/* Thai initialisation for the jQuery UI date picker plugin. */
/* Written by pipo (pipo@sixhead.com). */
jQuery(function($){
	$.datepicker._generateMonthYearHeader=function(inst, drawMonth, drawYear, minDate, maxDate,
			selectedDate, secondary, showStatus, initStatus, monthNames) {
		minDate = (inst.rangeStart && minDate && selectedDate < minDate ? selectedDate : minDate);
		var showMonthAfterYear = this._get(inst, 'showMonthAfterYear');
		var html = '<div class="ui-datepicker-header">';
		var monthHtml = '';
		// month selection
		if (secondary || !this._get(inst, 'changeMonth'))
			monthHtml += monthNames[drawMonth] + '&#xa0;';
		else {
			var inMinYear = (minDate && minDate.getFullYear() == drawYear);
			var inMaxYear = (maxDate && maxDate.getFullYear() == drawYear);
			monthHtml += '<select class="ui-datepicker-new-month" ' +
				'onchange="jQuery.datepicker._selectMonthYear(\'#' + inst.id + '\', this, \'M\');" ' +
				'onclick="jQuery.datepicker._clickMonthYear(\'#' + inst.id + '\');"' +
				this._addStatus(showStatus, inst.id, this._get(inst, 'monthStatus'), initStatus) + '>';
			for (var month = 0; month < 12; month++) {
				if ((!inMinYear || month >= minDate.getMonth()) &&
						(!inMaxYear || month <= maxDate.getMonth()))
					monthHtml += '<option value="' + month + '"' +
						(month == drawMonth ? ' selected="selected"' : '') +
						'>' + monthNames[month] + '</option>';
			}
			monthHtml += '</select>';
		}
		if (!showMonthAfterYear)
			html += monthHtml;
		// year selection
		if (secondary || !this._get(inst, 'changeYear'))
			html += drawYear;
		else {
			// determine range of years to display
			var years = this._get(inst, 'yearRange').split(':');
			var year = 0;
			var endYear = 0;
			if (years.length != 2) {
				year = drawYear - 10;
				endYear = drawYear + 10;
			} else if (years[0].charAt(0) == '+' || years[0].charAt(0) == '-') {
				year = endYear = new Date().getFullYear();
				year += parseInt(years[0], 10);
				endYear += parseInt(years[1], 10);
			} else {
				year = parseInt(years[0], 10);
				endYear = parseInt(years[1], 10);
			}
			year = (minDate ? Math.max(year, minDate.getFullYear()) : year);
			endYear = (maxDate ? Math.min(endYear, maxDate.getFullYear()) : endYear);
			html += '<select class="ui-datepicker-new-year" ' +
				'onchange="jQuery.datepicker._selectMonthYear(\'#' + inst.id + '\', this, \'Y\');" ' +
				'onclick="jQuery.datepicker._clickMonthYear(\'#' + inst.id + '\');"' +
				this._addStatus(showStatus, inst.id, this._get(inst, 'yearStatus'), initStatus) + '>';
			for (; year <= endYear; year++) {
				html += '<option value="' + year + '"' +
					(year == drawYear ? ' selected="selected"' : '') +
					'>' + (year+543) + '</option>';
			}
			html += '</select>';
		}
		if (showMonthAfterYear)
			html += monthHtml;
		html += '</div>'; // Close datepicker_header
		return html;
	};

