Debounced saver & bugfix & clean code

app/src/main/java/org/schabi/newpipe/database/playlist/PlaylistLocalItem.java

@@ -45,6 +45,10 @@ public interface PlaylistLocalItem extends LocalItem {
             addItem(result, localPlaylists.get(i), itemsWithSameIndex);
             i++;
         }
+        while (j < remotePlaylists.size()) {
+            addItem(result, remotePlaylists.get(j), itemsWithSameIndex);
+            j++;
+        }
         addItemsWithSameIndex(result, itemsWithSameIndex);
 
         return result;

app/src/main/java/org/schabi/newpipe/database/playlist/PlaylistMetadataEntry.java

@@ -17,7 +17,7 @@ public class PlaylistMetadataEntry implements PlaylistLocalItem {
     @ColumnInfo(name = PLAYLIST_THUMBNAIL_URL)
     public final String thumbnailUrl;
     @ColumnInfo(name = PLAYLIST_DISPLAY_INDEX)
-    public final long displayIndex;
+    public long displayIndex;
     @ColumnInfo(name = PLAYLIST_STREAM_COUNT)
     public final long streamCount;
 

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

@@ -2,6 +2,7 @@ package org.schabi.newpipe.database.playlist.dao;
 
 import androidx.room.Dao;
 import androidx.room.Query;
+import androidx.room.Transaction;
 
 import org.schabi.newpipe.database.BasicDAO;
 import org.schabi.newpipe.database.playlist.model.PlaylistEntity;
@@ -36,4 +37,17 @@ public interface PlaylistDAO extends BasicDAO<PlaylistEntity> {
 
     @Query("SELECT COUNT(*) FROM " + PLAYLIST_TABLE)
     Flowable<Long> getCount();
+
+    @Transaction
+    default long upsertPlaylist(final PlaylistEntity playlist) {
+        final long playlistId = playlist.getUid();
+
+        if (playlistId == -1) {
+            // This situation is probably impossible.
+            return insert(playlist);
+        } else {
+            update(playlist);
+            return playlistId;
+        }
+    }
 }

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

@@ -82,7 +82,19 @@ public interface PlaylistStreamDAO extends BasicDAO<PlaylistStreamEntity> {
             + " FROM " + PLAYLIST_TABLE
             + " LEFT JOIN " + PLAYLIST_STREAM_JOIN_TABLE
             + " ON " + PLAYLIST_ID + " = " + JOIN_PLAYLIST_ID
-            + " GROUP BY " + JOIN_PLAYLIST_ID
+            + " GROUP BY " + PLAYLIST_ID
             + " ORDER BY " + PLAYLIST_NAME + " COLLATE NOCASE ASC")
     Flowable<List<PlaylistMetadataEntry>> getPlaylistMetadata();
+
+    @Transaction
+    @Query("SELECT " + PLAYLIST_ID + ", " + PLAYLIST_NAME + ", " + PLAYLIST_THUMBNAIL_URL + ", "
+            + PLAYLIST_DISPLAY_INDEX + ", "
+            + "COALESCE(COUNT(" + JOIN_PLAYLIST_ID + "), 0) AS " + PLAYLIST_STREAM_COUNT
+
+            + " FROM " + PLAYLIST_TABLE
+            + " LEFT JOIN " + PLAYLIST_STREAM_JOIN_TABLE
+            + " ON " + PLAYLIST_ID + " = " + JOIN_PLAYLIST_ID
+            + " GROUP BY " + PLAYLIST_ID
+            + " ORDER BY " + PLAYLIST_DISPLAY_INDEX)
+    Flowable<List<PlaylistMetadataEntry>> getDisplayIndexOrderedPlaylistMetadata();
 }

app/src/main/java/org/schabi/newpipe/database/playlist/model/PlaylistEntity.java

@@ -2,12 +2,15 @@ package org.schabi.newpipe.database.playlist.model;
 
 import androidx.room.ColumnInfo;
 import androidx.room.Entity;
+import androidx.room.Ignore;
 import androidx.room.Index;
 import androidx.room.PrimaryKey;
 
 import static org.schabi.newpipe.database.playlist.model.PlaylistEntity.PLAYLIST_NAME;
 import static org.schabi.newpipe.database.playlist.model.PlaylistEntity.PLAYLIST_TABLE;
 
