[FEAT] 카카오페이 결제 구현 (#71)

src/main/java/com/brainpix/api/code/error/KakaoPayErrorCode.java

@@ -0,0 +1,22 @@
+package com.brainpix.api.code.error;
+
+import org.springframework.http.HttpStatus;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@Getter
+@RequiredArgsConstructor
+public enum KakaoPayErrorCode implements ErrorCode {
+
+	// 400 Bad Request - 잘못된 요청
+	IDEA_OWNER_PURCHASE_INVALID(HttpStatus.BAD_REQUEST, "KAKAOPAY400", "글 작성자는 구매할 수 없습니다."),
+	QUANTITY_INVALID(HttpStatus.BAD_REQUEST, "KAKAOPAY400", "구매 수량은 재고를 초과할 수 없습니다."),
+
+	// 500 Internal Server Error - 서버 내부 오류
+	API_RESPONSE_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, "KAKAOPAY500", "카카오페이 API 호출 중 오류가 발생하였습니다.");
+
+	private final HttpStatus httpStatus;
+	private final String code;
+	private final String message;
+}

src/main/java/com/brainpix/joining/entity/purchasing/IdeaMarketPurchasing.java

@@ -27,14 +27,24 @@ public class IdeaMarketPurchasing extends BaseTimeEntity {
 	private Long price;
 	private PaymentDuration paymentDuration;
 
+	private Payment payment;    // 결제 방식
+	private Long vat;    // 수수료
+	private Long quantity;    // 구매 수량
+
 	@ManyToOne
 	private IdeaMarket ideaMarket;
 
 	@Builder
-	public IdeaMarketPurchasing(User buyer, Long price, PaymentDuration paymentDuration, IdeaMarket ideaMarket) {
+	public IdeaMarketPurchasing(Long id, User buyer, Long price, PaymentDuration paymentDuration, Payment payment,
+		Long vat,
+		Long quantity, IdeaMarket ideaMarket) {
+		this.id = id;
 		this.buyer = buyer;
 		this.price = price;
 		this.paymentDuration = paymentDuration;
+		this.payment = payment;
+		this.vat = vat;
+		this.quantity = quantity;
 		this.ideaMarket = ideaMarket;
 	}
 }

src/main/java/com/brainpix/joining/entity/purchasing/Payment.java

@@ -0,0 +1,5 @@
+package com.brainpix.joining.entity.purchasing;
+
+public enum Payment {
+	KAKAO_PAY
+}

src/main/java/com/brainpix/joining/entity/quantity/BaseQuantity.java

@@ -21,4 +21,12 @@ public BaseQuantity(Long totalQuantity, Long occupiedQuantity) {
 		this.totalQuantity = totalQuantity;
 		this.occupiedQuantity = occupiedQuantity;
 	}
+
+	public Long getRemainingQuantity() {
+		return this.totalQuantity - this.occupiedQuantity;
+	}
+
+	public void increaseOccupiedQuantity(Long quantity) {
+		this.occupiedQuantity += quantity;
+	}
 }

src/main/java/com/brainpix/joining/repository/IdeaMarketPurchasingRepository.java

@@ -9,8 +9,6 @@
 import com.brainpix.user.entity.User;
 
 @Repository
-public interface IdeaMarketPurchasingRepository
-	extends JpaRepository<IdeaMarketPurchasing, Long> {
+public interface IdeaMarketPurchasingRepository extends JpaRepository<IdeaMarketPurchasing, Long> {
 	Page<IdeaMarketPurchasing> findByBuyer(User buyer, Pageable pageable);
-
 }

