Fix PlaylistAppendDialog showing when no local playlists exist

app/src/main/java/org/schabi/newpipe/database/playlist/dao/PlaylistDAO.java

@@ -33,4 +33,7 @@ public abstract class PlaylistDAO implements BasicDAO<PlaylistEntity> {
 
     @Query("DELETE FROM " + PLAYLIST_TABLE + " WHERE " + PLAYLIST_ID + " = :playlistId")
     public abstract int deletePlaylist(long playlistId);
+
+    @Query("SELECT COUNT(*) FROM " + PLAYLIST_TABLE)
+    public abstract Flowable<Long> getCount();
 }

app/src/main/java/org/schabi/newpipe/fragments/detail/VideoDetailFragment.java

@@ -80,6 +80,7 @@ import org.schabi.newpipe.fragments.EmptyFragment;
 import org.schabi.newpipe.fragments.list.comments.CommentsFragment;
 import org.schabi.newpipe.fragments.list.videos.RelatedVideosFragment;
 import org.schabi.newpipe.local.dialog.PlaylistAppendDialog;
+import org.schabi.newpipe.local.dialog.PlaylistCreationDialog;
 import org.schabi.newpipe.local.history.HistoryRecordManager;
 import org.schabi.newpipe.player.BasePlayer;
 import org.schabi.newpipe.player.MainPlayer;
@@ -482,8 +483,14 @@ public class VideoDetailFragment
                 break;
             case R.id.detail_controls_playlist_append:
                 if (getFM() != null && currentInfo != null) {
-                    PlaylistAppendDialog.fromStreamInfo(currentInfo)
+
-                            .show(getFM(), TAG);
+                    final PlaylistAppendDialog d = PlaylistAppendDialog.fromStreamInfo(currentInfo);
+                    disposables.add(
+                        PlaylistAppendDialog.checkPlaylists(getContext(),
+                            () -> d.show(getFM(), TAG),
+                            () -> PlaylistCreationDialog.newInstance(d).show(getFM(), TAG)
+                        )
+                    );
                 }
                 break;
             case R.id.detail_controls_download:

app/src/main/java/org/schabi/newpipe/local/dialog/PlaylistAppendDialog.java

@@ -1,5 +1,6 @@
 package org.schabi.newpipe.local.dialog;
 
+import android.content.Context;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -29,6 +30,7 @@ import java.util.List;
 
 import io.reactivex.android.schedulers.AndroidSchedulers;
 import io.reactivex.disposables.CompositeDisposable;
+import io.reactivex.disposables.Disposable;
 
 public final class PlaylistAppendDialog extends PlaylistDialog {
     private static final String TAG = PlaylistAppendDialog.class.getCanonicalName();
@@ -38,6 +40,27 @@ public final class PlaylistAppendDialog extends PlaylistDialog {
 
     private CompositeDisposable playlistDisposables = new CompositeDisposable();
 
+    public static Disposable checkPlaylists(
+            final Context context, final Invoker onSuccess, final Invoker onFailed
+    ) {
+        final LocalPlaylistManager playlistManager =
+                new LocalPlaylistManager(NewPipeDatabase.getInstance(context));
+
+        return playlistManager.hasPlaylists()
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(hasPlaylists -> {
+                    if (hasPlaylists) {
+                        onSuccess.invoke();
+                    } else {
+                        onFailed.invoke();
+                    }
+                });
+    }
+
+    public interface Invoker {
+        void invoke();
+    }
+
     public static PlaylistAppendDialog fromStreamInfo(final StreamInfo info) {
         final PlaylistAppendDialog dialog = new PlaylistAppendDialog();
         dialog.setInfo(Collections.singletonList(new StreamEntity(info)));
@@ -136,11 +159,6 @@ public final class PlaylistAppendDialog extends PlaylistDialog {
     }
 
     private void onPlaylistsReceived(@NonNull final List<PlaylistMetadataEntry> playlists) {
-        if (playlists.isEmpty()) {
-            openCreatePlaylistDialog();
-            return;
-        }
-
         if (playlistAdapter != null && playlistRecyclerView != null) {
             playlistAdapter.clearStreamItemList();
             playlistAdapter.addItems(playlists);

app/src/main/java/org/schabi/newpipe/local/dialog/PlaylistCreationDialog.java

@@ -26,6 +26,12 @@ public final class PlaylistCreationDialog extends PlaylistDialog {
         return dialog;
     }
 
