feat(perf): пагинация аудита и bulk-группы курса

services/identity-service/src/main/kotlin/ru/ysu/lms/identity/audit/AuditController.kt

@@ -17,5 +17,6 @@ class AuditController(
     fun list(
         @RequestParam(defaultValue = "100") limit: Int,
         @RequestParam(required = false) action: String?,
-    ): List<AuditEventDto> = auditService.list(limit, action)
+        @RequestParam(defaultValue = "0") page: Int,
+    ): List<AuditEventDto> = auditService.list(limit, action, page)
 }

services/identity-service/src/main/kotlin/ru/ysu/lms/identity/audit/AuditService.kt

@@ -38,15 +38,17 @@ class AuditService(
     fun list(
         limit: Int = DEFAULT_LIMIT,
         action: String? = null,
+        page: Int = 0,
     ): List<AuditEventDto> {
         val size = limit.coerceIn(1, MAX_LIMIT)
-        val page = PageRequest.of(0, size)
+        val pageIndex = page.coerceAtLeast(0)
+        val pageable = PageRequest.of(pageIndex, size)
         val filter = action?.trim()?.takeIf { it.isNotEmpty() }
         val found =
             if (filter == null) {
-                events.findAllByOrderByOccurredAtDescIdDesc(page)
+                events.findAllByOrderByOccurredAtDescIdDesc(pageable)
             } else {
-                events.findAllByActionOrderByOccurredAtDescIdDesc(filter, page)
+                events.findAllByActionOrderByOccurredAtDescIdDesc(filter, pageable)
             }
         return found.map(::toDto)
     }

services/identity-service/src/test/kotlin/ru/ysu/lms/identity/audit/AuditIntegrationTest.kt

@@ -29,6 +29,7 @@ import ru.ysu.lms.identity.repo.AccountRepository
 import ru.ysu.lms.identity.roster.CreateGroupRequest
 import ru.ysu.lms.identity.roster.CreateStudentRequest
 import ru.ysu.lms.identity.roster.GroupService
+import java.nio.charset.StandardCharsets
 import java.util.UUID
 
 @SpringBootTest(properties = ["lms.promotion.scheduler-enabled=false"])
@@ -198,6 +199,33 @@ class AuditIntegrationTest {
             }
     }
 
+    @Test
+    fun `pagination returns disjoint pages newest first`() {
+        repeat(5) { index ->
+            write(AuditEventRequest(action = "AUDIT_PAGE", entityType = "STUDENT", details = "page-${index + 1}"))
+        }
+
+        val first = detailsOfPage(limit = 2, page = 0)
+        val second = detailsOfPage(limit = 2, page = 1)
+        val third = detailsOfPage(limit = 2, page = 2)
+
+        assertEquals(listOf("page-5", "page-4"), first)
+        assertEquals(listOf("page-3", "page-2"), second)
+        assertEquals(listOf("page-1"), third)
+        assertTrue(first.intersect(second.toSet()).isEmpty())
+        assertTrue((first + second).intersect(third.toSet()).isEmpty())
+    }
+
+    @Test
+    fun `negative page is clamped to the first page and page past the end is empty`() {
+        repeat(3) { index ->
+            write(AuditEventRequest(action = "AUDIT_PAGE_CLAMP", entityType = "STUDENT", details = "page-${index + 1}"))
+        }
+
+        assertEquals(listOf("page-3", "page-2"), detailsOfPage(limit = 2, page = -5))
+        assertEquals(emptyList<String>(), detailsOfPage(limit = 2, page = 1000))
+    }
+
     @Test
     fun `blank action or entity type is rejected`() {
         writeExpectingBadRequest(AuditEventRequest(action = "   ", entityType = "STUDENT"))
@@ -291,6 +319,24 @@ class AuditIntegrationTest {
         assertTrue(auditEvents.findById(deleteEvent.id).isPresent)
     }
 
+    private fun detailsOfPage(
+        limit: Int,
+        page: Int,
+    ): List<String> {
+        val body =
+            mockMvc
+                .get("/api/v1/audit") {
+                    with(admin())
+                    param("limit", limit.toString())
+                    param("page", page.toString())
+                }.andExpect {
+                    status { isOk() }
+                }.andReturn()
+                .response
+                .getContentAsString(StandardCharsets.UTF_8)
+        return objectMapper.readTree(body).map { it.path("details").asText() }
+    }
+
     private fun write(request: AuditEventRequest) {
         mockMvc
             .post("/api/v1/internal/audit") {