add pagination to recentChapters (#246)

* add pagination to recentChapters

* Use kotlin native library

Co-authored-by: Mitchell Syer <Mitchellptbo@gmail.com>

Co-authored-by: Mitchell Syer <Mitchellptbo@gmail.com>

server/src/main/kotlin/suwayomi/tachidesk/manga/model/dataclass/PaginatedList.kt

@@ -0,0 +1,40 @@
+package suwayomi.tachidesk.manga.model.dataclass
+
+/*
+ * Copyright (C) Contributors to the Suwayomi project
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+import kotlin.math.min
+
+data class PaginatedList<T>(
+    val page: List<T>,
+    val hasNextPage: Boolean,
+)
+
+const val PaginationFactor = 50
+
+fun <T> paginatedFrom(
+    pageNum: Int,
+    paginationFactor: Int = PaginationFactor,
+    lister: () -> List<T>
+): PaginatedList<T> {
+    val list = lister()
+    val lastIndex = list.size - 1
+
+    val lowerIndex = pageNum * paginationFactor
+    val higherIndex = (pageNum + 1) * paginationFactor - 1
+
+    if (lowerIndex > lastIndex) {
+        return PaginatedList(emptyList(), false)
+    }
+
+    val sliced = list.slice(lowerIndex..min(lastIndex, higherIndex))
+
+    return PaginatedList(
+        sliced,
+        higherIndex < lastIndex
+    )
+}