+import org.schabi.newpipe.database.playlist.PlaylistMetadataEntry;
+
 @Entity(tableName = PLAYLIST_TABLE,
         indices = {@Index(value = {PLAYLIST_NAME})})
 public class PlaylistEntity {
@@ -36,6 +39,14 @@ public class PlaylistEntity {
         this.displayIndex = displayIndex;
     }
 
+    @Ignore
+    public PlaylistEntity(final PlaylistMetadataEntry item) {
+        this.uid = item.uid;
+        this.name = item.name;
+        this.thumbnailUrl = item.thumbnailUrl;
+        this.displayIndex = item.displayIndex;
+    }
+
     public long getUid() {
         return uid;
     }

app/src/main/java/org/schabi/newpipe/database/playlist/model/PlaylistRemoteEntity.java

@@ -54,7 +54,7 @@ public class PlaylistRemoteEntity implements PlaylistLocalItem {
     private String uploader;
 
     @ColumnInfo(name = REMOTE_PLAYLIST_DISPLAY_INDEX)
-    private long displayIndex;
+    private long displayIndex = -1; // Make sure the new item is on the top
 
     @ColumnInfo(name = REMOTE_PLAYLIST_STREAM_COUNT)
     private Long streamCount;

app/src/main/java/org/schabi/newpipe/local/LocalItemListAdapter.java

@@ -142,7 +142,6 @@ public class LocalItemListAdapter extends RecyclerView.Adapter<RecyclerView.View
     }
 
     public boolean swapItems(final int fromAdapterPosition, final int toAdapterPosition) {
-        // todo: reuse this code?
         final int actualFrom = adapterOffsetWithoutHeader(fromAdapterPosition);
         final int actualTo = adapterOffsetWithoutHeader(toAdapterPosition);
 

app/src/main/java/org/schabi/newpipe/local/bookmark/BookmarkFragment.java

@@ -6,6 +6,7 @@ import android.os.Bundle;
 import android.os.Parcelable;
 import android.text.InputType;
 import android.util.Log;
+import android.util.Pair;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -30,21 +31,32 @@ import org.schabi.newpipe.databinding.DialogEditTextBinding;
 import org.schabi.newpipe.error.ErrorInfo;
 import org.schabi.newpipe.error.UserAction;
 import org.schabi.newpipe.local.BaseLocalListFragment;
+import org.schabi.newpipe.local.holder.LocalPlaylistItemHolder;
+import org.schabi.newpipe.local.holder.RemotePlaylistItemHolder;
 import org.schabi.newpipe.local.playlist.LocalPlaylistManager;
 import org.schabi.newpipe.local.playlist.RemotePlaylistManager;
 import org.schabi.newpipe.util.NavigationHelper;
 import org.schabi.newpipe.util.OnClickGesture;
 
+import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import icepick.State;
 import io.reactivex.rxjava3.android.schedulers.AndroidSchedulers;
 import io.reactivex.rxjava3.core.Flowable;
-import io.reactivex.rxjava3.core.Single;
 import io.reactivex.rxjava3.disposables.CompositeDisposable;
 import io.reactivex.rxjava3.disposables.Disposable;
+import io.reactivex.rxjava3.subjects.PublishSubject;
 
 public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistLocalItem>, Void> {
+    // todo: add to playlists, item handle should be invisible
+
+    // Save the list 10s after the last change occurred
+    private static final long SAVE_DEBOUNCE_MILLIS = 10000;
     private static final int MINIMUM_INITIAL_DRAG_VELOCITY = 12;
     @State
     protected Parcelable itemsListState;
@@ -55,6 +67,16 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
     private RemotePlaylistManager remotePlaylistManager;
     private ItemTouchHelper itemTouchHelper;
 
