fix(agent-calculate): 정산 합계 계산 경로와 회귀 테스트를 보강한다

src/main/kotlin/kr/co/vividnext/sodalive/partner/agent/calculate/AgentCalculateService.kt

@@ -199,7 +199,6 @@ class AgentCalculateService(
 
         val totalCount = totalCountLoader(startDate, endDate)
         val total = totalRowsLoader(startDate, endDate)
-            .toMergedResponseItems()
             .toResponseTotal()
         val items = pagedRowsLoader(startDate, endDate)
             .toMergedResponseItems()

src/main/kotlin/kr/co/vividnext/sodalive/partner/agent/calculate/GetAgentCreatorSettlementSummaryQueryData.kt

@@ -75,3 +75,30 @@ fun List<GetAgentCreatorSettlementSummaryQueryData>.toMergedResponseItems(): Lis
             }
         }
 }
+
+fun List<GetAgentCreatorSettlementSummaryQueryData>.toResponseTotal(): GetAgentSettlementByCreatorTotal {
+    return fold(
+        GetAgentSettlementByCreatorTotal(
+            count = 0,
+            totalCan = 0,
+            krw = 0,
+            fee = 0,
+            settlementAmount = 0,
+            tax = 0,
+            depositAmount = 0,
+            agentSettlementAmount = 0
+        )
+    ) { total, row ->
+        val item = row.toResponseItem()
+        total.copy(
+            count = total.count + item.count,
+            totalCan = total.totalCan + item.totalCan,
+            krw = total.krw + item.krw,
+            fee = total.fee + item.fee,
+            settlementAmount = total.settlementAmount + item.settlementAmount,
+            tax = total.tax + item.tax,
+            depositAmount = total.depositAmount + item.depositAmount,
+            agentSettlementAmount = total.agentSettlementAmount + item.agentSettlementAmount
+        )
+    }
+}

src/test/kotlin/kr/co/vividnext/sodalive/partner/agent/calculate/AgentCalculateServiceTest.kt

@@ -597,6 +597,169 @@ class AgentCalculateServiceTest {
         Mockito.verifyNoInteractions(repository)
     }
 
