src/main/java/com/acquirex/service/AcquisitionService.java

@@ -0,0 +1,145 @@
+package com.acquirex.service;
+
+import com.acquirex.domain.Acquisition;
+import com.acquirex.domain.AcquisitionStatus;
+import com.acquirex.exception.AcquisitionNotFoundException;
+import com.acquirex.exception.InvalidAcquisitionStateException;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.math.BigDecimal;
+import java.time.LocalDateTime;
+import java.util.List;
+import java.util.Optional;
+import java.util.UUID;
+import java.util.stream.Collectors;
+
+/**
+ * 카드 매입 승인 서비스 - Spring Boot 3 트랜잭션 관리
+ */
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class AcquisitionService {
+
+    private final AcquisitionRepository acquisitionRepository;
+
+    @Transactional
+    public AcquisitionResponse registerAcquisition(AcquisitionRequest request) {
+        log.info("매입 요청 등록: merchantId={}, amount={}", request.getMerchantId(), request.getAmount());
+        String transactionId = generateTransactionId();
+
+        Acquisition acquisition = Acquisition.builder()
+                .merchantId(request.getMerchantId())
+                .cardNumber(maskCardNumber(request.getCardNumber()))
+                .amount(request.getAmount())
+                .transactionId(transactionId)
+                .status(AcquisitionStatus.PENDING)
+                .build();
+
+        Acquisition saved = acquisitionRepository.save(acquisition);
+        log.info("매입 요청 등록 완료: transactionId={}", transactionId);
+        return toResponse(saved);
+    }
+
+    @Transactional
+    public AcquisitionResponse approveAcquisition(String transactionId) {
+        log.info("매입 승인 처리: transactionId={}", transactionId);
+
+        Acquisition acquisition = acquisitionRepository.findByTransactionId(transactionId)
+                .orElseThrow(() -> new AcquisitionNotFoundException("매입 정보를 찾을 수 없습니다: " + transactionId));
+
+        if (acquisition.getStatus() != AcquisitionStatus.PENDING) {
+            throw new InvalidAcquisitionStateException("대기 상태의 매입만 승인할 수 있습니다. 현재 상태: " + acquisition.getStatus());
+        }
+
+        String approvalCode = generateApprovalCode();
+        acquisition.approve(approvalCode);
+        Acquisition saved = acquisitionRepository.save(acquisition);
+        log.info("매입 승인 완료: transactionId={}, approvalCode={}", transactionId, approvalCode);
+        return toResponse(saved);
+    }
+
+    @Transactional
+    public AcquisitionResponse rejectAcquisition(String transactionId, String reason) {
+        log.info("매입 거절 처리: transactionId={}, reason={}", transactionId, reason);
+
+        Acquisition acquisition = acquisitionRepository.findByTransactionId(transactionId)
+                .orElseThrow(() -> new AcquisitionNotFoundException("매입 정보를 찾을 수 없습니다: " + transactionId));
+
+        if (acquisition.getStatus() != AcquisitionStatus.PENDING) {
+            throw new InvalidAcquisitionStateException("대기 상태의 매입만 거절할 수 있습니다. 현재 상태: " + acquisition.getStatus());
+        }
+
+        acquisition.reject(reason);
+        return toResponse(acquisitionRepository.save(acquisition));
+    }
+
+    @Transactional(readOnly = true)
+    public AcquisitionResponse getAcquisition(String transactionId) {
+        return toResponse(acquisitionRepository.findByTransactionId(transactionId)
+                .orElseThrow(() -> new AcquisitionNotFoundException("매입 정보를 찾을 수 없습니다: " + transactionId)));
+    }
+
+    @Transactional(readOnly = true)
+    public List<AcquisitionResponse> getAcquisitionsByMerchant(String merchantId) {
+        return acquisitionRepository.findByMerchantId(merchantId).stream().map(this::toResponse).collect(Collectors.toList());
+    }
+
+    @Transactional(readOnly = true)
+    public List<AcquisitionResponse> getPendingAcquisitions() {
+        return acquisitionRepository.findByStatus(AcquisitionStatus.PENDING).stream().map(this::toResponse).collect(Collectors.toList());
+    }
+
+    private String generateTransactionId() {
+        return "TXN" + System.currentTimeMillis() + UUID.randomUUID().toString().substring(0, 8).toUpperCase();
+    }
+
+    private String generateApprovalCode() {
+        return String.format("%06d", (int) (Math.random() * 1000000));
+    }
+
+    private String maskCardNumber(String cardNumber) {
+        if (cardNumber == null || cardNumber.length() < 10) return cardNumber;
+        return cardNumber.substring(0, 6) + "****" + cardNumber.substring(cardNumber.length() - 4);
+    }
+
+    private AcquisitionResponse toResponse(Acquisition a) {
+        return AcquisitionResponse.builder()
+                .id(a.getId()).transactionId(a.getTransactionId()).merchantId(a.getMerchantId())
+                .cardNumber(a.getCardNumber()).amount(a.getAmount()).status(a.getStatus())
+                .approvalCode(a.getApprovalCode()).approvedAt(a.getApprovedAt())
+                .createdAt(a.getCreatedAt()).updatedAt(a.getUpdatedAt()).build();
+    }
+}
+
+/** DTOs */
+@lombok.Getter @lombok.Setter @lombok.NoArgsConstructor @lombok.AllArgsConstructor @lombok.Builder
+class AcquisitionRequest {
+    @jakarta.validation.constraints.NotBlank @jakarta.validation.constraints.Size(max = 20)
+    private String merchantId;
+    @jakarta.validation.constraints.NotBlank @jakarta.validation.constraints.Pattern(regexp = "\\d{13,19}")
+    private String cardNumber;
+    @jakarta.validation.constraints.NotNull @jakarta.validation.constraints.DecimalMin("0.01")
+    private BigDecimal amount;
+}
+
+@lombok.Getter @lombok.Setter @lombok.NoArgsConstructor @lombok.AllArgsConstructor @lombok.Builder
+class AcquisitionResponse {
+    private Long id; private String transactionId; private String merchantId;
+    private String cardNumber; private BigDecimal amount; private AcquisitionStatus status;
+    private String approvalCode; private LocalDateTime approvedAt;
+    private LocalDateTime createdAt; private LocalDateTime updatedAt;
+}
+
+/** Repository */
+@Repository
+interface AcquisitionRepository extends JpaRepository<Acquisition, Long> {
+    Optional<Acquisition> findByTransactionId(String transactionId);
+    List<Acquisition> findByMerchantId(String merchantId);
+    List<Acquisition> findByStatus(AcquisitionStatus status);
+}