+    private PublishSubject<Long> debouncedSaveSignal;
+
+    /* Has the playlist been fully loaded from db */
+    private AtomicBoolean isLoadingComplete;
+    /* Has the playlist been modified (e.g. items reordered or deleted) */
+    private AtomicBoolean isModified;
+
+    // Map from (uid, local/remote item) to the saved display index in the database.
+    private Map<Pair<Long, LocalItem.LocalItemType>, Long> displayIndexInDatabase;
+
     ///////////////////////////////////////////////////////////////////////////
     // Fragment LifeCycle - Creation
     ///////////////////////////////////////////////////////////////////////////
@@ -69,6 +91,12 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
         localPlaylistManager = new LocalPlaylistManager(database);
         remotePlaylistManager = new RemotePlaylistManager(database);
         disposables = new CompositeDisposable();
+
+        debouncedSaveSignal = PublishSubject.create();
+        isLoadingComplete = new AtomicBoolean();
+        isModified = new AtomicBoolean();
+
+        displayIndexInDatabase = new HashMap<>();
     }
 
     @Nullable
@@ -154,6 +182,10 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
     public void startLoading(final boolean forceLoad) {
         super.startLoading(forceLoad);
 
+        disposables.add(getDebouncedSaver());
+        isLoadingComplete.set(false);
+        isModified.set(false);
+
         Flowable.combineLatest(localPlaylistManager.getPlaylists(),
                 remotePlaylistManager.getPlaylists(), PlaylistLocalItem::merge)
                 .onBackpressureLatest()
@@ -169,6 +201,9 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
     public void onPause() {
         super.onPause();
         itemsListState = itemsList.getLayoutManager().onSaveInstanceState();
+
+        // Save on exit
+        saveImmediate();
     }
 
     @Override
@@ -189,14 +224,22 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
     @Override
     public void onDestroy() {
         super.onDestroy();
+        if (debouncedSaveSignal != null) {
+            debouncedSaveSignal.onComplete();
+        }
         if (disposables != null) {
             disposables.dispose();
         }
 
+        debouncedSaveSignal = null;
         disposables = null;
         localPlaylistManager = null;
         remotePlaylistManager = null;
         itemsListState = null;
+
+        isLoadingComplete = null;
+        isModified = null;
+        displayIndexInDatabase = null;
     }
 
     ///////////////////////////////////////////////////////////////////////////
@@ -208,6 +251,8 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
             @Override
             public void onSubscribe(final Subscription s) {
                 showLoading();
+                isLoadingComplete.set(false);
+
                 if (databaseSubscription != null) {
                     databaseSubscription.cancel();
                 }
@@ -217,14 +262,11 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
 
             @Override
             public void onNext(final List<PlaylistLocalItem> subscriptions) {
-
+                if (isModified == null || !isModified.get()) {
-                // If displayIndex does not match actual index, update displayIndex.
+                    checkDisplayIndexModified(subscriptions);
-                // This may happen when a new list is created
-                // or on the first run after database update
-                // or displayIndex is not continuous for some reason.
-                checkDisplayIndexUpdate(subscriptions);
-
                     handleResult(subscriptions);
+                    isLoadingComplete.set(true);
+                }
                 if (databaseSubscription != null) {
                     databaseSubscription.request(1);
                 }
@@ -296,86 +338,170 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
         disposables.add(disposable);
     }
 
-    private void changeLocalPlaylistDisplayIndex(final long id, final long displayIndex) {
+    private void deleteItem(final PlaylistLocalItem item) {
+        if (itemListAdapter == null) {
+            return;
+        }
+        itemListAdapter.removeItem(item);
 
-        if (localPlaylistManager == null) {
+        saveChanges();
+    }
+
+    private void checkDisplayIndexModified(@NonNull final List<PlaylistLocalItem> result) {
+        if (isModified != null && isModified.get()) {
             return;
         }
 
-        if (DEBUG) {
+        displayIndexInDatabase.clear();
-            Log.d(TAG, "Updating local playlist id=[" + id + "] "
-                    + "with new display_index=[" + displayIndex + "]");
-        }
 
