vite.config.ts

import react from '@vitejs/plugin-react';
import { defineConfig } from 'vite';
import { createHtmlPlugin } from 'vite-plugin-html';

// https://vitejs.dev/config/
export default defineConfig(() => {
  const gtagId = process.env.VITE_GTAG_ID;

  const analyticsScript = gtagId
    ? `
    <script async src="https://www.googletagmanager.com/gtag/js?id=${gtagId}"></script>
    <script>
      window.dataLayer = window.dataLayer || [];
      function gtag() {
        dataLayer.push(arguments);
      }
      gtag('js', new Date());

      gtag('config', '${gtagId}');
    </script>
    `
    : `
    <script>
      window.dataLayer = [];
      function gtag() { dataLayer.push(arguments); }
    </script>
    `;

  return {
    plugins: [
      react(),
      createHtmlPlugin({
        minify: true,
        inject: {
          data: {
            analyticsScript,
          },
        },
      }),
    ],
  };
});