토스 페이먼츠 결제 승인 로직 전의 주문 승인 로직 추가

src/main/java/com/hcommerce/heecommerce/common/GlobalControllerAdvice.java

@@ -1,6 +1,7 @@
 package com.hcommerce.heecommerce.common;
 
 import com.hcommerce.heecommerce.common.dto.ResponseDto;
+import com.hcommerce.heecommerce.order.InvalidPaymentAmountException;
 import com.hcommerce.heecommerce.order.MaxOrderQuantityExceededException;
 import com.hcommerce.heecommerce.order.OrderNotFoundException;
 import com.hcommerce.heecommerce.order.OrderOverStockException;
@@ -61,6 +62,15 @@ public ResponseDto methodArgumentNotValidExceptionHandler(MethodArgumentNotValid
             .build();
     }
 
+    @ResponseStatus(HttpStatus.BAD_REQUEST)
+    @ExceptionHandler
+    public ResponseDto invalidPaymentAmountExceptionHandler(InvalidPaymentAmountException e) {
+        return ResponseDto.builder()
+            .code(HttpStatus.BAD_REQUEST.name())
+            .message(e.getMessage())
+            .build();
+    }
+
     @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
     @ExceptionHandler
     public ResponseDto fallbackExceptionHandler(Exception e) {

src/main/java/com/hcommerce/heecommerce/order/InvalidPaymentAmountException.java

@@ -0,0 +1,11 @@
+package com.hcommerce.heecommerce.order;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.ResponseStatus;
+
+@ResponseStatus(HttpStatus.BAD_REQUEST)
+public class InvalidPaymentAmountException extends RuntimeException {
+    public InvalidPaymentAmountException() {
+        super("결제 금액이 유효하지 않습니다.");
+    }
+}

src/main/java/com/hcommerce/heecommerce/order/OrderApproveForm.java

@@ -0,0 +1,31 @@
+package com.hcommerce.heecommerce.order;
+
+import jakarta.validation.constraints.NotNull;
+import java.beans.ConstructorProperties;
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+public class OrderApproveForm {
+
+    @NotNull
+    private final String paymentKey; // 토스 키
+
+    @NotNull
+    private final String orderId; // 토스 주문 식별자
+
+    @NotNull
+    private final int amount; // 총 결제 금액
+
+    @Builder
+    @ConstructorProperties({
+        "paymentKey",
+        "orderId",
+        "amount"
+    })
+    public OrderApproveForm(String paymentKey, String orderId, int amount) {
+        this.paymentKey = paymentKey;
+        this.orderId = orderId;
+        this.amount = amount;
+    }
+}

src/main/java/com/hcommerce/heecommerce/order/OrderController.java

@@ -74,4 +74,20 @@ public ResponseDto placeOrderInAdvance(@Valid @RequestBody OrderForm orderForm)
             .data(new OrderUuid(orderUuid))
             .build();
     }
+
+    /**
+     * 클라이언트에서 결제 완료가 되고, 주문 승인을 하는 경우에 대한 것
+     */
+    @PostMapping("/orders/approve")
+    @ResponseStatus(HttpStatus.CREATED)
+    public ResponseDto approveOrder(@Valid @RequestBody OrderApproveForm orderApproveForm) {
+
+        UUID uuid = orderService.approveOrder(orderApproveForm);
+
+        return ResponseDto.builder()
+            .code(HttpStatus.CREATED.name())
+            .message("주문 접수가 완료되었습니다.")
+            .data(new OrderUuid(uuid))
+            .build();
+    }
 }

src/main/java/com/hcommerce/heecommerce/order/OrderEntityForOrderApproveValidation.java

@@ -0,0 +1,26 @@
+package com.hcommerce.heecommerce.order;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+public class OrderEntityForOrderApproveValidation {
+
+    private final byte[] dealProductUuid;
+    private final int orderQuantity;
+    private final int totalPaymentAmount;
+    private final OutOfStockHandlingOption outOfStockHandlingOption;
+
+    @Builder
+    public OrderEntityForOrderApproveValidation(
+        byte[] dealProductUuid,
+        int orderQuantity,
+        int totalPaymentAmount,
+        OutOfStockHandlingOption outOfStockHandlingOption
+    ) {
+        this.dealProductUuid = dealProductUuid;
+        this.orderQuantity = orderQuantity;
+        this.totalPaymentAmount = totalPaymentAmount;
+        this.outOfStockHandlingOption = outOfStockHandlingOption;
+    }
+}

