From bb861962046055e264be8197a9fbc76e1be59141 Mon Sep 17 00:00:00 2001
From: Eugene <ey.cheung@outlook.com>
Date: Wed, 9 Oct 2019 22:03:41 -0400
Subject: [PATCH] Unique chapter directory names to avoid download conflicts

---
 .../tachiyomi/data/download/DownloadCache.kt  |  2 +-
 .../data/download/DownloadProvider.kt         | 20 ++++++++++++++++---
 .../tachiyomi/data/download/Downloader.kt     |  6 +-----
 3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadCache.kt b/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadCache.kt
index bc6d6b42ee..2912cdca57 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadCache.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadCache.kt
@@ -82,7 +82,7 @@ class DownloadCache(
         if (sourceDir != null) {
             val mangaDir = sourceDir.files[provider.getMangaDirName(manga)]
             if (mangaDir != null) {
-                return provider.getChapterDirName(chapter) in mangaDir.files
+                return mangaDir.files.any { it in provider.getValidChapterDirNames(chapter) }
             }
         }
         return false
diff --git a/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadProvider.kt b/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadProvider.kt
index bed8c5e369..087891444d 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadProvider.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadProvider.kt
@@ -80,7 +80,7 @@ class DownloadProvider(private val context: Context) {
      */
     fun findChapterDir(chapter: Chapter, manga: Manga, source: Source): UniFile? {
         val mangaDir = findMangaDir(manga, source)
-        return mangaDir?.findFile(getChapterDirName(chapter))
+        return getValidChapterDirNames(chapter).mapNotNull { mangaDir?.findFile(it) }.firstOrNull()
     }
 
     /**
@@ -92,7 +92,7 @@ class DownloadProvider(private val context: Context) {
      */
     fun findChapterDirs(chapters: List<Chapter>, manga: Manga, source: Source): List<UniFile> {
         val mangaDir = findMangaDir(manga, source) ?: return emptyList()
-        return chapters.mapNotNull { mangaDir.findFile(getChapterDirName(it)) }
+        return chapters.flatMap { getValidChapterDirNames(it) }.mapNotNull { mangaDir.findFile(it) }
     }
 
     /**
@@ -119,7 +119,21 @@ class DownloadProvider(private val context: Context) {
      * @param chapter the chapter to query.
      */
     fun getChapterDirName(chapter: Chapter): String {
-        return DiskUtil.buildValidFilename(chapter.name)
+        return DiskUtil.buildValidFilename("${chapter.id}_${chapter.scanlator}_${chapter.name}")
+    }
+
+    /**
+     * Returns valid downloaded chapter directory names.
+     *
+     * @param chapter the chapter to query.
+     */
+    fun getValidChapterDirNames(chapter: Chapter): List<String> {
+        return listOf(
+                getChapterDirName(chapter),
+
+                // Legacy chapter directory name used in v0.8.4 and before
+                DiskUtil.buildValidFilename(chapter.name)
+        )
     }
 
 }
diff --git a/app/src/main/java/eu/kanade/tachiyomi/data/download/Downloader.kt b/app/src/main/java/eu/kanade/tachiyomi/data/download/Downloader.kt
index 2492891e69..dc7567898b 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/data/download/Downloader.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/data/download/Downloader.kt
@@ -232,13 +232,9 @@ class Downloader(
 
         // Called in background thread, the operation can be slow with SAF.
         val chaptersWithoutDir = async {
-            val mangaDir = provider.findMangaDir(manga, source)
-
             chapters
-                    // Avoid downloading chapters with the same name.
-                    .distinctBy { it.name }
                     // Filter out those already downloaded.
-                    .filter { mangaDir?.findFile(provider.getChapterDirName(it)) == null }
+                    .filter { provider.findChapterDir(it, manga, source) == null }
                     // Add chapters to queue from the start.
                     .sortedByDescending { it.source_order }
         }