-        final Disposable disposable =
+        // If the display index does not match actual index in the list, update the display index.
-                localPlaylistManager.changePlaylistDisplayIndex(id, displayIndex)
+        // This may happen when a new list is created
-                        .observeOn(AndroidSchedulers.mainThread())
+        // or on the first run after database update
-                        .subscribe(longs -> { /*Do nothing on success*/ }, throwable -> showError(
+        // or displayIndex is not continuous for some reason.
-                                new ErrorInfo(throwable,
+        boolean isDisplayIndexModified = false;
-                                        UserAction.REQUESTED_BOOKMARK,
-                                        "Changing local playlist display_index")));
-        disposables.add(disposable);
-    }
-
-    private void changeRemotePlaylistDisplayIndex(final long id, final long displayIndex) {
-
-        if (remotePlaylistManager == null) {
-            return;
-        }
-
-        if (DEBUG) {
-            Log.d(TAG, "Updating remote playlist id=[" + id + "] "
-                    + "with new display_index=[" + displayIndex + "]");
-        }
-
-        final Disposable disposable =
-                remotePlaylistManager.changePlaylistDisplayIndex(id, displayIndex)
-                        .observeOn(AndroidSchedulers.mainThread())
-                        .subscribe(longs -> { /*Do nothing on success*/ }, throwable -> showError(
-                                new ErrorInfo(throwable,
-                                        UserAction.REQUESTED_BOOKMARK,
-                                        "Changing remote playlist display_index")));
-        disposables.add(disposable);
-    }
-
-    private void checkDisplayIndexUpdate(@NonNull final List<PlaylistLocalItem> result) {
         for (int i = 0; i < result.size(); i++) {
             final PlaylistLocalItem item = result.get(i);
             if (item.getDisplayIndex() != i) {
-                if (item instanceof PlaylistMetadataEntry) {
+                isDisplayIndexModified = true;
-                    changeLocalPlaylistDisplayIndex(((PlaylistMetadataEntry) item).uid, i);
-                } else if (item instanceof PlaylistRemoteEntity) {
-                    changeRemotePlaylistDisplayIndex(((PlaylistRemoteEntity) item).getUid(), i);
             }
+
+            // Updating display index in the item does not affect the value inserts into
+            // database, which will be recalculated during the database update. Updating
+            // display index in the item here is to determine whether it is recently modified.
+            // Save the index read from the database.
+            if (item instanceof PlaylistMetadataEntry) {
+
+                displayIndexInDatabase.put(new Pair<>(((PlaylistMetadataEntry) item).uid,
+                        LocalItem.LocalItemType.PLAYLIST_LOCAL_ITEM), item.getDisplayIndex());
+                ((PlaylistMetadataEntry) item).displayIndex = i;
+
+            } else if (item instanceof PlaylistRemoteEntity) {
+
+                displayIndexInDatabase.put(new Pair<>(((PlaylistRemoteEntity) item).getUid(),
+                                LocalItem.LocalItemType.PLAYLIST_REMOTE_ITEM),
+                        item.getDisplayIndex());
+                ((PlaylistRemoteEntity) item).setDisplayIndex(i);
+
+            }
+        }
+
+        if (isDisplayIndexModified) {
+            saveChanges();
+        }
+    }
+
+    private void saveChanges() {
+        if (isModified == null || debouncedSaveSignal == null) {
+            return;
+        }
+
+        isModified.set(true);
+        debouncedSaveSignal.onNext(System.currentTimeMillis());
+    }
+
+    private Disposable getDebouncedSaver() {
+        if (debouncedSaveSignal == null) {
+            return Disposable.empty();
+        }
+
+        return debouncedSaveSignal
+                .debounce(SAVE_DEBOUNCE_MILLIS, TimeUnit.MILLISECONDS)
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(ignored -> saveImmediate(), throwable ->
+                        showError(new ErrorInfo(throwable, UserAction.SOMETHING_ELSE,
+                                "Debounced saver")));
+    }
+
+    private void saveImmediate() {
+        if (itemListAdapter == null) {
+            return;
+        }
+
+        // List must be loaded and modified in order to save
+        if (isLoadingComplete == null || isModified == null
+                || !isLoadingComplete.get() || !isModified.get()) {
+            Log.w(TAG, "Attempting to save playlists in bookmark when bookmark "
+                    + "is not loaded or playlists not modified");
+            return;
+        }
+
+        final List<LocalItem> items = itemListAdapter.getItemsList();
+        final List<PlaylistMetadataEntry> localItemsUpdate = new ArrayList<>();
+        final List<Long> localItemsDeleteUid = new ArrayList<>();
+        final List<PlaylistRemoteEntity> remoteItemsUpdate = new ArrayList<>();
+        final List<Long> remoteItemsDeleteUid = new ArrayList<>();
+
+        // Calculate display index
+        for (int i = 0; i < items.size(); i++) {
+            final LocalItem item = items.get(i);
+
+            if (item instanceof PlaylistMetadataEntry) {
+                ((PlaylistMetadataEntry) item).displayIndex = i;
+
+                final Long uid = ((PlaylistMetadataEntry) item).uid;
+                final Pair<Long, LocalItem.LocalItemType> key = new Pair<>(uid,
+                        LocalItem.LocalItemType.PLAYLIST_LOCAL_ITEM);
+                final Long databaseIndex = displayIndexInDatabase.remove(key);
+
+                if (databaseIndex != null) {
+                    if (databaseIndex != i) {
+                        localItemsUpdate.add((PlaylistMetadataEntry) item);
+                    }
+                } else {
+                    // This should be impossible.
+                    continue;
+                }
+            } else if (item instanceof PlaylistRemoteEntity) {
+                ((PlaylistRemoteEntity) item).setDisplayIndex(i);
+
+                final Long uid = ((PlaylistRemoteEntity) item).getUid();
+                final Pair<Long, LocalItem.LocalItemType> key = new Pair<>(uid,
+                        LocalItem.LocalItemType.PLAYLIST_REMOTE_ITEM);
+                final Long databaseIndex = displayIndexInDatabase.remove(key);
+
+                if (databaseIndex != null) {
+                    if (databaseIndex != i) {
+                        remoteItemsUpdate.add((PlaylistRemoteEntity) item);
+                    }
+                } else {
+                    // This should be impossible.
+                    continue;
                 }
             }
         }
 
