feat : 결제 관련 응답 수정 및 서비스 단 검증 조건 추가

src/main/java/com/threestar/trainus/domain/coupon/user/repository/UserCouponRepository.java

@@ -1,6 +1,7 @@
 package com.threestar.trainus.domain.coupon.user.repository;
 
 import java.util.List;
+import java.util.Optional;
 
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
@@ -12,6 +13,8 @@
 public interface UserCouponRepository extends JpaRepository<UserCoupon, Long> {
 	boolean existsByUserIdAndCouponId(Long userId, Long couponId);
 
+	Optional<UserCoupon> findByUserIdAndCouponId(Long userId, Long couponId);
+
 	@Query("SELECT uc FROM UserCoupon uc JOIN FETCH uc.coupon WHERE uc.user.id = :userId")
 	List<UserCoupon> findAllByUserIdWithCoupon(@Param("userId") Long userId);
 

src/main/java/com/threestar/trainus/domain/coupon/user/service/CouponService.java

@@ -94,4 +94,35 @@ public CouponPageResponseDto getCoupons(Long userId) {
 			.coupons(dtoList)
 			.build();
 	}
+
+	@Transactional
+	public UserCoupon getValidUserCoupon(Long userCouponId, Long userId) {
+		return userCouponRepository.findByUserIdAndCouponId(userId, userCouponId)
+			.filter(c -> c.getStatus() == CouponStatus.ACTIVE)
+			.orElseThrow(() -> new BusinessException(ErrorCode.COUPON_NOT_FOUND));
+	}
+
+	public int calculateDiscountedPrice(int originalPrice, UserCoupon coupon) {
+		String discountPrice = coupon.getCoupon().getDiscountPrice();
+		if (discountPrice.contains("%")) {
+			int discountPercentage = Integer.parseInt(discountPrice.substring(0, discountPrice.indexOf("%")));
+			return originalPrice * discountPercentage / 100;
+		} else {
+			return Integer.parseInt(discountPrice.replace("원", ""));
+		}
+	}
+
+	public void useCoupon(UserCoupon coupon) {
+		if (coupon.getStatus() == CouponStatus.ACTIVE) {
+			coupon.use();
+			userCouponRepository.save(coupon);
+		}
+	}
+
+	public void restoreCoupon(UserCoupon coupon) {
+		if (coupon.getStatus() == CouponStatus.INACTIVE) {
+			coupon.restore();
+			userCouponRepository.save(coupon);
+		}
+	}
 }

src/main/java/com/threestar/trainus/domain/lesson/student/service/StudentLessonService.java

@@ -306,4 +306,24 @@ public LessonSimpleResponseDto getLessonSimple(Long lessonId) {
 
 		return LessonSimpleMapper.toLessonSimpleDto(lesson);
 	}
+
+	@Transactional
+	public void cancelPayment(Long lessonId, Long userId) {
+		Lesson lesson = adminLessonService.findLessonById(lessonId);
+		lesson.decrementParticipantCount();
+		lessonRepository.save(lesson);
+
+		LessonParticipant lessonParticipant = lessonParticipantRepository.findByLessonIdAndUserId(lessonId, userId)
+			.orElseThrow(() -> new BusinessException(ErrorCode.INVALID_LESSON_PARTICIPANT));
+
+		lessonParticipantRepository.delete(lessonParticipant);
+	}
+
+	@Transactional
+	public void checkValidLessonParticipant(Lesson lesson, User user) {
+		boolean ifExists = lessonParticipantRepository.existsByLessonIdAndUserId(lesson.getId(), user.getId());
+		if (!ifExists) {
+			throw new BusinessException(ErrorCode.INVALID_LESSON_PARTICIPANT);
+		}
+	}
 }

src/main/java/com/threestar/trainus/domain/lesson/teacher/entity/Lesson.java

@@ -132,6 +132,16 @@ public void incrementParticipantCount() {
 		}
 	}
 
+	// 참가자 수 감소
+	public void decrementParticipantCount() {
+		this.participantCount--;
+
+		// 정원 달성 시 -> 모집완료로 상태 변경
+		if (this.participantCount < this.maxParticipants) {
+			this.status = LessonStatus.RECRUITING;
+		}
+	}
+
 	//레슨 이름 수정
 	public void updateLessonName(String lessonName) {
 		if (lessonName != null && !lessonName.trim().isEmpty()) {

src/main/java/com/threestar/trainus/domain/lesson/teacher/repository/LessonParticipantRepository.java

