var hiliteColor = 'ffff99';			// light yellow
var hiliteTimeout, hiliteTimeout2;
var fadeTime = '.5s';
var hiliteTime = 3000; 				// 3 seconds, amount of time to keep target highlighted
var cookieCheckInterval = 500; 		// 0.5 seconds.

///
// Check for highlight cookie and set up recurring checking
///
function check_for_hilite(){
	doHilite();
	///
	// We need to check for cookie fairly often because if the page is redisplayed, it may not reload, so 
	// we can't rely on using the onload function.
	///
	setInterval(function(){doHilite();}, cookieCheckInterval);
}

///
// Get cookie to let us know what to highlight
///
function doHilite(){
	var isHilite = getCookie('hilite-link-hilite');
	if (typeof isHilite !== 'undefined' && isHilite !== ''){
		hl(isHilite, 'd');
		deleteCookie('hilite-link-hilite');
	}
}

///
// Highlight a link target for a short time.
// Function name is short because it is used many times in the eBook.
// myType = (d) Direct, target is in current html file. (c) Use cookie, target is in another file
///
function hl(myTarget, myType){
	if (myType == 'd') hilite_function(myTarget);
	else setCookie('hilite-link-hilite', myTarget, 1);
}

// return the containing <p/> element for thisElem
function containingParagraph(thisElem) {
	var parent = thisElem.parentNode;
	if (parent.nodeName!='p') {
		parent = containingParagraph(parent);
	}
	return parent;
}

///
// Highlight spans or divs based on class name.
// myTarget = class name you want highlighted.
///
function hilite_function(myTarget){
	var myStyle = '-webkit-transition:background-color ' + fadeTime + ' ease-in; background:#' + hiliteColor;
	var myObj = document.getElementById(myTarget);
	var myEndObj = document.getElementById(myTarget + '_end');
	var myFoundEndObj = 0;
	var mySpanList = new Array(); // list of span elements that were added, these will need to be set to highlight.
	///
	// If there is no end element, just highlight the paragraph
	///
	if (typeof(myEndObj) === 'undefined' || myEndObj === null){
		mySpanList[0] = containingParagraph(myObj);
		mySpanList[0].setAttribute('style', myStyle);
	} else { // Highlight from start element to end element
		myFoundEndObj = 1;
		var myRange = document.createRange();
		myRange.setStart(myObj, 0);
		myRange.setEnd(myEndObj, 0);
		var pastStartNode = false, reachedEndNode = false;
		
		function getTextNodesInRange(node){
			if (node == myObj) {
				pastStartNode = true;
			} else if (node == myEndObj) {
				reachedEndNode = true;
			} else if (node.nodeType == 3) {
				if (pastStartNode && !reachedEndNode && !/^\s*$/.test(node.nodeValue)) {
					node.innerHTML = '<span class="target_highlight">' + node.textContent + '</span>';
					var span = document.createElement("span");
					span.className = "target_highlight";
					span.textContent = node.textContent;
					node.parentNode.replaceChild(span, node); 
				}
			} else {
				for (var i = 0, len = node.childNodes.length; !reachedEndNode && i < len; ++i){
					getTextNodesInRange(node.childNodes[i]);
				}
			}
		}
		getTextNodesInRange(myRange.commonAncestorContainer);
		var mySpanList = document.getElementsByClassName('target_highlight');
		for (var i = 0; i < mySpanList.length; i++)
		{
			mySpanList[i].setAttribute('style', myStyle);
		}
	}
	//remove hilite
	hiliteTimeout = setTimeout(function(){
		for (var i = 0; i < mySpanList.length; i++){
			mySpanList[i].setAttribute('style', '-webkit-transition:background-color ' + fadeTime + ' ease-out; background:none;');
		}
		hiliteTimeout = null;
		hiliteTimeout2 = null;
	}, hiliteTime);
	//remove spans 1 second later
	if (myFoundEndObj){
		hiliteTimeout2 = setTimeout(function(){
			for (var i = 0; i < myList.length; i++){
				var myText = createTextNode(mySpanList[i].textContent);
				mySpanList[i].parentNode.replaceChild(myText, mySpanList[i]);
			}
		}, hiliteTime + (parseFloat(fadeTime) * 1000));
	}
}

///
// Set highlight cookie
///
function setCookie(c_name, value, expdays){
	var expdate = new Date();
	expdate.setDate(expdate.getDate() + expdays);
	var c_value = escape(value) + ((expdays === null) ? "" : "; expires="+expdate.toUTCString());
	document.cookie=c_name + "=" + c_value;
}

///
// Retrieve highlight cookie
///
function getCookie(c_name){
	var i,x,y,ARRcookies=document.cookie.split(";");
	for (i = 0; i<ARRcookies.length; i++){
		x = ARRcookies[i].substr(0,ARRcookies[i].indexOf("="));
		y = ARRcookies[i].substr(ARRcookies[i].indexOf("=")+1);
		x = x.replace(/^\s+|\s+$/g,"");
		if (x == c_name) return unescape(y);
	}
	return "";
}

///
// Delete cookie after highlight has been set
///
function deleteCookie(c_name){
	if (getCookie(c_name)) document.cookie = c_name + "=;expires=Thu, 01-Jan-1970 00:00:01 GMT";
}