-    private void saveImmediate() {
+        // Find deleted items
-        if (localPlaylistManager == null || remotePlaylistManager == null
+        for (final Pair<Long, LocalItem.LocalItemType> key : displayIndexInDatabase.keySet()) {
-                || itemListAdapter == null) {
+            if (key.second.equals(LocalItem.LocalItemType.PLAYLIST_LOCAL_ITEM)) {
-            return;
+                localItemsDeleteUid.add(key.first);
-        }
+            } else if (key.second.equals(LocalItem.LocalItemType.PLAYLIST_REMOTE_ITEM)) {
-        // todo: debounce
+                remoteItemsDeleteUid.add(key.first);
-        /*
-        // List must be loaded and modified in order to save
-        if (isLoadingComplete == null || isModified == null
-                || !isLoadingComplete.get() || !isModified.get()) {
-            Log.w(TAG, "Attempting to save playlist when local playlist "
-                    + "is not loaded or not modified: playlist id=[" + playlistId + "]");
-            return;
-        }
-        */
-        // todo: is it correct?
-        final List<LocalItem> items = itemListAdapter.getItemsList();
-        for (int i = 0; i < items.size(); i++) {
-            final LocalItem item = items.get(i);
-            if (item instanceof PlaylistMetadataEntry) {
-                changeLocalPlaylistDisplayIndex(((PlaylistMetadataEntry) item).uid, i);
-            } else if (item instanceof PlaylistRemoteEntity) {
-                changeLocalPlaylistDisplayIndex(((PlaylistRemoteEntity) item).getUid(), i);
             }
         }
+
+        displayIndexInDatabase.clear();
+
+        // 1. Update local playlists
+        // 2. Update remote playlists
+        // 3. Set isModified false
+        disposables.add(localPlaylistManager.updatePlaylists(localItemsUpdate, localItemsDeleteUid)
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(() -> disposables.add(remotePlaylistManager.updatePlaylists(
+                        remoteItemsUpdate, remoteItemsDeleteUid)
+                        .observeOn(AndroidSchedulers.mainThread())
+                        .subscribe(() -> {
+                                    if (isModified != null) {
+                                        isModified.set(false);
+                                    }
+                                },
+                                throwable -> showError(new ErrorInfo(throwable,
+                                        UserAction.REQUESTED_BOOKMARK,
+                                        "Saving playlist"))
+                        )),
+                        throwable -> showError(new ErrorInfo(throwable,
+                                UserAction.REQUESTED_BOOKMARK, "Saving playlist"))
+                ));
+
     }
 
