전체 코드, 구조 검토 - P0 코드 수정 진행

lib/extension-requests.ts

@@ -3,7 +3,7 @@ import { z } from "zod";
 import { db } from "@/lib/db";
 import { logger } from "@/lib/logger";
 import { ApiError } from "@/lib/errors";
-import { PAID_ACCOUNT_TYPE_VALUES, REQUEST_STATUSES } from "@/lib/constants";
+import { ACTIVATE_STATUSES, PAID_ACCOUNT_TYPE_VALUES, REQUEST_STATUSES } from "@/lib/constants";
 import type { Prisma } from "@/lib/generated/prisma/client";
 import {
   calculateExtendedAvailableDate,
@@ -114,45 +114,70 @@ export async function approveExtensionRequest(
   maestroEmail: string;
 }> {
   return db.$transaction(async (tx) => {
-    const request = await getActionTarget(tx, maestroExtensionID);
+    // Atomically claim the request — prevents concurrent double-approval
+    const claimed = await tx.maestro_extension.updateMany({
+      where: { MaestroExtensionID: maestroExtensionID, Status: REQUEST_STATUSES.REQUESTED },
+      data: { Status: REQUEST_STATUSES.APPLIED },
+    });
+    if (claimed.count === 0) {
+      const exists = await tx.maestro_extension.count({
+        where: { MaestroExtensionID: maestroExtensionID },
+      });
+      throw new ApiError(
+        exists ? "이미 처리된 연장 신청입니다." : "연장 신청을 찾을 수 없습니다.",
+        exists ? 409 : 404
+      );
+    }
+
+    const request = await tx.maestro_extension.findUnique({
+      where: { MaestroExtensionID: maestroExtensionID },
+      select: {
+        MaestroID: true,
+        AccountType: true,
+        maestro: {
+          select: {
+            Name: true,
+            Email: true,
+            AvailableActivateDateTime: true,
+          },
+        },
+      },
+    });
+
     const availableActivateDateTime = calculateExtendedAvailableDate(
-      request.maestro.AvailableActivateDateTime
+      request!.maestro.AvailableActivateDateTime
     );
 
     await tx.maestro.update({
-      where: { MaestroID: request.MaestroID },
+      where: { MaestroID: request!.MaestroID },
       data: {
-        ActivateStatus: 2,
+        ActivateStatus: ACTIVATE_STATUSES.ACTIVE,
         AvailableActivateDateTime: availableActivateDateTime,
       },
     });
     await tx.maestro_extension.updateMany({
       where: {
-        MaestroID: request.MaestroID,
+        MaestroID: request!.MaestroID,
         Status: REQUEST_STATUSES.REQUESTED,
       },
       data: { Status: REQUEST_STATUSES.CLOSED },
     });
-    await tx.maestro_extension.update({
-      where: { MaestroExtensionID: request.MaestroExtensionID },
-      data: { Status: REQUEST_STATUSES.APPLIED },
-    });
     await tx.maestro_log.create({
       data: {
         Type: "extension_maestro",
-        MaestroID: request.MaestroID,
+        MaestroID: request!.MaestroID,
         LogDateTime: new Date(),
         Remark: buildExtensionLogRemark(
-          request.maestro.Name,
-          request.AccountType
+          request!.maestro.Name,
+          request!.AccountType
         ),
       },
     });
 
     return {
       availableActivateDateTime: availableActivateDateTime.toISOString(),
-      maestroName: request.maestro.Name.trim(),
-      maestroEmail: request.maestro.Email.trim(),
+      maestroName: request!.maestro.Name.trim(),
+      maestroEmail: request!.maestro.Email.trim(),
     };
   });
 }
@@ -198,20 +223,37 @@ export async function cancelExtensionRequest(
   maestroExtensionID: number
 ): Promise<void> {
   await db.$transaction(async (tx) => {
-    const request = await getActionTarget(tx, maestroExtensionID);
-
-    await tx.maestro_extension.update({
-      where: { MaestroExtensionID: request.MaestroExtensionID },
+    const claimed = await tx.maestro_extension.updateMany({
+      where: { MaestroExtensionID: maestroExtensionID, Status: REQUEST_STATUSES.REQUESTED },
       data: { Status: REQUEST_STATUSES.CLOSED },
     });
+    if (claimed.count === 0) {
+      const exists = await tx.maestro_extension.count({
+        where: { MaestroExtensionID: maestroExtensionID },
+      });
+      throw new ApiError(
+        exists ? "이미 처리된 연장 신청입니다." : "연장 신청을 찾을 수 없습니다.",
+        exists ? 409 : 404
+      );
+    }
+
+    const request = await tx.maestro_extension.findUnique({
+      where: { MaestroExtensionID: maestroExtensionID },
+      select: {
+        MaestroID: true,
+        AccountType: true,
+        maestro: { select: { Name: true } },
+      },
+    });
+
     await tx.maestro_log.create({
       data: {
         Type: "cancel_extension_maestro",
-        MaestroID: request.MaestroID,
+        MaestroID: request!.MaestroID,
         LogDateTime: new Date(),
         Remark: buildExtensionLogRemark(
-          request.maestro.Name,
-          request.AccountType
+          request!.maestro.Name,
+          request!.AccountType
         ),
       },
     });
@@ -226,25 +268,6 @@ export function parseExtensionRequestSearchParams(
   );
 }
 
-async function getActionTarget(
-  tx: Prisma.TransactionClient,
-  maestroExtensionID: number
-) {
-  const request = await tx.maestro_extension.findUnique({
-    where: { MaestroExtensionID: maestroExtensionID },
-    include: { maestro: true },
-  });
-
-  if (!request) {
-    throw new ApiError("연장 신청을 찾을 수 없습니다.", 404);
-  }
-
-  if (request.Status !== REQUEST_STATUSES.REQUESTED) {
-    throw new ApiError("이미 처리된 연장 신청입니다.", 409);
-  }
-
-  return request;
-}
 
 function buildExtensionRequestWhere(
   params: ExtensionRequestSearchParams