// attach hasjs class to body
if(document.documentElement){
	document.documentElement.className = "hasjs";
};

function init() {
	if (!document.getElementById || !document.createElement) return;
	random_image(); 
	current_nav(); 
}

window.onload = init;

/**
 * This works with nav that has subnav listed inside the main nav like so:
 * <ul>
 *  <li> <a href="#">Some Main Link</a>
 *    <ul>
 *      <li><a href="#">Some secondary link</a></li>
 *    </ul>
 *  </li>
 * </ul>
 */
function current_nav() {
	var href = '';
	current_page = get_path(document.URL);
	thedivs		 = document.getElementsBySelector('.photo-row');
	if (thedivs.length == 0) return;
	for(i=0; i < thedivs.length; i++) {
		thediv = thedivs[i];
		navas		= thediv.getElementsByTagName('a');
		if (navas.length == 0) return;
		
		// loop through nav a's
		for(j=0; j < navas.length; j++) {
			nava 	= navas[j];
			// if direct decendent of #nav ul
			if (nava.parentNode == thediv) {
				if (get_path(nava.href) == current_page) {
					navimgs		= nava.getElementsByTagName('img');
					if (navimgs.length == 0) break;
					if (navimgs[0].className != '') {
						navimgs[0].className += ' current';
					} else {
						navimgs[0].className = 'current';
					}
				}
			}
		}
	}
}

function get_path(url) {
	d 			= document;
	site 		= d.domain;
	sp 			= url.indexOf(site) + site.length;
	path 		= url.substring(sp);
	path 		= path.replace(/index.(shtml|cfm)/, '');
	return path;
}


function random_image() {

	var random_pics = new Array();
	random_pics[0] = ["New labs allow for cutting-edge instruction","VT1K6786"];
	random_pics[1] = ["Inside the Digital Visualization Theater","VT1K6439"];
	random_pics[2] = ["Jordan offers a creative environment to learn in","VT1K6973"];
	random_pics[3] = ["Rooftop facility offers unique telescope experiences","VT1K6478"]
	random_pics[4] = ["Modern research in a progressive environment","VT1K6715"]
	var random_pic = random_pics[rand(5)];

	var div	= $('featured');
	if (!div) return;

	var imgs = div.getElementsByTagName('img');
	if (imgs.length == 0) return;
	
	img = imgs[0];
	
	newimg = document.createElement('img');
	newimg.src = 'http://science.nd.edu/jordan/images/main/' + random_pic[1] + '.jpg';
	newimg.alt = random_pic[0]; 
	img.parentNode.insertBefore(newimg,img);
	img.parentNode.removeChild(img);
	
	
}

function random_dept_bug() {
	img_captions = new Array();

// captions: (link-url,image-path,alt-text)
	img_captions[0] = Array('http://science.nd.edu/jordan/academic-excellence/#science-departments','physics.jpg','Department of Physics');
	img_captions[1] = Array('http://science.nd.edu/jordan/academic-excellence/#science-departments','chemistry.jpg','Department of Chemistry');
	img_captions[2] = Array('http://science.nd.edu/jordan/academic-excellence/#science-departments','biological-sciences.jpg','Department of Biological Sciences');
	img_captions[3] = Array('http://science.nd.edu/jordan/academic-excellence/#science-departments','mathematics.jpg','Department of Mathematics');
	img_captions[4] = Array('http://science.nd.edu/jordan/academic-excellence/#science-departments','preprofessional.jpg','Department of Preprofessional Studies');

var num = img_captions.length;
	img_number  = Math.floor(Math.random()*(num));
	document.write('<a href="' + img_captions[img_number][0] + '"><img src="http://science.nd.edu/jordan/images/department-bugs/' + img_captions[img_number][1] + '" alt="' + img_captions[img_number][2] + '" border="0" class="last" /></a>');
}

function $(el) {
	return document.getElementById(el);
}

function rand(n) {
  return (Math.floor(Math.random() * n));
}

/* document.getElementsBySelector(selector)
   - returns an array of element objects from the current document
     matching the CSS selector. Selectors can contain element names, 
     class names and ids and can be nested. For example:
     
       elements = document.getElementsBySelect('div#main p a.external')
     
     Will return an array of all 'a' elements with 'external' in their 
     class attribute that are contained inside 'p' elements that are 
     contained inside the 'div' element which has id="main"

   New in version 0.4: Support for CSS2 and CSS3 attribute selectors:
   See http://www.w3.org/TR/css3-selectors/#attribute-selectors

