Render unknown URLs inside the app shell and move ListeningStats to the domain types

Add catch-all routes so unknown pages 404 inside the (app) layout and unknown
/api URLs return a JSON 404 instead of redirecting to the login page. Restore
the full root error page.

backend/.editorconfig

@@ -1,65 +0,0 @@
-root = true
-
-[*]
-charset = utf-8
-insert_final_newline = true
-trim_trailing_whitespace = true
-indent_style = space
-
-[*.{csproj,props,targets,slnx,xml}]
-indent_size = 2
-
-[*.json]
-indent_size = 4
-
-[**/Migrations/**.cs]
-generated_code = true
-
-[*.cs]
-indent_size = 4
-
-csharp_style_namespace_declarations = file_scoped:warning
-csharp_using_directive_placement = outside_namespace:warning
-dotnet_sort_system_directives_first = true
-dotnet_separate_import_directive_groups = false
-dotnet_diagnostic.IDE0005.severity = warning
-
-dotnet_style_require_accessibility_modifiers = always:warning
-csharp_style_var_for_built_in_types = true:suggestion
-csharp_style_var_when_type_is_apparent = true:suggestion
-csharp_style_var_elsewhere = true:suggestion
-csharp_prefer_braces = when_multiline:warning
-csharp_style_prefer_primary_constructors = true:suggestion
-csharp_style_expression_bodied_methods = when_on_single_line:suggestion
-dotnet_style_prefer_collection_expression = when_types_loosely_match:suggestion
-
-dotnet_naming_rule.private_fields.symbols = private_fields
-dotnet_naming_rule.private_fields.style = camel_case
-dotnet_naming_rule.private_fields.severity = warning
-dotnet_naming_symbols.private_fields.applicable_kinds = field
-dotnet_naming_symbols.private_fields.applicable_accessibilities = private
-dotnet_naming_symbols.private_fields.required_modifiers =
-dotnet_naming_style.camel_case.capitalization = camel_case
-
-dotnet_naming_rule.private_constants.symbols = private_constants
-dotnet_naming_rule.private_constants.style = pascal_case
-dotnet_naming_rule.private_constants.severity = warning
-dotnet_naming_symbols.private_constants.applicable_kinds = field
-dotnet_naming_symbols.private_constants.required_modifiers = const
-dotnet_naming_style.pascal_case.capitalization = pascal_case
-
-# Analyzer rules that would need behaviour or API changes; downgraded in P0, revisit in P15.
-dotnet_diagnostic.CA1848.severity = suggestion
-dotnet_diagnostic.CA1873.severity = suggestion
-dotnet_diagnostic.CA1305.severity = suggestion
-dotnet_diagnostic.CA1707.severity = suggestion
-dotnet_diagnostic.CA1859.severity = suggestion
-dotnet_diagnostic.CA1716.severity = suggestion
-dotnet_diagnostic.CA1000.severity = suggestion
-dotnet_diagnostic.CA1725.severity = suggestion
-dotnet_diagnostic.CA1816.severity = suggestion
-dotnet_diagnostic.CA1822.severity = suggestion
-dotnet_diagnostic.CA1852.severity = suggestion
-dotnet_diagnostic.CA1068.severity = suggestion
-dotnet_diagnostic.CA1711.severity = suggestion
-dotnet_diagnostic.CA1861.severity = suggestion

backend/Core/Musify.Application/Albums/AddTrackToAlbum.cs

@@ -0,0 +1,82 @@
+using ErrorOr;
+using Mediator;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+using Musify.Application.Contracts;
+using Musify.Domain.Entities;
+
+namespace Musify.Application.Albums
+{
+    public record AddTrackToAlbumCommand(long UserId, Guid AlbumId, Guid TrackId)
+        : ICommand<ErrorOr<Success>>;
+
+    public class AddTrackToAlbumCommandHandler(
+        IDatabase database,
+        ILogger<AddTrackToAlbumCommandHandler> logger)
+        : ICommandHandler<AddTrackToAlbumCommand, ErrorOr<Success>>
+    {
+        public async ValueTask<ErrorOr<Success>> Handle(AddTrackToAlbumCommand request, CancellationToken cancellationToken)
+        {
+            var album = await database.Albums
+                .AsNoTracking()
+                .SingleOrDefaultAsync(a => a.Id == request.AlbumId, cancellationToken);
+            if (album == null)
+            {
+                logger.LogInformation("Album {AlbumId} not found", request.AlbumId);
+                return Error.NotFound();
+            }
+
+            if (album.OwnerUserId != request.UserId)
+            {
+                logger.LogWarning("User {UserId} is not the owner of album {AlbumId}", request.UserId, request.AlbumId);
+                return Error.Unauthorized();
+            }
+
+            var track = await database.Tracks
+                .AsNoTracking()
+                .SingleOrDefaultAsync(t => t.Id == request.TrackId, cancellationToken);
+            if (track == null)
+            {
+                logger.LogInformation("Track {TrackId} not found", request.TrackId);
+                return Error.NotFound(description: $"Track {request.TrackId} not found");
+            }
+
+            if (track.OwnerUserId != request.UserId)
+            {
+                logger.LogWarning("User {UserId} does not own track {TrackId}", request.UserId, request.TrackId);
+                return Error.Unauthorized();
+            }
+
+            var alreadyAdded = await database.AlbumHasTracks
+                .AsNoTracking()
+                .AnyAsync(albumTrack => albumTrack.AlbumId == request.AlbumId && albumTrack.TrackId == request.TrackId, cancellationToken);
+            if (alreadyAdded)
+            {
+                logger.LogInformation("Track {TrackId} already in album {AlbumId}", request.TrackId, request.AlbumId);
+                return Error.Conflict(description: "Track is already in the album.");
+            }
+
+            var albumTracksQuery = database.AlbumHasTracks
+                .Where(albumTrack => albumTrack.AlbumId == request.AlbumId);
+
+            var hasTracks = await albumTracksQuery.AnyAsync(cancellationToken);
+            var nextTrackNumber = hasTracks
+                ? await albumTracksQuery.MaxAsync(albumTrack => albumTrack.TrackNumber, cancellationToken) + 1
+                : 1;
+
+            await database.AlbumHasTracks.AddAsync(new AlbumHasTrack
+            {
+                AlbumId = request.AlbumId,
+                TrackId = request.TrackId,
+                TrackNumber = nextTrackNumber
+            }, cancellationToken);
+
+            await database.SaveChangesAsync(cancellationToken);
+
+            logger.LogInformation("Added track {TrackId} to album {AlbumId} as number {TrackNumber}",
+                request.TrackId, request.AlbumId, nextTrackNumber);
+
+            return new Success();
+        }
+    }
+}

backend/Core/Musify.Application/Albums/AddTracksToAlbum.cs

@@ -1,77 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Albums;
-
-/// <summary>Appends your own tracks to an album in the given order, skipping the ones it already has.</summary>
-public record AddTracksToAlbumCommand(long UserId, Guid AlbumId, IReadOnlyList<Guid> TrackIds)
-    : ICommand<ErrorOr<Success>>;
-
-public class AddTracksToAlbumCommandHandler(
-    IDatabase database,
-    ILogger<AddTracksToAlbumCommandHandler> logger)
-    : ICommandHandler<AddTracksToAlbumCommand, ErrorOr<Success>>
-{
-    public async ValueTask<ErrorOr<Success>> Handle(AddTracksToAlbumCommand request, CancellationToken cancellationToken)
-    {
-        var album = await database.Albums.FindOwnedAsync(request.AlbumId, request.UserId, cancellationToken);
-        if (album.IsError)
-            return album.Errors;
-
-        var requestedIds = request.TrackIds.Distinct().ToList();
-
-        var tracks = await database.Tracks
-            .AsNoTracking()
-            .Where(track => requestedIds.Contains(track.Id) && track.LifeCycleStatus == LifeCycleStatus.Active)
-            .Select(track => new { track.Id, track.OwnerUserId })
-            .ToListAsync(cancellationToken);
-
-        var missing = requestedIds.FirstOrDefault(id => tracks.All(track => track.Id != id));
-        if (missing != Guid.Empty)
-            return AppErrors.NotFound("Track", missing);
-
-        var foreign = tracks.FirstOrDefault(track => track.OwnerUserId != request.UserId);
-        if (foreign != null)
-            return AppErrors.Forbidden("Track", foreign.Id);
-
-        var alreadyInAlbum = await database.AlbumHasTracks
-            .AsNoTracking()
-            .Where(link => link.AlbumId == request.AlbumId && requestedIds.Contains(link.TrackId))
-            .Select(link => link.TrackId)
-            .ToListAsync(cancellationToken);
-
-        var toAdd = requestedIds.Where(id => !alreadyInAlbum.Contains(id)).ToList();
-        if (toAdd.Count == 0)
-            return Result.Success;
-
-        // Album track numbers are user-visible, so they start at 1.
-        var nextTrackNumber = (await database.AlbumHasTracks
-            .Where(link => link.AlbumId == request.AlbumId)
-            .MaxAsync(link => (int?)link.TrackNumber, cancellationToken) ?? 0) + 1;
-
-        foreach (var trackId in toAdd)
-        {
-            await database.AlbumHasTracks.AddAsync(new AlbumHasTrack
-            {
-                AlbumId = request.AlbumId,
-                TrackId = trackId,
-                TrackNumber = nextTrackNumber++
-            }, cancellationToken);
-        }
-
-        var saved = await database.TrySaveChangesAsync(
-            AppErrors.Conflict("Album.ConcurrentChange", "The album changed while adding tracks. Try again."), cancellationToken);
-        if (saved.IsError)
-            return saved;
-
-        logger.LogInformation("Added {Count} tracks to album {AlbumId}", toAdd.Count, request.AlbumId);
-
-        return Result.Success;
-    }
-}

backend/Core/Musify.Application/Albums/CreateAlbum.cs

@@ -2,71 +2,127 @@ using ErrorOr;
 using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
-using Musify.Application.Albums.Responses;
 using Musify.Application.Configuration;
-using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Pictures;
-using Musify.Application.Services;
 using Musify.Application.Shared;
+using Musify.Application.Events;
+using Musify.Application.Albums.Responses;
+using Musify.Application.Services;
 using Musify.Domain.Entities;
 using Musify.Domain.ValueObjects;
+using Musify.Application.Contracts;
 
-namespace Musify.Application.Albums;
-
-public record CreateAlbumCommand(
-    long UserId,
-    string Title,
-    string? Description,
-    int? ReleaseYear,
-    Guid PictureIntentId)
-    : ICommand<ErrorOr<AlbumApplicationResponse>>;
-
-public class CreateAlbumCommandHandler(
-    IEventBus eventBus,
-    IDatabase database,
-    UploadIntentValidator uploadIntentValidator,
-    ILogger<CreateAlbumCommandHandler> logger,
-    AlbumConfiguration albumConfiguration)
-    : ICommandHandler<CreateAlbumCommand, ErrorOr<AlbumApplicationResponse>>
+namespace Musify.Application.Albums
 {
-    public async ValueTask<ErrorOr<AlbumApplicationResponse>> Handle(CreateAlbumCommand request, CancellationToken cancellationToken)
+    public record CreateAlbumCommand(
+        long UserId,
+        string Title,
+        string? Description,
+        int? ReleaseYear,
+        Guid PictureIntentId)
+        : ICommand<ErrorOr<AlbumApplicationResponse>>;
+
+    public class CreateAlbumCommandHandler(
+        IEventBus eventBus,
+        IDatabase database,
+        UploadIntentValidator uploadIntentValidator,
+        ILogger<CreateAlbumCommandHandler> logger,
+        ApplicationStorageConfiguration storageConfiguration,
+        AlbumConfiguration albumConfiguration,
+        UploadIntentConfiguration uploadIntentConfiguration)
+        : ICommandHandler<CreateAlbumCommand, ErrorOr<AlbumApplicationResponse>>
     {
-        var userExists = await database.Users
-            .AsNoTracking()
-            .AnyAsync(user => user.Id == request.UserId, cancellationToken);
-        if (!userExists)
-            return AppErrors.NotFound("User", request.UserId);
-
-        var prepared = await PictureSourceChange.PrepareAsync(
-            uploadIntentValidator, request.PictureIntentId, request.UserId, UploadIntentPurpose.AlbumPicture, albumConfiguration, cancellationToken);
-        if (prepared.IsError)
-            return prepared.Errors;
-
-        var picture = prepared.Value;
-        var title = request.Title.Trim();
-
-        var album = new Album
+        public async ValueTask<ErrorOr<AlbumApplicationResponse>> Handle(CreateAlbumCommand request, CancellationToken cancellationToken)
         {
-            OwnerUserId = request.UserId,
-            Title = title,
-            NormalizedTitle = TextNormalizer.Normalize(title),
-            Description = request.Description,
-            ReleaseYear = request.ReleaseYear,
-            Pictures = picture.Pictures
-        };
+            var userExists = await database.Users
+                .AsNoTracking()
+                .AnyAsync(user => user.Id == request.UserId, cancellationToken);
+            if (!userExists)
+            {
+                logger.LogWarning("User {UserId} not found", request.UserId);
+                return Error.NotFound(description: $"User {request.UserId} not found");
+            }
 
-        await database.Albums.AddAsync(album, cancellationToken);
+            var pictureIntent = await uploadIntentValidator.ValidateAndLoadAsync(
+                uploadIntentConfiguration, request.PictureIntentId, request.UserId, cancellationToken);
+            if (pictureIntent.IsError)
+                return pictureIntent.Errors;
 
-        await eventBus.PublishAsync(
-            new CreateAlbumResourcesEvent(
-                album.Id, picture.Intent.Id, picture.Intent.Bucket, picture.Intent.Key, picture.FinalKey, picture.Sizes),
-            cancellationToken);
+            var intent = pictureIntent.Value;
+            var title = request.Title.Trim();
 
-        await database.SaveChangesAsync(cancellationToken);
+            var album = new Album
+            {
+                OwnerUserId = request.UserId,
+                Title = title,
+                NormalizedTitle = title.ToUpperInvariant(),
+                Description = request.Description,
+                ReleaseYear = request.ReleaseYear,
+                Pictures = new AlbumPictures
+                {
+                    OriginalName = intent.ObjectName,
+                    SmallName = intent.ObjectName,
+                    MediumName = intent.ObjectName,
+                    LargeName = intent.ObjectName
+                }
+            };
 
-        logger.LogInformation("Created album {AlbumId} for user {UserId}", album.Id, request.UserId);
+            await database.Albums.AddAsync(album, cancellationToken);
 
-        return AlbumApplicationResponse.FromEntity(album, trackCount: 0);
+            var finalPictureKey = albumConfiguration.Routes.BuildOriginalPicturePath(request.UserId, intent.ObjectName);
+            var publishResult = await PublishCreateAlbumEventAsync(album.Id, intent, finalPictureKey, cancellationToken);
+            if (publishResult.IsError)
+                return publishResult.Errors;
+
+            try
+            {
+                await database.SaveChangesAsync(cancellationToken);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to save album for user {UserId}", request.UserId);
+                return Error.Failure(description: $"Failed to create album for user {request.UserId}");
+            }
+
+            logger.LogInformation("Created album {AlbumId} for user {UserId}", album.Id, request.UserId);
+
+            return AlbumApplicationResponse.FromEntity(album, trackCount: 0);
+        }
+
+        private async Task<ErrorOr<Success>> PublishCreateAlbumEventAsync(
+            Guid albumId,
+            UploadIntent pictureIntent,
+            string finalPictureKey,
+            CancellationToken cancellationToken)
+        {
+            try
+            {
+                await eventBus.PublishAsync(
+                    new CreateAlbumResourcesEvent(
+                        albumId,
+                        pictureIntent.Id,
+                        storageConfiguration.Bucket,
+                        pictureIntent.Key,
+                        finalPictureKey,
+                        new ImageSize(
+                            albumConfiguration.Routes.SmallPicturesPath,
+                            albumConfiguration.PicturesSizes.SmallPictureWidth,
+                            albumConfiguration.PicturesSizes.SmallPictureHeight),
+                        new ImageSize(
+                            albumConfiguration.Routes.MediumPicturesPath,
+                            albumConfiguration.PicturesSizes.MediumPictureWidth,
+                            albumConfiguration.PicturesSizes.MediumPictureHeight),
+                        new ImageSize(
+                            albumConfiguration.Routes.LargePicturesPath,
+                            albumConfiguration.PicturesSizes.LargePictureWidth,
+                            albumConfiguration.PicturesSizes.LargePictureHeight)),
+                    cancellationToken);
+                return new Success();
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to publish create album event for album {AlbumId}", albumId);
+                return Error.Failure(description: $"Failed to publish create album event for album {albumId}");
+            }
+        }
     }
 }

backend/Core/Musify.Application/Albums/DeleteAlbum.cs

@@ -1,36 +1,50 @@
 using ErrorOr;
 using Mediator;
+using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
 
