fix: import of new FreeTube playlist format

app/src/main/java/com/github/libretube/helpers/ImportHelper.kt

@@ -161,10 +161,16 @@ object ImportHelper {
             }
 
             ImportFormat.FREETUBE -> {
-                val playlistFile = activity.contentResolver.openInputStream(uri)?.use {
-                    JsonHelper.json.decodeFromStream<List<FreeTubeImportPlaylist>>(it)
+                val playlistFile = activity.contentResolver.openInputStream(uri)?.use { inputStream ->
+                    val text = inputStream.bufferedReader().readText()
+                    runCatching {
+                        JsonHelper.json.decodeFromString<List<FreeTubeImportPlaylist>>(text)
+                    }.getOrNull() ?: runCatching {
+                        listOf(JsonHelper.json.decodeFromString<FreeTubeImportPlaylist>(text))
+                    }.getOrNull()
                 }
-                val playlists = playlistFile?.map { playlist ->
+
+                val playlists = playlistFile.orEmpty().map { playlist ->
                     // convert FreeTube videos to list of string
                     // convert FreeTube playlists to piped playlists
                     PipedImportPlaylist(
@@ -174,7 +180,7 @@ object ImportHelper {
                         playlist.videos.map { it.videoId }
                     )
                 }
-                importPlaylists.addAll(playlists.orEmpty())
+                importPlaylists.addAll(playlists)
             }
 
             ImportFormat.YOUTUBECSV -> {
@@ -221,6 +227,12 @@ object ImportHelper {
 
             else -> throw IllegalArgumentException()
         }
+
+        if (importPlaylists.isEmpty()) {
+            activity.toastFromMainDispatcher(R.string.emptyList)
+            return
+        }
+
         try {
             PlaylistsHelper.importPlaylists(importPlaylists)
             activity.toastFromMainDispatcher(R.string.success)

app/src/main/java/com/github/libretube/ui/preferences/BackupRestoreSettings.kt

@@ -94,27 +94,27 @@ class BackupRestoreSettings : BasePreferenceFragment() {
 
     // result listeners for importing and exporting playlists
     private val getPlaylistsFile =
-        registerForActivityResult(ActivityResultContracts.OpenMultipleDocuments()) {
-            it?.forEach {
+        registerForActivityResult(ActivityResultContracts.OpenMultipleDocuments()) { files ->
+            for (file in files) {
                 CoroutineScope(Dispatchers.IO).launch {
-                    ImportHelper.importPlaylists(requireActivity(), it, importFormat)
+                    ImportHelper.importPlaylists(requireActivity(), file, importFormat)
                 }
             }
         }
 
     private val getWatchHistoryFile =
-        registerForActivityResult(ActivityResultContracts.OpenMultipleDocuments()) {
-            it?.forEach {
+        registerForActivityResult(ActivityResultContracts.OpenMultipleDocuments()) { files ->
+            for (file in files) {
                 CoroutineScope(Dispatchers.IO).launch {
-                    ImportHelper.importWatchHistory(requireActivity(), it, importFormat)
+                    ImportHelper.importWatchHistory(requireActivity(), file, importFormat)
                 }
             }
         }
 
-    private val createPlaylistsFile = registerForActivityResult(CreateDocument(JSON)) {
-        it?.let {
+    private val createPlaylistsFile = registerForActivityResult(CreateDocument(JSON)) { uri ->
+        uri?.let {
             lifecycleScope.launch(Dispatchers.IO) {
-                ImportHelper.exportPlaylists(requireActivity(), it, importFormat)
+                ImportHelper.exportPlaylists(requireActivity(), uri, importFormat)
             }
         }
     }