Add refund function

README.md

@@ -84,7 +84,8 @@ To receive the payment notifications in your app the Plugin expects 3 event hand
 
 ```php
 
-$eventManager = TableRegistry::getTableLocator()->get('PayPal.PayPalPayments')->getEventManager();
+$payPalPayments = TableRegistry::getTableLocator()->get('PayPal.PayPalPayments');
+$eventManager = $payPalPayments->getEventManager();
 $eventManager->setEventList(new EventList());
 
 // Will be called just after PayPal redirects the customer
@@ -111,6 +112,15 @@ function($event, $remittanceIdentifier) {});
 
 ```
 
+To issue a full refund lookup the payment and issue the refund.
+
+```php
+
+$payPalPayment = $payPalPayments->findByRemittanceIdentifier($remittanceIdentifier);
+$payPalPayments->refundPayment($payPalPayment);
+
+```
+
 ## Remarks
 
 The current implementation does not support automatic handling payments in pending state.

src/Model/Table/PayPalPaymentsTable.php

@@ -8,12 +8,16 @@
 use Cake\Routing\Router;
 use Cake\Utility\Security;
 use DateTime;
+use PayPal\Api\DetailedRefund;
 use PayPal\Api\Payment;
 use PayPal\Rest\ApiContext;
 use PayPal\Auth\OAuthTokenCredential;
 use PayPal\Api\RedirectUrls;
 use PayPal\Api\PaymentExecution;
+use PayPal\Api\Refund;
+use PayPal\Api\RefundRequest;
 use PayPal\Api\RelatedResources;
+use PayPal\Api\Sale;
 use PayPal\Api\Transaction;
 use PayPal\Model\Entity\PayPalPayment;
 
@@ -165,6 +169,33 @@ public function execute(int $id, ?string $payerId)
         }
     }
 
+    /**
+     * Performs a full refund.
+     * @return bool|DetailedRefund false when payment not found
+     */
+    public function refund(int $id)
+    {
+        /** @var PayPalPayment */
+        $payPalPayment = $this->findById($id)->first();
+        if (empty($payPalPayment))
+            return false;
+
+        return $this->refundPayment($payPalPayment);
+    }
+
+    /**
+     * Performs a full refund
+     * @return DetailedRefund
+     */
+    public function refundPayment(PayPalPayment $payPalPayment)
+    {
+        $ppReq = $this->ApiGet($payPalPayment->payment_id);
+        $transactions = $ppReq->getTransactions();
+        $relatedResources = $this->getRelatedResources($transactions);
+        $sale = $relatedResources->getSale();
+        return $this->ApiRefundSale($sale);
+    }
+
     public static function getApiContext(): ApiContext
     {
         $config = Configure::read('PayPal');
@@ -220,6 +251,11 @@ protected function ApiGet($paymentId): Payment
         return \PayPal\Api\Payment::get($paymentId, self::getApiContext());
     }
 
+    protected function ApiRefundSale(Sale $sale): DetailedRefund
+    {
+        return $sale->refundSale(new RefundRequest(), self::getApiContext());
+    }
+
     private static function getCredentials(): array
     {
         $config = Configure::read('PayPal');

tests/TestCase/Model/Table/PayPalPaymentsTableTest.php

@@ -4,11 +4,12 @@
 
 use Cake\Event\EventList;
 use Cake\Event\EventManager;
-use Cake\ORM\Entity;
 use Cake\TestSuite\TestCase;
+use PayPal\Api\DetailedRefund;
 use PayPal\Api\Payment;
 use PayPal\Api\RelatedResources;
 use PayPal\Api\Sale;
+use PayPal\Api\Transaction;
 use PayPal\Model\Entity\PayPalPayment;
 use PayPal\Model\Table\PayPalPaymentsTable;
 use PHPUnit\Framework\MockObject\MockObject;
@@ -63,6 +64,34 @@ public function testRefreshState()
         $model->refreshState('1');
     }
 
+    public function testRefund()
+    {
+        /** @var MockObject|PayPalPaymentsTable */
+        $model = $this->getMockForModel('PayPal.PayPalPayments', ['ApiGet', 'ApiRefundSale', 'savePayment']);
+
+        $payment = new Payment();
+        $transaction = new Transaction();
+        $sale = new Sale();
+        $sale->setId('123');
+        $relatedResources = new RelatedResources();
+        $relatedResources->setSale($sale);
+        $transaction->setRelatedResources($relatedResources);
+        $transactions = [$transaction];
+        $payment->setTransactions($transactions);
+        $model->expects($this->once())
+            ->method('ApiGet')
+            ->with('PayPalId')
+            ->willReturn($payment);
+        $detailRefund = new DetailedRefund();
+        $model->expects($this->once())
+            ->method('ApiRefundSale')
+            ->with($sale)
+            ->willReturn($detailRefund);
+
+        $actual = $model->refund(1);
+        $this->assertEquals($detailRefund, $actual);
+    }
+
     public function testSavePayment()
     {
         /** @var PayPalPaymentsTable */