-namespace Musify.Application.Albums;
-
-public record DeleteAlbumCommand(long UserId, Guid AlbumId)
-    : ICommand<ErrorOr<Success>>;
-
-public class DeleteAlbumCommandHandler(
-    IDatabase database,
-    IEventBus eventBus,
-    ILogger<DeleteAlbumCommandHandler> logger)
-    : ICommandHandler<DeleteAlbumCommand, ErrorOr<Success>>
+namespace Musify.Application.Albums
 {
-    public async ValueTask<ErrorOr<Success>> Handle(DeleteAlbumCommand request, CancellationToken cancellationToken)
+    public record DeleteAlbumCommand(long UserId, Guid AlbumId)
+        : ICommand<ErrorOr<Success>>;
+
+    public class DeleteAlbumCommandHandler(
+        IDatabase database,
+        ILogger<DeleteAlbumCommandHandler> logger)
+        : ICommandHandler<DeleteAlbumCommand, ErrorOr<Success>>
     {
-        var found = await database.Albums.FindOwnedAsync(request.AlbumId, request.UserId, cancellationToken);
-        if (found.IsError)
-            return found.Errors;
+        public async ValueTask<ErrorOr<Success>> Handle(DeleteAlbumCommand request, CancellationToken cancellationToken)
+        {
+            var album = await database.Albums
+                .SingleOrDefaultAsync(a => a.Id == request.AlbumId, cancellationToken);
+            if (album == null)
+            {
+                logger.LogDebug("Album {AlbumId} not found", request.AlbumId);
+                return Error.NotFound();
+            }
 
-        var album = found.Value;
-        album.LifeCycleStatus = LifeCycleStatus.Removing;
+            if (album.OwnerUserId != request.UserId)
+            {
+                logger.LogWarning("Album {AlbumId} does not belong to user {UserId}", request.AlbumId, request.UserId);
+                return Error.Unauthorized();
+            }
 
-        await eventBus.PublishAsync(new DeleteAlbumEvent(album.Id, request.UserId), cancellationToken);
-        await database.SaveChangesAsync(cancellationToken);
+            database.Albums.Remove(album);
 
-        logger.LogInformation("Marked album {AlbumId} as removing", request.AlbumId);
+            try
+            {
+                await database.SaveChangesAsync(cancellationToken);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to delete album {AlbumId}", request.AlbumId);
+                return Error.Failure(description: $"Failed to delete album {request.AlbumId}");
+            }
 
-        return Result.Success;
+            logger.LogInformation("Deleted album {AlbumId} for user {UserId}", request.AlbumId, request.UserId);
+
+            return new Success();
+        }
     }
 }

backend/Core/Musify.Application/Albums/GetAlbumById.cs

@@ -3,27 +3,36 @@ using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Musify.Application.Albums.Responses;
 using Musify.Application.Contracts;
-using Musify.Application.Shared;
 
-namespace Musify.Application.Albums;
-
-public record GetAlbumByIdQuery(Guid Id)
-    : IQuery<ErrorOr<AlbumApplicationResponse>>;
-
-public class GetAlbumByIdQueryHandler(IDatabase database)
-    : IQueryHandler<GetAlbumByIdQuery, ErrorOr<AlbumApplicationResponse>>
+namespace Musify.Application.Albums
 {
-    public async ValueTask<ErrorOr<AlbumApplicationResponse>> Handle(GetAlbumByIdQuery request, CancellationToken cancellationToken)
-    {
-        var album = await database.Albums
-            .AsNoTracking()
-            .Active()
-            .Where(a => a.Id == request.Id)
-            .SelectResponse()
-            .SingleOrDefaultAsync(cancellationToken);
+    public record GetAlbumByIdQuery(Guid Id)
+        : IQuery<ErrorOr<AlbumApplicationResponse>>;
 
-        return album == null
-            ? AppErrors.NotFound("Album", request.Id)
-            : album;
+    public class GetAlbumByIdQueryHandler(IDatabase database)
+        : IQueryHandler<GetAlbumByIdQuery, ErrorOr<AlbumApplicationResponse>>
+    {
+        public async ValueTask<ErrorOr<AlbumApplicationResponse>> Handle(GetAlbumByIdQuery request, CancellationToken cancellationToken)
+        {
+            var album = await database.Albums
+                .AsNoTracking()
+                .Where(a => a.Id == request.Id)
+                .Select(a => new
+                {
+                    Album = a,
+                    TrackCount = a.AlbumTracks.Count,
+                    CoverTrackIds = a.AlbumTracks
+                        .OrderBy(albumTrack => albumTrack.TrackNumber)
+                        .Take(AlbumApplicationResponse.CoverTrackCount)
+                        .Select(albumTrack => albumTrack.TrackId)
+                        .ToList()
+                })
+                .SingleOrDefaultAsync(cancellationToken);
+
+            if (album == null)
+                return Error.NotFound();
+
+            return AlbumApplicationResponse.FromEntity(album.Album, album.TrackCount, album.CoverTrackIds);
+        }
     }
 }

backend/Core/Musify.Application/Albums/GetAlbumCover.cs

@@ -0,0 +1,49 @@
+using ErrorOr;
+using Mediator;
+using Microsoft.EntityFrameworkCore;
+using MimeMapping;
+using Musify.Application.Configuration;
+using Musify.Application.Contracts;
+
+namespace Musify.Application.Albums
+{
+    public record GetAlbumCoverQuery(Guid AlbumId, string Size)
+        : IQuery<ErrorOr<AlbumCoverLocation>>;
+
+    public record AlbumCoverLocation(string Bucket, string Key, string ContentType);
+
+    public class GetAlbumCoverQueryHandler(
+        IDatabase database,
+        ApplicationStorageConfiguration storageConfiguration,
+        AlbumConfiguration albumConfiguration)
+        : IQueryHandler<GetAlbumCoverQuery, ErrorOr<AlbumCoverLocation>>
+    {
+        public async ValueTask<ErrorOr<AlbumCoverLocation>> Handle(GetAlbumCoverQuery request, CancellationToken cancellationToken)
+        {
+            var pictures = await database.Albums.AsNoTracking()
+                .Where(a => a.Id == request.AlbumId)
+                .Select(a => a.Pictures)
+                .SingleOrDefaultAsync(cancellationToken);
+
+            if (pictures == null)
+                return Error.NotFound();
+
+            var routes = albumConfiguration.Routes;
+            var (name, key) = request.Size.ToLowerInvariant() switch
+            {
+                "small" => (pictures.SmallName, BuildKey(routes.BuildSmallPicturePath, pictures.SmallName)),
+                "large" => (pictures.LargeName, BuildKey(routes.BuildLargePicturePath, pictures.LargeName)),
+                _ => (pictures.MediumName, BuildKey(routes.BuildMediumPicturePath, pictures.MediumName))
+            };
+
+            if (string.IsNullOrEmpty(name) || string.IsNullOrEmpty(key))
+                return Error.NotFound();
+
+            var contentType = MimeUtility.GetMimeMapping(name);
+            return new AlbumCoverLocation(storageConfiguration.Bucket, key, contentType);
+        }
+
+        private static string? BuildKey(Func<string, string> builder, string? name)
+            => string.IsNullOrEmpty(name) ? null : builder(name);
+    }
+}

backend/Core/Musify.Application/Albums/GetAlbumTracks.cs

@@ -1,38 +1,49 @@
 using ErrorOr;
 using Mediator;
 using Microsoft.EntityFrameworkCore;
-using Musify.Application.Albums.Responses;
 using Musify.Application.Contracts;
 using Musify.Application.Shared;
 using Musify.Application.Tracks.Responses;
+using X.PagedList;
+using X.PagedList.EF;
 
-namespace Musify.Application.Albums;
-
-public record GetAlbumTracksQuery(
-    Guid AlbumId,
-    int PageNumber,
-    int PageSize)
-    : IQuery<ErrorOr<PaginatedResponse<TrackApplicationResponse>>>;
-
-public class GetAlbumTracksQueryHandler(IDatabase database)
-    : IQueryHandler<GetAlbumTracksQuery, ErrorOr<PaginatedResponse<TrackApplicationResponse>>>
+namespace Musify.Application.Albums
 {
-    public async ValueTask<ErrorOr<PaginatedResponse<TrackApplicationResponse>>> Handle(GetAlbumTracksQuery request, CancellationToken cancellationToken)
-    {
-        var albumExists = await database.Albums
-            .AsNoTracking()
-            .Active()
-            .AnyAsync(album => album.Id == request.AlbumId, cancellationToken);
-        if (!albumExists)
-            return AppErrors.NotFound("Album", request.AlbumId);
+    public record GetAlbumTracksQuery(
+        Guid AlbumId,
+        int PageNumber,
+        int PageSize)
+        : IQuery<ErrorOr<PaginatedResponse<TrackApplicationResponse>>>;
 
-        return await database.AlbumHasTracks
-            .AsNoTracking()
-            .Where(albumTrack => albumTrack.AlbumId == request.AlbumId && albumTrack.Track.LifeCycleStatus == Domain.ValueObjects.LifeCycleStatus.Active)
-            .OrderBy(albumTrack => albumTrack.TrackNumber)
-            .ThenBy(albumTrack => albumTrack.Id)
-            .Select(albumTrack => albumTrack.Track)
-            .SelectResponse()
-            .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
+    public class GetAlbumTracksQueryHandler(IDatabase database)
+        : IQueryHandler<GetAlbumTracksQuery, ErrorOr<PaginatedResponse<TrackApplicationResponse>>>
+    {
+        public async ValueTask<ErrorOr<PaginatedResponse<TrackApplicationResponse>>> Handle(GetAlbumTracksQuery request, CancellationToken cancellationToken)
+        {
+            var albumExists = await database.Albums
+                .AsNoTracking()
+                .AnyAsync(album => album.Id == request.AlbumId, cancellationToken);
+            if (!albumExists)
+                return Error.NotFound();
+
+            var tracksQuery = database.AlbumHasTracks
+                .AsNoTracking()
+                .Include(albumTrack => albumTrack.Track.Owner)
+                .Include(albumTrack => albumTrack.Track.Tags)
+                .Where(albumTrack => albumTrack.AlbumId == request.AlbumId);
+
+            var totalCount = await tracksQuery.CountAsync(cancellationToken);
+
+            var pagedEntities = await tracksQuery
+                .OrderBy(albumTrack => albumTrack.TrackNumber)
+                .Select(albumTrack => new { albumTrack.Track, ListensCount = albumTrack.Track.ListeningHistories.Count(l => l.IsCounted) })
+                .ToPagedListAsync(request.PageNumber, request.PageSize, totalCount, cancellationToken);
+
+            var pagedTracks = new StaticPagedList<TrackApplicationResponse>(
+                pagedEntities.Select(entry => TrackApplicationResponse.FromEntity(entry.Track, entry.ListensCount)),
+                pagedEntities.PageNumber, pagedEntities.PageSize, pagedEntities.TotalItemCount);
+
+            return PaginatedResponse<TrackApplicationResponse>.FromPagedList(pagedTracks);
+        }
     }
 }

backend/Core/Musify.Application/Albums/GetAlbums.cs

@@ -1,33 +1,60 @@
+using ErrorOr;
 using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Musify.Application.Albums.Responses;
 using Musify.Application.Contracts;
-using Musify.Application.Shared;
+using X.PagedList;
+using X.PagedList.EF;
 
-namespace Musify.Application.Albums;
-
-public record GetAlbumsQuery(string? Title, int PageNumber, int PageSize)
-    : IQuery<PaginatedResponse<AlbumApplicationResponse>>;
-
-public class GetAlbumsQueryHandler(IDatabase database)
-    : IQueryHandler<GetAlbumsQuery, PaginatedResponse<AlbumApplicationResponse>>
+namespace Musify.Application.Albums
 {
-    public async ValueTask<PaginatedResponse<AlbumApplicationResponse>> Handle(GetAlbumsQuery request, CancellationToken cancellationToken)
+    public record GetAlbumsQuery(string? Title, int PageNumber, int PageSize)
+        : IQuery<ErrorOr<AlbumsSearchResponse>>;
+
+    public class GetAlbumsQueryHandler(IDatabase database)
+        : IQueryHandler<GetAlbumsQuery, ErrorOr<AlbumsSearchResponse>>
     {
-        var albumsQuery = database.Albums
-            .AsNoTracking()
-            .Active();
-
-        if (!string.IsNullOrWhiteSpace(request.Title))
+        public async ValueTask<ErrorOr<AlbumsSearchResponse>> Handle(GetAlbumsQuery request, CancellationToken cancellationToken)
         {
-            var normalizedTitle = TextNormalizer.Normalize(request.Title);
-            albumsQuery = albumsQuery.Where(album => album.NormalizedTitle.Contains(normalizedTitle));
-        }
+            var albumsQuery = database.Albums
+                .AsNoTracking()
+                .AsQueryable();
 
-        return await albumsQuery
-            .OrderByDescending(album => album.CreatedAt)
-            .ThenBy(album => album.Id)
-            .SelectResponse()
-            .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
+            if (!string.IsNullOrEmpty(request.Title))
+            {
+                var normalizedTitle = request.Title.Trim().ToUpperInvariant();
+                albumsQuery = albumsQuery.Where(album => album.NormalizedTitle.Contains(normalizedTitle));
+            }
+
+            var totalCount = await albumsQuery.CountAsync(cancellationToken);
+
+            var pagedEntities = await albumsQuery
+                .OrderByDescending(album => album.CreatedAt)
+                .Select(album => new
+                {
+                    Album = album,
+                    TrackCount = album.AlbumTracks.Count,
+                    CoverTrackIds = album.AlbumTracks
+                        .OrderBy(albumTrack => albumTrack.TrackNumber)
+                        .Take(AlbumApplicationResponse.CoverTrackCount)
+                        .Select(albumTrack => albumTrack.TrackId)
+                        .ToList()
+                })
+                .ToPagedListAsync(request.PageNumber, request.PageSize, totalCount, cancellationToken);
+
+            var items = pagedEntities
+                .Select(entry => AlbumSearchItemResponse.FromAlbum(
+                    AlbumApplicationResponse.FromEntity(entry.Album, entry.TrackCount, entry.CoverTrackIds)))
+                .ToList();
+
+            return new AlbumsSearchResponse(
+                items,
+                pagedEntities.PageNumber,
+                pagedEntities.PageSize,
+                pagedEntities.PageCount,
+                pagedEntities.TotalItemCount,
+                pagedEntities.HasPreviousPage,
+                pagedEntities.HasNextPage);
+        }
     }
 }

backend/Core/Musify.Application/Albums/GetAlbumsByUserId.cs

@@ -4,30 +4,50 @@ using Microsoft.EntityFrameworkCore;
 using Musify.Application.Albums.Responses;
 using Musify.Application.Contracts;
 using Musify.Application.Shared;
+using X.PagedList;
+using X.PagedList.EF;
 
