Fix/recognition of already downloaded chapters (#922)

* Remove overrides of "ChapterFilesProvider::downloadImpl"

* Check final download folder for existing page on download

Downloads were changed to get downloaded to the system temp folder instead to directly into the final download folder.

This broke the check for existing pages, because now only the temp folder was checked instead of both the temp and the final download folder.

Regression introduced with 1c9a139006

* Properly check for already existing downloaded pages

The previous check was always false because the file ending of the page file is unknown and thus, missing from the created file path

* Cleanup cache download folder

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/download/fileProvider/ChaptersFilesProvider.kt

@@ -13,6 +13,8 @@ import suwayomi.tachidesk.manga.impl.Page
 import suwayomi.tachidesk.manga.impl.download.model.DownloadChapter
 import suwayomi.tachidesk.manga.impl.util.createComicInfoFile
 import suwayomi.tachidesk.manga.impl.util.getChapterCachePath
+import suwayomi.tachidesk.manga.impl.util.getChapterDownloadPath
+import suwayomi.tachidesk.manga.impl.util.storage.ImageResponse
 import suwayomi.tachidesk.manga.model.table.ChapterTable
 import suwayomi.tachidesk.manga.model.table.MangaTable
 import java.io.File
@@ -28,21 +30,40 @@ abstract class ChaptersFilesProvider(val mangaId: Int, val chapterId: Int) : Dow
         return RetrieveFile1Args(::getImageImpl)
     }
 
+    /**
+     * Extract the existing download to the base download folder (see [getChapterDownloadPath])
+     */
+    protected abstract fun extractExistingDownload()
+
+    protected abstract suspend fun handleSuccessfulDownload()
+
     @OptIn(FlowPreview::class)
-    open suspend fun downloadImpl(
+    private suspend fun downloadImpl(
         download: DownloadChapter,
         scope: CoroutineScope,
         step: suspend (DownloadChapter?, Boolean) -> Unit,
     ): Boolean {
-        val pageCount = download.chapter.pageCount
+        extractExistingDownload()
-        val chapterDir = getChapterCachePath(mangaId, chapterId)
-        val folder = File(chapterDir)
-        folder.mkdirs()
 
+        val finalDownloadFolder = getChapterDownloadPath(mangaId, chapterId)
+
+        val cacheChapterDir = getChapterCachePath(mangaId, chapterId)
+        val downloadCacheFolder = File(cacheChapterDir)
+        downloadCacheFolder.mkdirs()
+
+        val pageCount = download.chapter.pageCount
         for (pageNum in 0 until pageCount) {
             var pageProgressJob: Job? = null
             val fileName = Page.getPageName(pageNum) // might have to change this to index stored in database
-            if (File(folder, fileName).exists()) continue
+
+            val pageExistsInFinalDownloadFolder = ImageResponse.findFileNameStartingWith(finalDownloadFolder, fileName) != null
+            val pageExistsInCacheDownloadFolder = ImageResponse.findFileNameStartingWith(cacheChapterDir, fileName) != null
+
+            val doesPageAlreadyExist = pageExistsInFinalDownloadFolder || pageExistsInCacheDownloadFolder
+            if (doesPageAlreadyExist) {
+                continue
+            }
+
             try {
                 Page.getPageImage(
                     mangaId = download.mangaId,
@@ -69,7 +90,7 @@ abstract class ChaptersFilesProvider(val mangaId: Int, val chapterId: Int) : Dow
         }
 
         createComicInfoFile(
-            folder.toPath(),
+            downloadCacheFolder.toPath(),
             transaction {
                 MangaTable.select { MangaTable.id eq mangaId }.first()
             },
@@ -78,6 +99,10 @@ abstract class ChaptersFilesProvider(val mangaId: Int, val chapterId: Int) : Dow
             },
         )
 
+        handleSuccessfulDownload()
+
+        File(cacheChapterDir).deleteRecursively()
+
         return true
     }
 

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/download/fileProvider/impl/ArchiveProvider.kt

@@ -1,6 +1,5 @@
 package suwayomi.tachidesk.manga.impl.download.fileProvider.impl
 
