if ($view->id() === 'more_like_this' &&
    $view->current_display === 'rest_similar_by_popularity'
  ) {
    $product_id = $view->args[0];
    $product = \Drupal::entityTypeManager()
      ->getStorage('commerce_product')
      ->load($product_id);
    $term = $product->get('app_group')->referencedEntities()[0];
    $top_term = get_top_level_parent($term);
    if ($top_term) {
      switch ($top_term->get('name')->value) {
        case 'Kültéri lámpák' || 'Beltéri lámpák':
          // Recommended manufacturer.
          $manufacturer = \Drupal::entityTypeManager()
            ->getStorage('taxonomy_term')
            ->loadByProperties([
              'vid' => 'manufacturer',
              'name' => 'AZzardo',
            ]);
          $manufacturer = reset($manufacturer);
          // Get all products belonging to the same term (group)
          // and recommended manufacturer.
          $products = \Drupal::entityTypeManager()
            ->getStorage('commerce_product')
            ->loadByProperties([
              'app_group' => $term->id(),
              'app_manufacturer' => $manufacturer->id(),
            ]);
          foreach ($products as $key => $product) {
            $onDiscount = checkIfOnDiscountAndOnStock($product);
            if (!$onDiscount) {
              unset($products[$key]);
            }
          }
          $product_ids = [];
          array_walk($products, function ($product) use (&$product_ids) {
            $product_ids[] = $product->id();
          });
          $query->addWhere(0, 'product_id', $product_ids, 'IN');
          break;
      }
    }
  }
  

function checkIfOnDiscountAndOnStock($product): bool {
  $variations = $product->getVariations();
  foreach ($variations as $variation) {
    if (!empty($variation->get('list_price')) && $variation->get('app_purchaseitem')->value == 1) {
      if ($variation->get('list_price')->number > $variation->get('price')->number) {
        return TRUE;
      }
    }
  }
  return FALSE;
}

function get_top_level_parent($term) {
  if ($term->hasField('parent') && $term->get('parent')->target_id !== '0') {
    $term = $term->get('parent')->referencedEntities()[0];
    return get_top_level_parent($term);
  }
  else {
    return $term;
  }
}