invoiceninja/app/Services/Invoice/HandleRestore.php

<?php
/**
 * Invoice Ninja (https://invoiceninja.com).
 *
 * @link https://github.com/invoiceninja/invoiceninja source repository
 *
 * @copyright Copyright (c) 2020. Invoice Ninja LLC (https://invoiceninja.com)
 *
 * @license https://opensource.org/licenses/AAL
 */

namespace App\Services\Invoice;

use App\Models\Invoice;
use App\Services\AbstractService;
use Illuminate\Support\Facades\DB;

class HandleRestore extends AbstractService
{

    private $invoice;

    public function __construct(Invoice $invoice)
    {
        $this->invoice = $invoice;
    }

    public function run()
    {

        if(!$this->invoice->is_deleted)
            return $this->invoice;

    	//determine whether we need to un-delete payments OR just modify the payment amount /applied balances.
    	
        foreach($this->invoice->payments as $payment)
        {
            //restore the payment record
            $payment->restore();

            //determine the paymentable amount before paymentable restoration
            $pre_restore_amount =    $payment->paymentables()
                                     ->where('paymentable_type', '=', 'invoices')
                                     ->sum(\DB::raw('amount'));

            //restore the paymentables
            $payment->paymentables()
                    ->where('paymentable_type', '=', 'invoices')
                    ->where('paymentable_id', $this->invoice->id)
                    ->restore();

            //determine the post restore paymentable amount (we need to increment the payment amount by the difference between pre and post)
            $payment_amount = $payment->paymentables()
                                     ->where('paymentable_type', '=', 'invoices')
                                     ->sum(\DB::raw('amount'));

            info($payment->amount . " == " . $payment_amount);

            if($payment->amount == $payment_amount) {

                $payment->is_deleted = false;
                $payment->save();

            }
            else {

                $payment->is_deleted = false;
                $payment->amount += ($payment_amount - $pre_restore_amount);
                $payment->applied += ($payment_amount - $pre_restore_amount);
                $payment->save();
            }

        }

    	//adjust ledger balance
    	$this->invoice->ledger()->updateInvoiceBalance($this->invoice->balance, 'Restored invoice {$this->invoice->number}')->save();

    	//adjust paid to dates
        $this->invoice->client->service()->updatePaidToDate($payment_amount - $pre_restore_amount)->save();

        $this->invoice->client->service()->updateBalance($this->invoice->balance)->save();

        $this->invoice->ledger()->updatePaymentBalance(($payment_amount - $pre_restore_amount), 'Restored payment for invoice {$this->invoice->number}')->save();

        $this->windBackInvoiceNumber();

        return $this->invoice;    	
    }


    private function windBackInvoiceNumber()
    {

        $findme = '_' . ctrans('texts.deleted');

        $pos = strpos($this->invoice->number, $findme);

        $new_invoice_number = substr($this->invoice->number, 0, $pos);

        try {
            $this->invoice->number = $new_invoice_number;
            $this->invoice->save();
        }
        catch(\Exception $e){
            info("I could not wind back the invoice number");
        }

    }
}