var fcAttribution = (function(fcAttribution) {

    var attrCookie = '_fc_attr',
        loggedInCookie = '_fc_logged_in',
        cookieDays = 182, // ~ 6 months
        attrParams = ['utm_medium', 'utm_source', 'utm_term', 'utm_content', 'utm_campaign', 'gclid'];

    function getCookie(name) {
        name = name + '=';
        var cookies = document.cookie.split(';');

        for (var i = 0; i < cookies.length; i++) {
            var cookie = cookies[i];
            while (cookie.charAt(0) == ' ') {
                cookie = cookie.substring(1);
            }
            if (cookie.indexOf(name) == 0) {
                return cookie.substring(name.length, cookie.length);
            }
        }

        return '';
    }

    function setCookie(name, value, expiryDays) {
        var d = new Date();
        d.setTime(d.getTime() + (expiryDays * 24 * 60 * 60 * 1000));
        var expires = 'expires=' +  d.toUTCString();
        document.cookie = name + '=' + value + '; ' + expires + '; domain=.fullcontact.com; path=/';
    }

    function deleteCookie(name) {
        setCookie(name, '', -1);
    }

    function getUrlParameter(name) {
        name = name.replace(/[\[]/, '\\[').replace(/[\]]/, '\\]');
        var regex = new RegExp('[\\?&]' + name + '=([^&#]*)'),
            results = regex.exec(location.search);

        return results === null ? '' : decodeURIComponent(results[1].replace(/\+/g, ' '));
    };

    function getFCAttrs() {
        var cookieVal = getCookie(attrCookie);
        if (cookieVal) {
            return JSON.parse(atob(cookieVal));
        }

        return [];
    }

    function storeAttributions() {
        var referrer = document.referrer,
            isLoggedIn = getCookie(loggedInCookie);

        // Make sure that there is a referrer, we aren't logged in, and the referrer does not match https://*.fullcontact.com*
        if (referrer && !referrer.match(/https:\/\/[\w]+\.fullcontact\.com.*/i) && !isLoggedIn && typeof atob === 'function' && typeof btoa === 'function') {
            var fcAttrs = getFCAttrs(),
                attrKey,
                paramVal,
                attr = { referrer: referrer };

            for (var i in attrParams) {
                attrKey = attrParams[i];
                paramVal = getUrlParameter(attrKey);
                if (paramVal) {
                    attr[attrKey] = paramVal;
                }
            }
            attr.click_time = (new Date()).toISOString().slice(0, -5);
            fcAttrs.push(attr);
            setCookie(attrCookie, btoa(JSON.stringify(fcAttrs)), cookieDays);
        }

        return false;
    }

    function clearCookies() {
        deleteCookie(attrCookie);
    }

    fcAttribution.storeAttributions = storeAttributions;
    fcAttribution.clearCookies = clearCookies;

    return fcAttribution;

})(fcAttribution || {});

fcAttribution.storeAttributions();