(() => {
  const GTM_ID = "GTM-MRBQ3D5";
  const GTM_SRC = `https://www.googletagmanager.com/gtm.js?id=${GTM_ID}`;
  const TRUSTARC_READY_EVENT = "ph:gdpr:OptanonWrapperUpdated";

  window.__phGtmLoaded = window.__phGtmLoaded || false;

  function isGtmAlreadyInjected() {
    const scriptExists = !!document.querySelector(
      `script[src*="googletagmanager.com/gtm.js?id=${GTM_ID}"]`
    );

    const gtmRuntimeExists =
      window.google_tag_manager &&
      Object.prototype.hasOwnProperty.call(window.google_tag_manager, GTM_ID);

    return scriptExists || gtmRuntimeExists;
  }

  function isGpcOptedOut() {
    return navigator.globalPrivacyControl === true;
  }

  function isTrustArcReady() {
    return !!(window.truste && window.truste.cma);
  }

  function loadGtm() {
    if (window.__phGtmLoaded) return;
    if (isGpcOptedOut()) return;
    if (isGtmAlreadyInjected()) return;

    window.dataLayer = window.dataLayer || [];
    window.dataLayer.push({
      "gtm.start": Date.now(),
      event: "gtm.js"
    });

    const script = document.createElement("script");
    script.async = true;
    script.src = GTM_SRC;

    const nonceEl = document.querySelector("[nonce]");
    if (nonceEl) {
      script.nonce = nonceEl.nonce || nonceEl.getAttribute("nonce");
    }

    script.onload = () => {
      window.__phGtmLoaded = true;
    };

    document.head.appendChild(script);
  }

  function onTrustArcReady() {
    loadGtm();
  }

  document.addEventListener(TRUSTARC_READY_EVENT, onTrustArcReady, { once: true });

  if (isTrustArcReady()) {
    onTrustArcReady();
  }
})();