */
		var this_year = this.lookup('year', now.getFullYear());

		if (this_year)
			this.year.selectedIndex = this_year;
		else
			this.year.selectedIndex = 1;
	}

	if (this.month && this.month.selectedIndex == 0)
		this.month.selectedIndex = 1;

	if (this.day && this.day.selectedIndex == 0)
		this.day.selectedIndex = 1;

	if (this.time_entry && set_time)
		this.time_entry.setDefault(false);
}

SwatDateEntry.prototype.update = function(field)
{
	// month is required for this, so stop if it doesn't exist
	if (!this.month)
		return;

	var index = null;
	switch (field) {
	case 'day':
		index = this.day.selectedIndex;
		break;
	case 'month':
		index = this.month.selectedIndex;
		break;
	case 'year':
		index = this.year.selectedIndex;
		break;
	}

	// don't do anything if we select the blank option
	if (index != 0) {
		var now = new Date();
		var this_month = now.getMonth() + 1;

		if (this.getMonth() == this_month && this.use_current_date)
			this.setNow(true);
		else
			this.setDefault(true);
	}
}

SwatDateEntry.prototype.getDay = function()
{
	var day = null;

	if (this.day)
		day = this.reverseLookup('day', this.day.selectedIndex);

	return day;
}

SwatDateEntry.prototype.getMonth = function()
{
	var month = null;

	if (this.month)
		month = this.reverseLookup('month', this.month.selectedIndex);

	return month;
}

SwatDateEntry.prototype.getYear = function()
{
	var year = null;

	if (this.year)
		year = this.reverseLookup('year', this.year.selectedIndex);

	return year;
}

SwatDateEntry.prototype.setDay = function(day)
{
	if (this.day) {
		var this_day = this.lookup('day', day);

		if (this_day)
			this.day.selectedIndex = this_day;
		else
			this.day.selectedIndex = 0;
	}
}

SwatDateEntry.prototype.setMonth = function(month)
{
	if (this.month) {
		var this_month = this.lookup('month', month);

		if (this_month)
			this.month.selectedIndex = this_month;
		else
			this.month.selectedIndex = 0;
	}
}

SwatDateEntry.prototype.setYear = function(year)
{
	if (this.year) {
		var this_year = this.lookup('year', year);

		if (this_year)
			this.year.selectedIndex = this_year;
		else
			this.year.selectedIndex = 0;
	}
}