import Script from "next/script";

/**
 * Google Consent Mode v2 — defaults set to "denied" before any tag loads.
 * After the user makes a choice, CookieBanner calls gtag('consent','update', ...).
 *
 * GTM/GA inject sadece site_settings.gtm_id doluysa yapılır.
 */
export function ConsentInit({ gtmId }: { gtmId?: string | null }) {
  return (
    <>
      <Script id="consent-default" strategy="beforeInteractive">
        {`
          window.dataLayer = window.dataLayer || [];
          function gtag(){dataLayer.push(arguments);}
          window.gtag = gtag;
          gtag('consent', 'default', {
            ad_storage: 'denied',
            ad_user_data: 'denied',
            ad_personalization: 'denied',
            analytics_storage: 'denied',
            functionality_storage: 'granted',
            personalization_storage: 'denied',
            security_storage: 'granted',
            wait_for_update: 500,
          });
        `}
      </Script>

      {gtmId && (
        <>
          <Script id="gtm-script" strategy="afterInteractive">
            {`
              (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start': new Date().getTime(),event:'gtm.js'});
              var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';
              j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
              })(window,document,'script','dataLayer','${gtmId}');
            `}
          </Script>
          <noscript>
            <iframe
              src={`https://www.googletagmanager.com/ns.html?id=${gtmId}`}
              height="0"
              width="0"
              style={{ display: "none", visibility: "hidden" }}
            />
          </noscript>
        </>
      )}
    </>
  );
}