From d308e0c29fca8319704a336b7e16628c4088bca5 Mon Sep 17 00:00:00 2001
From: Carlos <2092019+CarlosEsco@users.noreply.github.com>
Date: Sun, 9 Aug 2020 15:04:21 -0400
Subject: [PATCH] update nth chapter logic from stable (#504)

Co-authored-by: Jays2Kings <jays@outlook.com>
---
 .../tachiyomi/ui/reader/ReaderPresenter.kt    | 34 +++++++++++--------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderPresenter.kt b/app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderPresenter.kt
index be31699039..afc61aea30 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderPresenter.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderPresenter.kt
@@ -23,7 +23,6 @@ import eu.kanade.tachiyomi.source.online.HttpSource
 import eu.kanade.tachiyomi.ui.base.presenter.BasePresenter
 import eu.kanade.tachiyomi.ui.reader.chapter.ReaderChapterItem
 import eu.kanade.tachiyomi.ui.reader.loader.ChapterLoader
-import eu.kanade.tachiyomi.ui.reader.loader.DownloadPageLoader
 import eu.kanade.tachiyomi.ui.reader.model.ReaderChapter
 import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
 import eu.kanade.tachiyomi.ui.reader.model.ViewerChapters
@@ -370,7 +369,7 @@ class ReaderPresenter(
         if (selectedChapter.pages?.lastIndex == page.index) {
             selectedChapter.chapter.read = true
             updateTrackChapterRead(selectedChapter)
-            enqueueDeleteReadChapters(selectedChapter)
+            deleteChapterIfNeeded(selectedChapter)
         }
 
         if (selectedChapter != currentChapters.currChapter) {
@@ -382,6 +381,22 @@ class ReaderPresenter(
         return false
     }
 
+    /**
+     * Determines if deleting option is enabled and nth to last chapter actually exists.
+     * If both conditions are satisfied enqueues chapter for delete
+     * @param currentChapter current chapter, which is going to be marked as read.
+     */
+    private fun deleteChapterIfNeeded(currentChapter: ReaderChapter) {
+        // Determine which chapter should be deleted and enqueue
+        val currentChapterPosition = chapterList.indexOf(currentChapter)
+        val removeAfterReadSlots = preferences.removeAfterReadSlots()
+        val chapterToDelete = chapterList.getOrNull(currentChapterPosition - removeAfterReadSlots)
+        // Check if deleting option is enabled and chapter exists
+        if (removeAfterReadSlots != -1 && chapterToDelete != null) {
+            enqueueDeleteReadChapters(chapterToDelete)
+        }
+    }
+
     /**
      * Called when a chapter changed from [fromChapter] to [toChapter]. It updates [fromChapter]
      * on the database.
@@ -634,23 +649,12 @@ class ReaderPresenter(
      * manager handles persisting it across process deaths.
      */
     private fun enqueueDeleteReadChapters(chapter: ReaderChapter) {
-        if (!chapter.chapter.read || chapter.pageLoader !is DownloadPageLoader) return
+        if (!chapter.chapter.read) return
         val manga = manga ?: return
 
-        // Return if the setting is disabled
-        val removeAfterReadSlots = preferences.removeAfterReadSlots()
-        if (removeAfterReadSlots == -1) return
-
         Completable
             .fromCallable {
-                // Position of the read chapter
-                val position = chapterList.indexOf(chapter)
-
-                // Retrieve chapter to delete according to preference
-                val chapterToDelete = chapterList.getOrNull(position - removeAfterReadSlots)
-                if (chapterToDelete != null) {
-                    downloadManager.enqueueDeleteChapters(listOf(chapterToDelete.chapter), manga)
-                }
+                downloadManager.enqueueDeleteChapters(listOf(chapter.chapter), manga)
             }
             .onErrorComplete()
             .subscribeOn(Schedulers.io())