/**
* Filename.......: calendar.js
* Project........: Popup Calendar
* Last Modified..: $Date$
* CVS Revision...: $Revision$
* Copyright......: 2001, 2002 Richard Heyes
*/

/**
* Global variables
*/
	dynCalendar_layers          = new Array();
	dynCalendar_mouseoverStatus = false;
	dynCalendar_mouseX          = 0;
	dynCalendar_mouseY          = 0;

/**
* The calendar constructor
*
* @access public
* @param string objName      Name of the object that you create
* @param string objField     The field to be updated with the date
* @param string OPTIONAL     Optional layer name
* @param string OPTIONAL     Optional images path
*/
	function dynCalendar(objName, objField)
	{
		/**
        * Properties
        */
		// Todays date
		this.today          = new Date();
		this.date           = this.today.getDate();
		this.month          = this.today.getMonth();
		this.year           = this.today.getFullYear();

		this.objName        = objName;
		this.callbackFunc   = this.objName + '.calendarCallback';
		this.field          = objField;
		this.imagesPath     = arguments[2] ? arguments[2] : '/includes/scripts/calendar/images/';
		this.layerID        = arguments[3] ? arguments[3] : 'dynCalendar_layer_' + dynCalendar_layers.length;

		this.offsetX        = 5;
		this.offsetY        = 5;

		this.useMonthCombo  = false;
		this.useYearCombo   = false;
		this.yearComboRange = 5;

		this.currentMonth   = this.month;
		this.currentYear    = this.year;

		/**
        * Public Methods
        */
		this.hideCalendar      = dynCalendar_hideCalendar;
		this.show              = dynCalendar_show;
		this.writeHTML         = dynCalendar_writeHTML;
		this.setDate           = dynCalendar_setDate;
		this.calendarCallback  = dynCalendar_calendarCallback;

		// Accessor methods
		this.setOffset         = dynCalendar_setOffset;
		this.setOffsetX        = dynCalendar_setOffsetX;
		this.setOffsetY        = dynCalendar_setOffsetY;
		this.setImagesPath     = dynCalendar_setImagesPath;
		this.setMonthCombo     = dynCalendar_setMonthCombo;
		this.setYearCombo      = dynCalendar_setYearCombo;
		this.setCurrentMonth   = dynCalendar_setCurrentMonth;
		this.setCurrentYear    = dynCalendar_setCurrentYear;
		this.setYearComboRange = dynCalendar_setYearComboRange;

		/**
        * Private methods
        */
		// Layer manipulation
		this._getLayer         = dynCalendar_getLayer;
		this._hideLayer        = dynCalendar_hideLayer;
		this._showLayer        = dynCalendar_showLayer;
		this._setLayerPosition = dynCalendar_setLayerPosition;
		this._setHTML          = dynCalendar_setHTML;

		// Miscellaneous
		this._getDaysInMonth   = dynCalendar_getDaysInMonth;
		this._mouseover        = dynCalendar_mouseover;

		/**
        * Constructor type code
        */
		dynCalendar_layers[dynCalendar_layers.length] = this;
		//this.setDate(this.field.value);
		this.writeHTML();
	}

/**
* Shows the calendar, or updates the layer if
* already visible.
*
* @access public
* @param integer month Optional month number (0-11)
* @param integer year  Optional year (YYYY format)
*/
	function dynCalendar_show()
	{
		this.setDate(this.field.value);

		// Variable declarations to prevent globalisation
		var month, year, monthnames, numdays, thisMonth, firstOfMonth;
		var ret, row, i, cssClass, linkHTML, previousMonth, previousYear;
		var nextMonth, nextYear, prevImgHTML, prevLinkHTML, nextImgHTML, nextLinkHTML;
		var monthComboOptions, monthCombo, yearComboOptions, yearCombo, html;
		
		this.currentMonth = month = arguments[0] != null ? arguments[0] : this.currentMonth;
		this.currentYear  = year  = arguments[1] != null ? arguments[1] : this.currentYear;

		monthnames = new Array('January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December');
		numdays    = this._getDaysInMonth(month, year);

		thisMonth    = new Date(year, month, 1);
		firstOfMonth = thisMonth.getDay();