+    @Test
+    @DisplayName("에이전트 서비스는 generic 정산 결과가 없으면 total 0과 빈 items를 반환한다")
+    fun shouldReturnEmptyGenericSettlementResponseWhenNoRowsExist() {
+        val startDate = "2026-02-20".convertLocalDateTime()
+        val endDate = "2026-02-21".convertLocalDateTime(hour = 23, minute = 59, second = 59)
+
+        Mockito.`when`(repository.getCalculateLiveByCreatorTotalCount(startDate, endDate, 7L)).thenReturn(0)
+        Mockito.`when`(repository.getCalculateLiveByCreator(startDate, endDate, 7L)).thenReturn(emptyList())
+        Mockito.`when`(repository.getCalculateLiveByCreator(startDate, endDate, 7L, 0L, 20L)).thenReturn(emptyList())
+
+        val response = service.getCalculateLiveByCreator("2026-02-20", "2026-02-21", 7L, 0L, 20L)
+
+        assertEquals(0, response.totalCount)
+        assertEquals(0, response.total.count)
+        assertEquals(0, response.total.totalCan)
+        assertEquals(0, response.total.krw)
+        assertEquals(0, response.total.fee)
+        assertEquals(0, response.total.settlementAmount)
+        assertEquals(0, response.total.tax)
+        assertEquals(0, response.total.depositAmount)
+        assertEquals(0, response.total.agentSettlementAmount)
+        assertEquals(emptyList<GetAgentSettlementByCreatorItem>(), response.items)
+    }
+
+    @Test
+    @DisplayName("에이전트 서비스는 채널후원 결과가 없으면 total 0과 빈 items를 반환한다")
+    fun shouldReturnEmptyChannelDonationSettlementResponseWhenNoRowsExist() {
+        val startDate = "2026-02-20".convertLocalDateTime()
+        val endDate = "2026-02-21".convertLocalDateTime(hour = 23, minute = 59, second = 59)
+
+        Mockito.`when`(repository.getChannelDonationByCreatorTotalCount(startDate, endDate, 7L)).thenReturn(0)
+        Mockito.`when`(repository.getChannelDonationByCreator(startDate, endDate, 7L)).thenReturn(emptyList())
+        Mockito.`when`(repository.getChannelDonationByCreator(startDate, endDate, 7L, 0L, 20L)).thenReturn(emptyList())
+
+        val response = service.getChannelDonationByCreator("2026-02-20", "2026-02-21", 7L, 0L, 20L)
+
+        assertEquals(0, response.totalCount)
+        assertEquals(0, response.total.count)
+        assertEquals(0, response.total.totalCan)
+        assertEquals(0, response.total.krw)
+        assertEquals(0, response.total.fee)
+        assertEquals(0, response.total.settlementAmount)
+        assertEquals(0, response.total.withholdingTax)
+        assertEquals(0, response.total.depositAmount)
+        assertEquals(0, response.total.agentSettlementAmount)
+        assertEquals(emptyList<GetAgentChannelDonationSettlementByCreatorItem>(), response.items)
+    }
+
+    @Test
+    @DisplayName("에이전트 서비스는 finalized snapshot을 creatorId desc 순서로 페이지 조회한다")
+    fun shouldPageFinalizedSnapshotsByCreatorIdDesc() {
+        val startDate = "2026-02-20".convertLocalDateTime()
+        val endDate = "2026-02-21".convertLocalDateTime(hour = 23, minute = 59, second = 59)
+
+        Mockito.`when`(
+            snapshotRepository.findAllByPeriodStartAndPeriodEndAndSettlementTypeAndAgentIdOrderByCreatorIdDesc(
+                startDate,
+                endDate,
+                AgentSettlementSnapshotType.LIVE,
+                7L
+            )
+        ).thenReturn(
+            listOf(
+                createSnapshot(
+                    settlementType = AgentSettlementSnapshotType.LIVE,
+                    count = 3,
+                    totalCan = 300,
+                    krw = 30_000,
+                    fee = 1_980,
+                    settlementAmount = 19_614,
+                    tax = 647,
+                    depositAmount = 18_967,
+                    agentSettlementAmount = 1_961,
+                    appliedAgentSettlementRatio = 10
+                ).also { it.creatorId = 31L; it.creatorNickname = "creator-c" },
+                createSnapshot(
+                    settlementType = AgentSettlementSnapshotType.LIVE,
+                    count = 2,
+                    totalCan = 200,
+                    krw = 20_000,
+                    fee = 1_320,
+                    settlementAmount = 13_076,
+                    tax = 431,
+                    depositAmount = 12_645,
+                    agentSettlementAmount = 1_308,
+                    appliedAgentSettlementRatio = 10
+                ).also { it.creatorId = 21L; it.creatorNickname = "creator-b" },
+                createSnapshot(
+                    settlementType = AgentSettlementSnapshotType.LIVE,
+                    count = 1,
+                    totalCan = 100,
+                    krw = 10_000,
+                    fee = 660,
+                    settlementAmount = 6_538,
+                    tax = 216,
+                    depositAmount = 6_322,
+                    agentSettlementAmount = 654,
+                    appliedAgentSettlementRatio = 10
+                ).also { it.creatorId = 11L; it.creatorNickname = "creator-a" }
+            )
+        )
+
+        val response = service.getCalculateLiveByCreator("2026-02-20", "2026-02-21", 7L, 1L, 1L)
+
+        assertEquals(3, response.totalCount)
+        assertEquals(1, response.items.size)
+        assertEquals(21L, response.items[0].creatorId)
+        assertEquals("creator-b", response.items[0].creatorNickname)
+        Mockito.verifyNoInteractions(repository)
+    }
+
+    @Test
+    @DisplayName("finalized 이후 live 데이터가 바뀌어도 동일 기간 응답은 snapshot 값을 유지한다")
+    fun shouldKeepUsingFinalizedSnapshotAfterLiveDataChanges() {
+        val startDate = "2026-02-20".convertLocalDateTime()
+        val endDate = "2026-02-21".convertLocalDateTime(hour = 23, minute = 59, second = 59)
+
+        Mockito.`when`(
+            snapshotRepository.findAllByPeriodStartAndPeriodEndAndSettlementTypeAndAgentIdOrderByCreatorIdDesc(
+                startDate,
+                endDate,
+                AgentSettlementSnapshotType.LIVE,
+                7L
+            )
+        ).thenReturn(
+            listOf(
+                createSnapshot(
+                    settlementType = AgentSettlementSnapshotType.LIVE,
+                    count = 2,
+                    totalCan = 100,
+                    krw = 10_000,
+                    fee = 660,
+                    settlementAmount = 6_538,
+                    tax = 216,
+                    depositAmount = 6_322,
+                    agentSettlementAmount = 654,
+                    appliedAgentSettlementRatio = 10
+                )
+            )
+        )
+        Mockito.`when`(repository.getCalculateLiveByCreatorTotalCount(startDate, endDate, 7L)).thenReturn(99)
+        Mockito.`when`(repository.getCalculateLiveByCreator(startDate, endDate, 7L)).thenReturn(
+            listOf(
+                GetAgentCreatorSettlementSummaryQueryData(
+                    creatorId = 88L,
+                    creatorNickname = "changed-live",
+                    count = 10L,
+                    totalCan = 999,
+                    settlementRatio = 50,
+                    agentSettlementRatio = 30
+                )
+            )
+        )
+
+        val response = service.getCalculateLiveByCreator("2026-02-20", "2026-02-21", 7L, 0L, 20L)
+
+        assertEquals(1, response.totalCount)
+        assertEquals(21L, response.items[0].creatorId)
+        assertEquals(100, response.total.totalCan)
+        assertEquals(654, response.total.agentSettlementAmount)
+        Mockito.verifyNoInteractions(repository)
+    }
+
     private fun createSnapshot(
         settlementType: AgentSettlementSnapshotType,
         count: Int,