   Version 0.4 - Simon Willison, March 25th 2003
   -- Works in Phoenix 0.5, Mozilla 1.3, Opera 7, Internet Explorer 6, Internet Explorer 5 on Windows
   -- Opera 7 fails 
*/

function getAllChildren(e) {
  // Returns all children of element. Workaround required for IE5/Windows. Ugh.
  return e.all ? e.all : e.getElementsByTagName('*');
}

document.getElementsBySelector = function(selector) {
  // Attempt to fail gracefully in lesser browsers
  if (!document.getElementsByTagName) {
    return new Array();
  }
  // Split selector in to tokens
  var tokens = selector.split(' ');
  var currentContext = new Array(document);
  for (var i = 0; i < tokens.length; i++) {
    token = tokens[i].replace(/^\s+/,'').replace(/\s+$/,'');;
    if (token.indexOf('#') > -1) {
      // Token is an ID selector
      var bits = token.split('#');
      var tagName = bits[0];
      var id = bits[1];
      var element = document.getElementById(id);
      if (tagName && element.nodeName.toLowerCase() != tagName) {
        // tag with that ID not found, return false
        return new Array();
      }
      // Set currentContext to contain just this element
      currentContext = new Array(element);
      continue; // Skip to next token
    }
    if (token.indexOf('.') > -1) {
      // Token contains a class selector
      var bits = token.split('.');
      var tagName = bits[0];
      var className = bits[1];
      if (!tagName) {
        tagName = '*';
      }
      // Get elements matching tag, filter them for class selector
      var found = new Array;
      var foundCount = 0;
      for (var h = 0; h < currentContext.length; h++) {
        var elements;
        if (tagName == '*') {
            elements = getAllChildren(currentContext[h]);
        } else {
            elements = currentContext[h].getElementsByTagName(tagName);
        }
        for (var j = 0; j < elements.length; j++) {
          found[foundCount++] = elements[j];
        }
      }
      currentContext = new Array;
      var currentContextIndex = 0;
      for (var k = 0; k < found.length; k++) {
        if (found[k].className && found[k].className.match(new RegExp('\\b'+className+'\\b'))) {
          currentContext[currentContextIndex++] = found[k];
        }
      }
      continue; // Skip to next token
    }
    // Code to deal with attribute selectors
    if (token.match(/^(\w*)\[(\w+)([=~\|\^\$\*]?)=?"?([^\]"]*)"?\]$/)) {
      var tagName = RegExp.$1;
      var attrName = RegExp.$2;
      var attrOperator = RegExp.$3;
      var attrValue = RegExp.$4;
      if (!tagName) {
        tagName = '*';
      }
      // Grab all of the tagName elements within current context
      var found = new Array;
      var foundCount = 0;
      for (var h = 0; h < currentContext.length; h++) {
        var elements;
        if (tagName == '*') {
            elements = getAllChildren(currentContext[h]);
        } else {
            elements = currentContext[h].getElementsByTagName(tagName);
        }
        for (var j = 0; j < elements.length; j++) {
          found[foundCount++] = elements[j];
        }
      }
      currentContext = new Array;
      var currentContextIndex = 0;
      var checkFunction; // This function will be used to filter the elements
      switch (attrOperator) {
        case '=': // Equality
          checkFunction = function(e) { return (e.getAttribute(attrName) == attrValue); };
          break;
        case '~': // Match one of space seperated words 
          checkFunction = function(e) { return (e.getAttribute(attrName).match(new RegExp('\\b'+attrValue+'\\b'))); };
          break;
        case '|': // Match start with value followed by optional hyphen
          checkFunction = function(e) { return (e.getAttribute(attrName).match(new RegExp('^'+attrValue+'-?'))); };
          break;
        case '^': // Match starts with value
          checkFunction = function(e) { return (e.getAttribute(attrName).indexOf(attrValue) == 0); };
          break;
        case '$': // Match ends with value - fails with "Warning" in Opera 7
          checkFunction = function(e) { return (e.getAttribute(attrName).lastIndexOf(attrValue) == e.getAttribute(attrName).length - attrValue.length); };
          break;
        case '*': // Match ends with value
          checkFunction = function(e) { return (e.getAttribute(attrName).indexOf(attrValue) > -1); };
          break;
        default :
          // Just test for existence of attribute
          checkFunction = function(e) { return e.getAttribute(attrName); };
      }
      currentContext = new Array;
      var currentContextIndex = 0;
      for (var k = 0; k < found.length; k++) {
        if (checkFunction(found[k])) {
          currentContext[currentContextIndex++] = found[k];
        }
      }
      // alert('Attribute Selector: '+tagName+' '+attrName+' '+attrOperator+' '+attrValue);
      continue; // Skip to next token
    }
    // If we get here, token is JUST an element (not a class or ID selector)
    tagName = token;
    var found = new Array;
    var foundCount = 0;
    for (var h = 0; h < currentContext.length; h++) {
      var elements = currentContext[h].getElementsByTagName(tagName);
      for (var j = 0; j < elements.length; j++) {
        found[foundCount++] = elements[j];
      }
    }
    currentContext = found;
  }
  return currentContext;
}

/* That revolting regular expression explained 
/^(\w+)\[(\w+)([=~\|\^\$\*]?)=?"?([^\]"]*)"?\]$/
  \---/  \---/\-------------/    \-------/
    |      |         |               |
    |      |         |           The value
    |      |    ~,|,^,$,* or =
    |   Attribute 
   Tag
*/