feat: add transaction risk controls

Author: AliEmre007

backend/src/main/java/com/payledger/platform/payment/application/PaymentIntentService.java

@@ -393,7 +393,8 @@ private void requireRiskApproval(CreatePaymentIntentCommand command) {
                         command.merchantId(),
                         command.amountMinor(),
                         command.currency()
-                )
+                ),
+                command.externalSubject()
         );
 
         if (!decision.allowed()) {

backend/src/main/java/com/payledger/platform/payment/infrastructure/PaymentIntentRepository.java

@@ -8,6 +8,7 @@
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
 
+import java.time.Instant;
 import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
@@ -50,4 +51,38 @@ List<PaymentIntent> findUnsettledCapturedForUpdate(
             @Param("currency") String currency,
             @Param("status") PaymentIntentStatus status
     );
+
+    @Query("""
+            SELECT COALESCE(SUM(intent.amountMinor), 0)
+            FROM PaymentIntent intent
+            WHERE intent.customerId = :customerId
+              AND intent.currency = :currency
+              AND intent.status IN :statuses
+              AND intent.createdAt >= :startInclusive
+              AND intent.createdAt < :endExclusive
+            """)
+    long sumOutgoingAmountForCustomer(
+            @Param("customerId") UUID customerId,
+            @Param("currency") String currency,
+            @Param("statuses") List<PaymentIntentStatus> statuses,
+            @Param("startInclusive") Instant startInclusive,
+            @Param("endExclusive") Instant endExclusive
+    );
+
+    @Query("""
+            SELECT COUNT(intent)
+            FROM PaymentIntent intent
+            WHERE intent.customerId = :customerId
+              AND intent.currency = :currency
+              AND intent.status IN :statuses
+              AND intent.createdAt >= :startInclusive
+              AND intent.createdAt < :endExclusive
+            """)
+    long countOutgoingForCustomer(
+            @Param("customerId") UUID customerId,
+            @Param("currency") String currency,
+            @Param("statuses") List<PaymentIntentStatus> statuses,
+            @Param("startInclusive") Instant startInclusive,
+            @Param("endExclusive") Instant endExclusive
+    );
 }

backend/src/main/java/com/payledger/platform/risk/application/RiskDecision.java

@@ -7,4 +7,8 @@ public record RiskDecision(
     public static RiskDecision allow() {
         return new RiskDecision(true, "ALLOW");
     }
+
+    public static RiskDecision deny(String reasonCode) {
+        return new RiskDecision(false, reasonCode);
+    }
 }

backend/src/main/java/com/payledger/platform/risk/application/RiskDecisionAuditService.java

@@ -0,0 +1,57 @@
+package com.payledger.platform.risk.application;
+
+import com.payledger.platform.audit.application.AuditEventCommand;
+import com.payledger.platform.audit.application.AuditEventService;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Propagation;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.Map;
+import java.util.UUID;
+
+@Service
+public class RiskDecisionAuditService {
+
+    private final AuditEventService auditEventService;
+
+    public RiskDecisionAuditService(AuditEventService auditEventService) {
+        this.auditEventService = auditEventService;
+    }
+
+    @Transactional(propagation = Propagation.REQUIRES_NEW)
+    public void recordDenial(
+            String action,
+            UUID customerId,
+            UUID sourceWalletId,
+            UUID destinationWalletId,
+            UUID merchantId,
+            long amountMinor,
+            String currency,
+            String actorExternalSubject,
+            String reasonCode
+    ) {
+        auditEventService.record(
+                new AuditEventCommand(
+                        "RISK_DECISION_DENIED",
+                        actorExternalSubject,
+                        customerId,
+                        "RISK_DECISION",
+                        UUID.randomUUID(),
+                        Map.of(
+                                "action", action,
+                                "reasonCode", reasonCode,
+                                "customerId", customerId.toString(),
+                                "sourceWalletId", sourceWalletId.toString(),
+                                "destinationWalletId", destinationWalletId == null
+                                        ? ""
+                                        : destinationWalletId.toString(),
+                                "merchantId", merchantId == null
+                                        ? ""
+                                        : merchantId.toString(),
+                                "amountMinor", amountMinor,
+                                "currency", currency
+                        )
+                )
+        );
+    }
+}