/* http://www.kryogenix.org/code/browser/searchhi/ */
/* Modified 20021006 to fix query string parsing and add case insensitivity */
/* Modified 20070316 to stop highlighting inside nosearchhi nodes */
/* Modified 20070402 to add most of the search engines query strings */
/* Modified 20070401 to remove 2 letters words from query strings */
/* Modified 20070401 to add query strings from the very page */
/* Modified 20080224 to add UTF-8 detection and support! */

/* .searchword { background-color: yellow; } */


function highlightWord(node,word) {
	// Iterate into this nodes childNodes
	if (node.hasChildNodes) {
		var hi_cn;
		for (hi_cn=0;hi_cn<node.childNodes.length;hi_cn++) {
			highlightWord(node.childNodes[hi_cn],word);
		}
	}
	

	// And do this node itself
	if (node.nodeType == 3) { // text node
		tempNodeVal = node.nodeValue.toLowerCase();
		tempWordVal = word.toLowerCase(); // Lowercase
		if (tempNodeVal.indexOf(tempWordVal) != -1) {
			pn = node.parentNode;
			// check if we're inside a "nosearchhi" zone
			checkn = pn;
			while (checkn.nodeType != 9 && 
			checkn.nodeName.toLowerCase() != 'body') { 
			// 9 = top of doc
				if (checkn.className.match(/\bnosearchhi\b/)) { return; }
				checkn = checkn.parentNode;
			}
			if (pn.className != "searchword") {
				// word has not already been highlighted!
				nv = node.nodeValue;
				ni = tempNodeVal.indexOf(tempWordVal);
				// Create a load of replacement nodes
				before = document.createTextNode(nv.substr(0,ni));
				docWordVal = nv.substr(ni,word.length);
				after = document.createTextNode(nv.substr(ni+word.length));
				hiwordtext = document.createTextNode(docWordVal);
				hiword = document.createElement("span");
				hiword.className = "searchword";
				hiword.appendChild(hiwordtext);
				pn.insertBefore(before,node);
				pn.insertBefore(hiword,node);
				pn.insertBefore(after,node);
				pn.removeChild(node);
			}
		}
	}
}

function googleSearchHighlight() {
	// q= for Google, p= for Yahoo... Most of the search engines in the world
	var keywords = new Array('q','p','keywords','keyword','query','search','rdata');
	keywords = '='+keywords.join('=')+'=';
	if (!document.createElement) return;
	ref = window.location.search;
	if (ref.indexOf('?') == -1) ref = document.referrer;
	if (ref.indexOf('?') == -1) return;
	qs = ref.substr(ref.indexOf('?')+1);
	qs = qs.replace(/%22|%2B|[\"\-,\/]/g,' '); // Remove signs used by search requests
	qsa = qs.split('&');
	for (i=0;i<qsa.length;i++) {
		qsip = qsa[i].split('=');
	        if (qsip.length == 1) continue;
        	if (keywords.indexOf('='+qsip[0].toLowerCase()+'=') != -1) {
				words = qsip[1].replace(/\+/g,' ');
				// The tricks to add UTF-8 support
				try { words = decodeURIComponent(words); } catch(err) { }
				words = unescape(words).split(/\s+/);
				for (w=0;w<words.length;w++) {
					if(words[w].length>2) // Tricks to avoid 2 letters (or less) words
						highlightWord(document.getElementsByTagName("body")[0],words[w]);
				}
				break;
	        }
	}
}

window.onload = googleSearchHighlight;