// <![CDATA[

/* submenu.js (appropriately hide/show/highlight elements of an unordered list
 * used for navigation)
 * 
 * The "algorithm"
 *
 * 0.5. If we're in /dev/, set a base href tag, to /dev/
 * 
 * 1. Figure out which li/anchor corresponds to the page we're on by 
 *    pattern-matching the URL
 * 
 * 2. Expand the ul below that li, if it exists
 *
 * 3. Bounce up the tree, expanding ul's and setting .activelink on *anchors* 
 *    not on li's
 * 
 * 4. Have a beer (results in a beer on every page load)
 *
 */

/* whereAmI()
 * 
 * @param Object node of ul with anchors to search
 * @return Object page_anchor of anchor of the page you're on
 */
function whereAmI(ul){
	//Grab all of the anchor tags from the unordered list
	var all_the_anchors = nodeChildrenByTagName(ul, "a");
	var where_you_are = document.location.href;
	var return_anchor;

	for (var i=0; i<all_the_anchors.length; i++)
	{
		/* The 3 lines below remove '/formlogin' from the URL.
		 *
		 * Reason: if you are behind the formlogin portal, 
		 * '/formlogin' was automatically added to your URL 
		 * by formlogin.js. In order to keep the submenu 
		 * working properly, we must remove the '/formlogin' 
		 * from the temporary variable 'where_you_are'.
		 * - Chrys Bader (cbader@bu.edu)
		 */
		 
		var re = new RegExp ( '/formlogin', 'gi' );
		
		if( where_you_are.indexOf( "formlogin" ) >= 0 )
			where_you_are = where_you_are.replace( re, "" );
		/* end cbader */

		if (normalizeURL(where_you_are) == normalizeURL(all_the_anchors[i].href))
		{
			return_anchor = all_the_anchors[i];
			return return_anchor;
		}
	}

	/* If we haven't matched anything, try matching on the title 
	 * before returning false*/
	/* Moved this match up to before the path match and also made it so if
	   there were multiple matches on page title, use the one occurring
	   later in the title string so, for example, if title is:
	   Software Help | Basic System Usage | SCV Security and Access
	   a match on "SCV Security and Access" overrides a match on "Help" 
	   6/15/07 -aarondf (aarondf@bu.edu) */

	if (null == return_anchor) {
		//Try to match the page title against the text of the anchors
		var page_title = document.title;
		var link_text;
        var curval, bestval;
		
		//alert('title is'+page_title);
		
		bestlength=-1;
		bestval=-1;
		for (var i=0; i<all_the_anchors.length; i++)
		{
			link_text = all_the_anchors[i].childNodes[0].nodeValue;
			curval=page_title.indexOf(link_text);
			curlength=link_text.length;
			if ((curval>=bestval)&&(curlength>=bestlength)) {
				bestval=curval;
				bestlength=curlength;
				return_anchor = all_the_anchors[i];
			}				
		}
		if (bestval>-1) {
			return return_anchor;
		}
		//If we still haven't found an anchor
		if (null == return_anchor) {
			return false;
		}
	} 

	// if nothing has matched yet, let's try the path alone
	if (null == return_anchor) {
		for (var i=0; i<all_the_anchors.length; i++) {
			if (normalizeURL(where_you_are).indexOf(normalizeURL(all_the_anchors[i].href))>-1) {
				return_anchor = all_the_anchors[i];
			}
		}
	}

	return return_anchor;
}



/* Don't choke if we don't have getElementById*/
if (!document.getElementById)
    document.getElementById = function() { return null; }

/* Initializes (appropriately hides) all of the ul's below the
 * second level ul.
 * @param id string the id of  
 * @return void
 */
function initializeNavTree(tree_id) {
	var nav_tree = document.getElementById(tree_id);
	//hide the nav_tree to prevent flash of unstyled content
	if (nav_tree) { //in case the page doesn't have a nav_tree
	nav_tree.style.display = 'none';
	if (nav_tree) {
		var anchor = whereAmI(nav_tree);
		if (anchor) {
			hideChildUls(nav_tree); 
			//show the menu one below this anchor (if it exists)
			expandChildNavTree(anchor);
			//show the entire menu above this anchor
			expandParentsNavTree(anchor, tree_id);
		} else {
			hideChildUls(nav_tree); 
			//alert('This page is not linked to in the sidenav.');
		}
	}
	//show the nav_tree
	nav_tree.style.display = 'block';
	}
	return;
}


