Add authorize handling for using a stored billing agreement

Author: eileenmcnaughton

src/Message/RestAuthorizeRequest.php

@@ -253,7 +253,20 @@ public function getData()
             $data['transactions'][0]['item_list']["items"] = $itemList;
         }
 
-        if ($this->getCardReference()) {
+        if ($this->getCardReference() && substr($this->getCardReference(), 0, 2) === 'B-') {
+            // Card references can be for a billing agreement (format B-....) or a stored card format CARD-...
+            // here billing agreement
+            // https://developer.paypal.com/docs/limited-release/reference-transactions/#use-a-reference-transaction-to-make-a-payment
+            $this->validate('amount');
+            $data['payer']['funding_instruments'][] = array(
+              'billing' => array(
+                'billing_agreement_id' => $this->getCardReference(),
+              ),
+            );
+            $data['payer']['payment_method'] = 'paypal';
+        } elseif ($this->getCardReference()) {
+            // stored card
+            //https://developer.paypal.com/docs/integration/direct/vault/#pay-with-vaulted-card
             $this->validate('amount');
 
             $data['payer']['funding_instruments'][] = array(

src/Message/RestCompleteCreateCardRequest.php

@@ -6,7 +6,7 @@
 namespace Omnipay\PayPal\Message;
 
 /**
- * PayPal REST Complete Subscription Request
+ * PayPal REST Complete Create Card Request
  *
  * Use this call to create a billing agreement after the buyer approves it.
  *

src/Message/RestResponse.php

@@ -72,11 +72,26 @@ public function getCode()
 
     /**
      * Get a string that will represent the stored card in future requests.
+     *
+     * If they have authorised the payment through submitting a card through Omnipay
+     * this will be a reference to the card in the vault. If they have authorised the payment
+     * through paypal this will be a reference to an approved billing agreement.
      */
     public function getCardReference()
     {
+        if ($this->isPaypalApproval()) {
+            return $this->data['payer']['funding_instruments'][0]['billing']['billing_agreement_id'];
+        }
         if (isset($this->data['id'])) {
             return $this->data['id'];
         }
     }
+
+    public function isPaypalApproval()
+    {
+        if (!isset($this->data['payer']['payment_method'])) {
+            return false;
+        }
+        return ($this->data['payer']['payment_method'] === 'paypal');
+    }
 }