@@ -1,5 +1,7 @@
 package com.threestar.trainus.domain.lesson.teacher.repository;
 
+import java.util.Optional;
+
 import org.springframework.data.jpa.repository.Modifying;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.CrudRepository;
@@ -12,6 +14,8 @@ public interface LessonParticipantRepository extends CrudRepository<LessonPartic
 
 	boolean existsByLessonIdAndUserId(Long lessonId, Long userId);
 
+	Optional<LessonParticipant> findByLessonIdAndUserId(Long lessonId, Long userId);
+
 	long countByLessonId(Long lessonId);
 
 	@Modifying

src/main/java/com/threestar/trainus/domain/payment/controller/PaymentController.java

@@ -4,34 +4,33 @@
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.PathVariable;
 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.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
-import com.threestar.trainus.domain.payment.dto.CancelPaymentRequestDto;
 import com.threestar.trainus.domain.payment.dto.ConfirmPaymentRequestDto;
-import com.threestar.trainus.domain.payment.dto.PaymentClient;
 import com.threestar.trainus.domain.payment.dto.PaymentRequestDto;
 import com.threestar.trainus.domain.payment.dto.PaymentResponseDto;
 import com.threestar.trainus.domain.payment.dto.SaveAmountRequestDto;
-import com.threestar.trainus.domain.payment.dto.TossPaymentResponseDto;
-import com.threestar.trainus.domain.payment.dto.failure.FailurePaymentResponseDto;
-import com.threestar.trainus.domain.payment.dto.failure.PaymentFailureHistoryPageDto;
-import com.threestar.trainus.domain.payment.dto.failure.PaymentFailurePageWrapperDto;
+import com.threestar.trainus.domain.payment.dto.cancel.CancelPaymentRequestDto;
+import com.threestar.trainus.domain.payment.dto.cancel.CancelPaymentResponseDto;
+import com.threestar.trainus.domain.payment.dto.cancel.PaymentCancelHistoryPageDto;
+import com.threestar.trainus.domain.payment.dto.cancel.PaymentCancelPageWrapperDto;
 import com.threestar.trainus.domain.payment.dto.success.PaymentSuccessHistoryPageDto;
 import com.threestar.trainus.domain.payment.dto.success.PaymentSuccessPageWrapperDto;
 import com.threestar.trainus.domain.payment.dto.success.SuccessfulPaymentResponseDto;
 import com.threestar.trainus.domain.payment.mapper.PaymentMapper;
 import com.threestar.trainus.domain.payment.service.PaymentService;
+import com.threestar.trainus.global.annotation.LoginUser;
 import com.threestar.trainus.global.unit.BaseResponse;
 import com.threestar.trainus.global.unit.PagedResponse;
 
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.servlet.http.HttpSession;
+import jakarta.validation.Valid;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 
@@ -42,33 +41,32 @@
 @RequiredArgsConstructor
 public class PaymentController {
 
-	private final PaymentClient tossPaymentClient;
 	private final PaymentService paymentService;
 
 	@Value("${spring.page.size.limit}")
 	private int pageSizeLimit;
 
 	@PostMapping("/prepare")
 	@Operation(summary = "결제 준비", description = "실제 결제 전 최종 가격 적용 후 결제 준비")
-	public ResponseEntity<BaseResponse<PaymentResponseDto>> preparePayment(HttpSession session,
-		@RequestBody PaymentRequestDto request) {
-		Long userId = (Long)session.getAttribute("LOGIN_USER");
+	public ResponseEntity<BaseResponse<PaymentResponseDto>> preparePayment(
+		@Valid @RequestBody PaymentRequestDto request,
+		@LoginUser Long userId) {
 		PaymentResponseDto response = paymentService.preparePayment(request, userId);
 		return BaseResponse.ok("결제 정보 준비 완료", response, HttpStatus.OK);
 	}
 
