CF-991: Add extension support for payment link creation

server_extensions_api/src/main/java/com/generalbytes/batm/server/extensions/IExtension.java

@@ -25,6 +25,7 @@
 import com.generalbytes.batm.server.extensions.communication.ICommunicationProvider;
 import com.generalbytes.batm.server.extensions.communication.IPhoneLookupProvider;
 import com.generalbytes.batm.server.extensions.communication.voicecall.IVoiceCallProvider;
+import com.generalbytes.batm.server.extensions.payment.external.IExternalPaymentProvider;
 import com.generalbytes.batm.server.extensions.travelrule.ITravelRuleProvider;
 import com.generalbytes.batm.server.extensions.travelrule.ITravelRuleProviderFactory;
 import com.generalbytes.batm.server.extensions.travelrule.IWalletTypeEvaluationProvider;
@@ -86,6 +87,15 @@ public interface IExtension {
      */
     IPaymentProcessor createPaymentProcessor(String paymentProcessorLogin);
 
+    /**
+     * This method is used for creating implementation of an external payment provider
+     *
+     * @see com.generalbytes.batm.server.extensions.payment.external.IExternalPaymentProvider
+     */
+    default IExternalPaymentProvider createExternalPaymentProvider() {
+        return null;
+    }
+
     /**
      * This method is used for creating implementation of coin price source
      * @param sourceLogin

server_extensions_api/src/main/java/com/generalbytes/batm/server/extensions/payment/external/ExternalPaymentDetails.java

@@ -0,0 +1,17 @@
+package com.generalbytes.batm.server.extensions.payment.external;
+
+import lombok.Data;
+
+/**
+ * Represents the details of an external payment created using a third-party payment provider.
+ * This class typically encapsulates information required to complete the payment, such as the
+ * link (URL) to redirect the customer for payment processing.
+ */
+@Data
+public class ExternalPaymentDetails {
+
+    /**
+     * URL to redirect the customer to for payment processing.
+     */
+    private String paymentLink;
+}

server_extensions_api/src/main/java/com/generalbytes/batm/server/extensions/payment/external/ExternalPaymentRequest.java

@@ -0,0 +1,34 @@
+package com.generalbytes.batm.server.extensions.payment.external;
+
+import com.generalbytes.batm.common.currencies.FiatCurrency;
+import lombok.Data;
+
+import java.math.BigDecimal;
+
+/**
+ * Represents an external payment request containing payment and transaction identifications and amount details.
+ */
+@Data
+public class ExternalPaymentRequest {
+
+    /**
+     * Not null unique identifier (UUID) of the payment. Used to reference the payment.
+     *
+     */
+    private String externalPaymentId;
+
+    /**
+     * Not null transaction identifier (RID).
+     */
+    private String remoteTransactionId;
+
+    /**
+     * Not null payment amount in fiat currency.
+     */
+    private BigDecimal fiatAmount;
+
+    /**
+     * Not null fiat currency of the payment amount.
+     */
+    private FiatCurrency fiatCurrency;
+}

server_extensions_api/src/main/java/com/generalbytes/batm/server/extensions/payment/external/IExternalPaymentProvider.java

@@ -0,0 +1,22 @@
+package com.generalbytes.batm.server.extensions.payment.external;
+
+/**
+ * Interface for payment providers that can be used to initiate payments outside BATM.
+ * For example, by using a third-party payment gateway and redirecting the customer to their payment website.
+ */
+public interface IExternalPaymentProvider {
+
+    /**
+     * Name of the payment provider that can be noted in CAS.
+     */
+    String getPublicName();
+
+    /**
+     * Initiates an external payment session based on the provided request.
+     * <p>
+     * <b>Warning:</b> The payment session initiated by this call should expire before the order expires in CAS (see CAS configuration).
+     * @param request details of the payment to be initiated
+     * @return details of the initiated payment session (typically a payment link)
+     */
+    ExternalPaymentDetails initiateExternalPayment(ExternalPaymentRequest request);
+}