Safe code and changes

Application/Tracks/Handler/CreateTrackCommandHandler.cs

@@ -34,13 +34,35 @@ namespace Musify.Application.Tracks.Handler
             var fullPictureKey = trackConfiguration.Routes.BuildOriginalPicturePath(trackEntity.OriginalPictureName);
             var fullAudioKey = trackConfiguration.Routes.BuildOriginalAudioPath(trackEntity.OriginalAudioName);
 
-            await UploadFilesAsync(request, fullPictureKey, fullAudioKey, cancellationToken);
+            var uploadResult = await UploadFilesAsync(request, fullPictureKey, fullAudioKey, cancellationToken);
+            if (!uploadResult.IsSuccess)
+                return uploadResult;
 
-            await PublishUpdateEvent(trackEntity, cancellationToken);
-            await PublishTranscodeEvent(trackEntity, cancellationToken);
+            try
+            {
+                await database.Tracks.AddAsync(trackEntity, cancellationToken);
+                await database.SaveChangesAsync(cancellationToken);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to save track {Title} after uploading files", request.Title);
+                await RollbackFilesAsync(fullPictureKey, fullAudioKey, cancellationToken);
+                return Result.Error($"Failed to create track for {request.Title}");
+            }
 
-            await database.Tracks.AddAsync(trackEntity, cancellationToken);
-            await database.SaveChangesAsync(cancellationToken);
+            var publishPictureResult = await PublishUpdateEvent(trackEntity, cancellationToken);
+            if (!publishPictureResult.IsSuccess)
+            {
+                await RollbackTrackAfterPublishFailureAsync(trackEntity, fullPictureKey, fullAudioKey, cancellationToken);
+                return Result.Error($"Failed to create track for {request.Title}");
+            }
+
+            var publishTranscodeResult = await PublishTranscodeEvent(trackEntity, cancellationToken);
+            if (!publishTranscodeResult.IsSuccess)
+            {
+                await RollbackTrackAfterPublishFailureAsync(trackEntity, fullPictureKey, fullAudioKey, cancellationToken);
+                return Result.Error($"Failed to create track for {request.Title}");
+            }
 
             return Result.Created(TrackResponse.FromEntity(trackEntity));
         }
@@ -91,7 +113,7 @@ namespace Musify.Application.Tracks.Handler
             logger.LogInformation("Rolled back uploaded files {PictureKey}, {AudioKey}", pictureKey, audioKey);
         }
 
-        async Task PublishUpdateEvent(Track track, CancellationToken cancellationToken)
+        async Task<Result> PublishUpdateEvent(Track track, CancellationToken cancellationToken)
         {
             try
             {
@@ -111,14 +133,16 @@ namespace Musify.Application.Tracks.Handler
                         trackConfiguration.Routes.LargePicturesPath,
                         trackConfiguration.PicturesSizes.LargePictureWidth,
                         trackConfiguration.PicturesSizes.LargePictureHeight)), cancellationToken);
+                return Result.Success();
             }
             catch (Exception exception)
             {
                 logger.LogError(exception, "Failed to publish track picture update event for track {TrackId}", track.Id);
+                return Result.Error($"Failed to publish track picture update event for track {track.Id}");
             }
         }
 
-        async Task PublishTranscodeEvent(Track track, CancellationToken cancellationToken)
+        async Task<Result> PublishTranscodeEvent(Track track, CancellationToken cancellationToken)
         {
             var destinationFolderAudio = trackConfiguration.Routes.BuildProcessedAudioPath(Guid.NewGuid().ToString());
 
@@ -130,10 +154,38 @@ namespace Musify.Application.Tracks.Handler
                     trackConfiguration.Routes.BuildOriginalAudioPath(track.OriginalAudioName),
                     storageConfiguration.Bucket,
                     destinationFolderAudio), cancellationToken);
+                return Result.Success();
             }
             catch (Exception exception)
             {
                 logger.LogError(exception, "Failed to publish track audio update event for track {TrackId}", track.Id);
+                return Result.Error($"Failed to publish track audio update event for track {track.Id}");
+            }
+        }
+
+        async Task RollbackTrackAfterPublishFailureAsync(
+            Track track,
+            string pictureKey,
+            string audioKey,
+            CancellationToken cancellationToken)
+        {
+            try
+            {
+                database.Tracks.Remove(track);
+                await database.SaveChangesAsync(cancellationToken);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to rollback track {TrackId} persistence after publish failure", track.Id);
+            }
+
+            try
+            {
+                await RollbackFilesAsync(pictureKey, audioKey, cancellationToken);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to rollback uploaded files after publish failure for track {TrackId}", track.Id);
             }
         }
     }

Application/Tracks/Handler/DeleteTrackCommandHandler.cs

@@ -24,7 +24,10 @@ namespace Musify.Application.Tracks.Handler
                 return Result.NotFound();
             }
 
