/*
* styleswitcher - written by Paul Sowden (http://www.idontsmoke.co.uk/)
* downloaded from: http://alistapart.com/articles/alternate/
* see usage info at: http://alistapart.com/about/
* 
* modifications by Hugues Johnson (http://www.huguesjohnson.com)
* -added code in setActiveStyleSheet to call createCookie
* -added a method called writeStyleChooser that creates a dropdown list of styles
* -added a method called onStyleChooserChanged that updates the style when the style chooser dropdown is changed
* -updated getPreferredStyleSheet to return a hard-coded name if preferred style sheet isn't found
* -added getStyleNameFromCookie method
*/


function setActiveStyleSheet(title) {
  var i, a, main;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")) {
      a.disabled = true;
      if(a.getAttribute("title") == title){
         createCookie("style",title,365);
         a.disabled = false;
      }
    }
  }
}

function getActiveStyleSheet() {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title") && !a.disabled) return a.getAttribute("title");
  }
  return null;
}

function getPreferredStyleSheet() {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1
       && a.getAttribute("rel").indexOf("alt") == -1
       && a.getAttribute("title")
       ) return a.getAttribute("title");
  }
  return "white";
}

function createCookie(name,value,days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
  }
  else expires = "";
  document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(';');
  for(var i=0;i < ca.length;i++) {
    var c = ca[i];
    while (c.charAt(0)==' ') c = c.substring(1,c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
  }
  return null;
}

function writeStyleChooser(){
	document.write("style: ");
	document.write("<select id='selectstyle' onchange='onStyleChooserChanged();'>");
	var activeStyle = cookie ? cookie : getPreferredStyleSheet();
	for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    		if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")){
			var title=a.getAttribute("title");
			document.write("<option value='");
			document.write(title);
			document.write("'");
			if(title==activeStyle){
				document.write(" selected='selected'");
			}
			//selected here
			document.write(">");
			document.write(title);
			document.write("</option>");
		}
	}
	document.write("</select>");
}

function onStyleChooserChanged(){
	var value=document.getElementById('selectstyle').value;
	if(value!=null) setActiveStyleSheet(value);
	document.location.reload();	
}

function getStyleNameFromCookie(){
  	var cookie = readCookie("style");
  	var title = cookie ? cookie : getPreferredStyleSheet();
	return(title);
}

window.onload = function(e) {
  setActiveStyleSheet(getStyleNameFromCookie());
}

window.onunload = function(e) {
  var title = getActiveStyleSheet();
  createCookie("style", title, 365);
}

var cookie = readCookie("style");
var title = cookie ? cookie : getPreferredStyleSheet();
setActiveStyleSheet(title);