import { useEffect } from 'react';
import { useLocation } from 'react-router-dom';

declare global {
  interface Window {
    gtag?: (...args: any[]) => void;
    dataLayer?: any[];
    fbq?: (...args: any[]) => void;
    _fbq?: any;
  }
}

export function Analytics() {
  const location = useLocation();

  // Inicialização dos Scripts (Executado apenas uma vez)
  useEffect(() => {
    // 1. Google Analytics (GA4)
    const gaId = import.meta.env.VITE_GA_MEASUREMENT_ID;
    if (gaId && !document.getElementById('ga-script')) {
      const script1 = document.createElement('script');
      script1.async = true;
      script1.src = `https://www.googletagmanager.com/gtag/js?id=${gaId}`;
      script1.id = 'ga-script';
      document.head.appendChild(script1);

      const script2 = document.createElement('script');
      script2.innerHTML = `
        window.dataLayer = window.dataLayer || [];
        function gtag(){dataLayer.push(arguments);}
        gtag('js', new Date());
        gtag('config', '${gaId}');
      `;
      document.head.appendChild(script2);
    }

    // 2. Facebook Pixel
    const fbPixelId = import.meta.env.VITE_FB_PIXEL_ID;
    if (fbPixelId && !document.getElementById('fb-pixel-script')) {
      const script = document.createElement('script');
      script.id = 'fb-pixel-script';
      script.innerHTML = `
        !function(f,b,e,v,n,t,s)
        {if(f.fbq)return;n=f.fbq=function(){n.callMethod?
        n.callMethod.apply(n,arguments):n.queue.push(arguments)};
        if(!f._fbq)f._fbq=n;n.push=n;n.loaded=!0;n.version='2.0';
        n.queue=[];t=b.createElement(e);t.async=!0;
        t.src=v;s=b.getElementsByTagName(e)[0];
        s.parentNode.insertBefore(t,s)}(window, document,'script',
        'https://connect.facebook.net/en_US/fbevents.js');
        fbq('init', '${fbPixelId}');
        fbq('track', 'PageView');
      `;
      document.head.appendChild(script);
    }

    // 3. Google AdSense
    const adsenseId = import.meta.env.VITE_ADSENSE_CLIENT_ID;
    if (adsenseId && !document.getElementById('adsense-script')) {
      const script = document.createElement('script');
      script.id = 'adsense-script';
      script.async = true;
      script.src = `https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=${adsenseId}`;
      script.crossOrigin = 'anonymous';
      document.head.appendChild(script);
    }
  }, []);

  // Rastreamento de Mudança de Rota (Page Views)
  useEffect(() => {
    const gaId = import.meta.env.VITE_GA_MEASUREMENT_ID;
    if (gaId && window.gtag) {
      window.gtag('config', gaId, {
        page_path: location.pathname + location.search,
      });
    }

    const fbPixelId = import.meta.env.VITE_FB_PIXEL_ID;
    if (fbPixelId && typeof window.fbq === 'function') {
      window.fbq('track', 'PageView');
    }
  }, [location]);

  return null; // Este componente não renderiza nada na tela
}