-namespace Musify.Application.Albums;
-
-public record GetAlbumsByUserIdQuery(long UserId, int PageNumber, int PageSize)
-    : IQuery<ErrorOr<PaginatedResponse<AlbumApplicationResponse>>>;
-
-public class GetAlbumsByUserIdQueryHandler(IDatabase database)
-    : IQueryHandler<GetAlbumsByUserIdQuery, ErrorOr<PaginatedResponse<AlbumApplicationResponse>>>
+namespace Musify.Application.Albums
 {
-    public async ValueTask<ErrorOr<PaginatedResponse<AlbumApplicationResponse>>> Handle(GetAlbumsByUserIdQuery request, CancellationToken cancellationToken)
-    {
-        var userExists = await database.Users
-            .AsNoTracking()
-            .AnyAsync(user => user.Id == request.UserId, cancellationToken);
-        if (!userExists)
-            return AppErrors.NotFound("User", request.UserId);
+    public record GetAlbumsByUserIdQuery(long UserId, int PageNumber, int PageSize)
+        : IQuery<ErrorOr<PaginatedResponse<AlbumApplicationResponse>>>;
 
-        return await database.Albums
-            .AsNoTracking()
-            .Active()
-            .Where(album => album.OwnerUserId == request.UserId)
-            .OrderByDescending(album => album.CreatedAt)
-            .ThenBy(album => album.Id)
-            .SelectResponse()
-            .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
+    public class GetAlbumsByUserIdQueryHandler(IDatabase database)
+        : IQueryHandler<GetAlbumsByUserIdQuery, ErrorOr<PaginatedResponse<AlbumApplicationResponse>>>
+    {
+        public async ValueTask<ErrorOr<PaginatedResponse<AlbumApplicationResponse>>> Handle(GetAlbumsByUserIdQuery request, CancellationToken cancellationToken)
+        {
+            var userExists = await database.Users
+                .AsNoTracking()
+                .AnyAsync(user => user.Id == request.UserId, cancellationToken);
+            if (!userExists)
+                return Error.NotFound(description: $"User {request.UserId} not found");
+
+            var albumsQuery = database.Albums
+                .AsNoTracking()
+                .Where(album => album.OwnerUserId == request.UserId);
+
+            var totalCount = await albumsQuery.CountAsync(cancellationToken);
+
+            var pagedEntities = await albumsQuery
+                .OrderByDescending(album => album.CreatedAt)
+                .Select(album => new
+                {
+                    Album = album,
+                    TrackCount = album.AlbumTracks.Count,
+                    CoverTrackIds = album.AlbumTracks
+                        .OrderBy(albumTrack => albumTrack.TrackNumber)
+                        .Take(AlbumApplicationResponse.CoverTrackCount)
+                        .Select(albumTrack => albumTrack.TrackId)
+                        .ToList()
+                })
+                .ToPagedListAsync(request.PageNumber, request.PageSize, totalCount, cancellationToken);
+
+            var pagedAlbums = new StaticPagedList<AlbumApplicationResponse>(
+                pagedEntities.Select(entry => AlbumApplicationResponse.FromEntity(entry.Album, entry.TrackCount, entry.CoverTrackIds)),
+                pagedEntities.PageNumber, pagedEntities.PageSize, pagedEntities.TotalItemCount);
+
+            return PaginatedResponse<AlbumApplicationResponse>.FromPagedList(pagedAlbums);
+        }
     }
 }

backend/Core/Musify.Application/Albums/GetRecentlyListenedAlbums.cs

@@ -1,51 +1,61 @@
+using ErrorOr;
 using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Musify.Application.Albums.Responses;
 using Musify.Application.Contracts;
 
-namespace Musify.Application.Albums;
-
-public record GetRecentlyListenedAlbumsQuery(long UserId, int Limit)
-    : IQuery<IReadOnlyList<AlbumApplicationResponse>>;
-
-public class GetRecentlyListenedAlbumsQueryHandler(IDatabase database)
-    : IQueryHandler<GetRecentlyListenedAlbumsQuery, IReadOnlyList<AlbumApplicationResponse>>
+namespace Musify.Application.Albums
 {
-    public async ValueTask<IReadOnlyList<AlbumApplicationResponse>> Handle(GetRecentlyListenedAlbumsQuery request, CancellationToken cancellationToken)
+    public record GetRecentlyListenedAlbumsQuery(long UserId, int Limit)
+        : IQuery<ErrorOr<IReadOnlyList<AlbumApplicationResponse>>>;
+
+    public class GetRecentlyListenedAlbumsQueryHandler(IDatabase database)
+        : IQueryHandler<GetRecentlyListenedAlbumsQuery, ErrorOr<IReadOnlyList<AlbumApplicationResponse>>>
     {
-        var listens = database.ListeningHistories
-            .AsNoTracking()
-            .Where(history => history.UserId == request.UserId && history.IsCounted);
+        public async ValueTask<ErrorOr<IReadOnlyList<AlbumApplicationResponse>>> Handle(GetRecentlyListenedAlbumsQuery request, CancellationToken cancellationToken)
+        {
+            var listenedTrackIds = database.ListeningHistories
+                .AsNoTracking()
+                .Where(history => history.UserId == request.UserId && history.IsCounted);
 
-        var ranked = await database.AlbumHasTracks
-            .AsNoTracking()
-            .Where(albumTrack => albumTrack.Album.LifeCycleStatus == Domain.ValueObjects.LifeCycleStatus.Active)
-            .Join(
-                listens,
-                albumTrack => albumTrack.TrackId,
-                history => history.TrackId,
-                (albumTrack, history) => new { albumTrack.AlbumId, history.ListenedAt })
-            .GroupBy(entry => entry.AlbumId)
-            .Select(group => new { AlbumId = group.Key, LastListenedAt = group.Max(entry => entry.ListenedAt) })
-            .OrderByDescending(entry => entry.LastListenedAt)
-            .ThenBy(entry => entry.AlbumId)
-            .Take(request.Limit)
-            .ToListAsync(cancellationToken);
+            var ranked = await database.AlbumHasTracks
+                .AsNoTracking()
+                .Join(
+                    listenedTrackIds,
+                    albumTrack => albumTrack.TrackId,
+                    history => history.TrackId,
+                    (albumTrack, history) => new { albumTrack.AlbumId, history.ListenedAt })
+                .GroupBy(entry => entry.AlbumId)
+                .Select(group => new { AlbumId = group.Key, LastListenedAt = group.Max(entry => entry.ListenedAt) })
+                .OrderByDescending(entry => entry.LastListenedAt)
+                .Take(request.Limit)
+                .ToListAsync(cancellationToken);
 
-        if (ranked.Count == 0)
-            return [];
+            if (ranked.Count == 0)
+                return new List<AlbumApplicationResponse>();
 
-        var albumIds = ranked.Select(entry => entry.AlbumId).ToList();
+            var albumIds = ranked.Select(entry => entry.AlbumId).ToList();
 
-        var albumsById = await database.Albums
-            .AsNoTracking()
-            .Where(album => albumIds.Contains(album.Id))
-            .SelectResponse()
-            .ToDictionaryAsync(album => album.Id, cancellationToken);
+            var albums = await database.Albums
+                .AsNoTracking()
+                .Where(album => albumIds.Contains(album.Id))
+                .Select(album => new
+                {
+                    Album = album,
+                    TrackCount = album.AlbumTracks.Count,
+                    CoverTrackIds = album.AlbumTracks
+                        .OrderBy(albumTrack => albumTrack.TrackNumber)
+                        .Take(AlbumApplicationResponse.CoverTrackCount)
+                        .Select(albumTrack => albumTrack.TrackId)
+                        .ToList()
+                })
+                .ToDictionaryAsync(entry => entry.Album.Id, cancellationToken);
 
-        return ranked
-            .Where(entry => albumsById.ContainsKey(entry.AlbumId))
-            .Select(entry => albumsById[entry.AlbumId])
-            .ToList();
+            return ranked
+                .Where(entry => albums.ContainsKey(entry.AlbumId))
+                .Select(entry => albums[entry.AlbumId])
+                .Select(entry => AlbumApplicationResponse.FromEntity(entry.Album, entry.TrackCount, entry.CoverTrackIds))
+                .ToList();
+        }
     }
 }

backend/Core/Musify.Application/Albums/RemoveTrackFromAlbum.cs

@@ -3,43 +3,57 @@ using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using Musify.Application.Contracts;
-using Musify.Application.Shared;
 
-namespace Musify.Application.Albums;
-
-public record RemoveTrackFromAlbumCommand(long UserId, Guid AlbumId, Guid TrackId)
-    : ICommand<ErrorOr<Success>>;
-
-public class RemoveTrackFromAlbumCommandHandler(
-    IDatabase database,
-    ILogger<RemoveTrackFromAlbumCommandHandler> logger)
-    : ICommandHandler<RemoveTrackFromAlbumCommand, ErrorOr<Success>>
+namespace Musify.Application.Albums
 {
-    public async ValueTask<ErrorOr<Success>> Handle(RemoveTrackFromAlbumCommand request, CancellationToken cancellationToken)
+    public record RemoveTrackFromAlbumCommand(long UserId, Guid AlbumId, Guid TrackId)
+        : ICommand<ErrorOr<Success>>;
+
+    public class RemoveTrackFromAlbumCommandHandler(
+        IDatabase database,
+        ILogger<RemoveTrackFromAlbumCommandHandler> logger)
+        : ICommandHandler<RemoveTrackFromAlbumCommand, ErrorOr<Success>>
     {
-        var album = await database.Albums.FindOwnedAsync(request.AlbumId, request.UserId, cancellationToken);
-        if (album.IsError)
-            return album.Errors;
+        public async ValueTask<ErrorOr<Success>> Handle(RemoveTrackFromAlbumCommand request, CancellationToken cancellationToken)
+        {
+            var album = await database.Albums
+                .AsNoTracking()
+                .SingleOrDefaultAsync(a => a.Id == request.AlbumId, cancellationToken);
+            if (album == null)
+            {
+                logger.LogInformation("Album {AlbumId} not found", request.AlbumId);
+                return Error.NotFound();
+            }
 
-        var albumTracks = await database.AlbumHasTracks
-            .Where(albumTrack => albumTrack.AlbumId == request.AlbumId)
-            .OrderBy(albumTrack => albumTrack.TrackNumber)
-            .ToListAsync(cancellationToken);
+            if (album.OwnerUserId != request.UserId)
+            {
+                logger.LogWarning("User {UserId} is not the owner of album {AlbumId}", request.UserId, request.AlbumId);
+                return Error.Unauthorized();
+            }
 
-        var link = albumTracks.SingleOrDefault(albumTrack => albumTrack.TrackId == request.TrackId);
-        if (link == null)
-            return Error.NotFound("Album.TrackNotFound", "Track is not in the album.");
+            var albumTracks = await database.AlbumHasTracks
+                .Where(albumTrack => albumTrack.AlbumId == request.AlbumId)
+                .OrderBy(albumTrack => albumTrack.TrackNumber)
+                .ToListAsync(cancellationToken);
 
-        database.AlbumHasTracks.Remove(link);
+            var link = albumTracks.SingleOrDefault(albumTrack => albumTrack.TrackId == request.TrackId);
+            if (link == null)
+            {
+                logger.LogInformation("Track {TrackId} not in album {AlbumId}", request.TrackId, request.AlbumId);
+                return Error.NotFound(description: "Track is not in the album.");
+            }
 
-        var trackNumber = 1;
-        foreach (var remaining in albumTracks.Where(albumTrack => albumTrack.Id != link.Id))
-            remaining.TrackNumber = trackNumber++;
+            database.AlbumHasTracks.Remove(link);
 
-        await database.SaveChangesAsync(cancellationToken);
+            var trackNumber = 1;
+            foreach (var remaining in albumTracks.Where(albumTrack => albumTrack.Id != link.Id))
+                remaining.TrackNumber = trackNumber++;
 
-        logger.LogInformation("Removed track {TrackId} from album {AlbumId}", request.TrackId, request.AlbumId);
+            await database.SaveChangesAsync(cancellationToken);
 
-        return Result.Success;
+            logger.LogInformation("Removed track {TrackId} from album {AlbumId}", request.TrackId, request.AlbumId);
+
+            return new Success();
+        }
     }
 }

backend/Core/Musify.Application/Albums/RequestAlbumPictureUpload.cs

@@ -1,24 +1,105 @@
 using ErrorOr;
 using Mediator;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
 using Musify.Application.Configuration;
-using Musify.Application.Pictures.Responses;
+using Musify.Application.Albums.Responses;
 using Musify.Application.Services;
+using Musify.Domain.Entities;
 using Musify.Domain.ValueObjects;
+using Musify.Application.Contracts;
 
-namespace Musify.Application.Albums;
-
-public record RequestAlbumPictureUploadCommand(
-    long UserId,
-    string FileType,
-    string ContentType,
-    long? ExpectedSizeBytes = null)
-    : ICommand<ErrorOr<PictureUploadResponse>>;
-
-public class RequestAlbumPictureUploadCommandHandler(UploadIntentIssuer issuer, AlbumConfiguration albumConfiguration)
-    : ICommandHandler<RequestAlbumPictureUploadCommand, ErrorOr<PictureUploadResponse>>
+namespace Musify.Application.Albums
 {
-    public async ValueTask<ErrorOr<PictureUploadResponse>> Handle(RequestAlbumPictureUploadCommand request, CancellationToken cancellationToken) =>
-        await issuer.IssuePictureAsync(
-            request.UserId, UploadIntentPurpose.AlbumPicture, albumConfiguration,
-            request.FileType, request.ContentType, request.ExpectedSizeBytes, cancellationToken);
+    public record RequestAlbumPictureUploadCommand(
+        long UserId,
+        string FileType,
+        string ContentType,
+        long? ExpectedSizeBytes = null)
+        : ICommand<ErrorOr<AlbumPictureUploadResponse>>;
+
+    public class RequestAlbumPictureUploadCommandHandler(
+        IDatabase database,
+        UploadIntentValidator uploadIntentValidator,
+        IStorageService storageService,
+        ILogger<RequestAlbumPictureUploadCommandHandler> logger,
+        ApplicationStorageConfiguration storageConfiguration,
+        AlbumConfiguration albumConfiguration,
+        UploadIntentConfiguration uploadIntentConfiguration)
+        : ICommandHandler<RequestAlbumPictureUploadCommand, ErrorOr<AlbumPictureUploadResponse>>
+    {
+        public async ValueTask<ErrorOr<AlbumPictureUploadResponse>> Handle(RequestAlbumPictureUploadCommand request, CancellationToken cancellationToken)
+        {
+            var userExists = await database.Users
+                .AsNoTracking()
+                .AnyAsync(u => u.Id == request.UserId, cancellationToken);
+            if (!userExists)
+            {
+                logger.LogWarning("User {UserId} not found", request.UserId);
+                return Error.NotFound(description: $"User {request.UserId} not found");
+            }
+
+            var effectiveSizeBytes = request.ExpectedSizeBytes
+                ?? uploadIntentConfiguration.DefaultExpectedPictureSizeBytes;
+
+            var objectName = $"{Guid.NewGuid()}.{request.FileType.TrimStart('.').ToLowerInvariant()}";
+
+            var tempKey = albumConfiguration.Routes.BuildTempPicturePath(
+                uploadIntentConfiguration.TemporalRootPrefix, request.UserId, objectName);
+
+            try
+            {
+                var uploadUrl = await storageService.GetUploadUrlAsync(
+                    storageConfiguration.Bucket,
+                    tempKey,
+                    request.ContentType,
+                    TimeSpan.FromSeconds(uploadIntentConfiguration.UploadUrlExpiresInSeconds),
+                    cancellationToken);
+
+                await using var transaction = await database.BeginTransactionAsync(
+                    System.Data.IsolationLevel.Serializable, cancellationToken);
+
+                var quotaCheck = await uploadIntentValidator.CheckQuotaAsync(
+                    uploadIntentConfiguration,
+                    request.UserId, effectiveSizeBytes, 1, cancellationToken);
+                if (quotaCheck.IsError)
+                {
+                    logger.LogWarning("User {UserId} failed upload intent quota check", request.UserId);
+                    return quotaCheck.Errors;
+                }
+
+                var intent = new UploadIntent
+                {
+                    UserId = request.UserId,
+                    Bucket = storageConfiguration.Bucket,
+                    Key = tempKey,
+                    ObjectName = objectName,
+                    ContentType = request.ContentType,
+                    ExpectedSizeBytes = effectiveSizeBytes,
+                    Purpose = UploadIntentPurpose.AlbumPicture,
+                    ExpiresAt = DateTime.UtcNow.AddSeconds(uploadIntentConfiguration.UploadUrlExpiresInSeconds),
+                };
+
+                await database.UploadIntents.AddAsync(intent, cancellationToken);
+                await database.SaveChangesAsync(cancellationToken);
+                await transaction.CommitAsync(cancellationToken);
+
+                logger.LogInformation("Issued upload intent {IntentId} for user {UserId} (AlbumPicture, temp key: {Key})", intent.Id, request.UserId, tempKey);
+
+                return new AlbumPictureUploadResponse(
+                    intent.Id,
+                    storageConfiguration.Bucket,
+                    tempKey,
+                    objectName,
+                    request.ContentType,
+                    uploadIntentConfiguration.UploadUrlExpiresInSeconds,
+                    uploadUrl);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to generate album picture upload URL for user {UserId}", request.UserId);
+                return Error.Failure(description: "Failed to generate upload URL");
+            }
+        }
+    }
 }

backend/Core/Musify.Application/Albums/Responses/AlbumApplicationResponse.cs

@@ -1,40 +1,43 @@
+using System.Text.Json.Serialization;
 using Musify.Domain.Entities;
+using Musify.Application.Serialization;
 