		// First few blanks up to first day
		ret = new Array(new Array());
		for(i=0; i<firstOfMonth; i++){
			ret[0][ret[0].length] = '<td>&nbsp;</td>';
		}

		// Main body of calendar
		row = 0;
		i   = 1;
		while(i <= numdays){
			if(ret[row].length == 7){
				ret[++row] = new Array();
			}

			/**
            * Generate this cells' HTML
            */
			cssClass = (i == this.date && month == this.month && year == this.year) ? 'dynCalendar_today' : 'dynCalendar_day';
			linkHTML = sprintf('<a href="javascript: %s(%s, %s, %s); %s._hideLayer()">%s</a>',
			                   this.callbackFunc,
							   i,
							   Number(month) + 1,
							   year,
							   this.objName,
							   i++);
//			linkHTML = sprintf('<a href="javascript: %s._hideLayer()">%s</a>',this.objName,i++);

			ret[row][ret[row].length] = sprintf('<td align="center" class="%s">%s</td>', cssClass, linkHTML);
		}

		// Format the HTML
		for(i=0; i<ret.length; i++){
			ret[i] = ret[i].join('\n') + '\n';
		}

		previousYear  = thisMonth.getFullYear();
		previousMonth = thisMonth.getMonth() - 1;
		if(previousMonth < 0){
			previousMonth = 11;
			previousYear--;
		}
		
		nextYear  = thisMonth.getFullYear();
		nextMonth = thisMonth.getMonth() + 1;
		if(nextMonth > 11){
			nextMonth = 0;
			nextYear++;
		}

		prevImgHTML  = sprintf('<img src="%s/prev.gif" alt="<<" border="0" />', this.imagesPath);
		prevLinkHTML = sprintf('<a href="javascript: %s.show(%s, %s)">%s</a>',  this.objName, previousMonth, previousYear, prevImgHTML);
		nextImgHTML  = sprintf('<img src="%s/next.gif" alt="<<" border="0" />', this.imagesPath);
		nextLinkHTML = sprintf('<a href="javascript: %s.show(%s, %s)">%s</a>',  this.objName, nextMonth, nextYear, nextImgHTML);

		/**
        * Build month combo
        */
		if (this.useMonthCombo) {
			monthComboOptions = '';
			for (i=0; i<12; i++) {
				selected = (i == thisMonth.getMonth() ? 'selected="selected"' : '');
				monthComboOptions += sprintf('<option value="%s" %s>%s</option>', i, selected, monthnames[i]);
			}
			monthCombo = sprintf('<select name="months" onchange="%s.show(this.options[this.selectedIndex].value, %s.currentYear)">%s</select>', this.objName, this.objName, monthComboOptions);
		} else {
			monthCombo = monthnames[thisMonth.getMonth()];
		}
		
		/**
        * Build year combo
        */
		if (this.useYearCombo) {
			yearComboOptions = '';
			for (i = thisMonth.getFullYear() - this.yearComboRange; i <= (thisMonth.getFullYear() + this.yearComboRange); i++) {
				selected = (i == thisMonth.getFullYear() ? 'selected="selected"' : '');
				yearComboOptions += sprintf('<option value="%s" %s>%s</option>', i, selected, i);
			}
			yearCombo = sprintf('<select style="border: 1px groove" name="years" onchange="%s.show(%s.currentMonth, this.options[this.selectedIndex].value)">%s</select>', this.objName, this.objName, yearComboOptions);
		} else {
			yearCombo = thisMonth.getFullYear();
		}