+    public static PlaylistCreationDialog newInstance(final PlaylistAppendDialog appendDialog) {
+        final PlaylistCreationDialog dialog = new PlaylistCreationDialog();
+        dialog.setInfo(appendDialog.getStreams());
+        return dialog;
+    }
+
     /*//////////////////////////////////////////////////////////////////////////
     // Dialog
     //////////////////////////////////////////////////////////////////////////*/

app/src/main/java/org/schabi/newpipe/local/playlist/LocalPlaylistManager.java

@@ -126,4 +126,10 @@ public class LocalPlaylistManager {
                 }).subscribeOn(Schedulers.io());
     }
 
+    public Maybe<Boolean> hasPlaylists() {
+        return playlistTable.getCount()
+                .firstElement()
+                .map(count -> count > 0)
+                .subscribeOn(Schedulers.io());
+    }
 }

app/src/main/java/org/schabi/newpipe/player/ServicePlayerActivity.java

@@ -33,6 +33,7 @@ import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.stream.StreamInfo;
 import org.schabi.newpipe.fragments.OnScrollBelowItemsListener;
 import org.schabi.newpipe.local.dialog.PlaylistAppendDialog;
+import org.schabi.newpipe.local.dialog.PlaylistCreationDialog;
 import org.schabi.newpipe.player.event.PlayerEventListener;
 import org.schabi.newpipe.player.helper.PlaybackParameterDialog;
 import org.schabi.newpipe.player.playqueue.PlayQueue;
@@ -571,8 +572,13 @@ public abstract class ServicePlayerActivity extends AppCompatActivity
     }
 
     private void openPlaylistAppendDialog(final List<PlayQueueItem> playlist) {
-        PlaylistAppendDialog.fromPlayQueueItems(playlist)
+        final PlaylistAppendDialog d = PlaylistAppendDialog.fromPlayQueueItems(playlist);
-                .show(getSupportFragmentManager(), getTag());
+
+        PlaylistAppendDialog.checkPlaylists(getApplicationContext(),
+            () -> d.show(getSupportFragmentManager(), getTag()),
+            () -> PlaylistCreationDialog.newInstance(d)
+                    .show(getSupportFragmentManager(), getTag()
+        ));
     }
 
     ////////////////////////////////////////////////////////////////////////////

app/src/main/java/org/schabi/newpipe/util/StreamDialogEntry.java

@@ -7,6 +7,7 @@ import androidx.fragment.app.Fragment;
 import org.schabi.newpipe.R;
 import org.schabi.newpipe.extractor.stream.StreamInfoItem;
 import org.schabi.newpipe.local.dialog.PlaylistAppendDialog;
+import org.schabi.newpipe.local.dialog.PlaylistCreationDialog;
 import org.schabi.newpipe.player.MainPlayer;
 import org.schabi.newpipe.player.helper.PlayerHolder;
 import org.schabi.newpipe.player.playqueue.SinglePlayQueue;
@@ -58,8 +59,14 @@ public enum StreamDialogEntry {
 
     append_playlist(R.string.append_playlist, (fragment, item) -> {
         if (fragment.getFragmentManager() != null) {
-            PlaylistAppendDialog.fromStreamInfoItems(Collections.singletonList(item))
+            final PlaylistAppendDialog d = PlaylistAppendDialog
-                    .show(fragment.getFragmentManager(), "StreamDialogEntry@append_playlist");
+                    .fromStreamInfoItems(Collections.singletonList(item));
+
+            PlaylistAppendDialog.checkPlaylists(fragment.getContext(),
+                () -> d.show(fragment.getFragmentManager(), "StreamDialogEntry@append_playlist"),
+                () -> PlaylistCreationDialog.newInstance(d)
+                        .show(fragment.getFragmentManager(), "StreamDialogEntry@create_playlist")
+            );
         }
     }),