function calculate_sale_percentage() {
    // Get the current post object
    $post = get_post();

    // If it's not a product, return an empty string
    if ($post->post_type !== 'product') return '';

    // Get an instance of the WC_Product object
    $product = wc_get_product($post->ID);

    // If we don't have a valid product object, return an empty string
    if (!$product) return '';

    // Initialize output
    $output = '';

    if ($product->is_type('variable')) {
        // Handle variable products
        $regular_price = $product->get_variation_regular_price('min');
        $sale_price = $product->get_variation_sale_price('min');
    } else {
        // Handle simple and other types of products
        $regular_price = $product->get_regular_price();
        $sale_price = $product->get_sale_price();
    }

    // Check if the product is on sale and regular price is greater than 0
    if ($product->is_on_sale() && $regular_price > 0) {
        $percentage = round(((($regular_price - $sale_price) / $regular_price) * 100));

        // Create output with classes for styling
        $output = '<div class="sale-badge">';
        $output .= '<span class="sale-value">' . $percentage . '</span>';
        $output .= '<span class="sale-percentage">%</span>';
        $output .= '<span class="sale-text"> Off</span>';
        $output .= '</div>';
    }

    // Return the output
    return $output;
}

add_shortcode('sale_percentage', 'calculate_sale_percentage');