src/main/java/com/brainpix/kakaopay/controller/KakaoPayController.java

@@ -0,0 +1,54 @@
+package com.brainpix.kakaopay.controller;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.brainpix.api.ApiResponse;
+import com.brainpix.kakaopay.converter.KakaoPayApproveDtoConverter;
+import com.brainpix.kakaopay.converter.KakaoPayReadyDtoConverter;
+import com.brainpix.kakaopay.dto.KakaoPayApproveDto;
+import com.brainpix.kakaopay.dto.KakaoPayReadyDto;
+import com.brainpix.kakaopay.service.KakaoPayService;
+import com.brainpix.security.authorization.AllUser;
+import com.brainpix.security.authorization.UserId;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@RestController
+@RequestMapping("/kakao-pay")
+@RequiredArgsConstructor
+@Tag(name = "카카오페이 아이디어 결제 API", description = "아이디어를 카카오페이로 결제하는 API 입니다.<br>결제 과정 : 결제 준비 API 호출 -> 리다이렉트된 사용자의 결제 진행 -> 결제 승인 API 호출")
+public class KakaoPayController {
+
+	private final KakaoPayService kakaoPayService;
+
+	@AllUser
+	@Operation(summary = "결제 준비 API", description = "아이디어 식별자, 판매자 식별자, 상품 수량, 총 결제금액(vat 포함), vat를 json 본문으로 입력받아 카카오페이 쪽에 결제 정보를 생성합니다.<br>사용자를 결제 화면으로 이동시킬 수 있도록 리다이렉트 url과 주문 번호가 응답값으로 제공됩니다.<br>주문 번호는 이후 승인 단계에서 pgToken과 함께 전달해주시면 됩니다.")
+	@PostMapping("/ready")
+	public ResponseEntity<ApiResponse<KakaoPayReadyDto.Response>> kakaoPayReady(@UserId Long userId,
+		@RequestBody KakaoPayReadyDto.Request request) {
+		log.info("카카오페이 결제 준비 API 호출");
+		KakaoPayReadyDto.Parameter parameter = KakaoPayReadyDtoConverter.toParameter(userId, request);
+		KakaoPayReadyDto.Response response = kakaoPayService.kakaoPayReady(parameter);
+		return ResponseEntity.ok(ApiResponse.success(response));
+	}
+
+	@AllUser
+	@Operation(summary = "결제 승인 API", description = "pgToken과 주문 번호를 json 본문으로 입력받아 최종 승인을 처리합니다.")
+	@PostMapping("/approve")
+	public ResponseEntity<ApiResponse<KakaoPayApproveDto.Response>> kakaoPayApprove(
+		@UserId Long userId,
+		@RequestBody KakaoPayApproveDto.Request request) {
+		log.info("카카오페이 결제 최종 승인 API 호출");
+		KakaoPayApproveDto.Parameter parameter = KakaoPayApproveDtoConverter.toParameter(userId, request);
+		KakaoPayApproveDto.Response response = kakaoPayService.kakaoPayApprove(parameter);
+		return ResponseEntity.ok(ApiResponse.success(response));
+	}
+}

src/main/java/com/brainpix/kakaopay/converter/KakaoPayApproveDtoConverter.java

@@ -0,0 +1,42 @@
+package com.brainpix.kakaopay.converter;
+
+import com.brainpix.joining.entity.purchasing.IdeaMarketPurchasing;
+import com.brainpix.joining.entity.purchasing.Payment;
+import com.brainpix.joining.entity.quantity.PaymentDuration;
+import com.brainpix.kakaopay.dto.KakaoPayApproveDto;
+import com.brainpix.post.entity.idea_market.IdeaMarket;
+import com.brainpix.user.entity.User;
+
+public class KakaoPayApproveDtoConverter {
+
+	public static KakaoPayApproveDto.Parameter toParameter(Long userId, KakaoPayApproveDto.Request request) {
+
+		return KakaoPayApproveDto.Parameter.builder()
+			.userId(userId)
+			.orderId(request.getOrderId())
+			.pgToken(request.getPgToken())
+			.build();
+	}
+
+	public static IdeaMarketPurchasing toIdeaMarketPurchasing(KakaoPayApproveDto.KakaoApiResponse kakaoApiResponse,
+		User user,
+		IdeaMarket ideaMarket, PaymentDuration paymentDuration) {
+
+		return IdeaMarketPurchasing.builder()
+			.buyer(user)
+			.ideaMarket(ideaMarket)
+			.paymentDuration(paymentDuration)
+			.price(kakaoApiResponse.getAmount().getTotal())
+			.vat(kakaoApiResponse.getAmount().getVat())
+			.quantity(kakaoApiResponse.getQuantity())
+			.payment(Payment.KAKAO_PAY)
+			.build();
+	}
+
+	public static KakaoPayApproveDto.Response toResponse(IdeaMarketPurchasing ideaMarketPurchasing) {
+
+		return KakaoPayApproveDto.Response.builder()
+			.ideaMarketPurchasingId(ideaMarketPurchasing.getId())
+			.build();
+	}
+}