		html = '<table border="0" cellpadding="2" cellspacing="0" bgcolor="#eeeeee">';
		html += sprintf('<tr><td class="dynCalendar_header">%s</td><td colspan="5" align="center" class="dynCalendar_header">%s %s</td><td align="right" class="dynCalendar_header">%s</td></tr>', prevLinkHTML, monthCombo, yearCombo, nextLinkHTML);
		html += '<tr>';
		html += '<td class="dynCalendar_dayname" width="18">S</td>';
		html += '<td class="dynCalendar_dayname" width="18">M</td>';
		html += '<td class="dynCalendar_dayname" width="18">T</td>';
		html += '<td class="dynCalendar_dayname" width="18">W</td>';
		html += '<td class="dynCalendar_dayname" width="18">H</td>';
		html += '<td class="dynCalendar_dayname" width="18">F</td>';
		html += '<td class="dynCalendar_dayname" width="18">S</td></tr>';
		html += '<tr>' + ret.join('</tr>\n<tr>') + '</tr>';
		html += '</table>';

		this._setHTML(html);
		if (!arguments[0] && !arguments[1]) {
			this._showLayer();
			this._setLayerPosition();
		}
	}

/**
* Writes HTML to document for layer
*
* @access public
*/
	function dynCalendar_writeHTML()
	{
		if (is_ie5up || is_nav6up || is_gecko) {
			document.write(sprintf('<a href="javascript: %s.show()"><img src="%sdynCalendar.gif" border="0" width="16" height="16" /></a>', this.objName, this.imagesPath));
			document.write(sprintf('<div class="dynCalendar" id="%s" onmouseover="%s._mouseover(true)" onmouseout="%s._mouseover(false)"></div>', this.layerID, this.objName, this.objName));
		}
	}

/**
* Sets the offset to the mouse position
* that the calendar appears at.
*
* @access public
* @param integer Xoffset Number of pixels for vertical
*                        offset from mouse position
* @param integer Yoffset Number of pixels for horizontal
*                        offset from mouse position
*/
	function dynCalendar_setOffset(Xoffset, Yoffset)
	{
		this.setOffsetX(Xoffset);
		this.setOffsetY(Yoffset);
	}

/**
* Sets the X offset to the mouse position
* that the calendar appears at.
*
* @access public
* @param integer Xoffset Number of pixels for horizontal
*                        offset from mouse position
*/
	function dynCalendar_setOffsetX(Xoffset)
	{
		this.offsetX = Xoffset;
	}

/**
* Sets the Y offset to the mouse position
* that the calendar appears at.
*
* @access public
* @param integer Yoffset Number of pixels for vertical
*                        offset from mouse position
*/
	function dynCalendar_setOffsetY(Yoffset)
	{
		this.offsetY = Yoffset;
	}
	
/**
* Sets the images path
*
* @access public
* @param string path Path to use for images
*/
	function dynCalendar_setImagesPath(path)
	{
		this.imagesPath = path;
	}

/**
* Turns on/off the month dropdown
*
* @access public
* @param boolean useMonthCombo Whether to use month dropdown or not
*/
	function dynCalendar_setMonthCombo(useMonthCombo)
	{
		this.useMonthCombo = useMonthCombo;
	}

/**
* Turns on/off the year dropdown
*
* @access public
* @param boolean useYearCombo Whether to use year dropdown or not
*/
	function dynCalendar_setYearCombo(useYearCombo)
	{
		this.useYearCombo = useYearCombo;
	}

/**
* Sets the current month being displayed
*
* @access public
* @param boolean month The month to set the current month to
*/
	function dynCalendar_setCurrentMonth(month)
	{
		this.currentMonth = month;
	}

/**
* Sets the current month being displayed
*
* @access public
* @param boolean year The year to set the current year to
*/
	function dynCalendar_setCurrentYear(year)
	{
		this.currentYear = year;
	}

/**
* Sets the range of the year combo. Displays this number of
* years either side of the year being displayed.
*
* @access public
* @param integer range The range to set
*/
	function dynCalendar_setYearComboRange(range)
	{
		this.yearComboRange = range;
	}

/**
* Returns the layer object
*
* @access private
*/
	function dynCalendar_getLayer()
	{
		var layerID = this.layerID;

		if (document.getElementById(layerID)) {


			return document.getElementById(layerID);

