// JavaScript Document
/**
 *	@author:	Danny Ng (http://www.dannytalk.com/2010/08/19/read-google-an…-cookie-script/)
 *	@modified:	19/08/10
 *	@notes:		Free to use and distribute without altering this comment. Would appreciate a link back :)
 */

// Strip leading and trailing white-space
String.prototype.trim = function() { return this.replace(/^\s*|\s*$/g, ''); }

// Check if string is empty
String.prototype.empty = function() {
	if (this.length == 0)
		return true;
	else if (this.length > 0)
		return /^\s*$/.test(this);
}

// Breaks cookie into an object of keypair cookie values
function crumbleCookie(c)
{
	var cookie_array = document.cookie.split(';');
	var keyvaluepair = {};
	for (var cookie = 0; cookie < cookie_array.length; cookie++)
	{
		var key = cookie_array[cookie].substring(0, cookie_array[cookie].indexOf('=')).trim();
		var value = cookie_array[cookie].substring(cookie_array[cookie].indexOf('=')+1, cookie_array[cookie].length).trim();
		keyvaluepair[key] = value;
	}

	if (c)
		return keyvaluepair[c] ? keyvaluepair[c] : null;

	return keyvaluepair;
}

/**
 *	For GA cookie explanation, see http://services.google.com/analytics/breeze/en/ga_cookies/index.html.
 *
 *	@return				-	<void>
 *
 *	@pre-condition		-	pageTracker initialised properly
 *	@post-condition		-	provides 'get' methods to access specific values in the Google Analytics cookies
 */
function gaCookies()
{
	// Cookie syntax: domain-hash.unique-id.ftime.ltime.stime.session-counter
	var utma = function() {
		var utma_array;

		if (crumbleCookie('__utma'))
			utma_array =  crumbleCookie('__utma').split('.');
		else
			return null;

		var domainhash = utma_array[0];
		var uniqueid = utma_array[1];
		var ftime = utma_array[2];
		var ltime = utma_array[3];
		var stime = utma_array[4];
		var sessions = utma_array[5];

		return {
			'cookie': utma_array,
			'domainhash': domainhash,
			'uniqueid': uniqueid,
			'ftime': ftime,
			'ltime': ltime,
			'stime': stime,
			'sessions': sessions
		};
	};

	// Cookie syntax: domain-hash.gif-requests.10.stime
	var utmb = function() {
		var utmb_array;

		if (crumbleCookie('__utmb'))
			utmb_array = crumbleCookie('__utmb').split('.');
		else
			return null;
		var gifrequest = utmb_array[1];

		return {
			'cookie': utmb_array,
			'gifrequest': gifrequest
		};
	};

	// Cookie syntax: domain-hash.value
	var utmv = function() {
		var utmv_array;

		if (crumbleCookie('__utmv'))
			utmv_array = crumbleCookie('__utmv').split('.');
		else
			return null;

		var value = utmv_array[1];

		return {
			'cookie': utmv_array,
			'value': value
		};
	};

	// Cookie syntax: domain-hash.ftime.?.?.utmcsr=X|utmccn=X|utmcmd=X|utmctr=X
	var utmz = function() {
		var utmz_array, source, medium, name, term, content, gclid;

		if (crumbleCookie('__utmz'))
			utmz_array = crumbleCookie('__utmz').split('.');
		else
			return null;

		var utms = utmz_array[4].split('|');
		for (var i = 0; i < utms.length; i++) {
			var key = utms[i].substring(0, utms[i].indexOf('='));
			var val = decodeURIComponent(utms[i].substring(utms[i].indexOf('=')+1, utms[i].length));
			val = val.replace(/^\(|\)$/g, '');	// strip () brackets
			switch(key)
			{
				case 'utmcsr':
					source = val;
					break;
				case 'utmcmd':
					medium = val;
					break;
				case 'utmccn':
					name = val;
					break;
				case 'utmctr':
					term = val;
					break;
				case 'utmcct':
					content = val;
					break;
				case 'utmgclid':
					gclid = val;
					break;
			}
		}

		return {
			'cookie': utmz_array,
			'source': source,
			'medium': medium,
			'name': name,
			'term': term,
			'content': content,
			'gclid': gclid
		};
	};

	// Establish public methods

	// utma cookies
	this.getDomainHash = function() { return (utma() && utma().domainhash) ? utma().domainhash : null };
	this.getUniqueId = function() { return (utma() && utma().uniqueid) ? utma().uniqueid : null };

	this.getInitialVisitTime = function() { return (utma() && utma().ftime) ? utma().ftime : null };
	this.getPreviousVisitTime = function() { return (utma() && utma().ltime) ? utma().ltime : null };
	this.getCurrentVisitTime = function() { return (utma() && utma().stime) ? utma().stime : null };
	this.getSessionCounter = function() { return (utma() && utma().sessions) ? utma().sessions : null };

	// utmb cookies
	this.getGifRequests = function() { return (utmb() && utmb().gifrequest) ? utmb().gifrequest : null }; 

	// utmv cookies
	this.getUserDefinedValue = function () { return (utmv() && utmv().value) ? decodeURIComponent(utmv().value) : null };

	// utmz cookies
	this.getCampaignSource = function () { return (utmz() && utmz().source) ? utmz().source : null };
	this.getCampaignMedium = function () { return (utmz() && utmz().medium) ? utmz().medium : null };
	this.getCampaignName = function () { return (utmz() && utmz().name) ? utmz().name : null };
	this.getCampaignTerm = function () { return (utmz() && utmz().term) ? utmz().term : null};
	this.getCampaignContent = function () { return (utmz() && utmz().content) ? utmz().content : null };
	this.getGclid = function () { return (utmz() && utmz().gclid) ? utmz().gclid : null };
}