	$.datepicker.parseDate=function (format, value, settings) {
		if (format == null || value == null)
			throw 'Invalid arguments';
		value = (typeof value == 'object' ? value.toString() : value + '');
		if (value == '')
			return null;
		var shortYearCutoff = (settings ? settings.shortYearCutoff : null) || this._defaults.shortYearCutoff;
		var dayNamesShort = (settings ? settings.dayNamesShort : null) || this._defaults.dayNamesShort;
		var dayNames = (settings ? settings.dayNames : null) || this._defaults.dayNames;
		var monthNamesShort = (settings ? settings.monthNamesShort : null) || this._defaults.monthNamesShort;
		var monthNames = (settings ? settings.monthNames : null) || this._defaults.monthNames;
		var year = -1;
		var month = -1;
		var day = -1;
		var doy = -1;
		var literal = false;
		// Check whether a format character is doubled
		var lookAhead = function(match) {
			var matches = (iFormat + 1 < format.length && format.charAt(iFormat + 1) == match);
			if (matches)
				iFormat++;
			return matches;	
		};
		// Extract a number from the string value
		var getNumber = function(match) {
			lookAhead(match);
			var origSize = (match == '@' ? 14 : (match == 'y' ? 4 : (match == 'o' ? 3 : 2)));
			var size = origSize;
			var num = 0;
			while (size > 0 && iValue < value.length &&
					value.charAt(iValue) >= '0' && value.charAt(iValue) <= '9') {
				num = num * 10 + parseInt(value.charAt(iValue++),10);
				size--;
			}
			if (size == origSize)
				throw 'Missing number at position ' + iValue;
			return num;
		};
		// Extract a name from the string value and convert to an index
		var getName = function(match, shortNames, longNames) {
			var names = (lookAhead(match) ? longNames : shortNames);
			var size = 0;
			for (var j = 0; j < names.length; j++)
				size = Math.max(size, names[j].length);
			var name = '';
			var iInit = iValue;
			while (size > 0 && iValue < value.length) {
				name += value.charAt(iValue++);
				for (var i = 0; i < names.length; i++)
					if (name == names[i])
						return i + 1;
				size--;
			}
			throw 'Unknown name at position ' + iInit;
		};
		// Confirm that a literal character matches the string value
		var checkLiteral = function() {
			if (value.charAt(iValue) != format.charAt(iFormat))
				throw 'Unexpected literal at position ' + iValue;
			iValue++;
		};
		var iValue = 0;
		for (var iFormat = 0; iFormat < format.length; iFormat++) {
			if (literal)
				if (format.charAt(iFormat) == "'" && !lookAhead("'"))
					literal = false;
				else
					checkLiteral();
			else
				switch (format.charAt(iFormat)) {
					case 'd':
						day = getNumber('d');
						break;
					case 'D': 
						getName('D', dayNamesShort, dayNames);
						break;
					case 'o':
						doy = getNumber('o');
						break;
					case 'm': 
						month = getNumber('m');
						break;
					case 'M':
						month = getName('M', monthNamesShort, monthNames); 
						break;
					case 'y':
						year = getNumber('y');
						break;
					case '@':
						var date = new Date(getNumber('@'));
						year = date.getFullYear();
						month = date.getMonth() + 1;
						day = date.getDate();
						break;
					case "'":
						if (lookAhead("'"))
							checkLiteral();
						else
							literal = true;
						break;
					default:
						checkLiteral();
				}
		}
		year=year-543;
		if (year < 100)
			year += new Date().getFullYear() - new Date().getFullYear() % 100 +
				(year <= shortYearCutoff ? 0 : -100);
		if (doy > -1) {
			month = 1;
			day = doy;
			do {
				var dim = this._getDaysInMonth(year, month - 1);
				if (day <= dim)
					break;
				month++;
				day -= dim;
			} while (true);
		}
		var date = new Date(year, month - 1, day);
		if (date.getFullYear() != year || date.getMonth() + 1 != month || date.getDate() != day)
			throw 'Invalid date'; // E.g. 31/02/*
		return date;
	};

	$.datepicker.formatDate=function (format, date, settings) {
		if (!date)
			return '';
		var dayNamesShort = (settings ? settings.dayNamesShort : null) || this._defaults.dayNamesShort;
		var dayNames = (settings ? settings.dayNames : null) || this._defaults.dayNames;
		var monthNamesShort = (settings ? settings.monthNamesShort : null) || this._defaults.monthNamesShort;
		var monthNames = (settings ? settings.monthNames : null) || this._defaults.monthNames;
		// Check whether a format character is doubled
		var lookAhead = function(match) {
			var matches = (iFormat + 1 < format.length && format.charAt(iFormat + 1) == match);
			if (matches)
				iFormat++;
			return matches;	
		};
		// Format a number, with leading zero if necessary
		var formatNumber = function(match, value, len) {
			var num = '' + value;
			if (lookAhead(match))
				while (num.length < len)
					num = '0' + num;
			return num;
		};
		// Format a name, short or long as requested
		var formatName = function(match, value, shortNames, longNames) {
			return (lookAhead(match) ? longNames[value] : shortNames[value]);
		};
		var output = '';
		var literal = false;
		if (date)
			for (var iFormat = 0; iFormat < format.length; iFormat++) {
				if (literal)
					if (format.charAt(iFormat) == "'" && !lookAhead("'"))
						literal = false;
					else
						output += format.charAt(iFormat);
				else
					switch (format.charAt(iFormat)) {
						case 'd':
							output += formatNumber('d', date.getDate(), 2);
							break;
						case 'D': 
							output += formatName('D', date.getDay(), dayNamesShort, dayNames);
							break;
						case 'o':
							var doy = date.getDate();
							for (var m = date.getMonth() - 1; m >= 0; m--)
								doy += this._getDaysInMonth(date.getFullYear(), m);
							output += formatNumber('o', doy, 3);
							break;
						case 'm': 
							output += formatNumber('m', date.getMonth() + 1, 2);
							break;
						case 'M':
							output += formatName('M', date.getMonth(), monthNamesShort, monthNames); 
							break;
						case 'y':
							output += (lookAhead('y') ? date.getFullYear()+543 : 
								(date.getYear() % 100 < 10 ? '0' : '') + date.getYear() % 100);
							break;
						case '@':
							output += date.getTime(); 
							break;
						case "'":
							if (lookAhead("'"))
								output += "'";
							else
								literal = true;
							break;
						default:
							output += format.charAt(iFormat);
					}
			}
		return output;
	};

});