// This JavaScript Document 
// Created By Evan Olds
// February 2007
// Updated by Will Morrison, 5/2/08
// -fixed bugs seen on visiting.

// initNav initializes the navigation region by applying appropriate styles (via a
// class name assignment) and hiding sections of the pulldown menu that don't correspond
// to the active section
function initNav()
{

	var i = 0;
	
	// Find the unordered list that contains the navigtion links
	var navUL = findNonFeaturedUL();
	
	// Get all ULs within this one
	var allULs = navUL.getElementsByTagName("ul");
	
	// We will loop through the array of anchors in this UL
	var alist = navUL.getElementsByTagName("a");
	// Determine how many items are in the list
	var acount = alist.length;
	
	// Loop through the links until we find the one that corresponds to the current
	// page. It's new style will be applied and it will apply the style to its
	// "parent" links.
	for (i=0; i<acount; i++)
	{
		// If this anchor is in the navigation region, it is a
		// candidate for a style assignment
		if (putAnchorStyle(alist[i], navUL, allULs) == true)
		{			
			break;	
		}
	}
	
	/*
	if( ( triedDefaultASPX )&&( !foundAMatch ) )
	{
		for (i=0; i<acount; i++)
		{
			if (putAnchorStyle(alist[i], navUL, allULs) == true)
			{
				break;	
			}
		}		
	}
	*/
	
	
	
	
	// Now the styles are applied so we can hide all ULs that do not have any
	// styled anchors or a styled parent anchor
	for (i=0; i<allULs.length; i++)
	{
		var firstAnchor = allULs[i].getElementsByTagName("a")[0];
		var pAnchor = findParentAnchor(firstAnchor, navUL, allULs);
		if (pAnchor.className != "navcurrentpage" && 
			pAnchor.className != "navparentpath")
		{
			allULs[i].style.display = "none";
		}
	}
}

function doesULHaveStyledAnchor(objUL)
{
	var alist = objUL.getElementsByTagName("a");
	var i = 0;
	
	for (i=0; i<alist.length; i++)
	{
		if (alist[i].className == "navcurrentpage" || 
			alist[i].className == "navparentpath")
		{
			return true;	
		}
	}
	
	return false;
}

// Given an unordered list that this control resides in, this function returns 
// the immediate parent UL for the control.
function findImmediateParentUL(navUL, cntrl, strControlTagName)
{
	//EXAMPLE CALL: findImmediateParentUL(navUL, aobj, "a");
	
	var moreULs = navUL.getElementsByTagName("ul");
	var numULs = moreULs.length;
	var i = 0;
	var j = 0;
	
	// If there are no child ULs, return "navUL"
	if (numULs == 0)
	{
		return navUL;	
	}
	
	// Make an array of all the ULs that have this anchor within them
	var evenMoreULs = new Array();
	for (i=0; i<numULs; i++)
	{
		if (IsChild(moreULs[i], cntrl, strControlTagName) == true)
		{
			evenMoreULs[j] = moreULs[i];
			j++;
		}
	}
	
	// If the anchor is not within any of the ULs, return navUL
	if (evenMoreULs.length == 0)
	{
		return navUL;
	}
	
	// If this happens, someone has changed things beyond the original intent of
	// this script
	if (evenMoreULs.length > 3)
	{
		//alert("Your navigation directory goes more than 3 levels deep with unordered lists");	
	}
	
	//alert("There are "+evenMoreULs.length+" that contain the anchor: "+cntrl);
	
	// Sort the "evenMoreULs" with highest level parents at the bottom of
	// the list and return the top UL in the list
	for (i=0; i<evenMoreULs.length-1; i++)
	{
		for (j=0; j<evenMoreULs.length-1-i; j++)
		{
			// if UL[j+1] < UL[j]... if it's a child, move it up
			if (IsChild(evenMoreULs[j] , evenMoreULs[j+1], "ul") == true)
			{
				var temp = evenMoreULs[j];
				evenMoreULs[j] = evenMoreULs[j+1];
				evenMoreULs[j+1] = temp;
			}
		}
	}
	return evenMoreULs[0];
}

// findNonFeaturedUL
// Finds the first UL in the "nav" div that is not within the 'featured' section
function findNonFeaturedUL()
{
	var i=0;
	var featuredObj = document.getElementById('featured');
	var navObj = document.getElementById('nav');
	
	if (navObj == null)
	{
		alert("Page Error: 'nav' div not found.");
		return null;
	}
	if (featuredObj == null)
	{
		alert("Developer alert: Your page does not have the 'featured' div tag. "+
			  "Even if you do not have featured links it is recommended that you leave the featured div tag in your page.");
		return navObj.getElementsByTagName("ul")[0];
	}
	
