{% if ACTIVITY_REQUEST_ID %}
<script>
(function () {
  const requestId = "{{ ACTIVITY_REQUEST_ID|escapejs }}";
  if (!requestId) return;

  const start = Date.now();
  const url = "{% url 'page_time' %}";

  function sendDuration() {
    const seconds = Math.round((Date.now() - start) / 1000);
    if (seconds < 1) return;

    const body = JSON.stringify({ request_id: requestId, duration_seconds: seconds });
    if (navigator.sendBeacon) {
      navigator.sendBeacon(url, new Blob([body], { type: "application/json" }));
      return;
    }
    fetch(url, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: body,
      keepalive: true,
    }).catch(function () {});
  }

  document.addEventListener("visibilitychange", function () {
    if (document.visibilityState === "hidden") sendDuration();
  });
  window.addEventListener("pagehide", sendDuration);
})();
</script>
{% endif %}