-namespace Musify.Application.Albums.Responses;
-
-public record AlbumApplicationResponse(
-    Guid Id,
-    string Title,
-    string? Description,
-    int? ReleaseYear,
-    long OwnerUserId,
-    int TrackCount,
-    string? SmallImageKeyName,
-    string? MediumImageKeyName,
-    string? LargeImageKeyName,
-    DateTime CreatedAt,
-    DateTime UpdatedAt,
-    IReadOnlyList<Guid> CoverTrackIds)
+namespace Musify.Application.Albums.Responses
 {
-    public const int CoverTrackCount = AlbumProjections.CoverTrackCount;
-
-    public static AlbumApplicationResponse FromEntity(
-        Album album,
-        int trackCount,
-        IReadOnlyList<Guid>? coverTrackIds = null)
+    public record AlbumApplicationResponse(
+        Guid Id,
+        string Title,
+        string? Description,
+        int? ReleaseYear,
+        [property: JsonConverter(typeof(LongAsStringConverter))] long OwnerUserId,
+        int TrackCount,
+        string? SmallImageKeyName,
+        string? MediumImageKeyName,
+        string? LargeImageKeyName,
+        DateTime CreatedAt,
+        DateTime UpdatedAt,
+        IReadOnlyList<Guid> CoverTrackIds)
     {
-        return new AlbumApplicationResponse(
-            album.Id,
-            album.Title,
-            album.Description,
-            album.ReleaseYear,
-            album.OwnerUserId,
-            trackCount,
-            album.Pictures?.SmallName,
-            album.Pictures?.MediumName,
-            album.Pictures?.LargeName,
-            album.CreatedAt,
-            album.UpdatedAt,
-            coverTrackIds ?? []);
+        public const int CoverTrackCount = 4;
+
+        public static AlbumApplicationResponse FromEntity(
+            Album album,
+            int trackCount,
+            IReadOnlyList<Guid>? coverTrackIds = null)
+        {
+            return new AlbumApplicationResponse(
+                album.Id,
+                album.Title,
+                album.Description,
+                album.ReleaseYear,
+                album.OwnerUserId,
+                trackCount,
+                album.Pictures?.SmallName,
+                album.Pictures?.MediumName,
+                album.Pictures?.LargeName,
+                album.CreatedAt,
+                album.UpdatedAt,
+                coverTrackIds ?? []);
+        }
     }
 }

backend/Core/Musify.Application/Albums/Responses/AlbumPictureUploadResponse.cs

@@ -0,0 +1,11 @@
+namespace Musify.Application.Albums.Responses
+{
+    public record AlbumPictureUploadResponse(
+        Guid IntentId,
+        string Bucket,
+        string Key,
+        string PictureName,
+        string ContentType,
+        int ExpiresInSeconds,
+        string UploadUrl);
+}

backend/Core/Musify.Application/Albums/Responses/AlbumProjections.cs

@@ -1,31 +0,0 @@
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Albums.Responses;
-
-public static class AlbumProjections
-{
-    public const int CoverTrackCount = 4;
-
-    public static IQueryable<Album> Active(this IQueryable<Album> query) =>
-        query.Where(album => album.LifeCycleStatus == LifeCycleStatus.Active);
-
-    public static IQueryable<AlbumApplicationResponse> SelectResponse(this IQueryable<Album> query) =>
-        query.Select(album => new AlbumApplicationResponse(
-            album.Id,
-            album.Title,
-            album.Description,
-            album.ReleaseYear,
-            album.OwnerUserId,
-            album.AlbumTracks.Count,
-            album.Pictures!.SmallName,
-            album.Pictures!.MediumName,
-            album.Pictures!.LargeName,
-            album.CreatedAt,
-            album.UpdatedAt,
-            album.AlbumTracks
-                .OrderBy(albumTrack => albumTrack.TrackNumber)
-                .Take(CoverTrackCount)
-                .Select(albumTrack => albumTrack.TrackId)
-                .ToList()));
-}

backend/Core/Musify.Application/Albums/Responses/AlbumSearchItemResponse.cs

@@ -0,0 +1,7 @@
+namespace Musify.Application.Albums.Responses
+{
+    public record AlbumSearchItemResponse(AlbumApplicationResponse Album)
+    {
+        public static AlbumSearchItemResponse FromAlbum(AlbumApplicationResponse album) => new(album);
+    }
+}

backend/Core/Musify.Application/Albums/Responses/AlbumsSearchResponse.cs

@@ -0,0 +1,12 @@
+namespace Musify.Application.Albums.Responses
+{
+
+    public record AlbumsSearchResponse(
+        IReadOnlyList<AlbumSearchItemResponse> Items,
+        int PageNumber,
+        int PageSize,
+        int PageCount,
+        int TotalItemCount,
+        bool HasPreviousPage,
+        bool HasNextPage);
+}

backend/Core/Musify.Application/Albums/UpdateAlbum.cs

@@ -2,72 +2,149 @@ using ErrorOr;
 using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
-using Musify.Application.Albums.Responses;
 using Musify.Application.Configuration;
-using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Pictures;
-using Musify.Application.Services;
 using Musify.Application.Shared;
+using Musify.Application.Events;
+using Musify.Application.Albums.Responses;
+using Musify.Application.Services;
+using Musify.Domain.Entities;
 using Musify.Domain.ValueObjects;
+using Musify.Application.Contracts;
 
-namespace Musify.Application.Albums;
-
-public record UpdateAlbumCommand(
-    long UserId,
-    Guid AlbumId,
-    string Title,
-    string? Description,
-    int? ReleaseYear,
-    Guid? NewPictureIntentId)
-    : ICommand<ErrorOr<AlbumApplicationResponse>>;
-
-public class UpdateAlbumCommandHandler(
-    IEventBus eventBus,
-    IDatabase database,
-    UploadIntentValidator uploadIntentValidator,
-    ILogger<UpdateAlbumCommandHandler> logger,
-    AlbumConfiguration albumConfiguration)
-    : ICommandHandler<UpdateAlbumCommand, ErrorOr<AlbumApplicationResponse>>
+namespace Musify.Application.Albums
 {
-    public async ValueTask<ErrorOr<AlbumApplicationResponse>> Handle(UpdateAlbumCommand request, CancellationToken cancellationToken)
+    public record UpdateAlbumCommand(
+        long UserId,
+        Guid AlbumId,
+        string Title,
+        string? Description,
+        int? ReleaseYear,
+        Guid? NewPictureIntentId)
+        : ICommand<ErrorOr<AlbumApplicationResponse>>;
+
+    public class UpdateAlbumCommandHandler(
+        IEventBus eventBus,
+        IDatabase database,
+        UploadIntentValidator uploadIntentValidator,
+        ILogger<UpdateAlbumCommandHandler> logger,
+        ApplicationStorageConfiguration storageConfiguration,
+        AlbumConfiguration albumConfiguration,
+        UploadIntentConfiguration uploadIntentConfiguration)
+        : ICommandHandler<UpdateAlbumCommand, ErrorOr<AlbumApplicationResponse>>
     {
-        var found = await database.Albums.FindOwnedAsync(request.AlbumId, request.UserId, cancellationToken);
-        if (found.IsError)
-            return found.Errors;
-
-        var album = found.Value;
-        var title = request.Title.Trim();
-
-        album.Title = title;
-        album.NormalizedTitle = TextNormalizer.Normalize(title);
-        album.Description = request.Description;
-        album.ReleaseYear = request.ReleaseYear;
-
-        if (request.NewPictureIntentId is { } intentId)
+        public async ValueTask<ErrorOr<AlbumApplicationResponse>> Handle(UpdateAlbumCommand request, CancellationToken cancellationToken)
         {
-            var prepared = await PictureSourceChange.PrepareAsync(
-                uploadIntentValidator, intentId, request.UserId, UploadIntentPurpose.AlbumPicture, albumConfiguration, cancellationToken);
-            if (prepared.IsError)
-                return prepared.Errors;
+            var album = await database.Albums
+                .SingleOrDefaultAsync(a => a.Id == request.AlbumId, cancellationToken);
+            if (album == null)
+            {
+                logger.LogInformation("Album {AlbumId} not found", request.AlbumId);
+                return Error.NotFound();
+            }
 
-            var picture = prepared.Value;
-            album.Pictures = picture.Pictures;
+            if (album.OwnerUserId != request.UserId)
+            {
+                logger.LogWarning("Album {AlbumId} does not belong to user {UserId}", request.AlbumId, request.UserId);
+                return Error.Unauthorized();
+            }
 
-            await eventBus.PublishAsync(
-                new UpdateAlbumPictureSourceEvent(
-                    album.Id, picture.Intent.Id, picture.Intent.Bucket, picture.Intent.Key, picture.FinalKey, picture.Sizes),
-                cancellationToken);
+            var title = request.Title.Trim();
+
+            album.Title = title;
+            album.NormalizedTitle = title.ToUpperInvariant();
+            album.Description = request.Description;
+            album.ReleaseYear = request.ReleaseYear;
+
+            UploadIntent? pictureIntent = null;
+            string? finalPictureKey = null;
+
+            if (request.NewPictureIntentId.HasValue)
+            {
+                var validation = await uploadIntentValidator.ValidateAndLoadAsync(
+                    uploadIntentConfiguration,
+                    request.NewPictureIntentId.Value, request.UserId, cancellationToken);
+                if (validation.IsError)
+                    return validation.Errors;
+
+                pictureIntent = validation.Value;
+                album.Pictures = new AlbumPictures
+                {
+                    OriginalName = pictureIntent.ObjectName,
+                    SmallName = pictureIntent.ObjectName,
+                    MediumName = pictureIntent.ObjectName,
+                    LargeName = pictureIntent.ObjectName
+                };
+                finalPictureKey = albumConfiguration.Routes.BuildOriginalPicturePath(request.UserId, pictureIntent.ObjectName);
+            }
+
+            if (pictureIntent != null && finalPictureKey != null)
+            {
+                var publishResult = await PublishUpdateAlbumPictureSourceEventAsync(
+                    album.Id, pictureIntent, finalPictureKey, cancellationToken);
+                if (publishResult.IsError)
+                    return publishResult.Errors;
+            }
+
+            try
+            {
+                await database.SaveChangesAsync(cancellationToken);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to update album {AlbumId}", request.AlbumId);
+                return Error.Failure(description: $"Failed to update album {request.AlbumId}");
+            }
+
+            var albumTracks = database.AlbumHasTracks
+                .AsNoTracking()
+                .Where(albumTrack => albumTrack.AlbumId == album.Id);
+
+            var trackCount = await albumTracks.CountAsync(cancellationToken);
+            var coverTrackIds = await albumTracks
+                .OrderBy(albumTrack => albumTrack.TrackNumber)
+                .Take(AlbumApplicationResponse.CoverTrackCount)
+                .Select(albumTrack => albumTrack.TrackId)
+                .ToListAsync(cancellationToken);
+
+            logger.LogInformation("Updated album {AlbumId}", album.Id);
+            return AlbumApplicationResponse.FromEntity(album, trackCount, coverTrackIds);
         }
 
-        await database.SaveChangesAsync(cancellationToken);
-
-        logger.LogInformation("Updated album {AlbumId}", album.Id);
-
-        return await database.Albums
-            .AsNoTracking()
-            .Where(a => a.Id == album.Id)
-            .SelectResponse()
-            .SingleAsync(cancellationToken);
+        private async Task<ErrorOr<Success>> PublishUpdateAlbumPictureSourceEventAsync(
+            Guid albumId,
+            UploadIntent pictureIntent,
+            string finalPictureKey,
+            CancellationToken cancellationToken)
+        {
+            try
+            {
+                await eventBus.PublishAsync(
+                    new UpdateAlbumPictureSourceEvent(
+                        albumId,
+                        pictureIntent.Id,
+                        storageConfiguration.Bucket,
+                        pictureIntent.Key,
+                        finalPictureKey,
+                        new ImageSize(
+                            albumConfiguration.Routes.SmallPicturesPath,
+                            albumConfiguration.PicturesSizes.SmallPictureWidth,
+                            albumConfiguration.PicturesSizes.SmallPictureHeight),
+                        new ImageSize(
+                            albumConfiguration.Routes.MediumPicturesPath,
+                            albumConfiguration.PicturesSizes.MediumPictureWidth,
+                            albumConfiguration.PicturesSizes.MediumPictureHeight),
+                        new ImageSize(
+                            albumConfiguration.Routes.LargePicturesPath,
+                            albumConfiguration.PicturesSizes.LargePictureWidth,
+                            albumConfiguration.PicturesSizes.LargePictureHeight)),
+                    cancellationToken);
+                return new Success();
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to publish update album picture source event for album {AlbumId}", albumId);
+                return Error.Failure(description: $"Failed to publish update album picture source event for album {albumId}");
+            }
+        }
     }
 }

backend/Core/Musify.Application/Application.csproj

@@ -19,6 +19,8 @@
     <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" />
     <PackageReference Include="Microsoft.Extensions.Options.DataAnnotations" />
     <PackageReference Include="MimeMapping" />
+    <PackageReference Include="X.PagedList" />
+    <PackageReference Include="X.PagedList.EF" />
   </ItemGroup>
 
   <ItemGroup>

backend/Core/Musify.Application/ApplicationDependencyInjection.cs

@@ -11,17 +11,16 @@ public static class ApplicationDependencyInjection
     {
         services.AddMediator();
         services.AddScoped<UploadIntentValidator>();
-        services.AddScoped<UploadIntentIssuer>();
         services.AddScoped<TrackStreamIssuer>();
 
-        services.AddValidatedOptions<ApplicationStorageConfiguration>(configuration);
-        services.AddValidatedOptions<PlayListConfiguration>(configuration);
-        services.AddValidatedOptions<AlbumConfiguration>(configuration);
-        services.AddValidatedOptions<TrackConfiguration>(configuration);
-        services.AddValidatedOptions<MixConfiguration>(configuration);
-        services.AddValidatedOptions<StreamGatewayConfiguration>(configuration);
-        services.AddValidatedOptions<UploadIntentConfiguration>(configuration);
-        services.AddValidatedOptions<PlaybackConfiguration>(configuration);
+        services.AddValidatedOptions<ApplicationStorageConfiguration>(configuration, ApplicationStorageConfiguration.SectionName);
+        services.AddValidatedOptions<PlayListConfiguration>(configuration, PlayListConfiguration.SectionName);
+        services.AddValidatedOptions<AlbumConfiguration>(configuration, AlbumConfiguration.SectionName);
+        services.AddValidatedOptions<TrackConfiguration>(configuration, TrackConfiguration.SectionName);
+        services.AddValidatedOptions<MixConfiguration>(configuration, MixConfiguration.SectionName);
+        services.AddValidatedOptions<StreamGatewayConfiguration>(configuration, StreamGatewayConfiguration.SectionName);
+        services.AddValidatedOptions<UploadIntentConfiguration>(configuration, UploadIntentConfiguration.SectionName);
+        services.AddValidatedOptions<PlaybackConfiguration>(configuration, PlaybackConfiguration.SectionName);
 
         return services;
     }

backend/Core/Musify.Application/AssemblyInfo.cs

@@ -1,4 +1,4 @@
-using Mediator;
+using Mediator;
 using Microsoft.Extensions.DependencyInjection;
 