 	@PostMapping("/saveAmount")
 	@Operation(summary = "결제 검증 데이터 저장", description = "결제 무결성 검증을 위한 데이터 저장")
 	public ResponseEntity<BaseResponse<Void>> saveAmount(HttpSession session,
-		@RequestBody SaveAmountRequestDto request) {
+		@Valid @RequestBody SaveAmountRequestDto request) {
 		session.setAttribute(request.orderId(), request.amount());
 		return BaseResponse.ok("Payment temp save Successful", null, HttpStatus.OK);
 	}
 
 	@PostMapping("/verifyAmount")
 	@Operation(summary = "결제 검증 데이터 확인", description = "결제 무결성 검증을 위한 데이터 확인")
 	public ResponseEntity<BaseResponse<Void>> verifyAmount(HttpSession session,
-		@RequestBody SaveAmountRequestDto request) {
+		@Valid @RequestBody SaveAmountRequestDto request) {
 		Integer amount = (Integer)session.getAttribute(request.orderId());
 		try {
 			if (amount == null || !amount.equals(request.amount())) {
@@ -83,27 +81,23 @@ public ResponseEntity<BaseResponse<Void>> verifyAmount(HttpSession session,
 	@PostMapping("/confirm")
 	@Operation(summary = "결제 진행", description = "결제 진행")
 	public ResponseEntity<BaseResponse<SuccessfulPaymentResponseDto>> confirm(
-		@RequestBody ConfirmPaymentRequestDto request) {
-		TossPaymentResponseDto tossResponse = tossPaymentClient.confirmPayment(request);
-		SuccessfulPaymentResponseDto payResult = paymentService.processConfirm(tossResponse);
-		return BaseResponse.ok("결제 성공", payResult, HttpStatus.OK);
+		@Valid @RequestBody ConfirmPaymentRequestDto request) {
+		return BaseResponse.ok("결제 성공", paymentService.processConfirm(request), HttpStatus.OK);
 	}
 
 	@PostMapping("/cancel")
 	@Operation(summary = "결제 취소", description = "결제 취소")
-	public ResponseEntity<BaseResponse<FailurePaymentResponseDto>> cancel(
-		@RequestBody CancelPaymentRequestDto request) {
-		TossPaymentResponseDto tossResponse = tossPaymentClient.cancelPayment(request);
-		FailurePaymentResponseDto payResult = paymentService.processCancel(tossResponse, request.cancelReason());
-		return BaseResponse.ok("결제 취소 성공", payResult, HttpStatus.OK);
+	public ResponseEntity<BaseResponse<CancelPaymentResponseDto>> cancel(
+		@Valid @RequestBody CancelPaymentRequestDto request) {
+		return BaseResponse.ok("결제 취소 성공", paymentService.processCancel(request), HttpStatus.OK);
 	}
 
 	@GetMapping("/view/success")
 	@Operation(summary = "완료 결제 조회", description = "완료된 결제 내역 조회")
-	public ResponseEntity<PagedResponse<PaymentSuccessPageWrapperDto>> readAll(HttpSession session,
+	public ResponseEntity<PagedResponse<PaymentSuccessPageWrapperDto>> readAll(
 		@RequestParam("page") int page,
-		@RequestParam("pageSize") int pageSize) {
-		Long userId = (Long)session.getAttribute("LOGIN_USER");
+		@RequestParam("pageSize") int pageSize,
+		@LoginUser Long userId) {
 		int correctPage = Math.max(page, 1);
 		int correctPageSize = Math.max(1, Math.min(pageSize, pageSizeLimit));
 		PaymentSuccessHistoryPageDto paymentSuccessHistoryPageDto = paymentService.viewAllSuccessTransaction(userId,
@@ -115,24 +109,16 @@ public ResponseEntity<PagedResponse<PaymentSuccessPageWrapperDto>> readAll(HttpS
 