src/main/java/com/brainpix/kakaopay/converter/KakaoPayReadyDtoConverter.java

@@ -0,0 +1,44 @@
+package com.brainpix.kakaopay.converter;
+
+import com.brainpix.kakaopay.dto.KakaoPayReadyDto;
+import com.brainpix.kakaopay.entity.KakaoPaymentData;
+import com.brainpix.post.entity.idea_market.IdeaMarket;
+import com.brainpix.user.entity.User;
+
+public class KakaoPayReadyDtoConverter {
+
+	public static KakaoPayReadyDto.Parameter toParameter(Long userId, KakaoPayReadyDto.Request request) {
+
+		return KakaoPayReadyDto.Parameter.builder()
+			.buyerId(userId)
+			.sellerId(request.getSellerId())
+			.ideaId(request.getIdeaId())
+			.quantity(request.getQuantity())
+			.totalPrice(request.getTotalPrice())
+			.vat(request.getVat())
+			.build();
+	}
+
+	public static KakaoPayReadyDto.Response toResponse(KakaoPayReadyDto.KakaoApiResponse kakaoApiResponse,
+		String orderId) {
+
+		return KakaoPayReadyDto.Response.builder()
+			.nextRedirectPcUrl(kakaoApiResponse.getNext_redirect_pc_url())
+			.orderId(orderId)
+			.build();
+	}
+
+	public static KakaoPaymentData toKakaoPaymentData(KakaoPayReadyDto.KakaoApiResponse kakaoApiResponse,
+		KakaoPayReadyDto.Parameter parameter,
+		String orderId, User buyer,
+		IdeaMarket ideaMarket) {
+
+		return KakaoPaymentData.builder()
+			.tid(kakaoApiResponse.getTid())
+			.quantity(parameter.getQuantity())
+			.orderId(orderId)
+			.buyer(buyer)
+			.ideaMarket(ideaMarket)
+			.build();
+	}
+}

src/main/java/com/brainpix/kakaopay/dto/KakaoPayApproveDto.java

@@ -0,0 +1,53 @@
+package com.brainpix.kakaopay.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+public class KakaoPayApproveDto {
+
+	@NoArgsConstructor
+	@Getter
+	public static class Request {
+		@NotBlank(message = "토큰을 입력해주세요.")
+		private String pgToken;    // 결제 최종 완료를 위한 토큰
+		@NotBlank(message = "주문 번호를 입력해주세요.")
+		private String orderId;    // 주문 번호 (세션에서 결제 정보 탐색 Key)
+	}
+
+	@Getter
+	@Builder
+	public static class Parameter {
+		private Long userId;    // 유저 ID
+		private String orderId;    // 주문 번호 (결제 정보 탐색 Key)
+		private String pgToken;    // 결제 최종 완료를 위한 토큰
+	}
+
+	@Getter
+	@Builder
+	public static class KakaoApiResponse {
+		private String aid;    // 요청 고유 번호
+		private String tid;    // 결제 고유 번호
+		private String cid;    // 가맹점 코드
+		private String partner_order_id;    // 주문 번호 (DB에 저장)
+		private String partner_user_id;    // 구매자 ID
+		private String item_name;    // 상품 이름
+		private Long quantity;    // 상품 수량
+		private Amount amount;    // 결제 금액 관련
+		private String approved_at;    // 결제 승인 시각
+	}
+
+	@Getter
+	@Builder
+	public static class Amount {
+		private Long total;    // 총 결제 금액
+		private Long vat;    // 부가세 금액
+	}
+
+	@Getter
+	@Builder
+	public static class Response {
+		private Long ideaMarketPurchasingId;
+	}
+}

