refactor: extract List.toPage() implementation (#269)

2 files changed, 49 insertions, 16 deletions

diff --git a/src/main/kotlin/dev/dnpm/etl/processor/functions.kt b/src/main/kotlin/dev/dnpm/etl/processor/functions.kt
new file mode 100644
index 0000000..aa4fc75
--- /dev/null
+++ b/src/main/kotlin/dev/dnpm/etl/processor/functions.kt
@@ -0,0 +1,35 @@
+/*
+ * This file is part of ETL-Processor
+ *
+ * Copyright (c) 2026  Comprehensive Cancer Center Mainfranken, Datenintegrationszentrum Philipps-Universität Marburg and Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package dev.dnpm.etl.processor
+
+import org.springframework.data.domain.Page
+import org.springframework.data.domain.PageImpl
+import org.springframework.data.domain.Pageable
+
+fun <T : Any> List<T>.toPage(pageable: Pageable): Page<T> {
+    return PageImpl(
+        this.subList(
+            pageable.offset.toInt().coerceIn(0, this.size),
+            (pageable.offset.toInt() + pageable.pageSize).coerceIn(0, this.size)
+        ),
+        pageable,
+        this.size.toLong()
+    )
+}
diff --git a/src/main/kotlin/dev/dnpm/etl/processor/services/RequestService.kt b/src/main/kotlin/dev/dnpm/etl/processor/services/RequestService.kt
index 6e7c2f3..ba33fd6 100644
--- a/src/main/kotlin/dev/dnpm/etl/processor/services/RequestService.kt
+++ b/src/main/kotlin/dev/dnpm/etl/processor/services/RequestService.kt
@@ -23,11 +23,11 @@ import dev.dnpm.etl.processor.PatientPseudonym
 import dev.dnpm.etl.processor.RequestId
 import dev.dnpm.etl.processor.Tan
 import dev.dnpm.etl.processor.monitoring.*
-import java.util.*
+import dev.dnpm.etl.processor.toPage
 import org.springframework.data.domain.Page
-import org.springframework.data.domain.PageImpl
 import org.springframework.data.domain.Pageable
 import org.springframework.stereotype.Service
+import java.util.*
 
 @Service
 class RequestService(private val requestRepository: RequestRepository) {
@@ -98,18 +98,16 @@ class RequestService(private val requestRepository: RequestRepository) {
 }
 
 fun List<Request>.filter(filter: RequestService.Filter, pageable: Pageable): Page<Request> {
-    val list =
-        this
-            .toList()
-            .filter {
-                it.type == RequestType.MTB_FILE
-                        && sequenceOf(RequestStatus.SUCCESS, RequestStatus.WARNING).contains(it.status)
-            }
-            .filter {
-                filter == RequestService.Filter.ALL_DIP
-                        || filter == RequestService.Filter.CONFIRMED && it.submissionAccepted
-                        || filter == RequestService.Filter.UNCONFIRMED && !it.submissionAccepted
-            }
-
-    return PageImpl(list, pageable, list.size.toLong())
+    return this
+        .toList()
+        .filter {
+            it.type == RequestType.MTB_FILE
+                    && sequenceOf(RequestStatus.SUCCESS, RequestStatus.WARNING).contains(it.status)
+        }
+        .filter {
+            filter == RequestService.Filter.ALL_DIP
+                    || filter == RequestService.Filter.CONFIRMED && it.submissionAccepted
+                    || filter == RequestService.Filter.UNCONFIRMED && !it.submissionAccepted
+        }
+        .toPage(pageable)
 }