// JavaScript Document
// From the book Simply JavaScript by SitePoint
var Accordion = {
	init: function() {
		Accordion.frameRate = 25;
		Accordion.duration = 0.5;
		var accordions = Core.getElementsByClass("accordion");
		for (var i = 0; i < accordions.length; i++) {
			var folds = accordions[i].childNodes;
			for (var j = 0; j < folds.length; j++) {
				if (folds[j].nodeType == 1) {
					var accordionContent = document.createElement("div");
					accordionContent.className = "accordionContent";
					for (var k = 0; k < folds[j].childNodes.length; k++) {
						if (folds[j].childNodes[k].nodeName.toLowerCase() != "h2") {
							accordionContent.appendChild(folds[j].childNodes[k]);
							k--;
						}
					}
					folds[j].appendChild(accordionContent);
					folds[j]._accordionContent = accordionContent;
					Accordion.collapse(folds[j]);
					var foldLinks = folds[j].getElementsByTagName("a");
					var foldTitleLink = foldLinks[0];
					Core.addEventListener(foldTitleLink, "click", Accordion.clickListener); 
//			The focus listener (TABS) was removed so people with slow click times could still follow links within the accordion
//					for (var k = 1; k < foldLinks.length; k++) {
//						Core.addEventListener(foldLinks[k], "focus", Accordion.focusListener);
//					}
				}
			}
			if (location.hash.length > 1) {
				var activeFold = document.getElementById(location.hash.substring(1));
				if (activeFold && activeFold.parentNode == accordions[i]) {
					Accordion.expand(activeFold);
				}
			}
		}
	},
	collapse: function(fold) {
		var content = fold._accordionContent;
		content._height = parseInt(content.style.height, 10);
		content._increment = content._height / (Accordion.frameRate * Accordion.duration);
		if (Core.hasClass(fold, "expanded")) {
			clearTimeout(content._timer);
			Accordion.collapseAnimate(content);
		} else {
			Core.addClass(fold, "collapsed");
		}
	},
	collapseAnimate: function(content) {
	    var newHeight = content._height - content._increment;
		if (newHeight < 0)	{
			newHeight = 0;
			Core.removeClass(content.parentNode, "expanded");
			Core.addClass(content.parentNode, "collapsed");
		} else {
			content._timer = setTimeout(function(){Accordion.collapseAnimate(content);}, 1000 / Accordion.frameRate);
		}
		content._height = newHeight;
		content.style.height = Math.round(newHeight) + "px";
	},
	collapseAll: function(accordion) {
		var folds = accordion.childNodes;
		for (var i = 0; i < folds.length; i++) {
			if (folds[i].nodeType == 1) {
				Accordion.collapse(folds[i]);
			}
		}
	},
	expand: function(fold) {
		var content = fold._accordionContent;
		Accordion.collapseAll(fold.parentNode);
		if (!Core.hasClass(fold, "expanded")) {
			content.style.height = "0";
			content._height = 0;
			Core.removeClass(fold, "collapsed");
			Core.addClass(fold, "expanded");
			content._increment = content.scrollHeight / (Accordion.frameRate * Accordion.duration);
			Accordion.expandAnimate(content);
		}
	},
	expandAnimate: function(content) {
		var newHeight = content._height + content._increment;
		if (newHeight > content.scrollHeight) {
			newHeight = content.scrollHeight;
		} else {
			content._timer = setTimeout(function(){Accordion.expandAnimate(content);}, 1000 / Accordion.frameRate);
		}
		content._height = newHeight;
		content.style.height = Math.round(newHeight) + "px";
		content.scrollTop = 0;
	},
  clickListener: function(event) {
	  var fold = this.parentNode.parentNode;
	  if (Core.hasClass(fold, "collapsed")) {
		  Accordion.expand(fold);
	  } else {
		  Accordion.collapse(fold);
	  }
	  Core.preventDefault(event);
  },
  focusListener: function(event) {
	  var element = this;
	  while (element.parentNode) {
		  if (Core.hasClass(element.parentNode, "accordion")) {
			  Accordion.expand(element);
			  return;
		  }
		  element = element.parentNode;
	  }
  }
};
Core.start(Accordion);