@Entity
@Table(name = "stocks")
@Getter  // ⭐ 이 어노테이션이 있는지 반드시 확인!
@NoArgsConstructor(access = AccessLevel.PROTECTED)
public class Stock extends BaseTimeEntity {
    
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "stock_id")
    private Long stockId;
    
    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "product_id", nullable = false)
    private Product product;
    
    @Column(name = "barcode_number", unique = true)
    private String barcodeNumber;
    
    // Lombok이 자동으로 생성할 메서드들:
    // - getStockId()
    // - getProduct()
    // - getBarcodeNumber()
}

// ✅ ProductService.java
@Service
@RequiredArgsConstructor
public class ProductService {
    
    private final ProductRepository productRepository;
    
    public Long createProduct(ProductCreateRequest request) {
        Product newProduct = Product.builder()  // @Builder 어노테이션으로 생성
                .name(request.getName())         // @Getter로 생성된 메서드
                .price(request.getPrice())
                .stockQuantity(request.getStockQuantity())
                .category(request.getCategory())
                .costPrice(request.getCostPrice())
                .productSupplier(request.getProductSupplier())
                .barcodeNumber(request.getBarcodeNumber())
                .build();
        
        Product savedProduct = productRepository.save(newProduct);
        return savedProduct.getProductId();  // @Getter로 생성된 메서드
    }
}

// ✅ StockResponse.java
public record StockResponse(
    Long stockId,
    String productName,
    BigDecimal costPrice,
    BigDecimal sellingPrice,
    Integer stockQuantity,
    String category,
    LocalDateTime createdAt,
    LocalDateTime updatedAt,
    String productSupplier
) {
    public static StockResponse from(Stock stock) {
        return new StockResponse(
            stock.getStockId(),              // ✅ 정상 작동
            stock.getProduct().getName(),    // ✅ 정상 작동
            stock.getProduct().getCostPrice(),
            stock.getProduct().getCostPrice(),
            stock.getProduct().getStockQuantity(),
            stock.getProduct().getCategory(),
            stock.getCreatedAt(),            // BaseTimeEntity에서 상속
            stock.getUpdatedAt(),
            stock.getProduct().getProductSupplier()
        );
    }
}

@SpringBootTest
@Transactional
class ProductServiceTest {
    
    @Autowired
    private ProductService productService;
    
    @Autowired
    private ProductRepository productRepository;
    
    @Test
    @DisplayName("상품 생성 테스트 - H2 데이터베이스 사용")
    void createProduct_Success() {
        // given
        ProductCreateRequest request = ProductCreateRequest.builder()
            .name("맥북 프로 16인치")
            .price(new BigDecimal("2490000"))
            .stockQuantity(10)
            .category("전자제품")
            .costPrice(new BigDecimal("2000000"))
            .productSupplier("Apple Korea")
            .barcodeNumber("8801234567890")
            .build();
        
        // when
        Long productId = productService.createProduct(request);
        
        // then
        assertThat(productId).isNotNull();
        
        Optional<Product> savedProduct = productRepository.findById(productId);
        assertThat(savedProduct).isPresent();
        assertThat(savedProduct.get().getName()).isEqualTo("맥북 프로 16인치");
    }
    
    @Test
    @DisplayName("재고 조회 테스트 - 연관관계 포함")
    void findStockWithProduct_Success() {
        // given - 테스트 데이터 준비
        Product product = Product.builder()
            .name("아이폰 15 Pro")
            .price(new BigDecimal("1350000"))
            .stockQuantity(5)
            .category("스마트폰")
            .costPrice(new BigDecimal("1100000"))
            .productSupplier("Apple Korea")
            .barcodeNumber("8801234567891")
            .build();
        
        Product savedProduct = productRepository.save(product);
        
        Stock stock = Stock.builder()
            .product(savedProduct)
            .barcodeNumber("STOCK_8801234567891")
            .build();
        
        // when & then - H2 데이터베이스에서 정상 작동
        assertThat(stock.getProduct().getName()).isEqualTo("아이폰 15 Pro");
    }
}