src/main/java/com/hcommerce/heecommerce/order/OrderQueryMapper.java

@@ -0,0 +1,10 @@
+package com.hcommerce.heecommerce.order;
+
+import org.apache.ibatis.annotations.Mapper;
+import org.apache.ibatis.annotations.Param;
+
+@Mapper
+public interface OrderQueryMapper {
+
+    OrderEntityForOrderApproveValidation findOrderEntityForOrderApproveValidation(@Param("orderUuid") byte[] orderUuid);
+}

src/main/java/com/hcommerce/heecommerce/order/OrderQueryRepository.java

@@ -0,0 +1,26 @@
+package com.hcommerce.heecommerce.order;
+
+import com.hcommerce.heecommerce.common.utils.TypeConversionUtils;
+import java.util.UUID;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public class OrderQueryRepository {
+
+    private final OrderQueryMapper orderQueryMapper;
+
+    @Autowired
+    public OrderQueryRepository(OrderQueryMapper orderQueryMapper) {
+        this.orderQueryMapper = orderQueryMapper;
+    }
+
+    public OrderEntityForOrderApproveValidation findOrderEntityForOrderApproveValidation(String orderId) {
+
+        UUID orderUuid = UUID.fromString(orderId);
+
+        byte[] orderUuidByte = TypeConversionUtils.convertUuidToBinary(orderUuid);
+
+        return orderQueryMapper.findOrderEntityForOrderApproveValidation(orderUuidByte);
+    }
+}

src/main/java/com/hcommerce/heecommerce/order/OrderService.java

@@ -13,6 +13,8 @@
 @Service
 public class OrderService {
 
+    private final OrderQueryRepository orderQueryRepository;
+
     private final OrderCommandRepository orderCommandRepository;
 
     private final InventoryQueryRepository inventoryQueryRepository;
@@ -23,11 +25,13 @@ public class OrderService {
 
     @Autowired
     public OrderService(
+        OrderQueryRepository orderQueryRepository,
         OrderCommandRepository orderCommandRepository,
         InventoryQueryRepository inventoryQueryRepository,
         InventoryCommandRepository inventoryCommandRepository,
         DealProductQueryRepository dealProductQueryRepository
     ) {
+        this.orderQueryRepository = orderQueryRepository;
         this.orderCommandRepository = orderCommandRepository;
         this.inventoryQueryRepository = inventoryQueryRepository;
         this.inventoryCommandRepository = inventoryCommandRepository;
@@ -93,6 +97,10 @@ public void placeOrder(OrderForm orderForm) {
      * @param orderQuantity : 주문량
      * @param outOfStockHandlingOption : 재고 부족 처리 옵션
      * @return realOrderQuantity : 실제 주문량
+     *
+     * realOrderQuantity 이 필요한 이유는 "부분 주문" 때문이다.
+     * 재고량이 0은 아니지만, 사용자가 주문한 수량에 비해 재고량이 없는 경우가 있다.
+     * 이때, 재고량만큼만 주문하도록 할 수 있도록 "부문 주문"이 가능한데, 사용자가 주문한 수량과 혼동되지 않도록 실제 주문하는 수량이라는 의미를 내포하기 위해서 필요하다.
      */
     private int calculateRealOrderQuantity(int inventoryAfterDecrease, int orderQuantity, OutOfStockHandlingOption outOfStockHandlingOption) {
 
@@ -243,4 +251,53 @@ private int calculateTotalPaymentAmount(int originPrice, DiscountType discountTy
 
