Revert "Always save pages/covers in subfolders"

This reverts commit 8568d5d6c3.

Closes #10052

app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderViewModel.kt

@@ -758,14 +758,17 @@ class ReaderViewModel @JvmOverloads constructor(
 
         val filename = generateFilename(manga, page)
 
-        // Copy file in background
+        // Pictures directory.
+        val relativePath = if (readerPreferences.folderPerManga().get()) DiskUtil.buildValidFilename(manga.title) else ""
+
+        // Copy file in background.
         viewModelScope.launchNonCancellable {
             try {
                 val uri = imageSaver.save(
                     image = Image.Page(
                         inputStream = page.stream!!,
                         name = filename,
-                        location = Location.Pictures(DiskUtil.buildValidFilename(manga.title)),
+                        location = Location.Pictures.create(relativePath),
                     ),
                 )
                 withUIContext {

app/src/main/java/eu/kanade/tachiyomi/ui/reader/setting/ReaderPreferences.kt

@@ -56,6 +56,8 @@ class ReaderPreferences(
 
     fun readerHideThreshold() = preferenceStore.getEnum("reader_hide_threshold", ReaderHideThreshold.LOW)
 
+    fun folderPerManga() = preferenceStore.getBoolean("create_folder_per_manga", false)
+
     fun skipRead() = preferenceStore.getBoolean("skip_read", false)
 
     fun skipFiltered() = preferenceStore.getBoolean("skip_filtered", true)