/* Zyap OS Website Intelligence — first-party tracking */
(function () {
  var script = document.currentScript;
  var siteKey = script && script.getAttribute('data-site-key');
  if (!siteKey) { return; }

  var endpoint = script.src.replace(/\/zyap-analytics\.js.*$/, '/collect');
  var STORAGE_VISITOR = 'zyap_wi_visitor';
  var STORAGE_SESSION = 'zyap_wi_session';

  function id() {
    return 'x' + Math.random().toString(36).slice(2) + Date.now().toString(36);
  }
  function stored(store, key) {
    try { var v = store.getItem(key); if (!v) { v = id(); store.setItem(key, v); } return v; }
    catch (e) { return id(); }
  }

  var visitorId = stored(window.localStorage, STORAGE_VISITOR);
  var sessionId = stored(window.sessionStorage, STORAGE_SESSION);
  var params = new URLSearchParams(window.location.search);

  function send(body) {
    var payload = JSON.stringify(Object.assign({
      site_key: siteKey,
      session_id: sessionId,
      visitor_id: visitorId
    }, body));
    // sendBeacon survives the page unloading; fetch is the fallback.
    if (navigator.sendBeacon) {
      navigator.sendBeacon(endpoint, new Blob([payload], { type: 'application/json' }));
    } else {
      fetch(endpoint, { method: 'POST', headers: { 'Content-Type': 'application/json' },
                        body: payload, keepalive: true }).catch(function () {});
    }
  }

  function pageview() {
    var timing = window.performance && window.performance.timing;
    var loadMs = timing && timing.loadEventEnd && timing.navigationStart
      ? timing.loadEventEnd - timing.navigationStart : null;
    send({
      referrer: document.referrer || null,
      utm_source: params.get('utm_source'),
      utm_medium: params.get('utm_medium'),
      utm_campaign: params.get('utm_campaign'),
      screen_resolution: window.screen.width + 'x' + window.screen.height,
      language: navigator.language,
      pageviews: [{
        path: window.location.pathname,
        title: document.title,
        load_time_ms: loadMs && loadMs > 0 ? loadMs : null
      }]
    });
  }

  window.zyapTrack = function (name, properties, value) {
    send({ events: [{ name: name, path: window.location.pathname,
                      properties: properties || {}, value: value }] });
  };

  function loadTags() {
    fetch(endpoint.replace(/\/collect$/, '/tags') + '?site_key=' + encodeURIComponent(siteKey))
      .then(function (r) { return r.ok ? r.json() : null; })
      .then(function (cfg) {
        if (!cfg || !cfg.tracking_enabled) { return; }
        function loadScript(src, onload) {
          if (document.querySelector('script[src="' + src + '"]')) { return; }
          var s = document.createElement('script');
          s.async = true; s.src = src; if (onload) { s.onload = onload; }
          document.head.appendChild(s);
        }
        var ga4 = cfg.ga4_measurement_id && encodeURIComponent(cfg.ga4_measurement_id);
        var gtm = cfg.gtm_container_id && encodeURIComponent(cfg.gtm_container_id);
        if (ga4) {
          window.dataLayer = window.dataLayer || [];
          window.gtag = window.gtag || function () { window.dataLayer.push(arguments); };
          loadScript('https://www.googletagmanager.com/gtag/js?id=' + ga4, function () {
            window.gtag('js', new Date());
            window.gtag('config', cfg.ga4_measurement_id);
          });
        }
        if (gtm) {
          window.dataLayer = window.dataLayer || [];
          window.dataLayer.push({ 'gtm.start': new Date().getTime(), event: 'gtm.js' });
          loadScript('https://www.googletagmanager.com/gtm.js?id=' + gtm);
        }
      })
      .catch(function () {});
  }

  if (document.readyState === 'complete') { pageview(); loadTags(); }
  else { window.addEventListener('load', function () { pageview(); loadTags(); }); }
})();