invoiceninja/app/Factory/CloneCreditFactory.php

<?php

/**
 * Invoice Ninja (https://invoiceninja.com).
 *
 * @link https://github.com/invoiceninja/invoiceninja source repository
 *
 * @copyright Copyright (c) 2021. Invoice Ninja LLC (https://invoiceninja.com)
 *
 * @license https://opensource.org/licenses/AAL
 */

namespace App\Factory;

use App\Models\Credit;

class CloneCreditFactory
{
    public static function create(Credit $credit, $user_id) : ?Credit
    {
        $clone_credit = $credit->replicate();
        $clone_credit->status_id = credit::STATUS_DRAFT;
        $clone_credit->number = null;
        $clone_credit->date = null;
        $clone_credit->due_date = null;
        $clone_credit->partial_due_date = null;
        $clone_credit->user_id = $user_id;
        //$clone_credit->balance = $credit->amount;
        $clone_credit->line_items = $credit->line_items;

        return $clone_credit;
    }
}