//End menuExpandable

/**
 * Hides all child ul's from a starting ul, descending into
 * child nodes
 * @param Object el node to initialize
 * @return void
 */
function hideChildUls(el)
{
  try {
	var children = el.childNodes;
  }
  catch (er) {
	  return;
  }
  for (var n=0; n < children.length; n++) {
    var item = children[n];
    
    if (String(item.tagName).toUpperCase() == "LI") {

      var nodes = item.childNodes;
	  for (var t=0; t < nodes.length; t++) {
	    if (String(nodes[t].tagName).toUpperCase() == "UL") {
		  nodes[t].style.display = 'none';
		  hideChildUls(nodes[t]);
        }
      }// end for loop
    } 
  }
}

/* Starting from an anchor nested within a UL, displays the UL it's nested in,
 * then all of its parents', grandparents', great-grandparents' ULs
 * stopping only when it gets to a specific id
 * @param Object node ul
 * @param string id ID of node to stop at
 * @return void
 */
function expandParentsNavTree(a, id) {
	//show this ul and all of its parents
	var node = a;
	if (node != null)
	{
		while (node.id != id)
		{
			if (String(node.tagName).toUpperCase() == "LI")
			{
				var children = nodeChildrenByTagName(node, "A", 1);
				if (children[0]) {
					nodeAddClass(children[0], 'activelink');
				}
			}
			if (String(node.tagName).toUpperCase() == "UL")
			{
				node.style.display = 'block';
			}
			node = node.parentNode;
		}
	}
}

/* Starting from an anchor nested within a ul, displays its li,
 * then all of its parents, grandparents, great-grandparents, etc.
 * stopping only when it gets to a specific id
 * @param Object node ul
 * @param string id ID of node to stop at
 * @return void
 */
function expandChildNavTree(a) {
	var node = a;
	//get the LI that the anchor is nested in
	while (String(node.tagName).toUpperCase() != "LI")
	{
		node = node.parentNode;
	}
	
	//loop through the children of that li, display the ul if it's in there
	var node_children = node.childNodes;
	for (var n=0; n < node_children.length; n++)
	{
		var this_node = node_children.item(n);
		if (String(this_node.tagName).toUpperCase() == "UL" )
		{
			this_node.style.display = 'block';
		}
	}
}

/* chop index.html, index.php, page anchors, and weblogin cruft,
 *  from the end of URLs*/
function normalizeURL(url_string) {
	var file_names = Array('index.html','index.shtml', 'index.htm', 'index.php');
	for (var i=0; i<file_names.length; i++ ){
		if (url_string.toLowerCase().indexOf(file_names[i]) != -1) {
			/* Removed the toLowerCase in line below as was causing
			   things to not match which should have.  6/15/07
			   -aarondf (aarondf@bu.edu) */
			url_string = url_string.replace(file_names[i], '');
		}
	}

	//Split on # and disregard everything after the #
	//Gets rid of page anchors
	var url_arr = url_string.split('#');
	url_string = url_arr[0];
	
	//Get rid of weblogin_random=XXXXXX
	var wl_arr = url_string.split('weblogin_random');
	url_string = wl_arr[0];
	//If we need to add back GET variables after the weblogin_random
	if (wl_arr[1]) {
		var query_string = wl_arr[1].split('&');
		if (query_string[1]) {
			url_string = wl_arr[0] + query_string[1];
		}
	}
	
	//Remove trailing question mark
	if (url_string.charAt(url_string.length-1)=='?') {
		url_string = url_string.substring(0,url_string.length-1);
	}
	
	return url_string;
}


// ]]>