Add an option to disable the MD5 suffix in chapter names (#3966)

Co-authored-by: AntsyLich <59261191+AntsyLich@users.noreply.github.com>

app/src/main/java/eu/kanade/presentation/more/settings/screen/SettingsAdvancedScreen.kt

@@ -318,6 +318,11 @@ object SettingsAdvancedScreen : SearchableSettings {
                     title = stringResource(MR.strings.pref_disallow_non_ascii_filenames),
                     subtitle = stringResource(MR.strings.pref_disallow_non_ascii_filenames_details),
                 ),
+                Preference.PreferenceItem.SwitchPreference(
+                    preference = libraryPreferences.enableChapterNameHash,
+                    title = stringResource(MR.strings.pref_enable_chapter_name_hash),
+                    subtitle = stringResource(MR.strings.pref_enable_chapter_name_hash_details),
+                ),
             ),
         )
     }

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

@@ -167,15 +167,25 @@ class DownloadProvider(
         chapterScanlator: String?,
         chapterUrl: String,
         disallowNonAsciiFilenames: Boolean = libraryPreferences.disallowNonAsciiFilenames.get(),
+        enableChapterNameHash: Boolean = libraryPreferences.enableChapterNameHash.get(),
     ): String {
-        var dirName = sanitizeChapterName(chapterName)
-        if (!chapterScanlator.isNullOrBlank()) {
-            dirName = chapterScanlator + "_" + dirName
+        return buildString {
+            if (!chapterScanlator.isNullOrBlank()) {
+                append(chapterScanlator + "_")
+            }
+
+            // Subtract 7 bytes for hash and underscore, 4 bytes for .cbz
+            append(
+                DiskUtil.buildValidFilename(
+                    sanitizeChapterName(chapterName),
+                    DiskUtil.MAX_FILE_NAME_BYTES - 11,
+                    disallowNonAsciiFilenames,
+                ),
+            )
+            if (enableChapterNameHash) {
+                append("_${md5(chapterUrl).take(6)}")
+            }
         }
-        // Subtract 7 bytes for hash and underscore, 4 bytes for .cbz
-        dirName = DiskUtil.buildValidFilename(dirName, DiskUtil.MAX_FILE_NAME_BYTES - 11, disallowNonAsciiFilenames)
-        dirName += "_" + md5(chapterUrl).take(6)
-        return dirName
     }
 
     /**
@@ -191,7 +201,7 @@ class DownloadProvider(
         chapterName: String,
         chapterScanlator: String?,
         chapterUrl: String,
-    ): List<String> {
+    ): Set<String> {
         val sanitizedChapterName = sanitizeChapterName(chapterName)
         val chapterNameV1 = DiskUtil.buildValidFilename(
             when {
@@ -200,23 +210,27 @@ class DownloadProvider(
             },
         )
 
-        // Get the filename that would be generated if the user were
-        // using the other value for the disallow non-ASCII
-        // filenames setting. This ensures that chapters downloaded
-        // before the user changed the setting can still be found.
-        val otherChapterDirName =
-            getChapterDirName(
-                chapterName,
-                chapterScanlator,
-                chapterUrl,
-                !libraryPreferences.disallowNonAsciiFilenames.get(),
-            )
+        // Generate all possible legacy directory name variations by combining
+        // different states of non-ASCII filenames and chapter name hash settings.
+        // This ensures that chapters downloaded under any past configuration
+        // combination can still be successfully found.
+        val booleanPairPermutation = listOf(false to false, false to true, true to false, true to true)
+        val othersChapterDirNames = booleanPairPermutation
+            .map { (disallowNonAsciiFilenames, enableChapterNameHash) ->
+                getChapterDirName(
+                    chapterName,
+                    chapterScanlator,
+                    chapterUrl,
+                    disallowNonAsciiFilenames,
+                    enableChapterNameHash,
+                )
+            }
 
-        return buildList(2) {
+        return buildSet {
             // Chapter name without hash (unable to handle duplicate
             // chapter names)
             add(chapterNameV1)
-            add(otherChapterDirName)
+            addAll(othersChapterDirNames)
         }
     }
 

app/src/main/java/mihon/core/migration/migrations/ChapterNameSuffixMigration.kt

@@ -0,0 +1,23 @@
+package mihon.core.migration.migrations
+
+import dev.zacsweers.metro.AppScope
+import dev.zacsweers.metro.ContributesIntoSet
+import dev.zacsweers.metro.Inject
+import mihon.core.migration.Migration
+import mihon.core.migration.MigrationContext
+import tachiyomi.domain.library.service.LibraryPreferences
+
+@Inject
+@ContributesIntoSet(AppScope::class)
+class ChapterNameSuffixMigration(
+    private val preference: LibraryPreferences,
+) : Migration {
+    override val version: Float = 34f
+
+    override suspend fun invoke(migrationContext: MigrationContext): Boolean {
+        if (migrationContext.previousVersion in 13..33) {
+            preference.enableChapterNameHash.set(true)
+        }
+        return true
+    }
+}