		} else if (document.all(layerID)) {
			return document.all(layerID);
		}
	}

/**
* Hides the calendar layer
*
* @access private
*/
	function dynCalendar_hideLayer()
	{
		this._getLayer().style.visibility = 'hidden';
	}

/**
* Shows the calendar layer
*
* @access private
*/
	function dynCalendar_showLayer()
	{
		this._getLayer().style.visibility = 'visible';
	}

/**
* Sets the layers position
*
* @access private
*/
	function dynCalendar_setLayerPosition()
	{
		this._getLayer().style.top  = (dynCalendar_mouseY + this.offsetY) + 'px';
		this._getLayer().style.left = (dynCalendar_mouseX + this.offsetX) + 'px';
	}

/**
* Sets the innerHTML attribute of the layer
*
* @access private
*/
	function dynCalendar_setHTML(html)
	{
		this._getLayer().innerHTML = html;
	}

/**
* Returns number of days in the supplied month
*
* @access private
* @param integer month The month to get number of days in
* @param integer year  The year of the month in question
*/
	function dynCalendar_getDaysInMonth(month, year)
	{
		monthdays = [30, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
		if (month != 1) {
			return monthdays[month];
		} else {
			return ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0 ? 29 : 28);
		}
	}

/**
* onMouse(Over|Out) event handler
*
* @access private
* @param boolean status Whether the mouse is over the
*                       calendar or not
*/
	function dynCalendar_mouseover(status)
	{
		dynCalendar_mouseoverStatus = status;
		return true;
	}

/**
* onMouseMove event handler
*/
	dynCalendar_oldOnmousemove = document.onmousemove ? document.onmousemove : new Function;

	document.onmousemove = function ()
	{
		if (arguments[0]) {
			dynCalendar_mouseX = arguments[0].pageX;
			dynCalendar_mouseY = arguments[0].pageY;
		} else {
			dynCalendar_mouseX = window.event.x// + document.body.scrollLeft;
			dynCalendar_mouseY = window.event.y// + document.body.scrollTop;
			arguments[0] = null;
		}

		dynCalendar_oldOnmousemove(arguments[0]);
	}

/**
* Callbacks for document.onclick
*/
	dynCalendar_oldOnclick = document.onclick ? document.onclick : new Function;


	function dynCalendar_hideCalendar()	 {
		if(!dynCalendar_mouseoverStatus){
			for(i=0; i<dynCalendar_layers.length; ++i){
				dynCalendar_layers[i]._hideLayer();
			}
		}

		dynCalendar_oldOnclick(arguments[0] ? arguments[0] : null);
	}

/*	document.onclick = function ()
	{
		if(!dynCalendar_mouseoverStatus){
			for(i=0; i<dynCalendar_layers.length; ++i){
				dynCalendar_layers[i]._hideLayer();
			}
		}

		dynCalendar_oldOnclick(arguments[0] ? arguments[0] : null);
	}*/

/**
* Javascript mini implementation of sprintf()
*/
	function sprintf(strInput)
	{
		var strOutput  = '';
		var currentArg = 1;
	
		for (var i=0; i<strInput.length; i++) {
			if (strInput.charAt(i) == '%' && i != (strInput.length - 1) && typeof(arguments[currentArg]) != 'undefined') {
				switch (strInput.charAt(++i)) {
					case 's':
						strOutput += arguments[currentArg];
						break;
					case '%':
						strOutput += '%';
						break;
				}
				currentArg++;
			} else {
				strOutput += strInput.charAt(i);
			}
		}
	
		return strOutput;
	}

	function dynCalendar_setDate(strDate)
	{
		if (dynCalendar_checkValidDate(strDate)) {
			strDate = strDate.replace("-","/");
			var dateArray = strDate.split("/");
			this.today = new Date(dateArray[2],parseInt(dateArray[0])-1,dateArray[1]);
		}
		else
			this.today = new Date;
		this.date           = this.today.getDate();
		this.month          = this.today.getMonth();
		this.year           = this.today.getFullYear();
		this.currentMonth   = this.month;
		this.currentYear    = this.year;
		