-            if (track.Id != request.UserId)
+            var isOwner = await database.UserHasTracks
+                .AsNoTracking()
+                .AnyAsync(ut => ut.TrackId == request.TrackId && ut.UserId == request.UserId, cancellationToken);
+            if (!isOwner)
             {
                 logger.LogWarning("User {UserId} unauthorized to delete track {TrackId}", request.UserId, request.TrackId);
                 return Result.Unauthorized();
@@ -37,13 +40,46 @@ namespace Musify.Application.Tracks.Handler
                 return Result.Conflict("Track is currently being processed and cannot be deleted");
             }
 
+            var previousPicturesStatus = track.PicturesProcessingStatus;
+            var previousAudioStatus = track.AudioTranscodeProcessingStatus;
+
             track.PicturesProcessingStatus = ProcessingStatus.Processing;
             track.AudioTranscodeProcessingStatus = ProcessingStatus.Processing;
-            await database.SaveChangesAsync(cancellationToken);
 
-            await eventBus.PublishAsync(
-                new DeleteTrackEvent(track.Id, request.UserId),
-                cancellationToken);
+            try
+            {
+                await database.SaveChangesAsync(cancellationToken);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to mark track {TrackId} as processing before deletion", request.TrackId);
+                return Result.Error($"Failed to delete track {request.TrackId}");
+            }
+
+            try
+            {
+                await eventBus.PublishAsync(
+                    new DeleteTrackEvent(track.Id, request.UserId),
+                    cancellationToken);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to publish delete track event for track {TrackId}", request.TrackId);
+
+                track.PicturesProcessingStatus = previousPicturesStatus;
+                track.AudioTranscodeProcessingStatus = previousAudioStatus;
+
+                try
+                {
+                    await database.SaveChangesAsync(cancellationToken);
+                }
+                catch (Exception rollbackException)
+                {
+                    logger.LogError(rollbackException, "Failed to rollback track {TrackId} processing flags after publish failure", request.TrackId);
+                }
+
+                return Result.Error($"Failed to delete track {request.TrackId}");
+            }
 
             return Result.NoContent();
         }

Application/Tracks/Handler/GetTracksByUserIdQueryHandler.cs

@@ -16,15 +16,17 @@ namespace Musify.Application.Tracks.Handler
         {
             var pageNumber = request.PageNumber < 1 ? 1 : request.PageNumber;
             var pageSize = request.PageSize < 1 ? 10 : request.PageSize;
-            var normalizedName = request.Name?.Trim().ToUpperInvariant() ?? string.Empty;
 
             var tracksQuery = database.UserHasTracks
                 .AsNoTracking()
                 .Include(ut => ut.Track)
                 .Where(p => p.UserId == request.UserId);
 
-            if (!string.IsNullOrWhiteSpace(normalizedName))
+            if (request.Name is not null)
+            {
+                var normalizedName = request.Name.Trim().ToUpperInvariant();
                 tracksQuery = tracksQuery.Where(t => t.Track.NormalizedTitle.Contains(normalizedName));
+            }
 
             var totalCount = await tracksQuery.CountAsync(cancellationToken);
 

Application/Tracks/Handler/GetTracksQueryHandler.cs

@@ -17,15 +17,16 @@ namespace Musify.Application.Tracks.Handler
             var pageNumber = request.PageNumber < 1 ? 1 : request.PageNumber;
             var pageSize = request.PageSize < 1 ? 10 : request.PageSize;
 
-            var totalCount = await database.PlayLists.CountAsync(cancellationToken);
-            var pagedPlayLists = await database.UserHasTracks
+            var tracksQuery = database.UserHasTracks
                 .AsNoTracking()
                 .OrderBy(t => t.Id)
                 .Include(ut => ut.Track)
-                .Select(t => TrackResponse.FromEntity(t.Track))
-                .ToPagedListAsync(pageNumber, pageSize, totalCount, cancellationToken);
+                .Select(t => TrackResponse.FromEntity(t.Track));
 
-            return Result.Success(PaginatedResponse<TrackResponse>.FromPagedList(pagedPlayLists));
+            var totalCount = await tracksQuery.CountAsync(cancellationToken);
+            var pagedTracks = await tracksQuery.ToPagedListAsync(pageNumber, pageSize, totalCount, cancellationToken);
+
+            return Result.Success(PaginatedResponse<TrackResponse>.FromPagedList(pagedTracks));
         }
     }
 }

Application/Tracks/Queries/GetTracksByUserIdQuery.cs

@@ -7,7 +7,7 @@ namespace Musify.Application.Tracks.Queries
 {
     public record GetTracksByUserIdQuery(
         Guid UserId,
-        string Name = "",
+    string? Name = null,
         int PageNumber = 1,
         int PageSize = 10)
         : IQuery<Result<PaginatedResponse<TrackResponse> > >;