Add refund request

modification_gateway.go

@@ -6,9 +6,10 @@ import "encoding/json"
   Adyen Modification actions
 */
 const (
-	CaptureType    = "capture"
-	CancelType     = "cancel"
-	CancelOrRefund = "cancelOrRefund"
+	CaptureType        = "capture"
+	CancelType         = "cancel"
+	CancelOrRefundType = "cancelOrRefund"
+	RefundType         = "refund"
 )
 
 // ModificationGateway - Adyen modification transaction logic, capture, cancel, refunds and e.t.c
@@ -47,7 +48,7 @@ func (a *ModificationGateway) Cancel(req *Cancel) (*CancelResponse, error) {
 // CancelOrRefund - Perform cancellation for not captured transaction
 // otherwise perform refund action
 func (a *ModificationGateway) CancelOrRefund(req *Cancel) (*CancelOrRefundResponse, error) {
-	resp, err := a.execute(CancelOrRefund, req)
+	resp, err := a.execute(CancelOrRefundType, req)
 
 	if err != nil {
 		return nil, err
@@ -58,3 +59,17 @@ func (a *ModificationGateway) CancelOrRefund(req *Cancel) (*CancelOrRefundRespon
 
 	return &val, nil
 }
+
+// Refund - perform refund for already captured request
+func (a *ModificationGateway) Refund(req *Refund) (*RefundResponse, error) {
+	resp, err := a.execute(RefundType, req)
+
+	if err != nil {
+		return nil, err
+	}
+
+	var val RefundResponse
+	json.NewDecoder(resp.Body).Decode(&val)
+
+	return &val, nil
+}

refund.go

@@ -0,0 +1,15 @@
+package adyen
+
+// Refund structure for refund request
+type Refund struct {
+	ModificationAmount *Amount `json:"modificationAmount"`
+	Reference          string  `json:"reference"`
+	MerchantAccount    string  `json:"merchantAccount"`
+	OriginalReference  string  `json:"originalReference"`
+}
+
+// RefundResponse is a response structure for Adyen refund request
+type RefundResponse struct {
+	PspReference string `json:"pspReference"`
+	Response     string `json:"response"`
+}