/**
 * MD: Source from http://www.nsftools.com/misc/SearchAndHighlight.htm,
 * but modified for toggling and cookie preferences by me.
 */

var holdOriginal = "";
var holdSearchTerms = "";

/*
 * This is the function that actually highlights a text string by
 * adding HTML tags before and after all occurrences of the search
 * term. You can pass your own tags if you'd like, or if the
 * highlightStartTag or highlightEndTag parameters are omitted or
 * are empty strings then the default <font> tags will be used.
 */
function doHighlight(bodyText, searchTerm, highlightStartTag, highlightEndTag) 
{
  // the highlightStartTag and highlightEndTag parameters are optional
  if ((!highlightStartTag) || (!highlightEndTag)) {
    highlightStartTag = "<font style='background-color:#FFFF77;'>";
    highlightEndTag = "</font>";
  }
  
  // find all occurences of the search term in the given text,
  // and add some "highlight" tags to them (we're not using a
  // regular expression search, because we want to filter out
  // matches that occur within HTML tags and script blocks, so
  // we have to do a little extra validation)
  var newText = "";
  var i = -1;
  var lcSearchTerm = searchTerm.toLowerCase();
  var lcBodyText = bodyText.toLowerCase();
    
  while (bodyText.length > 0) {
    i = lcBodyText.indexOf(lcSearchTerm, i+1);
    if (i < 0) {
      newText += bodyText;
      bodyText = "";
    } else {
      // skip anything inside an HTML tag
      if (bodyText.lastIndexOf(">", i) >= bodyText.lastIndexOf("<", i)) {
        // skip anything inside a <script> block
        if (lcBodyText.lastIndexOf("/script>", i) >= lcBodyText.lastIndexOf("<script", i)) {
          newText += bodyText.substring(0, i) + highlightStartTag + bodyText.substr(i, searchTerm.length) + highlightEndTag;
          bodyText = bodyText.substr(i + searchTerm.length);
          lcBodyText = bodyText.toLowerCase();
          i = -1;
        }
      }
    }
  }
  
  return newText;
}

function toggleHighlighting()
{
  var hiliteElem = document.getElementById('hiliteBox');
  var today = new Date();
  var expire = new Date();
  expire.setTime(today.getTime() + 3600000*24*90); // 90 days
  if (holdOriginal.length==0) {
  	holdOriginal = document.body.innerHTML;
  }
  if (!hiliteElem.checked) {
    document.cookie = "hiliteTerms=no;expires="+expire.toGMTString();
  	document.body.innerHTML = holdOriginal.replace(/id="hiliteBox" checked/,'id="hiliteBox"');
  	document.getElementById('hiliter').style.backgroundColor='#E0E0E0';
  	document.getElementById('hiliteBox').checked = false;
  } else {
    document.cookie = "hiliteTerms=yes;expires="+expire.toGMTString();
    if (holdSearchTerms.length>0) {
	    highlightSearchTerms();
	}
  	document.getElementById('hiliter').style.backgroundColor='#FFFF77';
  	document.getElementById('hiliteBox').checked = true;
  }
}

/*
 * This is sort of a wrapper function to the doHighlight function.
 * It takes the searchText that you pass, optionally splits it into
 * separate words, and transforms the text on the current web page.
 * Only the "searchText" parameter is required; all other parameters
 * are optional and can be omitted.
 */
function highlightSearchTerms(searchText, treatAsPhrase, warnOnFailure, highlightStartTag, highlightEndTag)
{
  var oldStuff=0;
  if (((searchText==null)||(searchText.length==0))&&(holdSearchTerms.length>0)) {
  	searchText = holdSearchTerms;
  	oldStuff=1;
  }
  
  if ((searchText==null)||(searchText.length==0)) {
    return false;
  }
  
  holdSearchTerms = searchText;

  // if the treatAsPhrase parameter is true, then we should search for 
  // the entire phrase that was entered; otherwise, we will split the
  // search string so that each word is searched for and highlighted
  // individually
  if (treatAsPhrase) {
    searchArray = [searchText];
  } else {
    searchArray = searchText.split(" ");
  }
  
  if (!document.body || typeof(document.body.innerHTML) == "undefined") {
    if (warnOnFailure) {
      alert("Sorry, for some reason the text of this page is unavailable. Searching will not work.");
    }
    return false;
  }
    
  var bodyText = document.body.innerHTML;
  holdOriginal = bodyText;
  if ((document.cookie!=null)&&(document.cookie.indexOf("hiliteTerms=no")!=-1)) {
  	return true;
  }

  for (var i = 0; i < searchArray.length; i++) {
    bodyText = doHighlight(bodyText, searchArray[i], highlightStartTag, highlightEndTag);
  }
  
  document.body.innerHTML = bodyText;
  return true;
}