-[assembly: MediatorOptions(ServiceLifetime = ServiceLifetime.Scoped)]
+[assembly: MediatorOptions(ServiceLifetime = ServiceLifetime.Scoped)]

backend/Core/Musify.Application/Configuration/AlbumConfiguration.cs

@@ -1,14 +1,79 @@
 using System.ComponentModel.DataAnnotations;
+using Musify.Application.Shared;
 
-namespace Musify.Application.Configuration;
-
-public class AlbumConfiguration : IConfigurationOptions, IPictureOwnerConfiguration
+namespace Musify.Application.Configuration
 {
-    public static string SectionName => "Album";
+    public class AlbumConfiguration
+    {
+        public const string SectionName = "Album";
 
-    [Required]
-    public PictureRoutes Routes { get; set; } = new() { ParentFolder = "Albums" };
+        [Required]
+        public AlbumRoutes Routes { get; set; } = new AlbumRoutes();
 
-    [Required]
-    public PictureSizes PicturesSizes { get; set; } = new();
+        [Required]
+        public AlbumPicturesSizes PicturesSizes { get; set; } = new AlbumPicturesSizes();
+    }
+
+    public class AlbumRoutes
+    {
+        [Required]
+        public string UploadsFolder { get; set; } = "uploads";
+
+        [Required]
+        public string ParentFolders { get; set; } = "Albums";
+
+        [Required]
+        public string OriginalPicturesFolder { get; set; } = "OriginalPictures";
+
+        [Required]
+        public string SmallPicturesFolder { get; set; } = "SmallPictures";
+
+        [Required]
+        public string MediumPicturesFolder { get; set; } = "MediumPictures";
+
+        [Required]
+        public string LargePicturesFolder { get; set; } = "LargePictures";
+
+        public string SmallPicturesPath => StorageKey.Combine(ParentFolders, SmallPicturesFolder);
+
+        public string MediumPicturesPath => StorageKey.Combine(ParentFolders, MediumPicturesFolder);
+
+        public string LargePicturesPath => StorageKey.Combine(ParentFolders, LargePicturesFolder);
+
+        public string OriginalPicturesPath => StorageKey.Combine(ParentFolders, OriginalPicturesFolder);
+
+        public string BuildOriginalPicturePath(string pictureName) => StorageKey.Combine(ParentFolders, OriginalPicturesFolder, pictureName);
+
+        public string BuildOriginalPicturePath(long userId, string pictureName) => StorageKey.Combine(UploadsFolder, userId.ToString(), ParentFolders, OriginalPicturesFolder, pictureName);
+
+        public string BuildSmallPicturePath(string pictureName) => StorageKey.Combine(ParentFolders, SmallPicturesFolder, pictureName);
+
+        public string BuildMediumPicturePath(string pictureName) => StorageKey.Combine(ParentFolders, MediumPicturesFolder, pictureName);
+
+        public string BuildLargePicturePath(string pictureName) => StorageKey.Combine(ParentFolders, LargePicturesFolder, pictureName);
+
+        public string BuildTempPicturePath(string tempRootPrefix, long userId, string objectName) =>
+            StorageKey.Combine(tempRootPrefix, userId.ToString(), ParentFolders, objectName);
+    }
+
+    public class AlbumPicturesSizes
+    {
+        [Range(1, 1024)]
+        public int SmallPictureWidth { get; set; } = 128;
+
+        [Range(1, 1024)]
+        public int SmallPictureHeight { get; set; } = 128;
+
+        [Range(1, 1024)]
+        public int MediumPictureWidth { get; set; } = 256;
+
+        [Range(1, 1024)]
+        public int MediumPictureHeight { get; set; } = 256;
+
+        [Range(1, 1024)]
+        public int LargePictureWidth { get; set; } = 512;
+
+        [Range(1, 1024)]
+        public int LargePictureHeight { get; set; } = 512;
+    }
 }

backend/Core/Musify.Application/Configuration/ApplicationStorageConfiguration.cs

@@ -1,12 +1,13 @@
 using System.ComponentModel.DataAnnotations;
 
-namespace Musify.Application.Configuration;
-
-public class ApplicationStorageConfiguration : IConfigurationOptions
+namespace Musify.Application.Configuration
 {
-    public static string SectionName => "ApplicationStorage";
+    public class ApplicationStorageConfiguration
+    {
+        public const string SectionName = "ApplicationStorage";
 
-    [Required]
-    [StringLength(128, MinimumLength = 1)]
-    public required string Bucket { get; set; }
+        [Required]
+        [StringLength(128, MinimumLength = 1)]
+        public required string Bucket { get; set; }
+    }
 }

backend/Core/Musify.Application/Configuration/ConfigurationDependencyInjection.cs

@@ -6,10 +6,6 @@ namespace Musify.Application.Configuration;
 
 public static class ConfigurationDependencyInjection
 {
-    public static IServiceCollection AddValidatedOptions<T>(this IServiceCollection services, IConfiguration configuration)
-        where T : class, IConfigurationOptions =>
-        services.AddValidatedOptions<T>(configuration, T.SectionName);
-
     public static IServiceCollection AddValidatedOptions<T>(
         this IServiceCollection services,
         IConfiguration configuration,

backend/Core/Musify.Application/Configuration/GetPlaybackPublicConfig.cs

@@ -1,16 +1,17 @@
 using Mediator;
 using Musify.Application.Configuration.Responses;
 
-namespace Musify.Application.Configuration;
-
-
-public record GetPlaybackPublicConfigQuery : IQuery<PlaybackPublicConfigResponse>;
-
-public class GetPlaybackPublicConfigQueryHandler(PlaybackConfiguration playbackConfiguration)
-    : IQueryHandler<GetPlaybackPublicConfigQuery, PlaybackPublicConfigResponse>
+namespace Musify.Application.Configuration
 {
-    public ValueTask<PlaybackPublicConfigResponse> Handle(GetPlaybackPublicConfigQuery query, CancellationToken cancellationToken) =>
-        ValueTask.FromResult(new PlaybackPublicConfigResponse(
-            playbackConfiguration.AllowAnonymousListening,
-            playbackConfiguration.AnonymousFragmentSeconds));
+
+    public record GetPlaybackPublicConfigQuery : IQuery<PlaybackPublicConfigResponse>;
+
+    public class GetPlaybackPublicConfigQueryHandler(PlaybackConfiguration playbackConfiguration)
+        : IQueryHandler<GetPlaybackPublicConfigQuery, PlaybackPublicConfigResponse>
+    {
+        public ValueTask<PlaybackPublicConfigResponse> Handle(GetPlaybackPublicConfigQuery query, CancellationToken cancellationToken) =>
+            ValueTask.FromResult(new PlaybackPublicConfigResponse(
+                playbackConfiguration.AllowAnonymousListening,
+                playbackConfiguration.AnonymousFragmentSeconds));
+    }
 }

backend/Core/Musify.Application/Configuration/IConfigurationOptions.cs

@@ -1,6 +0,0 @@
-namespace Musify.Application.Configuration;
-
-public interface IConfigurationOptions
-{
-    public static abstract string SectionName { get; }
-}

backend/Core/Musify.Application/Configuration/MixConfiguration.cs

@@ -1,11 +1,12 @@
 using System.ComponentModel.DataAnnotations;
 
-namespace Musify.Application.Configuration;
-
-public class MixConfiguration : IConfigurationOptions
+namespace Musify.Application.Configuration
 {
-    public static string SectionName => "Mix";
+    public class MixConfiguration
+    {
+        public const string SectionName = "Mix";
 
-    [Range(4, 100)]
-    public int ItemsPerMix { get; set; } = 12;
+        [Range(4, 100)]
+        public int ItemsPerMix { get; set; } = 12;
+    }
 }

backend/Core/Musify.Application/Configuration/Pictures.cs

@@ -1,90 +0,0 @@
-using System.ComponentModel.DataAnnotations;
-using Musify.Application.Shared;
-
-namespace Musify.Application.Configuration;
-
-public enum PictureSize
-{
-    Small,
-    Medium,
-    Large
-}
-
-public class PictureRoutes
-{
-    [Required]
-    public string UploadsFolder { get; set; } = "uploads";
-
-    [Required]
-    public string ParentFolder { get; set; } = string.Empty;
-
-    [Required]
-    public string OriginalPicturesFolder { get; set; } = "OriginalPictures";
-
-    [Required]
-    public string SmallPicturesFolder { get; set; } = "SmallPictures";
-
-    [Required]
-    public string MediumPicturesFolder { get; set; } = "MediumPictures";
-
-    [Required]
-    public string LargePicturesFolder { get; set; } = "LargePictures";
-
-    public string FolderPath(PictureSize size) => StorageKey.Combine(ParentFolder, size switch
-    {
-        PictureSize.Small => SmallPicturesFolder,
-        PictureSize.Medium => MediumPicturesFolder,
-        PictureSize.Large => LargePicturesFolder,
-        _ => throw new ArgumentOutOfRangeException(nameof(size), size, null)
-    });
-
-    public string BuildPicturePath(PictureSize size, string pictureName) => StorageKey.Combine(FolderPath(size), pictureName);
-
-    public string BuildOriginalPicturePath(long userId, string pictureName) =>
-        StorageKey.Combine(UploadsFolder, userId.ToString(), ParentFolder, OriginalPicturesFolder, pictureName);
-
-    public string BuildTempPath(string tempRootPrefix, long userId, string objectName) =>
-        StorageKey.Combine(tempRootPrefix, userId.ToString(), ParentFolder, objectName);
-}
-
-public class PictureSizes
-{
-    [Range(1, 1024)]
-    public int SmallWidth { get; set; } = 128;
-
-    [Range(1, 1024)]
-    public int SmallHeight { get; set; } = 128;
-
-    [Range(1, 1024)]
-    public int MediumWidth { get; set; } = 256;
-
-    [Range(1, 1024)]
-    public int MediumHeight { get; set; } = 256;
-
-    [Range(1, 1024)]
-    public int LargeWidth { get; set; } = 512;
-
-    [Range(1, 1024)]
-    public int LargeHeight { get; set; } = 512;
-
-    public ImageSizes ToImageSizes(PictureRoutes routes) => new(
-        new ImageSize(routes.FolderPath(PictureSize.Small), SmallWidth, SmallHeight),
-        new ImageSize(routes.FolderPath(PictureSize.Medium), MediumWidth, MediumHeight),
-        new ImageSize(routes.FolderPath(PictureSize.Large), LargeWidth, LargeHeight));
-}
-
-public interface IPictureOwnerConfiguration
-{
-    public PictureRoutes Routes { get; }
-
-    public PictureSizes PicturesSizes { get; }
-}
-
-public static class PictureSizeParser
-{
-    /// <summary>Parses the <c>size</c> query value; anything unknown means <see cref="PictureSize.Medium"/>.</summary>
-    public static PictureSize Parse(string? value) =>
-        Enum.TryParse<PictureSize>(value, ignoreCase: true, out var size) && Enum.IsDefined(size)
-            ? size
-            : PictureSize.Medium;
-}

backend/Core/Musify.Application/Configuration/PlayListConfiguration.cs

@@ -1,14 +1,79 @@
 using System.ComponentModel.DataAnnotations;
+using Musify.Application.Shared;
 
-namespace Musify.Application.Configuration;
-
-public class PlayListConfiguration : IConfigurationOptions, IPictureOwnerConfiguration
+namespace Musify.Application.Configuration
 {
-    public static string SectionName => "PlayList";
+    public class PlayListConfiguration
+    {
+        public const string SectionName = "PlayList";
 
-    [Required]
-    public PictureRoutes Routes { get; set; } = new() { ParentFolder = "PlayLists" };
+        [Required]
+        public PlayListRoutes Routes { get; set; } = new PlayListRoutes();
 
-    [Required]
-    public PictureSizes PicturesSizes { get; set; } = new();
-}
+        [Required]
+        public PlayListPicturesSizes PicturesSizes { get; set; } = new PlayListPicturesSizes();
+    }
+
+    public class PlayListRoutes
+    {
+        [Required]
+        public string UploadsFolder { get; set; } = "uploads";
+
+        [Required]
+        public string ParentFolders { get; set; } = "PlayLists";
+
+        [Required]
+        public string OriginalPicturesFolder { get; set; } = "OriginalPictures";
+
+        [Required]
+        public string SmallPicturesFolder { get; set; } = "SmallPictures";
+
+        [Required]
+        public string MediumPicturesFolder { get; set; } = "MediumPictures";
+
+        [Required]
+        public string LargePicturesFolder { get; set; } = "LargePictures";
+
+        public string SmallPicturesPath => StorageKey.Combine(ParentFolders, SmallPicturesFolder);
+
+        public string MediumPicturesPath => StorageKey.Combine(ParentFolders, MediumPicturesFolder);
+
+        public string LargePicturesPath => StorageKey.Combine(ParentFolders, LargePicturesFolder);
+
+        public string OriginalPicturesPath => StorageKey.Combine(ParentFolders, OriginalPicturesFolder);
+
+        public string BuildOriginalPicturePath(string pictureName) => StorageKey.Combine(ParentFolders, OriginalPicturesFolder, pictureName);
+
+        public string BuildOriginalPicturePath(long userId, string pictureName) => StorageKey.Combine(UploadsFolder, userId.ToString(), ParentFolders, OriginalPicturesFolder, pictureName);
+
+        public string BuildSmallPicturePath(string pictureName) => StorageKey.Combine(ParentFolders, SmallPicturesFolder, pictureName);
+
+        public string BuildMediumPicturePath(string pictureName) => StorageKey.Combine(ParentFolders, MediumPicturesFolder, pictureName);
+
+        public string BuildLargePicturePath(string pictureName) => StorageKey.Combine(ParentFolders, LargePicturesFolder, pictureName);
+
+        public string BuildTempPicturePath(string tempRootPrefix, long userId, string objectName) =>
+            StorageKey.Combine(tempRootPrefix, userId.ToString(), ParentFolders, objectName);
+    }
+
+    public class PlayListPicturesSizes
+    {
+        [Range(1, 1024)]
+        public int SmallPictureWidth { get; set; } = 128;
+
+        [Range(1, 1024)]
+        public int SmallPictureHeight { get; set; } = 128;
+
+        [Range(1, 1024)]
+        public int MediumPictureWidth { get; set; } = 256;
+
+        [Range(1, 1024)]
+        public int MediumPictureHeight { get; set; } = 256;
+
+        [Range(1, 1024)]
+        public int LargePictureWidth { get; set; } = 512;
+
+        [Range(1, 1024)]
+        public int LargePictureHeight { get; set; } = 512;
+    }
+}

backend/Core/Musify.Application/Configuration/PlaybackConfiguration.cs

@@ -1,17 +1,18 @@
 using System.ComponentModel.DataAnnotations;
 
-namespace Musify.Application.Configuration;
-
-
-public sealed class PlaybackConfiguration : IConfigurationOptions
+namespace Musify.Application.Configuration
 {
-    public static string SectionName => "Playback";
 
-    public bool AllowAnonymousListening { get; set; }
+    public sealed class PlaybackConfiguration
+    {
+        public const string SectionName = "Playback";
 
-    [Range(0, 3600)]
-    public int AnonymousFragmentSeconds { get; set; }
+        public bool AllowAnonymousListening { get; set; }
 
-    [Range(1, int.MaxValue)]
-    public int EstimatedAudioBytesPerSecond { get; set; } = 16_000;
+        [Range(0, 3600)]
+        public int AnonymousFragmentSeconds { get; set; }
+
+        [Range(1, int.MaxValue)]
+        public int EstimatedAudioBytesPerSecond { get; set; } = 16_000;
+    }
 }

backend/Core/Musify.Application/Configuration/Responses/PlaybackPublicConfigResponse.cs

@@ -1,4 +1,5 @@
-namespace Musify.Application.Configuration.Responses;
+namespace Musify.Application.Configuration.Responses
+{
 
