backend: add endpoint to add a whole album to a playlist

2026-09-24 12:04:28 +02:00
parent bd07b1134e
commit 4b708aa987
4 changed files with 203 additions and 0 deletions
@@ -0,0 +1,86 @@
+using ErrorOr;
+using Mediator;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+using Musify.Application.Contracts;
+using Musify.Application.PlayLists.Responses;
+using Musify.Domain.Entities;
+
+namespace Musify.Application.PlayLists
+{
+    public record AddAlbumToPlayListCommand(long UserId, Guid PlayListId, Guid AlbumId)
+        : ICommand<ErrorOr<AddAlbumToPlayListResponse>>;
+
+    public class AddAlbumToPlayListCommandHandler(
+        IDatabase database,
+        ILogger<AddAlbumToPlayListCommandHandler> logger)
+        : ICommandHandler<AddAlbumToPlayListCommand, ErrorOr<AddAlbumToPlayListResponse>>
+    {
+        public async ValueTask<ErrorOr<AddAlbumToPlayListResponse>> Handle(AddAlbumToPlayListCommand request, CancellationToken cancellationToken)
+        {
+            var playList = await database.PlayLists
+                .SingleOrDefaultAsync(pl => pl.Id == request.PlayListId, cancellationToken);
+            if (playList == null)
+            {
+                logger.LogInformation("Playlist {PlayListId} not found", request.PlayListId);
+                return Error.NotFound();
+            }
+
+            if (playList.UserId != request.UserId)
+            {
+                logger.LogWarning("User {UserId} is not the owner of playlist {PlayListId}", request.UserId, request.PlayListId);
+                return Error.Unauthorized();
+            }
+
+            var albumExists = await database.Albums
+                .AsNoTracking()
+                .AnyAsync(album => album.Id == request.AlbumId, cancellationToken);
+            if (!albumExists)
+            {
+                logger.LogInformation("Album {AlbumId} not found", request.AlbumId);
+                return Error.NotFound(description: $"Album {request.AlbumId} not found");
+            }
+
+            var albumTrackIds = await database.AlbumHasTracks
+                .AsNoTracking()
+                .Where(albumTrack => albumTrack.AlbumId == request.AlbumId)
+                .OrderBy(albumTrack => albumTrack.TrackNumber)
+                .Select(albumTrack => albumTrack.TrackId)
+                .ToListAsync(cancellationToken);
+
+            var playListTracksQuery = database.PlayListHasTracks
+                .Where(plt => plt.PlayListId == request.PlayListId);
+
+            var existingTrackIds = (await playListTracksQuery
+                .Select(plt => plt.TrackId)
+                .ToListAsync(cancellationToken)).ToHashSet();
+
+            var newTrackIds = albumTrackIds
+                .Where(trackId => !existingTrackIds.Contains(trackId))
+                .ToList();
+
+            if (newTrackIds.Count == 0)
+                return new AddAlbumToPlayListResponse(0);
+
+            var nextPosition = existingTrackIds.Count > 0
+                ? await playListTracksQuery.MaxAsync(plt => plt.Position, cancellationToken) + 1
+                : 0;
+
+            await database.PlayListHasTracks.AddRangeAsync(
+                newTrackIds.Select((trackId, index) => new PlayListHasTrack
+                {
+                    PlayListId = request.PlayListId,
+                    TrackId = trackId,
+                    Position = nextPosition + index
+                }),
+                cancellationToken);
+
+            await database.SaveChangesAsync(cancellationToken);
+
+            logger.LogInformation("Added {Count} tracks from album {AlbumId} to playlist {PlayListId}",
+                newTrackIds.Count, request.AlbumId, request.PlayListId);
+
+            return new AddAlbumToPlayListResponse(newTrackIds.Count);
+        }
+    }
+}
@@ -0,0 +1,4 @@
+namespace Musify.Application.PlayLists.Responses
+{
+    public record AddAlbumToPlayListResponse(int AddedCount);
+}