function create_used_product(WP_REST_Request $request) {
    $base_sku = $request->get_param('sku');
    $discount_percentage = $request->get_param('discount'); // Get discount percentage from request
    $base_product = wc_get_product_id_by_sku($base_sku);

    if (!$base_product) {
        return new WP_Error('no_product', 'Base product not found', array('status' => 404));
    }

    $base_product_obj = wc_get_product($base_product);
    $used_sku_prefix = $base_sku . '-USED-';

    // Collect all existing used SKUs for the base product
    $existing_skus = [];
    $args = [
        'post_type' => 'product',
        'posts_per_page' => -1,
        'post_status' => 'publish',
        'meta_query' => [
            [
                'key' => '_sku',
                'value' => $used_sku_prefix,
                'compare' => 'LIKE'
            ]
        ]
    ];
    
    $query = new WP_Query($args);
    if ($query->have_posts()) {
        while ($query->have_posts()) {
            $query->the_post();
            $existing_skus[] = get_post_meta(get_the_ID(), '_sku', true);
        }
    }
    wp_reset_postdata(); // Reset post data

    // Find the next available SKU
    $i = 1; // Start from 1 for USED-0001
    $used_sku = $used_sku_prefix . str_pad($i, 4, '0', STR_PAD_LEFT);
    while (in_array($used_sku, $existing_skus)) {
        $i++;
        $used_sku = $used_sku_prefix . str_pad($i, 4, '0', STR_PAD_LEFT);
    }

    // Validate discount percentage
    if (!is_numeric($discount_percentage) || $discount_percentage <= 0 || $discount_percentage >= 100) {
        return new WP_Error('invalid_discount', 'Discount percentage must be a number between 0 and 100', array('status' => 400));
    }

    // Calculate the used product price based on the discount percentage
    $regular_price = $base_product_obj->get_regular_price();
    if (empty($regular_price) || !is_numeric($regular_price)) {
        return new WP_Error('invalid_price', 'Base product price is not set or invalid', array('status' => 400));
    }
    $regular_price = floatval($regular_price); // Ensure it's a float
    $used_price = $regular_price * (1 - ($discount_percentage / 100)); // Apply discount

    // Create the new product
    $used_product = array(
        'post_title'   => 'Used ' . $base_product_obj->get_name(),
        'post_status'  => 'publish',
        'post_type'    => 'product',
        'post_excerpt' => $base_product_obj->get_description(),
        'post_content' => $base_product_obj->get_description(), // Copy description
        'post_excerpt' => $base_product_obj->get_short_description(), // Copy short description
    );

    // Insert the product into the database
    $product_id = wp_insert_post($used_product);
    if (!$product_id) {
        return new WP_Error('product_creation_failed', 'Failed to create product', array('status' => 500));
    }

    // Set the SKU and price
    update_post_meta($product_id, '_sku', $used_sku);
    update_post_meta($product_id, '_price', $used_price);
    update_post_meta($product_id, '_regular_price', $used_price);
    update_post_meta($product_id, '_discount_percentage', $discount_percentage); // Store discount percentage

    // Copy product categories
    $terms = wp_get_post_terms($base_product, 'product_cat', array("fields" => "ids"));
    if (!empty($terms)) {
        wp_set_object_terms($product_id, $terms, 'product_cat');
    }

    // Copy stock status
    $stock_status = $base_product_obj->get_stock_status();
    update_post_meta($product_id, '_stock_status', $stock_status);

    // Copy any additional meta data you need
    // Example: update_post_meta($product_id, 'custom_meta_key', get_post_meta($base_product, 'custom_meta_key', true));

    return array('product_id' => $product_id, 'sku' => $used_sku);
}