 	@GetMapping("/view/cancel")
 	@Operation(summary = "취소 결제 조회", description = "취소된 결제 내역 조회")
-	public ResponseEntity<PagedResponse<PaymentFailurePageWrapperDto>> readAllFailure(HttpSession session,
+	public ResponseEntity<PagedResponse<PaymentCancelPageWrapperDto>> readAllFailure(HttpSession session,
 		@RequestParam("page") int page,
-		@RequestParam("pageSize") int pageSize) {
-		Long userId = (Long)session.getAttribute("LOGIN_USER");
+		@RequestParam("pageSize") int pageSize,
+		@LoginUser Long userId) {
 		int correctPage = Math.max(page, 1);
 		int correctPageSize = Math.max(1, Math.min(pageSize, pageSizeLimit));
-		PaymentFailureHistoryPageDto paymentFailureHistoryPageDto = paymentService.viewAllFailureTransaction(userId,
+		PaymentCancelHistoryPageDto paymentCancelHistoryPageDto = paymentService.viewAllFailureTransaction(userId,
 			correctPage, correctPageSize);
-		PaymentFailurePageWrapperDto payments = PaymentMapper.toPaymentFailurePageWrapperDto(
-			paymentFailureHistoryPageDto);
-		return PagedResponse.ok("취소 결제 조회 성공", payments, paymentFailureHistoryPageDto.count(), HttpStatus.OK);
+		PaymentCancelPageWrapperDto payments = PaymentMapper.toPaymentFailurePageWrapperDto(
+			paymentCancelHistoryPageDto);
+		return PagedResponse.ok("취소 결제 조회 성공", payments, paymentCancelHistoryPageDto.count(), HttpStatus.OK);
 	}
-
-	@GetMapping("/{paymentKey}")
-	@Operation(summary = "상세 결제 조회", description = "상세 결제 내역 조회")
-	public ResponseEntity<BaseResponse<TossPaymentResponseDto>> readDetailPayment(
-		@PathVariable("paymentKey") String paymentKey) {
-		return BaseResponse.ok("상세 결제 조회 완료", tossPaymentClient.viewDetailPayment(paymentKey), HttpStatus.OK);
-	}
-
 }

src/main/java/com/threestar/trainus/domain/payment/dto/PaymentClient.java

@@ -9,6 +9,7 @@
 import org.springframework.stereotype.Component;
 import org.springframework.web.client.RestClient;
 
+import com.threestar.trainus.domain.payment.dto.cancel.TossCancelRequestDto;
 import com.threestar.trainus.global.exception.domain.ErrorCode;
 import com.threestar.trainus.global.exception.handler.BusinessException;
 
@@ -50,7 +51,7 @@ public TossPaymentResponseDto confirmPayment(ConfirmPaymentRequestDto request) {
 			.body(TossPaymentResponseDto.class);
 	}
 
-	public TossPaymentResponseDto cancelPayment(CancelPaymentRequestDto request) {
+	public TossPaymentResponseDto cancelPayment(TossCancelRequestDto request) {
 		return restClient.post()
 			.uri(String.format(paymentProperties.getCancelEndPoint(), request.paymentKey()))
 			.contentType(MediaType.APPLICATION_JSON)
@@ -61,15 +62,4 @@ public TossPaymentResponseDto cancelPayment(CancelPaymentRequestDto request) {
 			})
 			.body(TossPaymentResponseDto.class);
 	}
-
-	public TossPaymentResponseDto viewDetailPayment(String paymentKey) {
-		return restClient.get()
-			.uri(paymentProperties.getViewEndPoint() + "/" + paymentKey)
-			.retrieve()
-			.onStatus(HttpStatusCode::isError, (req, res) -> {
-				throw new BusinessException(ErrorCode.INVALID_PAYMENT);
-			})
-			.body(TossPaymentResponseDto.class);
-	}
-
 }

src/main/java/com/threestar/trainus/domain/payment/dto/TossPaymentResponseDto.java

