Added randomize/reverse songs logic. Added initial UI-side locking logic.

Harmonia.WinUI/ViewModels/PlaylistDetailViewModel.cs

@@ -147,6 +147,11 @@ public partial class PlaylistDetailViewModel : ViewModelBase
     public IAsyncRelayCommand DeletePlaylistCommand { get; }
     public IRelayCommand<SortItem> SortAllCommand { get; }
     public IRelayCommand<SortItem> SortSelectedCommand { get; }
+    public IRelayCommand RandomizeAllCommand { get; }
+    public IRelayCommand RandomizeSelectedCommand { get; }
+    public IRelayCommand ReverseAllCommand { get; }
+    public IRelayCommand ReverseSelectedCommand { get; }
+    public IRelayCommand ToggleLockCommand { get; }
 
     public bool IsUserUpdating { get; set; }
     private bool _isUserInitiatingSongChange;
@@ -195,6 +200,11 @@ public partial class PlaylistDetailViewModel : ViewModelBase
         DeletePlaylistCommand = new AsyncRelayCommand(DeletePlaylistAsync);
         SortAllCommand = new RelayCommand<SortItem>(SortAllSongs);
         SortSelectedCommand = new RelayCommand<SortItem>(SortSelectedSongs, _ => AreMultipleSongsSelected());
+        RandomizeAllCommand = new RelayCommand(RandomizeAllSongs);
+        RandomizeSelectedCommand = new RelayCommand(RandomizeSelectedSongs, AreMultipleSongsSelected);
+        ReverseAllCommand = new RelayCommand(ReverseAllSongs);
+        ReverseSelectedCommand = new RelayCommand(ReverseSelectedSongs, AreMultipleSongsSelected);
+        ToggleLockCommand = new RelayCommand(ToggleLock);
 
         FilteredPlaylistSongs.CollectionChanged += OnFilteredPlaylistSongsCollectionChanged;
 
@@ -211,6 +221,8 @@ public partial class PlaylistDetailViewModel : ViewModelBase
         PasteSongsCommand.NotifyCanExecuteChanged();
         OpenFileLocationCommand.NotifyCanExecuteChanged();
         SortSelectedCommand.NotifyCanExecuteChanged();
+        RandomizeSelectedCommand.NotifyCanExecuteChanged();
+        ReverseSelectedCommand.NotifyCanExecuteChanged();
     }
 
     private void OnFilteredPlaylistSongsCollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
@@ -669,7 +681,75 @@ public partial class PlaylistDetailViewModel : ViewModelBase
         if (SelectedPlaylistSongs.Count < 2)
             return;
 
+        string[] selectedPlaylistSongIds = [.. SelectedPlaylistSongs.Select(x => x.UID)];
+
         Playlist.SortSongs([.. SelectedPlaylistSongs], [.. sortItem.SortOptions]);
+
+        RestoreSelectedSongs(selectedPlaylistSongIds);
+    }
+
+    private void RestoreSelectedSongs(string[] playlistSongIds)
+    {
+        _dispatcherQueue.TryEnqueue(() =>
+        {
+            PlaylistSong[] selectedPlaylistSongs = [.. Playlist?.Songs.Where(x => playlistSongIds.Contains(x.UID)) ?? []];
+            SelectedPlaylistSongs = new ObservableCollection<PlaylistSong>(selectedPlaylistSongs);
+        });
+    }
+
+    private void RandomizeAllSongs()
+    {
+        if (Playlist == null || Playlist.Songs.Count < 2)
+            return;
+
+        Playlist.Randomize([.. Playlist.Songs]);
+    }
+
+    private void RandomizeSelectedSongs()
+    {
+        if (Playlist == null || SelectedPlaylistSongs.Count < 2)
+            return;
+
+        string[] selectedPlaylistSongIds = [.. SelectedPlaylistSongs.Select(x => x.UID)];
+
+        Playlist.Randomize([.. SelectedPlaylistSongs]);
+
+        RestoreSelectedSongs(selectedPlaylistSongIds);
+    }
+
+    private void ReverseAllSongs()
+    {
+        if (Playlist == null || Playlist.Songs.Count < 2)
+            return;
+
+        Playlist.Reverse([.. Playlist.Songs]);
+    }
+
+    private void ReverseSelectedSongs()
+    {
+        if (Playlist == null || SelectedPlaylistSongs.Count < 2)
+            return;
+
+        string[] selectedPlaylistSongIds = [.. SelectedPlaylistSongs.Select(x => x.UID)];
+
+        Playlist.Reverse([.. SelectedPlaylistSongs]);
+
+        RestoreSelectedSongs(selectedPlaylistSongIds);
+    }
+
+    private void ToggleLock()
+    {
+        if (Playlist == null)
+            return;
+
+        if (Playlist.IsLocked)
+        {
+            Playlist.Unlock();
+        }
+        else
+        {
+            Playlist.Lock();
+        }
     }
 
     #endregion