(function () {
    'use strict';
    if (window.fiTrafficTracking || window.top !== window.self) return;
    window.fiTrafficTracking = true;

    var path = location.pathname.replace(/\/index\.php$/, '/').replace(/\/$/, '');
    var area = path.split('/')[1] || (location.hostname === 'school.feisinfo.org' ? 'crm' : 'home');
    var selected = new URLSearchParams(location.search).get('section') || '';
    var lastSent = null;
    var timer;
    var pending = Promise.resolve();

    function send() {
        if (document.visibilityState !== 'visible' || selected === lastSent) return;
        lastSent = selected;
        var body = new URLSearchParams({
            section: selected,
            device: matchMedia('(max-width: 767px)').matches ? 'mobile' : 'desktop'
        });
        pending = pending.then(function () {
            return fetch('/layout/traffic-collect.php', {
                method: 'POST', body: body, credentials: 'same-origin',
                referrerPolicy: 'same-origin', keepalive: true
            });
        }).catch(function () {});
    }

    function schedule() {
        clearTimeout(timer);
        timer = setTimeout(send, 180);
    }

    document.addEventListener('fi:section-view', function (event) {
        if (!event.detail || event.detail.area !== area || typeof event.detail.section !== 'string') return;
        selected = event.detail.section;
        schedule();
    });
    window.addEventListener('pageshow', function (event) {
        if (!event.persisted) return;
        lastSent = null;
        schedule();
    });
    document.addEventListener('visibilitychange', function () {
        if (document.visibilityState === 'visible') schedule();
    });
    if (document.readyState === 'loading') document.addEventListener('DOMContentLoaded', schedule);
    else schedule();
})();