	// Get the list of ULs within the featured section
	var featuredULs = featuredObj.getElementsByTagName("ul");
	if (featuredULs.length == 0)
	{
		return navObj.getElementsByTagName("ul")[0];
	}
	// else...
	
	var ullist = navObj.getElementsByTagName("ul");
	while (ullist[i] === featuredULs[0])
	{
		i++;	
	}
	return ullist[i];
}

// Finds and returns the anchor in the UL above this one
function findParentAnchor(aobj, navUL, allULs)
{
	var i = 0;
	
	// First find this anchor's parent UL
	var parentUL = findImmediateParentUL(navUL, aobj, "a");
	
	// If the parentUL is the main navigation UL, then we're top-level
	// and have no parent anchor
	
	if (parentUL === navUL)
	{
		return null;	
	}
	
	// Next find the parent of that UL, this is where the parent anchor will reside
	var ppUL = findImmediateParentUL(navUL, parentUL, "ul");
	
	// Get the index of this anchor within the parent-parent list
	var index = getChildIndex(ppUL, aobj, "a");
	
	var alist = ppUL.getElementsByTagName("a");
	var acount = alist.length;
	
	
	// Iterate upwards until we have an immediate parent of "ppUL"
	index--;
	while (index >= 0)
	{
		if (ppUL == findImmediateParentUL(navUL, alist[index], "a"))
		{
			return alist[index];	
		}
		index--;
	}
	
	return null;
}

function getChildIndex(parentcntrl, childcntrl, strTagName)
{
	var children = parentcntrl.getElementsByTagName(strTagName);
	var i = 0;
	
	for (i=0; i<children.length; i++)
	{
		if (children[i] === childcntrl)
		{
			return i;	
		}
	}
	return -1;
}

function IsChild(parentcntrl, childcntrl, strTagName)
{
	var children = parentcntrl.getElementsByTagName(strTagName);
	var i = 0;
	
	for (i=0; i<children.length; i++)
	{
		if (children[i] === childcntrl)
		{
			return true;	
		}
	}
	return false;
}

// Takes a best guess at whether or not a link string is absolute. Returns true if the link is believed
// to be absolute, false otherwise (relative link).
function IsLinkAbsolute(LinkString)
{
	var s = LinkString.toLowerCase();

	if (s.indexOf(":") != -1)
	{
		// If the link has a colon in it, it's most likely absolute
		return true;
	}
	else if (s.substring(0,4) == "www.")
	{
		// We will assume that if the first four characters are "www." then it's absolute
		return true;
	}
	return false;
}

function putAnchorStyle(aobj, navUL, allULs)
{
	var i;
	
	// Retreive the URL of the page
	var currentURL = location.href.toLowerCase();
	
	
	// If "navcurrentpage" has been previously defined as a global variable, then
	// it will override the URL of the page
	if (typeof navcurrentpage != 'undefined')
	{
		if (IsLinkAbsolute(navcurrentpage) == false)
		{
			// Append our path to the string
			i = currentURL.lastIndexOf("\\");
			if (i==-1)
			{
				i = currentURL.lastIndexOf("/");
			}
			currentURL = (currentURL.substring(0, i+1) + navcurrentpage).toLowerCase();
		}
		else
		{
			currentURL = navcurrentpage.toLowerCase();
		}
	}
	
	
	
	// Chop off "?" and anything after it
	i = currentURL.lastIndexOf("?");
	if (i != -1)
	{
		currentURL = currentURL.substring(0, i);
	}
	
	
	
	
	// If its a folder path "www.google.com/" rather than "www.google.com/default.aspx"
	// Then this should look for a default.aspx or index.html
	if (currentURL.lastIndexOf("/") > currentURL.lastIndexOf("."))
	{
		var oldURL = currentURL;
		//if current URL doesnt match, try /default.aspx
		if (aobj.href.toLowerCase() != currentURL)
		{
			currentURL = currentURL + 'default.aspx';
		}
		//if default.aspx doesnt match, try /index.html
		if (aobj.href.toLowerCase() != currentURL)
		{
			currentURL = oldURL;
			//Now try index.html
			currentURL = currentURL + 'index.html';
		}
	}

	
	
	
	if (aobj.href.toLowerCase() == currentURL)
	{
		// First change the class of this anchor object
		aobj.className = "navcurrentpage";
		
		// Next find the "parent anchor" (anchors are not really containers for other 
		// anchors so we must work around this)
		panchor = findParentAnchor(aobj, navUL, allULs);
		while (panchor != null)
		{
			panchor.className = "navparentpath";
			panchor = findParentAnchor(panchor, navUL, allULs);
		}
		
		return true;
	}

		
		

	return false;
}