     private ItemTouchHelper.SimpleCallback getItemTouchCallback() {
@@ -404,17 +530,26 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
                                   @NonNull final RecyclerView.ViewHolder target) {
                 if (source.getItemViewType() != target.getItemViewType()
                         || itemListAdapter == null) {
+                    // Allow swap LocalPlaylistItemHolder and RemotePlaylistItemHolder.
+                    if (!(
+                            (
+                                    (source instanceof LocalPlaylistItemHolder)
+                                            || (source instanceof RemotePlaylistItemHolder)
+                            )
+                                    && (
+                                    (target instanceof LocalPlaylistItemHolder)
+                                            || (target instanceof RemotePlaylistItemHolder)
+                            )
+                    )) {
                         return false;
                     }
+                }
 
-                // todo: is it correct
                 final int sourceIndex = source.getBindingAdapterPosition();
                 final int targetIndex = target.getBindingAdapterPosition();
                 final boolean isSwapped = itemListAdapter.swapItems(sourceIndex, targetIndex);
                 if (isSwapped) {
-                    // todo
+                    saveChanges();
-                    //saveChanges();
-                    saveImmediate();
                 }
                 return isSwapped;
             }
@@ -441,7 +576,7 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
     ///////////////////////////////////////////////////////////////////////////
 
     private void showRemoteDeleteDialog(final PlaylistRemoteEntity item) {
-        showDeleteDialog(item.getName(), remotePlaylistManager.deletePlaylist(item.getUid()));
+        showDeleteDialog(item.getName(), item);
     }
 
     private void showLocalDialog(final PlaylistMetadataEntry selectedItem) {
@@ -459,15 +594,14 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
                                 dialogBinding.dialogEditText.getText().toString()))
                 .setNegativeButton(R.string.cancel, null)
                 .setNeutralButton(R.string.delete, (dialog, which) -> {
-                    showDeleteDialog(selectedItem.name,
+                    showDeleteDialog(selectedItem.name, selectedItem);
-                            localPlaylistManager.deletePlaylist(selectedItem.uid));
                     dialog.dismiss();
                 })
                 .create()
                 .show();
     }
 
-    private void showDeleteDialog(final String name, final Single<Integer> deleteReactor) {
+    private void showDeleteDialog(final String name, final PlaylistLocalItem item) {
         if (activity == null || disposables == null) {
             return;
         }
@@ -476,13 +610,7 @@ public final class BookmarkFragment extends BaseLocalListFragment<List<PlaylistL
                 .setTitle(name)
                 .setMessage(R.string.delete_playlist_prompt)
                 .setCancelable(true)
-                .setPositiveButton(R.string.delete, (dialog, i) ->
+                .setPositiveButton(R.string.delete, (dialog, i) -> deleteItem(item))
-                        disposables.add(deleteReactor
-                                .observeOn(AndroidSchedulers.mainThread())
-                                .subscribe(ignored -> { /*Do nothing on success*/ }, throwable ->
-                                        showError(new ErrorInfo(throwable,
-                                                UserAction.REQUESTED_BOOKMARK,
-                                                "Deleting playlist")))))
                 .setNegativeButton(R.string.cancel, null)
                 .show();
     }

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

@@ -85,7 +85,7 @@ public final class PlaylistAppendDialog extends PlaylistDialog {
         final View newPlaylistButton = view.findViewById(R.id.newPlaylist);
         newPlaylistButton.setOnClickListener(ignored -> openCreatePlaylistDialog());
 
-        playlistDisposables.add(playlistManager.getPlaylists()
+        playlistDisposables.add(playlistManager.getDisplayIndexOrderedPlaylists()
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(this::onPlaylistsReceived));
     }

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

@@ -41,6 +41,7 @@ public class LocalPlaylistManager {
         }
         final StreamEntity defaultStream = streams.get(0);
 
