Feature: Migrate Downloaded Chapters

.editorconfig

@@ -1,5 +1,9 @@
+# prevent user settings outside of the project from propagating into this project
+root = true
+
 [*.{kt,kts}]
 max_line_length = 120
+indent_style = space
 indent_size = 4
 insert_final_newline = true
 ij_kotlin_allow_trailing_comma = true

app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadManager.kt

@@ -1,6 +1,8 @@
 package eu.kanade.tachiyomi.data.download
 
 import android.content.Context
+import android.net.Uri
+import android.provider.DocumentsContract
 import eu.kanade.tachiyomi.data.download.model.Download
 import eu.kanade.tachiyomi.source.Source
 import eu.kanade.tachiyomi.source.model.Page
@@ -16,10 +18,12 @@ import kotlinx.coroutines.runBlocking
 import logcat.LogPriority
 import tachiyomi.core.common.i18n.stringResource
 import tachiyomi.core.common.storage.extension
+import tachiyomi.core.common.storage.nameWithoutExtension
 import tachiyomi.core.common.util.lang.launchIO
 import tachiyomi.core.common.util.system.ImageUtil
 import tachiyomi.core.common.util.system.logcat
 import tachiyomi.domain.category.interactor.GetCategories
+import tachiyomi.domain.chapter.interactor.GetChaptersByMangaId
 import tachiyomi.domain.chapter.model.Chapter
 import tachiyomi.domain.download.service.DownloadPreferences
 import tachiyomi.domain.manga.model.Manga
@@ -40,6 +44,7 @@ class DownloadManager(
     private val getCategories: GetCategories = Injekt.get(),
     private val sourceManager: SourceManager = Injekt.get(),
     private val downloadPreferences: DownloadPreferences = Injekt.get(),
+    private val getChaptersByMangaId: GetChaptersByMangaId = Injekt.get(),
 ) {
 
     /**
@@ -239,6 +244,69 @@ class DownloadManager(
         }
     }
 
+    /**
+     * Migrates manga from one source to another.
+     *
+     * @param oldManga the origin manga for migration..
+     * @param oldSource the origin source for migration..
+     * @param newManga the target manga for migration.
+     * @param newSource the target source for migration.
+     */
+    fun migrateManga(oldManga: Manga, oldSource: Source, newManga: Manga, newSource: Source) {
+        launchIO {
+            val oldMangaDir = provider.findMangaDir(oldManga.title, oldSource) ?: return@launchIO
+            val newMangaDir = provider.getMangaDir(newManga.title, newSource)
+            val downloadedChapters = oldMangaDir.listFiles()
+            val downloadedChaptersMap =
+                downloadedChapters?.associateBy({ it.nameWithoutExtension }, { it }) ?: return@launchIO
+
+            // map old chapters to new chapters.  The names may not be the same.
+            val oldChapters = getChaptersByMangaId.await(oldManga.id)
+            val newChapters = getChaptersByMangaId.await(newManga.id)
+            val oldChaptersByChapterNumber = oldChapters.associateBy { it.chapterNumber }
+
+            // If the chapter is downloaded, migrate it.
+            for (chapter in newChapters) {
+                val oldChapter = oldChaptersByChapterNumber[chapter.chapterNumber]
+                if (oldChapter != null) {
+                    val oldChapterName = provider.getChapterDirName(oldChapter.name, oldChapter.scanlator)
+                    val oldChapterFile = downloadedChaptersMap[oldChapterName]
+                    if (oldChapterFile != null) {
+                        val newChapterName = if (oldChapterFile.extension == null) {
+                            provider.getChapterDirName(chapter.name, chapter.scanlator)
+                        } else {
+                            provider.getChapterDirName(chapter.name, chapter.scanlator) + "." + oldChapterFile.extension
+                        }
+
+                        // move the file to newMangaDir, renaming the file/folder in the process
+                        var chapterUri: Uri? = oldChapterFile.uri
+
+                        // Rename the file.
+                        chapterUri = chapterUri?.let {
+                            DocumentsContract.renameDocument(
+                                context.contentResolver,
+                                it, newChapterName,
+                            )
+                        }
+
+                        // Move the file to the new source folder.
+                        chapterUri = chapterUri?.let {
+                            DocumentsContract.moveDocument(
+                                context.contentResolver,
+                                it, oldMangaDir.uri, newMangaDir.uri,
+                            )
+                        }
+
+                        // Can save chapterUri somewhere here if needed.
+
+                        cache.removeChapter(oldChapter, oldManga)
+                        cache.addChapter(newChapterName, newMangaDir, newManga)
+                    }
+                }
+            }
+        }
+    }
+
     /**
      * Deletes the directory of a downloaded manga.
      *