-
-public record PlaybackPublicConfigResponse(bool AllowAnonymousListening, int AnonymousFragmentSeconds);
+    public record PlaybackPublicConfigResponse(bool AllowAnonymousListening, int AnonymousFragmentSeconds);
+}

backend/Core/Musify.Application/Configuration/StreamGatewayConfiguration.cs

@@ -1,15 +1,16 @@
 using System.ComponentModel.DataAnnotations;
 
-namespace Musify.Application.Configuration;
-
-public class StreamGatewayConfiguration : IConfigurationOptions
+namespace Musify.Application.Configuration
 {
-    public static string SectionName => "StreamGateway";
+    public class StreamGatewayConfiguration
+    {
+        public const string SectionName = "StreamGateway";
 
-    [Url]
-    [Required]
-    public required string PublicBaseUrl { get; set; }
+        [Url]
+        [Required]
+        public required string PublicBaseUrl { get; set; }
 
-    [Required]
-    public string AudioFileName { get; set; } = "audio.m4a";
+        [Required]
+        public string AudioFileName { get; set; } = "audio.m4a";
+    }
 }

backend/Core/Musify.Application/Configuration/TrackConfiguration.cs

@@ -1,55 +1,116 @@
 using System.ComponentModel.DataAnnotations;
 using Musify.Application.Shared;
 
-namespace Musify.Application.Configuration;
-
-public class TrackConfiguration : IConfigurationOptions, IPictureOwnerConfiguration
+namespace Musify.Application.Configuration
 {
-    public static string SectionName => "Track";
-
-    [Required]
-    public TrackRoutes Routes { get; set; } = new();
-
-    [Required]
-    public PictureSizes PicturesSizes { get; set; } = new();
-
-    PictureRoutes IPictureOwnerConfiguration.Routes => Routes;
-}
-
-public class TrackRoutes : PictureRoutes
-{
-    public TrackRoutes()
+    public class TrackConfiguration
     {
-        ParentFolder = "Tracks";
+        public const string SectionName = "Track";
+
+        [Required]
+        public TrackRoutes Routes { get; set; } = new TrackRoutes();
+
+        [Required]
+        public TrackPicturesSizes PicturesSizes { get; set; } = new TrackPicturesSizes();
     }
 
-    [Required]
-    public string PresetOriginalPicture { get; set; } = "PresetOriginalPicture.webp";
+    public class TrackRoutes
+    {
+        [Required]
+        public string UploadsFolder { get; set; } = "uploads";
 
-    [Required]
-    public string PresetSmallPicture { get; set; } = "PresetSmallPicture.webp";
+        [Required]
+        public string ParentFolder { get; set; } = "Tracks";
 
-    [Required]
-    public string PresetMediumPicture { get; set; } = "PresetMediumPicture.webp";
+        [Required]
+        public string OriginalPicturesFolder { get; set; } = "OriginalPictures";
 
-    [Required]
-    public string PresetLargePicture { get; set; } = "PresetLargePicture.webp";
+        [Required]
+        public string SmallPicturesFolder { get; set; } = "SmallPictures";
 
-    [Required]
-    public string OriginalAudiosFolder { get; set; } = "OriginalAudios";
+        [Required]
+        public string MediumPicturesFolder { get; set; } = "MediumPictures";
 
-    [Required]
-    public string ProcessedAudiosFolder { get; set; } = "ProcessedAudios";
+        [Required]
+        public string LargePicturesFolder { get; set; } = "LargePictures";
 
-    public string PresetSmallPicturePath => StorageKey.Combine(ParentFolder, PresetSmallPicture);
+        [Required]
+        public string PresetOriginalPicture { get; set; } = "PresetOriginalPicture.webp";
 
-    public string PresetMediumPicturePath => StorageKey.Combine(ParentFolder, PresetMediumPicture);
+        [Required]
+        public string PresetSmallPicture { get; set; } = "PresetSmallPicture.webp";
 
-    public string PresetLargePicturePath => StorageKey.Combine(ParentFolder, PresetLargePicture);
+        [Required]
+        public string PresetMediumPicture { get; set; } = "PresetMediumPicture.webp";
 
-    public string BuildOriginalAudioPath(long userId, string audioName) =>
-        StorageKey.Combine(UploadsFolder, userId.ToString(), ParentFolder, OriginalAudiosFolder, audioName);
+        [Required]
+        public string PresetLargePicture { get; set; } = "PresetLargePicture.webp";
 
-    public string BuildProcessedAudioPath(string folderName) =>
-        StorageKey.Combine(ParentFolder, ProcessedAudiosFolder, folderName);
-}
+        [Required]
+        public string OriginalAudiosFolder { get; set; } = "OriginalAudios";
+
+        [Required]
+        public string ProcessedAudioFolder { get; set; } = "ProcessedAudios";
+
+        public string SmallPicturesPath => StorageKey.Combine(ParentFolder, SmallPicturesFolder);
+
+        public string MediumPicturesPath => StorageKey.Combine(ParentFolder, MediumPicturesFolder);
+
+        public string LargePicturesPath => StorageKey.Combine(ParentFolder, LargePicturesFolder);
+
+        public string PresetSmallPicturePath => StorageKey.Combine(ParentFolder, PresetSmallPicture);
+
+        public string PresetMediumPicturePath => StorageKey.Combine(ParentFolder, PresetMediumPicture);
+
+        public string PresetLargePicturePath => StorageKey.Combine(ParentFolder, PresetLargePicture);
+
+        public string OriginalPicturesPath => StorageKey.Combine(ParentFolder, OriginalPicturesFolder);
+
+        public string OriginalAudiosPath => StorageKey.Combine(ParentFolder, OriginalAudiosFolder);
+
+        public string ProcessedAudiosPath => StorageKey.Combine(ParentFolder, ProcessedAudioFolder);
+
+        public string BuildOriginalPicturePath(string pictureName) => StorageKey.Combine(OriginalPicturesPath, pictureName);
+
+        public string BuildOriginalPicturePath(long userId, string pictureName) => StorageKey.Combine(UploadsFolder, userId.ToString(), OriginalPicturesPath, pictureName);
+
+        public string BuildSmallPicturePath(string pictureName) => StorageKey.Combine(SmallPicturesPath, pictureName);
+
+        public string BuildMediumPicturePath(string pictureName) => StorageKey.Combine(MediumPicturesPath, pictureName);
+
+        public string BuildLargePicturePath(string pictureName) => StorageKey.Combine(LargePicturesPath, pictureName);
+
+        public string BuildOriginalAudioPath(string audioName) => StorageKey.Combine(OriginalAudiosPath, audioName);
+
+        public string BuildOriginalAudioPath(long userId, string audioName) => StorageKey.Combine(UploadsFolder, userId.ToString(), OriginalAudiosPath, audioName);
+
+        public string BuildProcessedAudioPath(string audioName) => StorageKey.Combine(ProcessedAudiosPath, audioName);
+
+        public string BuildTempPicturePath(string tempRootPrefix, long userId, string objectName) =>
+            StorageKey.Combine(tempRootPrefix, userId.ToString(), ParentFolder, objectName);
+
+        public string BuildTempAudioPath(string tempRootPrefix, long userId, string objectName) =>
+            StorageKey.Combine(tempRootPrefix, userId.ToString(), ParentFolder, objectName);
+    }
+
+    public class TrackPicturesSizes
+    {
+        [Range(1, 1024)]
+        public int SmallPictureWidth { get; set; } = 128;
+
+        [Range(1, 1024)]
+        public int SmallPictureHeight { get; set; } = 128;
+
+        [Range(1, 1024)]
+        public int MediumPictureWidth { get; set; } = 256;
+
+        [Range(1, 1024)]
+        public int MediumPictureHeight { get; set; } = 256;
+
+        [Range(1, 1024)]
+        public int LargePictureWidth { get; set; } = 512;
+
+        [Range(1, 1024)]
+        public int LargePictureHeight { get; set; } = 512;
+    }
+}

backend/Core/Musify.Application/Configuration/UploadIntentConfiguration.cs

@@ -1,41 +1,42 @@
 using System.ComponentModel.DataAnnotations;
 
-namespace Musify.Application.Configuration;
-
-public class UploadIntentConfiguration : IConfigurationOptions
+namespace Musify.Application.Configuration
 {
-    public static string SectionName => "UploadIntent";
+    public class UploadIntentConfiguration
+    {
+        public const string SectionName = "UploadIntent";
 
-    [Range(10, 3600)]
-    public int UploadUrlExpiresInSeconds { get; set; } = 120;
+        [Range(10, 3600)]
+        public int UploadUrlExpiresInSeconds { get; set; } = 120;
 
-    [Range(1, 100)]
-    public int MaxActiveUploadIntentsPerUser { get; set; } = 5;
+        [Range(1, 100)]
+        public int MaxActiveUploadIntentsPerUser { get; set; } = 5;
 
-    [Range(1, long.MaxValue)]
-    public long MaxActiveUploadBytesPerUser { get; set; } = 200L * 1024 * 1024;
+        [Range(1, long.MaxValue)]
+        public long MaxActiveUploadBytesPerUser { get; set; } = 200L * 1024 * 1024;
 
-    [Range(1, long.MaxValue)]
-    public long MaxUploadBytes { get; set; } = 100L * 1024 * 1024;
+        [Range(1, long.MaxValue)]
+        public long MaxUploadBytes { get; set; } = 100L * 1024 * 1024;
 
-    [Range(1, long.MaxValue)]
-    public long DefaultExpectedPictureSizeBytes { get; set; } = 10L * 1024 * 1024;
+        [Range(1, long.MaxValue)]
+        public long DefaultExpectedPictureSizeBytes { get; set; } = 10L * 1024 * 1024;
 
-    [Range(1, long.MaxValue)]
-    public long DefaultExpectedAudioSizeBytes { get; set; } = 100L * 1024 * 1024;
+        [Range(1, long.MaxValue)]
+        public long DefaultExpectedAudioSizeBytes { get; set; } = 100L * 1024 * 1024;
 
-    [Range(30, 86400)]
-    public int ExpirationJobIntervalSeconds { get; set; } = 300;
+        [Range(30, 86400)]
+        public int ExpirationJobIntervalSeconds { get; set; } = 300;
 
-    [Range(0, 365)]
-    public int ExpiredIntentsRetentionDays { get; set; } = 7;
+        [Range(0, 365)]
+        public int ExpiredIntentsRetentionDays { get; set; } = 7;
 
-    [Required, MinLength(1)]
-    public string TempRootPrefix { get; set; } = "temp";
+        [Required, MinLength(1)]
+        public string TemporalRootPrefix { get; set; } = "temporal";
 
-    [Range(1, 30)]
-    public int TempUploadsRetentionDays { get; set; } = 3;
+        [Range(1, 30)]
+        public int TemporalUploadsRetentionDays { get; set; } = 3;
 
-    [Range(60, 86400)]
-    public int TempCleanupJobIntervalSeconds { get; set; } = 3600;
+        [Range(60, 86400)]
+        public int TemporalCleanUpJobIntervalSeconds { get; set; } = 3600;
+    }
 }

backend/Core/Musify.Application/Contracts/AudioTranscodeResult.cs

@@ -1,3 +1,4 @@
-namespace Musify.Application.Contracts;
-
-public record AudioTranscodeResult(int StatusCode, TimeSpan Duration);
+namespace Musify.Application.Contracts
+{
+    public record AudioTranscodeResult(int StatusCode, TimeSpan Duration);
+}

backend/Core/Musify.Application/Contracts/IAudioTranscoderService.cs

@@ -1,6 +1,9 @@
-namespace Musify.Application.Contracts;
-
-public interface IAudioTranscoderService
+namespace Musify.Application.Contracts
 {
-    public Task<AudioTranscodeResult> TranscodeToAudioFileAsync(Stream audioStream, string destinationPath, CancellationToken cancellationToken);
-}
+    public interface IAudioTranscoderService
+    {
+        Task<AudioTranscodeResult> TranscodeToAudioFileAsync(Stream audioStream, string destinationPath, CancellationToken cancellationToken);
+
+        Task<bool> IsValidAudioFileAsync(string filePath, CancellationToken cancellationToken);
+    }
+}

backend/Core/Musify.Application/Contracts/IDatabase.cs

@@ -1,40 +1,42 @@
-using ErrorOr;
 using Microsoft.EntityFrameworkCore;
 using Musify.Domain.Entities;
 
-namespace Musify.Application.Contracts;
-
-public interface IDatabase
+namespace Musify.Application.Contracts
 {
-    public DbSet<User> Users { get; }
+    public interface IDatabase
+    {
+        DbSet<User> Users { get; }
 
-    public DbSet<PlayList> PlayLists { get; }
+        DbSet<PlayList> PlayLists { get; }
 
-    public DbSet<Album> Albums { get; }
+        DbSet<Album> Albums { get; }
 
-    public DbSet<AlbumHasTrack> AlbumHasTracks { get; }
+        DbSet<AlbumHasTrack> AlbumHasTracks { get; }
 
-    public DbSet<Track> Tracks { get; }
+        DbSet<Track> Tracks { get; }
 
-    public DbSet<PlayListHasTrack> PlayListHasTracks { get; }
+        DbSet<UserHasTrack> UserHasTracks { get; }
 
-    public DbSet<Mix> Mixes { get; }
+        DbSet<PlayListHasTrack> PlayListHasTracks { get; }
 
-    public DbSet<MixItem> MixItems { get; }
+        DbSet<Mix> Mixes { get; }
 
-    public DbSet<UploadIntent> UploadIntents { get; }
+        DbSet<MixItem> MixItems { get; }
 
-    public DbSet<ListeningHistory> ListeningHistories { get; }
+        DbSet<Upload> Uploads { get; }
 
-    public DbSet<TrackLike> TrackLikes { get; }
+        DbSet<UploadIntent> UploadIntents { get; }
 
-    public DbSet<TrackTag> TrackTags { get; }
+        DbSet<ListeningHistory> ListeningHistories { get; }
 
-    public DbSet<UserFollow> UserFollows { get; }
+        DbSet<TrackLike> TrackLikes { get; }
 
-    public Task<IDatabaseTransaction> BeginTransactionAsync(System.Data.IsolationLevel isolationLevel, CancellationToken cancellationToken);
+        DbSet<TrackTag> TrackTags { get; }
 
-    public Task<int> SaveChangesAsync(CancellationToken cancellationToken);
+        DbSet<UserFollow> UserFollows { get; }
 
-    public Task<ErrorOr<Success>> TrySaveChangesAsync(Error onUniqueViolation, CancellationToken cancellationToken);
-}
+        Task<IDatabaseTransaction> BeginTransactionAsync(System.Data.IsolationLevel isolationLevel, CancellationToken cancellationToken);
+
+        Task<int> SaveChangesAsync(CancellationToken cancellationToken);
+    }
+}

backend/Core/Musify.Application/Contracts/IDatabaseTransaction.cs

@@ -1,6 +1,7 @@
-namespace Musify.Application.Contracts;
-
-public interface IDatabaseTransaction : IAsyncDisposable
+namespace Musify.Application.Contracts
 {
-    public Task CommitAsync(CancellationToken cancellationToken = default);
+    public interface IDatabaseTransaction : IAsyncDisposable
+    {
+        Task CommitAsync(CancellationToken cancellationToken = default);
+    }
 }

backend/Core/Musify.Application/Contracts/IEventBus.cs

@@ -1,6 +1,7 @@
-namespace Musify.Application.Contracts;
-
-public interface IEventBus
+namespace Musify.Application.Contracts
 {
-    public Task PublishAsync<T>(T message, CancellationToken cancellationToken) where T : class;
-}
+    public interface IEventBus
+    {
+        Task PublishAsync<T>(T message, CancellationToken cancellationToken) where T : class;
+    }
+}

backend/Core/Musify.Application/Contracts/IPictureService.cs

@@ -1,6 +1,7 @@
-namespace Musify.Application.Contracts;
-
-public interface IPictureService
+namespace Musify.Application.Contracts
 {
-    public Task<Stream> ResizePictureAsWebpAsync(Stream pictureStream, int width, int height, CancellationToken cancellationToken);
-}
+    public interface IPictureService
+    {
+        Task<Stream> ResizePictureAsWebpAsync(Stream pictureStream, int width, int height, CancellationToken cancellationToken);
+    }
+}

backend/Core/Musify.Application/Contracts/IStorageService.cs

@@ -1,24 +1,28 @@
-namespace Musify.Application.Contracts;
-
-public interface IStorageService
+namespace Musify.Application.Contracts
 {
-    /// <summary>Opens an object for reading, or returns null when it does not exist.</summary>
-    public Task<Stream?> GetFileAsync(string bucket, string key, CancellationToken cancellationToken);
+    public interface IStorageService
+    {
+        Task<Stream> GetFileAsync(string bucket, string key, CancellationToken cancellationToken);
 
