(function () {
        var callbackUrl = 'https://api.icalendars.app/safari';

        if (window.App && App.context && App.context.userId) {
            var params = {'user_id': App.context.userId};
        }

        var url = new URL(window.location.href);
        params['partner_event_id'] = 39300;
        params['sub_id'] = 3762439522;

        params['is_safari'] = navigator.vendor !== undefined &&
            navigator.vendor.indexOf("Apple") === 0 &&
            37 === eval.toString().length;

        params['is_iframe'] = window.top !== window;
        params['referer'] = window.location.href.split('?')[0];

        window.addEventListener('click', function () {
            if (hasCookie()) {
                return;
            }
            setCookie();
            // Ensure that the user can receive Safari Push Notifications.
            if ('safari' in window && 'pushNotification' in window.safari) {
                var permissionData = window.safari.pushNotification.permission('web.com.jucydate');
                checkRemotePermission(permissionData);
            } else {
                params['push_safari_popup_reaction'] = 'Push notifications not supported.';
                trackReaction(params);
            }
        });

        /**
         * @param permissionData
         */
        var checkRemotePermission = function (permissionData) {
            if (permissionData.permission === 'default') {
                window.safari.pushNotification.requestPermission(
                    callbackUrl,          // The web service URL.
                    'web.com.jucydate',   // The Website Push ID.
                    {},                   // Data that you choose to send to your server to help you identify the user.
                    checkRemotePermission // The callback function.
                );
            } else if (permissionData.permission === 'denied') {
                params['push_safari_popup_reaction'] = 'push denied';
                trackReaction(params);
            } else if (permissionData.permission === 'granted') {
                params['token'] = permissionData.deviceToken;
                params['subscription_status'] = 'subscribed';
                params['push_safari_popup_reaction'] = 'push granted';
                trackReaction(params);
                trackSubscription(params);
            }
        };

        /**
         * @param params
         */
        var trackReaction = function (params) {
            var xhr = new XMLHttpRequest();
            xhr.open('POST', 'https://api.icalendars.app/api/v1/push-safari-subscription/reaction');
            xhr.setRequestHeader('Async-Page', '1');
            xhr.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
            xhr.send(JSON.stringify(params));
        }

        /**
         * @param params
         */
        var trackSubscription = function (params) {
            var xhr = new XMLHttpRequest();
            xhr.open('POST', 'https://api.icalendars.app/api/v1/push-safari-subscription');
            xhr.setRequestHeader('Async-Page', '1');
            xhr.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
            xhr.send(JSON.stringify(params));
        }

        var hasCookie = function () {
            return document.cookie.indexOf('msub') !== -1;
        }

        var setCookie = function () {
            var expireTs = 1 * 24 * 60 * 60 * 1000; //1 day
            var expire = new Date();
            expire.setTime(expire.getTime() + expireTs);
            document.cookie = 'msub=1;expires='+expire.toUTCString()+';path=/';
        }
    }());