app/src/main/java/eu/kanade/tachiyomi/ui/browse/migration/MigrationFlags.kt

@@ -30,24 +30,33 @@ object MigrationFlags {
     private const val CATEGORIES = 0b00010
     private const val CUSTOM_COVER = 0b01000
     private const val DELETE_DOWNLOADED = 0b10000
+    private const val MIGRATE_DOWNLOADED = 0b100000
 
     private val coverCache: CoverCache by injectLazy()
     private val downloadCache: DownloadCache by injectLazy()
 
     fun hasChapters(value: Int): Boolean {
-        return value and CHAPTERS != 0
+        return isFlagSet(value, CHAPTERS)
     }
 
     fun hasCategories(value: Int): Boolean {
-        return value and CATEGORIES != 0
+        return isFlagSet(value, CATEGORIES)
     }
 
     fun hasCustomCover(value: Int): Boolean {
-        return value and CUSTOM_COVER != 0
+        return isFlagSet(value, CUSTOM_COVER)
+    }
+
+    fun hasMigrateDownloaded(value: Int): Boolean {
+        return isFlagSet(value, MIGRATE_DOWNLOADED)
     }
 
     fun hasDeleteDownloaded(value: Int): Boolean {
-        return value and DELETE_DOWNLOADED != 0
+        return isFlagSet(value, DELETE_DOWNLOADED)
+    }
+
+    private fun isFlagSet(value: Int, flag: Int): Boolean {
+        return (value and flag) == flag
     }
 
     /** Returns information about applicable flags with default selections. */
@@ -61,6 +70,7 @@ object MigrationFlags {
                 flags += MigrationFlag.create(CUSTOM_COVER, defaultSelectedBitMap, MR.strings.custom_cover)
             }
             if (downloadCache.getDownloadCount(manga) > 0) {
+                flags += MigrationFlag.create(MIGRATE_DOWNLOADED, defaultSelectedBitMap, MR.strings.migrate_downloaded)
                 flags += MigrationFlag.create(DELETE_DOWNLOADED, defaultSelectedBitMap, MR.strings.delete_downloaded)
             }
         }

app/src/main/java/eu/kanade/tachiyomi/ui/browse/migration/search/MigrateDialog.kt

@@ -212,6 +212,7 @@ internal class MigrateDialogScreenModel(
         val migrateChapters = MigrationFlags.hasChapters(flags)
         val migrateCategories = MigrationFlags.hasCategories(flags)
         val migrateCustomCover = MigrationFlags.hasCustomCover(flags)
+        val migrateDownloaded = MigrationFlags.hasMigrateDownloaded(flags)
         val deleteDownloaded = MigrationFlags.hasDeleteDownloaded(flags)
 
         try {
@@ -276,6 +277,13 @@ internal class MigrateDialogScreenModel(
             .takeIf { it.isNotEmpty() }
             ?.let { insertTrack.awaitAll(it) }
 
+        // Migrate downloaded chapters
+        if (migrateDownloaded) {
+            if (oldSource != null) {
+                downloadManager.migrateManga(oldManga, oldSource, newManga, newSource)
+            }
+        }
+
         // Delete downloaded
         if (deleteDownloaded) {
             if (oldSource != null) {

i18n/src/commonMain/moko-resources/base/strings.xml

@@ -16,6 +16,7 @@
     <string name="manga">Library entries</string>
     <string name="chapters">Chapters</string>
     <string name="track">Tracking</string>
+    <string name="migrate_downloaded">Migrate downloaded</string>
     <string name="delete_downloaded">Delete downloaded</string>
     <string name="history">History</string>
     <string name="scanlator">Scanlator</string>