(function ($, Drupal, drupalSettings) {
  function getCookie(cname) {
    var name = cname + "=";
    var decodedCookie = decodeURIComponent(document.cookie);
    var ca = decodedCookie.split(";");
    for (var i = 0; i < ca.length; i++) {
      var c = ca[i];
      while (c.charAt(0) == " ") {
        c = c.substring(1);
      }
      if (c.indexOf(name) == 0) return c.substring(name.length, c.length);
    }
    return "";
  }

  function injectGTM(gtmId) {
    // Check if GTM is already loaded
    const check = document.getElementById("gtm-v2-loader");
    if (check) {
      console.log("[info] GTM v2 already loaded.");
      return;
    }

    var ifr = document.createElement("iframe");
    ifr.src = `https://www.googletagmanager.com/ns.html?id=${gtmId}`;
    ifr.height = "0";
    ifr.width = "0";
    ifr.style.display = "none";
    ifr.style.visibility = "hidden";

    var ns = document.createElement("noscript");
    ns.appendChild(ifr);
    document.body.insertBefore(ns, document.body.firstChild);

    var s = document.createElement("script");
    s.id = "gtm-v2-loader";
    s.setAttribute(
      "src",
      `https://www.googletagmanager.com/gtm.js?id=${gtmId}`
    );
    s.async = true;
    document.head.appendChild(s);

    window.dataLayer = window.dataLayer || [];
    window.gtag = function () {
      window.dataLayer.push({
        "gtm.start": new Date().getTime(),
        event: "gtm.js",
      });
    };
    window.gtag();
    console.log("[info] GTM v2 loaded.");
  }

  /**
   * @param {string} gtmId
   */
  function checkAndInject(gtmId) {
    var cookieValue = getCookie("CookieConsent");
    if (cookieValue !== "" && cookieValue.indexOf("statistics:true") > 0) {
      return injectGTM(gtmId);
    }
    console.log("[info] No privacy cookies accepted.");
    return false;
  }

  Drupal.behaviors.dabGTMv2 = {
    attach: function (context, settings) {
      /**
       * @type {string|undefined} gtmId
       */
      const gtmId = drupalSettings?.dab_google_gtm_v2?.gtm_id;
      const gtmCookiebotEnabled =
        drupalSettings?.dab_google_gtm_v2?.gtm_cookiebot_enabled || false;

      if (!gtmId || gtmId.length <= 0) {
        return;
      }

      $(document.body)
        .once("dab-gtm-v2")
        .each(function () {
          $(function () {
            if (!gtmCookiebotEnabled) {
              return injectGTM(gtmId);
            }

            checkAndInject(gtmId);

            $(window).on("CookiebotOnAccept", function (e) {
              console.log("[event] Cookies accepted.");
              injectGTM(gtmId);
            });
          });
        });
    },
  };
})(jQuery, Drupal, drupalSettings);