         return originPrice - discountValue; // 정률 할인
     }
-}
+
+    /**
+     * approveOrder 는 주문 승인을 하기 위한 함수이다.
+     */
+    public UUID approveOrder(OrderApproveForm orderApproveForm) {
+        String orderId = orderApproveForm.getOrderId();
+
+        // 0. DB에서 검증에 필요한 데이터 가져오기
+        OrderEntityForOrderApproveValidation orderForm = orderQueryRepository.findOrderEntityForOrderApproveValidation(orderApproveForm.getOrderId());
+
+        // 1. orderApproveForm 검증
+        validateOrderApproveForm(orderApproveForm, orderForm);
+
+        // 2. 재고 감소
+        UUID dealProductUuid = TypeConversionUtils.convertBinaryToUuid(orderForm.getDealProductUuid());
+
+        int orderQuantity = orderForm.getOrderQuantity();
+
+        int inventoryAfterDecrease = inventoryCommandRepository.decreaseByAmount(dealProductUuid, orderQuantity);
+
+        try {
+            // 3. 실제 주문 수량 계산
+            int inventoryBeforeDecrease = orderQuantity + inventoryAfterDecrease;
+
+            OutOfStockHandlingOption outOfStockHandlingOption = orderForm.getOutOfStockHandlingOption();
+
+            int realOrderQuantity = calculateRealOrderQuantity(inventoryAfterDecrease, orderQuantity, outOfStockHandlingOption);
+
+            if (inventoryBeforeDecrease < orderQuantity && outOfStockHandlingOption == OutOfStockHandlingOption.PARTIAL_ORDER) {
+                inventoryCommandRepository.set(dealProductUuid, 0); // 데이터 일관성 맞춰주기 위해
+            }
+
+            // 4. 토스 페이먼트 결제 승인
+
+            // 5. 주문 관련 데이터 저장
+
+        } catch (OrderOverStockException orderOverStockException) {
+            rollbackReducedInventory(dealProductUuid, orderQuantity);
+            throw orderOverStockException;
+        }
+
+        return UUID.fromString(orderId); // TODO : 임시 데이터
+    }
+
+    public void validateOrderApproveForm(OrderApproveForm orderApproveForm, OrderEntityForOrderApproveValidation orderForm) {
+        if(orderApproveForm.getAmount() != orderForm.getTotalPaymentAmount()) {
+            throw new InvalidPaymentAmountException();
+        }
+    }
+}

src/main/resources/mappers/OrderQueryMapper.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
+  "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
+<mapper namespace="com.hcommerce.heecommerce.order.OrderQueryMapper">
+
+  <!-- 주문 검증을 위해 주문 조회  -->
+  <select id="findOrderEntityForOrderApproveValidation" resultType="OrderEntityForOrderApproveValidation">
+    SELECT deal_product_uuid, order_quantity, total_payment_amount, out_of_stock_handling_option FROM `order` WHERE uuid = #{orderUuid}
+  </select>
+</mapper>

src/test/java/com/hcommerce/heecommerce/order/OrderControllerRestDocs.java

@@ -41,6 +41,18 @@ public static RestDocumentationResultHandler placeOrderInAdvance() {
         );
     }
 
+    public static RestDocumentationResultHandler approveOrder() {
+        return document("approve-order",
+            preprocessRequest(prettyPrint()),
+            preprocessResponse(prettyPrint()),
+            responseFields(
+                fieldWithPath("code").type(JsonFieldType.STRING).description("코드"),
+                fieldWithPath("message").type(JsonFieldType.STRING).description("메시지"),
+                fieldWithPath("data.orderUuid").type(JsonFieldType.STRING).description("주문 UUID")
+            )
+        );
+    }
+
     public static RestDocumentationResultHandler placeOrder() {
         return document("place-order",
             preprocessRequest(prettyPrint()),

src/test/java/com/hcommerce/heecommerce/order/OrderControllerTest.java

@@ -595,4 +595,36 @@ void It_returns_409_Error() throws Exception {
             }
         }
     }
+
+    @Nested
+    @DisplayName("POST /orders/approve")
+    class Describe_ApproveOrder_API {
+        @Test
+        @DisplayName("returns 201")
+        void It_returns_201() throws Exception {
+            OrderApproveForm orderForm = OrderApproveForm.builder()
+                .paymentKey("5zJ4xY7m0kODnyRpQWGrN2xqGlNvLrKwv1M9ENjbeoPaZdL6")
+                .orderId(UUID.randomUUID().toString())
+                .amount(15000)
+                .build();
+
+            // given
+            given(orderService.approveOrder(any())).willReturn(UUID.randomUUID());
+
+            // when
+            String content = objectMapper.writeValueAsString(orderForm);
+
+            ResultActions resultActions = mockMvc.perform(
+                post("/orders/approve")
+                    .accept(MediaType.APPLICATION_JSON)
+                    .contentType(MediaType.APPLICATION_JSON)
+                    .content(content)
+            );
+
+            // then
+            resultActions.andExpect(status().isCreated())
+                .andDo(OrderControllerRestDocs.approveOrder());
+
+        }
+    }
 }