환불 로직 상상 코딩

Author: golony6449

payment/clients.py

@@ -0,0 +1,85 @@
+import requests
+import constance
+
+
+class PortOneClient:
+    # TODO: 상황에 맞는 Error로 변경하기: 지금은 모두 ValueError
+    def __init__(self):
+        self.url = "https://api.iamport.kr"
+
+    # TODO: 잘 말아서 Singleton 패턴으로 만들기
+    def get_access_token(self) -> str:
+        endpoint = self.url + "/users/getToken"
+
+        if constance.config["imp_key"] is None or constance.config["imp_secret"] is None:
+            raise ValueError("Access Token 발급 실패: imp_key 또는 imp_secret을 찾을 수 없습니다.")
+
+        request_dto = {
+            "imp_key": constance.config["imp_key"],
+            "imp_secret": constance.config["imp_secret"]
+        }
+
+        response = requests.post(
+            endpoint,
+            request_dto
+        )
+
+        if not response.ok:
+            raise ValueError("Access Token 발급에 실패했습니다.")
+
+        return response.json().get("access_token")
+
+    def find_payment_info(self, payment_key: str):
+        endpoint = self.url + "/payments/{}"
+
+        if payment_key is None or payment_key == "":
+            raise ValueError("payment_key (merchant_uid)는 필수값입니다.")
+
+        request_header = {
+            "Authorization": self.get_access_token()
+        }
+
+        response = requests.get(endpoint.format(payment_key), headers=request_header)
+
+        if not response.ok:
+            raise ValueError("결제 정보 조회에 실패했습니다.")
+
+        return response.json()
+
+    def req_cancel_payment(self, payment_key: str, price: int, reason: str = ""):
+        endpoint = self.url + "/payments/cancel"
+
+        if payment_key is None or payment_key == "":
+            raise ValueError("payment_key (merchant_uid)는 필수값입니다.")
+
+        if price is None or price == 0:
+            raise ValueError("금액은 필수값입니다.")
+
+        request_header = {
+            "Authorization": self.get_access_token()
+        }
+
+        request_dto = {
+            "merchant_uid": payment_key,
+            "amount": price,
+            "checksum": price   # 지금은 전액환불하는 케이스만 존재함 -> 환불요청금액과 결제 건의 환불가능금액은 동일해야함
+        }
+
+        if reason is not None and reason != "":
+            request_dto["reason"] = reason
+
+        response = requests.post(
+            endpoint,
+            request_dto,
+            headers=request_header
+        )
+
+        if not response.ok:
+            raise ValueError("Portone에서 비정상 응답: {}".format(payment_key))
+
+        response_data = response.json()
+
+        if response_data.get("code") is None or response_data.get("code") != 0:
+            raise ValueError("환불 처리 실패: {}".format(payment_key))
+
+        return True

payment/logic.py

@@ -44,3 +44,14 @@ def _save_history(payment_key: str, status: int):
     )
 
     new_payment_history.save()
+
+
+@transaction.atomic
+def cancel_payment(payment: Payment):
+    payment.status = PaymentStatus.REFUND_SUCCESS.value
+    payment.save()
+
+    payment_history = PaymentHistory(
+        payment_key=payment.payment_key,
+        status=PaymentStatus.REFUND_SUCCESS.value
+    )

payment/utils.py

@@ -6,8 +6,9 @@
 from rest_framework.views import APIView
 
 from payment import enum
+from payment.clients import PortOneClient
 from ticket.models import TicketType, Ticket
-from payment.logic import generate_payment_key
+from payment.logic import generate_payment_key, cancel_payment
 from payment.models import Payment, PaymentHistory
 
 from django.conf import settings
@@ -95,3 +96,31 @@ def post__generate_payment_key(request):
     }
 
     return Response(response_data)
+
+
+@api_view(["POST"])
+@transaction.atomic
+def post__cancel_payment(request):
+    portone_client = PortOneClient()
+
+    target_payment = Payment.objects.get(payment_key=request.data["payment_key"])
+    target_ticket = Ticket.objects.get(payment=target_payment)
+
+    portone_client.req_cancel_payment(
+        target_payment.payment_key,
+        target_payment.money,
+        "구매자의 환불요청"
+    )
+
+    cancel_payment(target_payment)
+
+    target_ticket.is_refunded = True
+    target_ticket.refunded_at = datetime.datetime.now()
+    target_ticket.save()
+
+    dto = {
+        "msg": "ok"
+    }
+
+    return Response(dto)
+

payment/views.py

@@ -9,7 +9,7 @@
 from django.views import View
 from django.views.decorators.csrf import csrf_exempt
 
-import payment.utils
+import payment.logic
 from program.models import CONFERENCE, TUTORIAL, SPRINT
 from .models import Ticket, TicketType
 from .requests import (
@@ -181,7 +181,7 @@ def get__ticket_list(request):
 class TicketDetailView(View):
     def get(self, request, item_id: int):
         ticket_type = TicketType.objects.get(id=item_id)
-        payment_key = payment.utils.generate_payment_key(request.user, ticket_type=ticket_type)
+        payment_key = payment.logic.generate_payment_key(request.user, ticket_type=ticket_type)
         user = request.user
 
         dto = {