// Cookie length in days
let iCookieLength = 30;
// Name of the first party cookie to utilise for last click referrer de-duplication
let sCookieName = 'source';
// The parameter used by networks and other marketing channels to tell you who drove the traffic
let sSourceParameterName = 'utm_source';

let _getQueryStringValue = function (sParameterName) {
    let aQueryStringPairs = document.location.search.substring(1).split('&');
    for (let i = 0; i < aQueryStringPairs.length; i++) {
        let aQueryStringParts = aQueryStringPairs[i].split('=');
        if (sParameterName.toLowerCase() === aQueryStringParts[0].toLowerCase()) {
            return aQueryStringParts[1];
        }
    }
};

let _setCookie = function (sCookieName, sCookieContents, iCookieLength) {
    let dCookieExpires = new Date();
    dCookieExpires.setTime(dCookieExpires.getTime() + (iCookieLength * 24 * 60 * 60 * 1000));
    document.cookie = sCookieName + '=' + sCookieContents + '; expires=' + dCookieExpires.toGMTString() + '; path=/;';
};


if (_getQueryStringValue(sSourceParameterName)) {
    _setCookie(sCookieName, _getQueryStringValue(sSourceParameterName), iCookieLength);
} else if (_getQueryStringValue('gclid')) {
    _setCookie(sCookieName, 'googleAds', iCookieLength);
}
else if (_getQueryStringValue('fbclid')) {
    _setCookie(sCookieName, 'facebook', iCookieLength);
}
else if (_getQueryStringValue('msclid')) {
    _setCookie(sCookieName, 'bing', iCookieLength);
}
else if (_getQueryStringValue('insid')) {
    _setCookie(sCookieName, 'instagram_stories', iCookieLength);
}