-import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import org.apache.commons.compress.archivers.zip.ZipArchiveEntry
@@ -11,7 +10,6 @@ import org.kodein.di.DI
 import org.kodein.di.conf.global
 import org.kodein.di.instance
 import suwayomi.tachidesk.manga.impl.download.fileProvider.ChaptersFilesProvider
-import suwayomi.tachidesk.manga.impl.download.model.DownloadChapter
 import suwayomi.tachidesk.manga.impl.util.getChapterCachePath
 import suwayomi.tachidesk.manga.impl.util.getChapterCbzPath
 import suwayomi.tachidesk.manga.impl.util.getMangaDownloadDir
@@ -32,17 +30,21 @@ class ArchiveProvider(mangaId: Int, chapterId: Int) : ChaptersFilesProvider(mang
         return Pair(inputStream.buffered(), "image/$fileType")
     }
 
-    override suspend fun downloadImpl(
+    override fun extractExistingDownload() {
-        download: DownloadChapter,
+        val outputFile = File(getChapterCbzPath(mangaId, chapterId))
-        scope: CoroutineScope,
+        val chapterCacheFolder = File(getChapterCachePath(mangaId, chapterId))
-        step: suspend (DownloadChapter?, Boolean) -> Unit,
+
-    ): Boolean {
+        if (!outputFile.exists()) {
+            return
+        }
+
+        extractCbzFile(outputFile, chapterCacheFolder)
+    }
+
+    override suspend fun handleSuccessfulDownload() {
         val mangaDownloadFolder = File(getMangaDownloadDir(mangaId))
         val outputFile = File(getChapterCbzPath(mangaId, chapterId))
         val chapterCacheFolder = File(getChapterCachePath(mangaId, chapterId))
-        if (outputFile.exists()) handleExistingCbzFile(outputFile, chapterCacheFolder)
-
-        super.downloadImpl(download, scope, step)
 
         withContext(Dispatchers.IO) {
             mangaDownloadFolder.mkdirs()
@@ -68,8 +70,6 @@ class ArchiveProvider(mangaId: Int, chapterId: Int) : ChaptersFilesProvider(mang
         if (chapterCacheFolder.exists() && chapterCacheFolder.isDirectory) {
             chapterCacheFolder.deleteRecursively()
         }
-
-        return true
     }
 
     override fun delete(): Boolean {
@@ -83,7 +83,7 @@ class ArchiveProvider(mangaId: Int, chapterId: Int) : ChaptersFilesProvider(mang
         return cbzDeleted
     }
 
-    private fun handleExistingCbzFile(
+    private fun extractCbzFile(
         cbzFile: File,
         chapterFolder: File,
     ) {

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/download/fileProvider/impl/FolderProvider.kt

@@ -1,11 +1,9 @@
 package suwayomi.tachidesk.manga.impl.download.fileProvider.impl
 
-import kotlinx.coroutines.CoroutineScope
 import org.kodein.di.DI
 import org.kodein.di.conf.global
 import org.kodein.di.instance
 import suwayomi.tachidesk.manga.impl.download.fileProvider.ChaptersFilesProvider
-import suwayomi.tachidesk.manga.impl.download.model.DownloadChapter
 import suwayomi.tachidesk.manga.impl.util.getChapterCachePath
 import suwayomi.tachidesk.manga.impl.util.getChapterDownloadPath
 import suwayomi.tachidesk.manga.impl.util.storage.FileDeletionHelper
@@ -29,23 +27,16 @@ class FolderProvider(mangaId: Int, chapterId: Int) : ChaptersFilesProvider(manga
         return Pair(FileInputStream(file).buffered(), "image/$fileType")
     }
 
-    override suspend fun downloadImpl(
+    override fun extractExistingDownload() {
-        download: DownloadChapter,
+        // nothing to do
-        scope: CoroutineScope,
+    }
-        step: suspend (DownloadChapter?, Boolean) -> Unit,
+
-    ): Boolean {
+    override suspend fun handleSuccessfulDownload() {
         val chapterDir = getChapterDownloadPath(mangaId, chapterId)
         val folder = File(chapterDir)
 
-        val downloadSucceeded = super.downloadImpl(download, scope, step)
-        if (!downloadSucceeded) {
-            return false
-        }
-
         val cacheChapterDir = getChapterCachePath(mangaId, chapterId)
         File(cacheChapterDir).copyRecursively(folder, true)
-
-        return true
     }
 
     override fun delete(): Boolean {