Drupal 8 Send Google Analytics Event from PHP Back-end

  /**
   * Send Google analytics tracking event.
   *
   * @param mixed $action
   *   Event action.
   */
  public function sendGoogleTrackingEvent($action) {
    if (!$this->isProduction()) return;

    $googleAnalyticsUA = 'UA-XXXXXXXX-XX';

    // phpcs:disable
    $data = [
      'v' => 1,
      't' => 'event',
      'tid' => $googleAnalyticsUA,
      'cid' => \Drupal::service('uuid')->generate(),
      'ec' => 'Category name',
      'ea' => 'Action name,
      'el' => 'Label name',
      'uip' => \Drupal::request()->getClientIp(),
      'ua' => $_SERVER['HTTP_USER_AGENT'],
    ];
    // phpcs:enable

    $url = 'https://www.google-analytics.com/collect';
    $content = http_build_query($data);
    $content = utf8_encode($content);

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT']);
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-type: application/x-www-form-urlencoded']);
    curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
    curl_setopt($ch, CURLOPT_POST, TRUE);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $content);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
    curl_exec($ch);
    curl_close($ch);
  }

  /**
   * Check if app is running in production.
   */
  public function isProduction() {
    return (strpos($_SERVER['HTTP_HOST'], 'production.com') !== FALSE);
  }

}