-    public Task<ObjectMetaData?> HeadObjectAsync(string bucket, string key, CancellationToken cancellationToken);
+        Task<ObjectMetaData?> HeadObjectAsync(string bucket, string key, CancellationToken cancellationToken);
 
-    public Task<string> GetUploadUrlAsync(string bucket, string key, string contentType, TimeSpan expirationTime, bool preventOverwrite = true, CancellationToken cancellationToken = default);
+        Task<string> GetUrlAsync(string bucket, string key, TimeSpan ExpirationTime, CancellationToken cancellationToken);
 
-    public Task UploadFileAsync(string filePath, string bucket, string key, CancellationToken cancellationToken);
+        Task<string> GetUploadUrlAsync(string bucket, string key, string contentType, TimeSpan expirationTime, CancellationToken cancellationToken, bool preventOverwrite = true);
 
-    public Task UploadFileAsync(Stream sourceStream, string contentType, string bucket, string key, CancellationToken cancellationToken);
+        Task UploadFileAsync(string filePath, string bucket, string key, CancellationToken cancellationToken);
 
-    public Task<IReadOnlyList<string>> TransferFilesAsync(string sourceDirectory, string bucket, string route, CancellationToken cancellationToken);
+        Task UploadFileAsync(Stream sourceStream, string contentType, string bucket, string key, CancellationToken cancellationToken);
 
-    public Task RemoveFileAsync(string bucket, string key, CancellationToken cancellationToken);
+        Task<IReadOnlyList<string>> TransferFilesAsync(string sourceDirectory, string bucket, string route, CancellationToken cancellationToken);
 
-    public Task CopyFileAsync(string sourceBucket, string sourceKey, string destinationBucket, string destinationKey,
-        CancellationToken cancellationToken);
+        Task RemoveFileAsync(string bucket, string key, CancellationToken cancellationToken);
 
-    public IAsyncEnumerable<StorageObject> ListObjectsAsync(string bucket, string prefix, CancellationToken cancellationToken);
-}
+        Task CopyFileAsync(string sourceBucket, string sourceKey, string destinationBucket, string destinationKey,
+            CancellationToken cancellationToken);
+
+        Task RemoveFolderAsync(string bucket, string folderKey, CancellationToken cancellationToken);
+        
+        IAsyncEnumerable<StorageObject> ListObjectsAsync(string bucket, string prefix, CancellationToken cancellationToken);
+    }
+}

backend/Core/Musify.Application/Contracts/IStreamTicketService.cs

@@ -1,8 +1,10 @@
-namespace Musify.Application.Contracts;
-
-public interface IStreamTicketService
+namespace Musify.Application.Contracts
 {
-    public StreamTicket IssueTicket(long? userId, string keyPrefix, long? maxBytes = null);
-}
+    public interface IStreamTicketService
+    {
 
-public record StreamTicket(string Token, int ExpiresInSeconds);
+        StreamTicket IssueTicket(long? userId, string keyPrefix, long? maxBytes = null);
+    }
+
+    public record StreamTicket(string Token, int ExpiresInSeconds);
+}

backend/Core/Musify.Application/Contracts/ObjectMetaData.cs

@@ -1,3 +1,4 @@
-namespace Musify.Application.Contracts;
-
-public record ObjectMetaData(string ContentType, long ContentLength);
+namespace Musify.Application.Contracts
+{
+    public record ObjectMetaData(string ContentType, long ContentLength);
+}

backend/Core/Musify.Application/Contracts/StorageObject.cs

@@ -1,3 +1,4 @@
-namespace Musify.Application.Contracts;
-
-public record StorageObject(string Key, DateTime LastModifiedUtc);
+namespace Musify.Application.Contracts
+{
+    public record StorageObject(string Key, DateTime LastModifiedUtc);
+}

backend/Core/Musify.Application/Events/AlbumPictureProcessed.cs

@@ -1,3 +1,4 @@
-namespace Musify.Application.Events;
-
-public record AlbumPictureProcessed(Guid AlbumId);
+namespace Musify.Application.Events
+{
+    public record AlbumPictureProcessed(Guid AlbumId);
+}

backend/Core/Musify.Application/Events/AlbumPictureProcessingFailed.cs

@@ -1,3 +1,4 @@
-namespace Musify.Application.Events;
-
-public record AlbumPictureProcessingFailed(Guid AlbumId);
+namespace Musify.Application.Events
+{
+    public record AlbumPictureProcessingFailed(Guid AlbumId);
+}

backend/Core/Musify.Application/Events/AlbumProcessingFailed.cs

@@ -1,6 +1,7 @@
-namespace Musify.Application.Events;
-
-public record AlbumProcessingFailed(
-    Guid AlbumId,
-    string? Bucket,
-    string? PictureKey);
+namespace Musify.Application.Events
+{
+    public record AlbumProcessingFailed(
+        Guid AlbumId,
+        string? Bucket,
+        string? PictureKey);
+}

backend/Core/Musify.Application/Events/CreateAlbumResourcesEvent.cs

@@ -1,11 +1,14 @@
 using Musify.Application.Shared;
 
-namespace Musify.Application.Events;
-
-public record CreateAlbumResourcesEvent(
-    Guid AlbumId,
-    Guid PictureIntentId,
-    string Bucket,
-    string PictureSourceKey,
-    string PictureDestinationKey,
-    ImageSizes Sizes);
+namespace Musify.Application.Events
+{
+    public record CreateAlbumResourcesEvent(
+        Guid AlbumId,
+        Guid PictureIntentId,
+        string Bucket,
+        string PictureSourceKey,
+        string PictureDestinationKey,
+        ImageSize Small,
+        ImageSize Medium,
+        ImageSize Large);
+}

backend/Core/Musify.Application/Events/CreatePlayListResourcesEvent.cs

@@ -1,11 +1,14 @@
 using Musify.Application.Shared;
 
-namespace Musify.Application.Events;
-
-public record CreatePlayListResourcesEvent(
-    Guid PlayListId,
-    Guid PictureIntentId,
-    string Bucket,
-    string PictureSourceKey,
-    string PictureDestinationKey,
-    ImageSizes Sizes);
+namespace Musify.Application.Events
+{
+    public record CreatePlayListResourcesEvent(
+        Guid PlayListId,
+        Guid PictureIntentId,
+        string Bucket,
+        string PictureSourceKey,
+        string PictureDestinationKey,
+        ImageSize Small,
+        ImageSize Medium,
+        ImageSize Large);
+}

backend/Core/Musify.Application/Events/CreateTrackResourcesEvent.cs

@@ -1,15 +1,18 @@
 using Musify.Application.Shared;
 
-namespace Musify.Application.Events;
-
-public record CreateTrackResourcesEvent(
-    Guid TrackId,
-    Guid PictureIntentId,
-    Guid AudioIntentId,
-    string Bucket,
-    string PictureSourceKey,
-    string PictureDestinationKey,
-    string AudioSourceKey,
-    string AudioDestinationKey,
-    string AudioProcessedFolderKey,
-    ImageSizes Sizes);
+namespace Musify.Application.Events
+{
+    public record CreateTrackResourcesEvent(
+        Guid TrackId,
+        Guid PictureIntentId,
+        Guid AudioIntentId,
+        string Bucket,
+        string PictureSourceKey,
+        string PictureDestinationKey,
+        string AudioSourceKey,
+        string AudioDestinationKey,
+        string AudioProcessedFolderKey,
+        ImageSize Small,
+        ImageSize Medium,
+        ImageSize Large);
+}

backend/Core/Musify.Application/Events/DeleteAlbumEvent.cs

@@ -1,5 +0,0 @@
-namespace Musify.Application.Events;
-
-public record DeleteAlbumEvent(
-    Guid AlbumId,
-    long UserId);

backend/Core/Musify.Application/Events/DeletePlayListEvent.cs

@@ -1,5 +1,6 @@
-namespace Musify.Application.Events;
-
-public record DeletePlayListEvent(
-    Guid PlayListId,
-    long UserId);
+namespace Musify.Application.Events
+{
+    public record DeletePlayListEvent(
+        Guid PlayListId,
+        long UserId);
+}

backend/Core/Musify.Application/Events/DeleteTrackEvent.cs

@@ -1,5 +1,6 @@
-namespace Musify.Application.Events;
-
-public record DeleteTrackEvent(
-    Guid TrackId,
-    long UserId);
+namespace Musify.Application.Events
+{
+    public record DeleteTrackEvent(
+        Guid TrackId,
+        long UserId);
+}

backend/Core/Musify.Application/Events/PlayListPictureProcessed.cs

@@ -1,3 +1,4 @@
-namespace Musify.Application.Events;
-
-public record PlayListPictureProcessed(Guid PlayListId);
+namespace Musify.Application.Events
+{
+    public record PlayListPictureProcessed(Guid PlayListId);
+}

backend/Core/Musify.Application/Events/PlayListPictureProcessingFailed.cs

@@ -1,3 +1,4 @@
-namespace Musify.Application.Events;
-
-public record PlayListPictureProcessingFailed(Guid PlayListId);
+namespace Musify.Application.Events
+{
+    public record PlayListPictureProcessingFailed(Guid PlayListId);
+}

backend/Core/Musify.Application/Events/PlayListProcessingFailed.cs

@@ -1,6 +1,7 @@
-namespace Musify.Application.Events;
-
-public record PlayListProcessingFailed(
-    Guid PlayListId,
-    string? Bucket,
-    string? PictureKey);
+namespace Musify.Application.Events
+{
+    public record PlayListProcessingFailed(
+        Guid PlayListId,
+        string? Bucket,
+        string? PictureKey);
+}

backend/Core/Musify.Application/Events/TrackAudioProcessed.cs

@@ -1,3 +1,4 @@
-namespace Musify.Application.Events;
-
-public record TrackAudioProcessed(Guid TrackId);
+namespace Musify.Application.Events
+{
+    public record TrackAudioProcessed(Guid TrackId);
+}

backend/Core/Musify.Application/Events/TrackAudioProcessingFailed.cs

@@ -1,3 +1,4 @@
-namespace Musify.Application.Events;
-
-public record TrackAudioProcessingFailed(Guid TrackId);
+namespace Musify.Application.Events
+{
+    public record TrackAudioProcessingFailed(Guid TrackId);
+}

backend/Core/Musify.Application/Events/TrackPictureProcessed.cs

@@ -1,3 +1,4 @@
-namespace Musify.Application.Events;
-
-public record TrackPictureProcessed(Guid TrackId);
+namespace Musify.Application.Events
+{
+    public record TrackPictureProcessed(Guid TrackId);
+}

backend/Core/Musify.Application/Events/TrackPictureProcessingFailed.cs

@@ -1,3 +1,4 @@
-namespace Musify.Application.Events;
-
-public record TrackPictureProcessingFailed(Guid TrackId);
+namespace Musify.Application.Events
+{
+    public record TrackPictureProcessingFailed(Guid TrackId);
+}

backend/Core/Musify.Application/Events/TrackProcessingFailed.cs

@@ -1,7 +1,8 @@
-namespace Musify.Application.Events;
-
-public record TrackProcessingFailed(
-    Guid TrackId,
-    string? Bucket,
-    string? PictureKey,
-    string? AudioKey);
+namespace Musify.Application.Events
+{
+    public record TrackProcessingFailed(
+        Guid TrackId,
+        string? Bucket,
+        string? PictureKey,
+        string? AudioKey);
+}

backend/Core/Musify.Application/Events/UpdateAlbumPictureEvent.cs

@@ -1,9 +1,12 @@
 using Musify.Application.Shared;
 
-namespace Musify.Application.Events;
-
-public record UpdateAlbumPictureEvent(
-    Guid AlbumId,
-    string Bucket,
-    string SourceKey,
-    ImageSizes Sizes);
+namespace Musify.Application.Events
+{
+    public record UpdateAlbumPictureEvent(
+        Guid AlbumId,
+        string Bucket,
+        string SourceKey,
+        ImageSize Small,
+        ImageSize Medium,
+        ImageSize Large);
+}

backend/Core/Musify.Application/Events/UpdateAlbumPictureSourceEvent.cs

@@ -1,11 +1,14 @@
 using Musify.Application.Shared;
 
-namespace Musify.Application.Events;
-
-public record UpdateAlbumPictureSourceEvent(
-    Guid AlbumId,
-    Guid PictureIntentId,
-    string Bucket,
-    string PictureSourceKey,
-    string PictureDestinationKey,
-    ImageSizes Sizes);
+namespace Musify.Application.Events
+{
+    public record UpdateAlbumPictureSourceEvent(
+        Guid AlbumId,
+        Guid PictureIntentId,
+        string Bucket,
+        string PictureSourceKey,
+        string PictureDestinationKey,
+        ImageSize Small,
+        ImageSize Medium,
+        ImageSize Large);
+}

backend/Core/Musify.Application/Events/UpdatePlayListPictureEvent.cs

@@ -1,9 +1,12 @@
 using Musify.Application.Shared;
 
-namespace Musify.Application.Events;
-
-public record UpdatePlayListPictureEvent(
-    Guid PlayListId,
-    string Bucket,
-    string SourceKey,
-    ImageSizes Sizes);
+namespace Musify.Application.Events
+{
+    public record UpdatePlayListPictureEvent(
+        Guid PlayListId,
+        string Bucket,
+        string SourceKey,
+        ImageSize Small,
+        ImageSize Medium,
+        ImageSize Large);
+}

backend/Core/Musify.Application/Events/UpdatePlayListPictureSourceEvent.cs

@@ -1,11 +1,14 @@
 using Musify.Application.Shared;
 
-namespace Musify.Application.Events;
-
-public record UpdatePlayListPictureSourceEvent(
-    Guid PlayListId,
-    Guid PictureIntentId,
-    string Bucket,
-    string PictureSourceKey,
-    string PictureDestinationKey,
-    ImageSizes Sizes);
+namespace Musify.Application.Events
+{
+    public record UpdatePlayListPictureSourceEvent(
+        Guid PlayListId,
+        Guid PictureIntentId,
+        string Bucket,
+        string PictureSourceKey,
+        string PictureDestinationKey,
+        ImageSize Small,
+        ImageSize Medium,
+        ImageSize Large);
+}

backend/Core/Musify.Application/Events/UpdateTrackAudioEvent.cs

@@ -1,8 +1,9 @@
-namespace Musify.Application.Events;
-
-public record UpdateTrackAudioEvent(
-    Guid TrackId,
-    string SourceBucket,
-    string SourceKey,
-    string DestinationBucket,
-    string DestinationFolderKey);
+namespace Musify.Application.Events
+{
+    public record UpdateTrackAudioEvent(
+        Guid TrackId,
+        string SourceBucket,
+        string SourceKey,
+        string DestinationBucket,
+        string DestinationFolderKey);
+}

backend/Core/Musify.Application/Events/UpdateTrackPictureEvent.cs

@@ -1,9 +1,12 @@
 using Musify.Application.Shared;
 
-namespace Musify.Application.Events;
-
-public record UpdateTrackPictureEvent(
-    Guid TrackId,
-    string Bucket,
-    string SourceKey,
-    ImageSizes Sizes);
+namespace Musify.Application.Events
+{
+    public record UpdateTrackPictureEvent(
+        Guid TrackId,
+        string Bucket,
+        string SourceKey,
+        ImageSize Small,
+        ImageSize Medium,
+        ImageSize Large);
+}

backend/Core/Musify.Application/Genres/GetAvailableGenres.cs

@@ -1,24 +1,26 @@
 using Mediator;
 using Musify.Domain.ValueObjects;
-using Musify.Application.Genres.Responses;
 