	}

function dynCalendar_checkValidDate(dateStr) {
    // dateStr must be of format month day year with either slashes
    // or dashes separating the parts. Some minor changes would have
    // to be made to use day month year or another format.
    // This function returns True if the date is valid.
    var slash1 = dateStr.indexOf("/");
    if (slash1 == -1) { slash1 = dateStr.indexOf("-"); }
    // if no slashes or dashes, invalid date
    if (slash1 == -1) { return false; }
    var dateMonth = dateStr.substring(0, slash1)
    var dateMonthAndYear = dateStr.substring(slash1+1, dateStr.length);
    var slash2 = dateMonthAndYear.indexOf("/");
    if (slash2 == -1) { slash2 = dateMonthAndYear.indexOf("-"); }
    // if not a second slash or dash, invalid date
    if (slash2 == -1) { return false; }
    var dateDay = dateMonthAndYear.substring(0, slash2);
    var dateYear = dateMonthAndYear.substring(slash2+1, dateMonthAndYear.length);
    if ( (dateMonth == "") || (dateDay == "") || (dateYear == "") ) { return false; }
    // if any non-digits in the month, invalid date
    for (var x=0; x < dateMonth.length; x++) {
        var digit = dateMonth.substring(x, x+1);
        if ((digit < "0") || (digit > "9")) { return false; }
    }
    // convert the text month to a number
    var numMonth = 0;
    for (var x=0; x < dateMonth.length; x++) {
        digit = dateMonth.substring(x, x+1);
        numMonth *= 10;
        numMonth += parseInt(digit);
    }
    if ((numMonth <= 0) || (numMonth > 12)) { return false; }
    // if any non-digits in the day, invalid date
    for (var x=0; x < dateDay.length; x++) {
        digit = dateDay.substring(x, x+1);
        if ((digit < "0") || (digit > "9")) { return false; }
    }
    // convert the text day to a number
    var numDay = 0;
    for (var x=0; x < dateDay.length; x++) {
        digit = dateDay.substring(x, x+1);
        numDay *= 10;
        numDay += parseInt(digit);
    }
    if ((numDay <= 0) || (numDay > 31)) { return false; }
    // February can't be greater than 29 (leap year calculation comes later)
    if ((numMonth == 2) && (numDay > 29)) { return false; }
    // check for months with only 30 days
    if ((numMonth == 4) || (numMonth == 6) || (numMonth == 9) || (numMonth == 11)) { 
        if (numDay > 30) { return false; } 
    }
    // if any non-digits in the year, invalid date
    for (var x=0; x < dateYear.length; x++) {
        digit = dateYear.substring(x, x+1);
        if ((digit < "0") || (digit > "9")) { return false; }
    }
    // convert the text year to a number
    var numYear = 0;
    for (var x=0; x < dateYear.length; x++) {
        digit = dateYear.substring(x, x+1);
        numYear *= 10;
        numYear += parseInt(digit);
    }
    // Year must be a 2-digit year or a 4-digit year
    if ( (dateYear.length != 2) && (dateYear.length != 4) ) { return false; }
    // if 2-digit year, use 50 as a pivot date
    if ( (numYear < 50) && (dateYear.length == 2) ) { numYear += 2000; }
    if ( (numYear < 100) && (dateYear.length == 2) ) { numYear += 1900; }
    if ((numYear <= 0) || (numYear > 9999)) { return false; }
    // check for leap year if the month and day is Feb 29
    if ((numMonth == 2) && (numDay == 29)) {
        var div4 = numYear % 4;
        var div100 = numYear % 100;
        var div400 = numYear % 400;
        // if not divisible by 4, then not a leap year so Feb 29 is invalid
        if (div4 != 0) { return false; }
        // at this point, year is divisible by 4. So if year is divisible by
        // 100 and not 400, then it's not a leap year so Feb 29 is invalid
        if ((div100 == 0) && (div400 != 0)) { return false; }
    }
    // date is valid
    return true;
}

function dynCalendar_calendarCallback(date, month, year)
	{
			this.field.value = month + '/' + date + '/' + year;
	}