+        // Save to the database directly.
         // Make sure the new playlist is always on the top of bookmark.
         // The index will be reassigned to non-negative number in BookmarkFragment.
         final PlaylistEntity newPlaylist =
@@ -85,10 +86,31 @@ public class LocalPlaylistManager {
         })).subscribeOn(Schedulers.io());
     }
 
+    public Completable updatePlaylists(final List<PlaylistMetadataEntry> updateItems,
+                                       final List<Long> deletedItems) {
+        final List<PlaylistEntity> items = new ArrayList<>(updateItems.size());
+        for (final PlaylistMetadataEntry item : updateItems) {
+            items.add(new PlaylistEntity(item));
+        }
+        return Completable.fromRunnable(() -> database.runInTransaction(() -> {
+            for (final Long uid: deletedItems) {
+                playlistTable.deletePlaylist(uid);
+            }
+            for (final PlaylistEntity item: items) {
+                playlistTable.upsertPlaylist(item);
+            }
+        })).subscribeOn(Schedulers.io());
+    }
+
     public Flowable<List<PlaylistMetadataEntry>> getPlaylists() {
         return playlistStreamTable.getPlaylistMetadata().subscribeOn(Schedulers.io());
     }
 
+    public Flowable<List<PlaylistMetadataEntry>> getDisplayIndexOrderedPlaylists() {
+        return playlistStreamTable.getDisplayIndexOrderedPlaylistMetadata()
+                .subscribeOn(Schedulers.io());
+    }
+
     public Flowable<List<PlaylistStreamEntry>> getPlaylistStreams(final long playlistId) {
         return playlistStreamTable.getOrderedStreamsOf(playlistId).subscribeOn(Schedulers.io());
     }
@@ -107,7 +129,7 @@ public class LocalPlaylistManager {
         return modifyPlaylist(playlistId, null, thumbnailUrl, -1);
     }
 
-    public Maybe<Integer> changePlaylistDisplayIndex(final long playlistId,
+    public Maybe<Integer> updatePlaylistDisplayIndex(final long playlistId,
                                                      final long displayIndex) {
         return modifyPlaylist(playlistId, null, null, displayIndex);
     }

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

@@ -7,16 +7,18 @@ import org.schabi.newpipe.extractor.playlist.PlaylistInfo;
 
 import java.util.List;
 
+import io.reactivex.rxjava3.core.Completable;
 import io.reactivex.rxjava3.core.Flowable;
-import io.reactivex.rxjava3.core.Maybe;
 import io.reactivex.rxjava3.core.Single;
 import io.reactivex.rxjava3.schedulers.Schedulers;
 
 public class RemotePlaylistManager {
 
+    private final AppDatabase database;
     private final PlaylistRemoteDAO playlistRemoteTable;
 
     public RemotePlaylistManager(final AppDatabase db) {
+        database = db;
         playlistRemoteTable = db.playlistRemoteDAO();
     }
 
@@ -34,18 +36,16 @@ public class RemotePlaylistManager {
                 .subscribeOn(Schedulers.io());
     }
 
-    public Maybe<Integer> changePlaylistDisplayIndex(final long playlistId,
+    public Completable updatePlaylists(final List<PlaylistRemoteEntity> updateItems,
-                                                     final long displayIndex) {
+                                       final List<Long> deletedItems) {
-        return playlistRemoteTable.getPlaylist(playlistId)
+        return Completable.fromRunnable(() -> database.runInTransaction(() -> {
-                .firstElement()
+            for (final Long uid: deletedItems) {
-                .filter(playlistRemoteEntities -> !playlistRemoteEntities.isEmpty())
+                playlistRemoteTable.deletePlaylist(uid);
-                .map(playlistRemoteEntities -> {
-                    final PlaylistRemoteEntity playlist = playlistRemoteEntities.get(0);
-                    if (displayIndex != -1) {
-                        playlist.setDisplayIndex(displayIndex);
             }
-                    return playlistRemoteTable.update(playlist);
+            for (final PlaylistRemoteEntity item: updateItems) {
-                }).subscribeOn(Schedulers.io());
+                playlistRemoteTable.upsert(item);
+            }
+        })).subscribeOn(Schedulers.io());
     }
 
     public Single<Long> onBookmark(final PlaylistInfo playlistInfo) {