/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+                        Calendar JS/DOM  v3.0                         +
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Copyright (C) 2005-07 by Michael Loesler, http://derletztekick.de    +
+                                                                      +
+                                                                      +
+ This program is free software; you can redistribute it and/or modify +
+ it under the terms of the GNU General Public License as published by +
+ the Free Software Foundation; either version 2 of the License, or    +
+ (at your option) any later version.                                  +
+                                                                      +
+ This program is distributed in the hope that it will be useful,      +
+ but WITHOUT ANY WARRANTY; without even the implied warranty of       +
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        +
+ GNU General Public License for more details.                         +
+                                                                      +
+ You should have received a copy of the GNU General Public License    +
+ along with this program; if not, write to the                        +
+ Free Software Foundation, Inc.,                                      +
+ 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.            +
+                                                                      +
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/

	var CalendarJS = {
		now : new Date(),
		dayname : ["Mo","Di","Mi","Do","Fr","Sa","So"],
		monthname : ["Januar","Februar","März","April","Mai","Juni","Juli","August","September","Oktober","November","Dezember"],
		dayspermonth : [31,28,31,30,31,30,31,31,30,31,30,31],
		tooltip : ["vorheriger Monat","nächster Monat"],
		monthCell : document.createElement("th"),
		tableHead : null,
		parEl : null,
		init : function( id ) {
			this.date = this.now.getDate();
			this.month = this.mm = this.now.getMonth();
			this.year = this.yy = this.now.getFullYear();
			this.monthCell.colSpan = 5;
			this.monthCell.appendChild(document.createTextNode( this.monthname[this.mm]+" "+this.yy ));
			this.tableHead = this.createTableHead();
			this.parEl = document.getElementById( id );
			this.show();
		},
		
		removeElements : function( Obj ) {
			for (var i=0; i<Obj.childNodes.length; i++)
				Obj.removeChild(Obj.childNodes[i]);
			return Obj;
		},
			
		show : function() {
			this.parEl = this.removeElements( this.parEl );
			this.monthCell.firstChild.replaceData(0, this.monthCell.firstChild.nodeValue.length, this.monthname[this.mm]+" "+this.yy);
			var table = document.createElement("table");
			table.appendChild( this.createTableBody() );
			table.appendChild( this.tableHead );
			this.parEl.appendChild( table );
		},
				
		createTableHead : function() {
			var thead = document.createElement("thead");
			var tr = document.createElement("tr");
			var th = document.createElement("th");
			th.appendChild(document.createTextNode( "\u00AB" ));
			th.Instanz = this;
			th.onclick = function() { this.Instanz.switchMonth("prev"); };
			th.title = this.tooltip[0];
			try { th.style.cursor = "pointer"; } catch(e){ th.style.cursor = "hand"; }
			tr.appendChild( th );
			tr.appendChild( this.monthCell );			
			th = document.createElement("th");
			th.appendChild(document.createTextNode( "\u00BB" ));
			th.Instanz = this;
			th.onclick = function() { this.Instanz.switchMonth("next"); };
			th.title = this.tooltip[1];
			try { th.style.cursor = "pointer"; } catch(e){ th.style.cursor = "hand"; }
			tr.appendChild( th );
			thead.appendChild( tr );
			tr = document.createElement('tr');
			for (var i=0; i<this.dayname.length; i++)
				tr.appendChild( this.getCell("th", this.dayname[i], "weekday" ) );
			thead.appendChild( tr );
			return thead;
		},
		
		createTableBody : function() {
			var sevendaysaweek = 0;
			var begin = new Date(this.yy, this.mm, 1);
			var firstday = begin.getDay()-1;
			if (firstday < 0)
				firstday = 6;
			if ((this.yy%4==0) && ((this.yy%100!=0) || (this.yy%400==0)))
				this.dayspermonth[1] = 29;
			
			var tbody = document.createElement("tbody");
			var tr = document.createElement('tr');
			
			for (var i=0; i<firstday; i++, sevendaysaweek++)
				tr.appendChild( this.getCell( "td", " ", null ) );

			for (var i=1; i<=this.dayspermonth[this.mm]; i++, sevendaysaweek++){
				if (this.dayname.length == sevendaysaweek){
					tbody.appendChild( tr );
					tr = document.createElement('tr');
					sevendaysaweek = 0;
				}
				if (i==this.date && this.mm==this.month && this.yy==this.year && (sevendaysaweek == 5 || sevendaysaweek == 6))
					tr.appendChild( this.getCell( "td", i, "today weekend" ) );
				else if (i==this.date && this.mm==this.month && this.yy==this.year)
					tr.appendChild( this.getCell( "td", i, "today" ) );
				else if (sevendaysaweek == 5 || sevendaysaweek == 6)
					tr.appendChild( this.getCell( "td", i, "weekend" ) );
				else
					tr.appendChild( this.getCell( "td", i, null ) );
			}
	
			for (var i=sevendaysaweek; i<this.dayname.length; i++)
				tr.appendChild( this.getCell( "td", " ", null  ) );
	
			tbody.appendChild( tr );
			return tbody;
			
		},
		
		getCell : function(tag, str, cssClass) {
			var El = document.createElement( tag );
			El.appendChild(document.createTextNode( str ));
			if (cssClass != null)
				El.className = cssClass;
			return El;
		},
		
		switchMonth : function( s ){
			switch (s) {
				case "prev": 
					this.yy = (this.mm == 0)?this.yy-1:this.yy;
					this.mm = (this.mm == 0)?11:this.mm-1;
				break;
				
				case "next":
					this.yy = (this.mm == 11)?this.yy+1:this.yy;
					this.mm = (this.mm == 11)?0:this.mm+1;
				break;
			}
			this.show();
		}
	}
	
	var DOMContentLoaded = false;
	function addContentLoadListener (func) {
		if (document.addEventListener) {
			var DOMContentLoadFunction = function () {
				window.DOMContentLoaded = true;
				func();
			};
			document.addEventListener("DOMContentLoaded", DOMContentLoadFunction, false);
		}
		var oldfunc = (window.onload || new Function());
		window.onload = function () {
			if (!window.DOMContentLoaded) {
				oldfunc();
				func();
			}
		};
	}
	
	addContentLoadListener( function() { CalendarJS.init("calendar"); } );