@@ -1,5 +1,9 @@
 package com.threestar.trainus.domain.payment.dto;
 
+import java.util.List;
+
+import com.threestar.trainus.domain.payment.dto.cancel.CancelDetail;
+
 public record TossPaymentResponseDto(
 	String paymentKey,
 	String orderId,
@@ -8,6 +12,7 @@ public record TossPaymentResponseDto(
 	String requestedAt,
 	String approvedAt,
 	int totalAmount,
-	String method
+	String method,
+	List<CancelDetail> cancels
 ) {
 }

src/main/java/com/threestar/trainus/domain/payment/dto/cancel/CancelDetail.java

@@ -0,0 +1,9 @@
+package com.threestar.trainus.domain.payment.dto.cancel;
+
+public record CancelDetail(
+	String cancelReason,
+	String canceledAt,
+	int cancelAmount,
+	int refundableAmount
+) {
+}

src/main/java/com/threestar/trainus/domain/payment/dto/CancelPaymentRequestDto.java → src/main/java/com/threestar/trainus/domain/payment/dto/cancel/CancelPaymentRequestDto.java

@@ -1,10 +1,10 @@
-package com.threestar.trainus.domain.payment.dto;
+package com.threestar.trainus.domain.payment.dto.cancel;
 
 import jakarta.validation.constraints.NotNull;
 
 public record CancelPaymentRequestDto(
 	@NotNull(message = "필수 값입니다.")
-	String paymentKey,
+	String orderId,
 	@NotNull(message = "실패 원인은 필수입니다.")
 	String cancelReason
 ) {

src/main/java/com/threestar/trainus/domain/payment/dto/failure/FailurePaymentResponseDto.java → src/main/java/com/threestar/trainus/domain/payment/dto/cancel/CancelPaymentResponseDto.java

@@ -1,16 +1,17 @@
-package com.threestar.trainus.domain.payment.dto.failure;
+package com.threestar.trainus.domain.payment.dto.cancel;
 
 import java.time.LocalDateTime;
 
 import lombok.Builder;
 
 @Builder
-public record FailurePaymentResponseDto(
+public record CancelPaymentResponseDto(
 	String lessonName,
 	String cancelReason,
 	LocalDateTime startAt,
 	LocalDateTime endAt,
 	LocalDateTime paymentCancelledAt,
-	int payPrice
+	int payPrice,
+	int refundableAmount
 ) {
 }

src/main/java/com/threestar/trainus/domain/payment/dto/cancel/PaymentCancelHistoryPageDto.java

@@ -0,0 +1,12 @@
+package com.threestar.trainus.domain.payment.dto.cancel;
+
+import java.util.List;
+
+import lombok.Builder;
+
+@Builder
+public record PaymentCancelHistoryPageDto(
+	Integer count,
+	List<PaymentCancelHistoryResponseDto> failureHistory
+) {
+}

src/main/java/com/threestar/trainus/domain/payment/dto/failure/PaymentFailureHistoryResponseDto.java → src/main/java/com/threestar/trainus/domain/payment/dto/cancel/PaymentCancelHistoryResponseDto.java

@@ -1,4 +1,4 @@
-package com.threestar.trainus.domain.payment.dto.failure;
+package com.threestar.trainus.domain.payment.dto.cancel;
 
 import java.time.LocalDateTime;
 
@@ -8,7 +8,7 @@
 import lombok.Builder;
 
 @Builder
-public record PaymentFailureHistoryResponseDto(
+public record PaymentCancelHistoryResponseDto(
 	String lessonTitle,
 	LocalDateTime paymentCancelledAt,
 	LocalDateTime lessonStartAt,
@@ -17,9 +17,9 @@ public record PaymentFailureHistoryResponseDto(
 	String city,
 	String district,
 	String dong,
-	Integer originalPrice,
+	Integer payPrice,
+	Integer refundPrice,
 	PaymentStatus paymentStatus,
-	String paymentKey,
 	String orderId,
 	String detailAddress,
 	String cancelReason