src/main/java/com/brainpix/kakaopay/dto/KakaoPayReadyDto.java

@@ -0,0 +1,49 @@
+package com.brainpix.kakaopay.dto;
+
+import jakarta.validation.constraints.NotNull;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+public class KakaoPayReadyDto {
+
+	@NoArgsConstructor
+	@Getter
+	public static class Request {
+		@NotNull(message = "아이디어 ID가 필요합니다.")
+		private Long ideaId;        // 아이디어 ID
+		@NotNull(message = "판매자 ID가 필요합니다.")
+		private Long sellerId;        // 판매자 ID
+		@NotNull(message = "상품 수량 필수입니다.")
+		private Long quantity;        // 상품 수량
+		@NotNull(message = "총 결제 금액은 필수입니다.")
+		private Long totalPrice;     // 총 결제금액
+		@NotNull(message = "VAT는 필수입니다.")
+		private Long vat;        // VAT
+	}
+
+	@Getter
+	@Builder
+	public static class Parameter {
+		private Long buyerId;    // 구매자 ID
+		private Long ideaId;        // 아이디어 ID
+		private Long sellerId;        // 판매자 ID
+		private Long quantity;        // 상품 수량
+		private Long totalPrice;     // 총 결제금액
+		private Long vat;        // VAT
+	}
+
+	@Getter
+	@Builder
+	public static class KakaoApiResponse {
+		private String tid;        // 카카오페이 쪽 결제 고유 번호
+		private String next_redirect_pc_url;    // 카카오페이가 생성한 결제 경로, 사용자는 해당 경로로 이동하여 결제 진행
+	}
+
+	@Getter
+	@Builder
+	public static class Response {
+		private String nextRedirectPcUrl;
+		private String orderId;    // 최종 승인(approve)때, 세션에서 결제 정보를 가져오는데 Key로 사용하기 위함
+	}
+}

src/main/java/com/brainpix/kakaopay/entity/KakaoPaymentData.java

@@ -0,0 +1,43 @@
+package com.brainpix.kakaopay.entity;
+
+import com.brainpix.jpa.BaseTimeEntity;
+import com.brainpix.post.entity.idea_market.IdeaMarket;
+import com.brainpix.user.entity.User;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Entity
+@Getter
+@NoArgsConstructor
+public class KakaoPaymentData extends BaseTimeEntity {
+
+	@Id
+	@GeneratedValue(strategy = GenerationType.IDENTITY)
+	private Long id;
+
+	private String orderId;
+	private String tid;
+	private Long quantity;
+
+	@ManyToOne
+	private User buyer;
+	@ManyToOne
+	private IdeaMarket ideaMarket;
+
+	@Builder
+	public KakaoPaymentData(Long id, String orderId, String tid, Long quantity, User buyer, IdeaMarket ideaMarket) {
+		this.id = id;
+		this.orderId = orderId;
+		this.tid = tid;
+		this.quantity = quantity;
+		this.buyer = buyer;
+		this.ideaMarket = ideaMarket;
+	}
+}

src/main/java/com/brainpix/kakaopay/repository/KakaoPaymentDataRepository.java

@@ -0,0 +1,12 @@
+package com.brainpix.kakaopay.repository;
+
+import java.util.Optional;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import com.brainpix.kakaopay.entity.KakaoPaymentData;
+
+public interface KakaoPaymentDataRepository extends JpaRepository<KakaoPaymentData, Long> {
+
+	Optional<KakaoPaymentData> findByOrderId(String orderId);
+}