-namespace Musify.Application.Genres;
-
-public record GetAvailableGenresQuery : IQuery<IReadOnlyList<AvailableGenreResponse>>;
-
-public class GetAvailableGenresQueryHandler
-    : IQueryHandler<GetAvailableGenresQuery, IReadOnlyList<AvailableGenreResponse>>
+namespace Musify.Application.Genres
 {
-    public ValueTask<IReadOnlyList<AvailableGenreResponse>> Handle(GetAvailableGenresQuery request, CancellationToken cancellationToken)
+    public record GetAvailableGenresQuery : IQuery<IReadOnlyList<AvailableGenreResponse>>;
+
+    public record AvailableGenreResponse(Genre Genre, IReadOnlyList<Genre> IncompatibleWith);
+
+    public class GetAvailableGenresQueryHandler
+        : IQueryHandler<GetAvailableGenresQuery, IReadOnlyList<AvailableGenreResponse>>
     {
-        var all = Enum.GetValues<Genre>();
+        public ValueTask<IReadOnlyList<AvailableGenreResponse>> Handle(GetAvailableGenresQuery request, CancellationToken cancellationToken)
+        {
+            var all = Enum.GetValues<Genre>();
 
-        IReadOnlyList<AvailableGenreResponse> result = all
-            .Select(genre => new AvailableGenreResponse(
-                genre,
-                all.Where(other => !GenreCompatibility.AreCompatible(genre, other)).ToList()))
-            .ToList();
+            IReadOnlyList<AvailableGenreResponse> result = all
+                .Select(genre => new AvailableGenreResponse(
+                    genre,
+                    all.Where(other => !GenreCompatibility.AreCompatible(genre, other)).ToList()))
+                .ToList();
 
-        return ValueTask.FromResult(result);
+            return ValueTask.FromResult(result);
+        }
     }
 }

backend/Core/Musify.Application/Genres/GetGenres.cs

@@ -2,28 +2,30 @@ using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Musify.Application.Contracts;
 using Musify.Domain.ValueObjects;
-using Musify.Application.Genres.Responses;
 
-namespace Musify.Application.Genres;
-
-public record GetGenresQuery : IQuery<IReadOnlyList<GenreResponse>>;
-
-public class GetGenresQueryHandler(IDatabase database)
-    : IQueryHandler<GetGenresQuery, IReadOnlyList<GenreResponse>>
+namespace Musify.Application.Genres
 {
-    public async ValueTask<IReadOnlyList<GenreResponse>> Handle(GetGenresQuery request, CancellationToken cancellationToken)
-    {
-        var rows = await database.TrackTags
-            .AsNoTracking()
-            .Where(tag => tag.Track.LifeCycleStatus == LifeCycleStatus.Active)
-            .GroupBy(tag => tag.Tag)
-            .Select(group => new { Genre = group.Key, TrackCount = group.Select(tag => tag.TrackId).Distinct().Count() })
-            .ToListAsync(cancellationToken);
+    public record GetGenresQuery : IQuery<IReadOnlyList<GenreResponse>>;
 
-        return rows
-            .OrderByDescending(row => row.TrackCount)
-            .ThenBy(row => row.Genre)
-            .Select(row => new GenreResponse(row.Genre, row.TrackCount))
-            .ToList();
+    public record GenreResponse(Genre Genre, int TrackCount);
+
+    public class GetGenresQueryHandler(IDatabase database)
+        : IQueryHandler<GetGenresQuery, IReadOnlyList<GenreResponse>>
+    {
+        public async ValueTask<IReadOnlyList<GenreResponse>> Handle(GetGenresQuery request, CancellationToken cancellationToken)
+        {
+            var rows = await database.TrackTags
+                .AsNoTracking()
+                .Where(tag => database.UserHasTracks.Any(userTrack => userTrack.TrackId == tag.TrackId))
+                .GroupBy(tag => tag.Tag)
+                .Select(group => new { Genre = group.Key, TrackCount = group.Select(tag => tag.TrackId).Distinct().Count() })
+                .ToListAsync(cancellationToken);
+
+            return rows
+                .OrderByDescending(row => row.TrackCount)
+                .ThenBy(row => row.Genre)
+                .Select(row => new GenreResponse(row.Genre, row.TrackCount))
+                .ToList();
+        }
     }
 }

backend/Core/Musify.Application/Genres/Responses/AvailableGenreResponse.cs

@@ -1,5 +0,0 @@
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Genres.Responses;
-
-public record AvailableGenreResponse(Genre Genre, IReadOnlyList<Genre> IncompatibleWith);

backend/Core/Musify.Application/Genres/Responses/GenreResponse.cs

@@ -1,5 +0,0 @@
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Genres.Responses;
-
-public record GenreResponse(Genre Genre, int TrackCount);

backend/Core/Musify.Application/Likes/GetLikedTracks.cs

@@ -1,30 +1,43 @@
+using ErrorOr;
 using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Musify.Application.Contracts;
 using Musify.Application.Shared;
 using Musify.Application.Tracks.Responses;
-using Musify.Domain.ValueObjects;
+using X.PagedList;
+using X.PagedList.EF;
 
-namespace Musify.Application.Likes;
-
-public record GetLikedTracksQuery(
-    long UserId,
-    int PageNumber,
-    int PageSize)
-    : IQuery<PaginatedResponse<TrackApplicationResponse>>;
-
-public class GetLikedTracksQueryHandler(IDatabase database)
-    : IQueryHandler<GetLikedTracksQuery, PaginatedResponse<TrackApplicationResponse>>
+namespace Musify.Application.Likes
 {
-    public async ValueTask<PaginatedResponse<TrackApplicationResponse>> Handle(GetLikedTracksQuery request, CancellationToken cancellationToken)
+    public record GetLikedTracksQuery(
+        long UserId,
+        int PageNumber,
+        int PageSize)
+        : IQuery<ErrorOr<PaginatedResponse<TrackApplicationResponse>>>;
+
+    public class GetLikedTracksQueryHandler(IDatabase database)
+        : IQueryHandler<GetLikedTracksQuery, ErrorOr<PaginatedResponse<TrackApplicationResponse>>>
     {
-        return await database.TrackLikes
-            .AsNoTracking()
-            .Where(like => like.UserId == request.UserId && like.Track.LifeCycleStatus == LifeCycleStatus.Active)
-            .OrderByDescending(like => like.CreatedAt)
-            .ThenBy(like => like.Id)
-            .Select(like => like.Track)
-            .SelectResponse()
-            .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
+        public async ValueTask<ErrorOr<PaginatedResponse<TrackApplicationResponse>>> Handle(GetLikedTracksQuery request, CancellationToken cancellationToken)
+        {
+            var likesQuery = database.TrackLikes
+                .AsNoTracking()
+                .Include(like => like.Track.Owner)
+                .Include(like => like.Track.Tags)
+                .Where(like => like.UserId == request.UserId);
+
+            var totalCount = await likesQuery.CountAsync(cancellationToken);
+
+            var pagedEntities = await likesQuery
+                .OrderByDescending(like => like.CreatedAt)
+                .Select(like => new { like.Track, ListensCount = like.Track.ListeningHistories.Count(l => l.IsCounted) })
+                .ToPagedListAsync(request.PageNumber, request.PageSize, totalCount, cancellationToken);
+
+            var pagedTracks = new StaticPagedList<TrackApplicationResponse>(
+                pagedEntities.Select(x => TrackApplicationResponse.FromEntity(x.Track, x.ListensCount)),
+                pagedEntities.PageNumber, pagedEntities.PageSize, pagedEntities.TotalItemCount);
+
+            return PaginatedResponse<TrackApplicationResponse>.FromPagedList(pagedTracks);
+        }
     }
 }

backend/Core/Musify.Application/Likes/ToggleTrackLike.cs

@@ -3,56 +3,54 @@ using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using Musify.Application.Contracts;
-using Musify.Application.Shared;
 using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
 
-namespace Musify.Application.Likes;
-
-public record ToggleTrackLikeCommand(long UserId, Guid TrackId)
-    : ICommand<ErrorOr<bool>>;
-
-public class ToggleTrackLikeCommandHandler(
-    IDatabase database,
-    ILogger<ToggleTrackLikeCommandHandler> logger)
-    : ICommandHandler<ToggleTrackLikeCommand, ErrorOr<bool>>
+namespace Musify.Application.Likes
 {
-    public async ValueTask<ErrorOr<bool>> Handle(ToggleTrackLikeCommand request, CancellationToken cancellationToken)
+    public record ToggleTrackLikeCommand(long UserId, Guid TrackId)
+        : ICommand<ErrorOr<bool>>;
+
+    public class ToggleTrackLikeCommandHandler(
+        IDatabase database,
+        ILogger<ToggleTrackLikeCommandHandler> logger)
+        : ICommandHandler<ToggleTrackLikeCommand, ErrorOr<bool>>
     {
-        var trackExists = await database.Tracks
-            .AsNoTracking()
-            .AnyAsync(t => t.Id == request.TrackId && t.LifeCycleStatus == LifeCycleStatus.Active, cancellationToken);
-        if (!trackExists)
-            return AppErrors.NotFound("Track", request.TrackId);
-
-        var existingLike = await database.TrackLikes
-            .SingleOrDefaultAsync(like => like.UserId == request.UserId && like.TrackId == request.TrackId, cancellationToken);
-
-        bool nowLiked;
-        if (existingLike != null)
+        public async ValueTask<ErrorOr<bool>> Handle(ToggleTrackLikeCommand request, CancellationToken cancellationToken)
         {
-            database.TrackLikes.Remove(existingLike);
-            nowLiked = false;
-        }
-        else
-        {
-            await database.TrackLikes.AddAsync(new TrackLike
+            var trackExists = await database.Tracks
+                .AsNoTracking()
+                .AnyAsync(t => t.Id == request.TrackId, cancellationToken);
+            if (!trackExists)
             {
-                UserId = request.UserId,
-                TrackId = request.TrackId
-            }, cancellationToken);
-            nowLiked = true;
+                logger.LogInformation("Track {TrackId} not found", request.TrackId);
+                return Error.NotFound(description: $"Track {request.TrackId} not found");
+            }
+
+            var existingLike = await database.TrackLikes
+                .SingleOrDefaultAsync(like => like.UserId == request.UserId && like.TrackId == request.TrackId, cancellationToken);
+
+            bool nowLiked;
+            if (existingLike != null)
+            {
+                database.TrackLikes.Remove(existingLike);
+                nowLiked = false;
+            }
+            else
+            {
+                await database.TrackLikes.AddAsync(new TrackLike
+                {
+                    UserId = request.UserId,
+                    TrackId = request.TrackId
+                }, cancellationToken);
+                nowLiked = true;
+            }
+
+            await database.SaveChangesAsync(cancellationToken);
+
+            logger.LogInformation("User {UserId} {Action} track {TrackId}",
+                request.UserId, nowLiked ? "liked" : "unliked", request.TrackId);
+
+            return nowLiked;
         }
-
-        // A concurrent double click can hit the unique index; the outcome is already in place, so treat it as a no-op.
-        var saved = await database.TrySaveChangesAsync(
-            AppErrors.Conflict("TrackLike.Duplicate", "Track is already liked."), cancellationToken);
-        if (saved.IsError)
-            return true;
-
-        logger.LogInformation("User {UserId} {Action} track {TrackId}",
-            request.UserId, nowLiked ? "liked" : "unliked", request.TrackId);
-
-        return nowLiked;
     }
 }

backend/Core/Musify.Application/Mixes/GenerateMixesForUser.cs

@@ -1,3 +1,4 @@
+using ErrorOr;
 using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
@@ -6,124 +7,146 @@ using Musify.Application.Contracts;
 using Musify.Domain.Entities;
 using Musify.Domain.ValueObjects;
 
-namespace Musify.Application.Mixes;
-
-public record GenerateMixesForUserCommand(long UserId)
-    : ICommand;
-
-public class GenerateMixesForUserCommandHandler(
-    IDatabase database,
-    MixConfiguration mixConfiguration,
-    ILogger<GenerateMixesForUserCommandHandler> logger)
-    : ICommandHandler<GenerateMixesForUserCommand>
+namespace Musify.Application.Mixes
 {
-    private sealed record MixDraft(MixKind Kind, IReadOnlyList<Guid> TrackIds);
+    public record GenerateMixesForUserCommand(long UserId)
+        : ICommand<ErrorOr<Success>>;
 
-    public async ValueTask<Unit> Handle(GenerateMixesForUserCommand request, CancellationToken cancellationToken)
+    public class GenerateMixesForUserCommandHandler(
+        IDatabase database,
+        MixConfiguration mixConfiguration,
+        ILogger<GenerateMixesForUserCommandHandler> logger)
+        : ICommandHandler<GenerateMixesForUserCommand, ErrorOr<Success>>
     {
-        var userId = request.UserId;
+        private sealed record MixDraft(string Title, string? Subtitle, IReadOnlyList<Guid> TrackIds);
 
-        var libraryTrackIds = await database.Tracks
-            .AsNoTracking()
-            .Where(track => track.OwnerUserId == userId && track.LifeCycleStatus == LifeCycleStatus.Active)
-            .Select(track => track.Id)
-            .ToListAsync(cancellationToken);
-
-        if (libraryTrackIds.Count == 0)
+        public async ValueTask<ErrorOr<Success>> Handle(GenerateMixesForUserCommand request, CancellationToken cancellationToken)
         {
-            logger.LogInformation("User {UserId} has no tracks yet, skipping mix generation", userId);
-            return Unit.Value;
-        }
+            var userId = request.UserId;
 
-        var historyTrackIds = await database.ListeningHistories
-            .AsNoTracking()
-            .Where(history => history.UserId == userId && history.IsCounted)
-            .Select(history => history.TrackId)
-            .Distinct()
-            .ToListAsync(cancellationToken);
+            var libraryTrackIds = await database.UserHasTracks
+                .AsNoTracking()
+                .Where(userTrack => userTrack.UserId == userId && userTrack.Track.LifeCycleStatus == LifeCycleStatus.Active)
+                .Select(userTrack => userTrack.TrackId)
+                .ToListAsync(cancellationToken);
 
-        var historySet = new HashSet<Guid>(historyTrackIds);
-        var unheardTrackIds = libraryTrackIds.Where(id => !historySet.Contains(id)).ToList();
-
-        var drafts = new List<MixDraft>();
-
-        var discovery = Take(Shuffle(unheardTrackIds));
-        if (discovery.Count > 0)
-        {
-            drafts.Add(new MixDraft(MixKind.Discovery, discovery));
-        }
-
-        var daily = Take(Interleave(Shuffle(historyTrackIds), Shuffle(unheardTrackIds)));
-        if (daily.Count > 0)
-        {
-            drafts.Add(new MixDraft(MixKind.Daily, daily));
-        }
-
-        if (drafts.Count == 0)
-        {
-            logger.LogInformation("No candidate songs found for user {UserId}, skipping mix generation", userId);
-            return Unit.Value;
-        }
-
-        await ReplaceMixesAsync(userId, drafts, cancellationToken);
-
-        await database.SaveChangesAsync(cancellationToken);
-
-        logger.LogInformation("Generated {Count} mixes for user {UserId}", drafts.Count, userId);
-        return Unit.Value;
-    }
-
-    private List<Guid> Take(IEnumerable<Guid> trackIds) =>
-        [.. trackIds.Take(mixConfiguration.ItemsPerMix)];
-
-    private static List<Guid> Shuffle(IEnumerable<Guid> trackIds) =>
-        [.. trackIds.OrderBy(_ => Guid.NewGuid())];
-
-    private static List<Guid> Interleave(IReadOnlyList<Guid> first, IReadOnlyList<Guid> second)
-    {
-        var merged = new List<Guid>(first.Count + second.Count);
-        for (var index = 0; index < Math.Max(first.Count, second.Count); index++)
-        {
-            if (index < first.Count)
-                merged.Add(first[index]);
-            if (index < second.Count)
-                merged.Add(second[index]);
-        }
-
-        return merged;
-    }
-
-    private async Task ReplaceMixesAsync(long userId, IReadOnlyList<MixDraft> drafts, CancellationToken cancellationToken)
-    {
-        var previousMixes = await database.Mixes
-            .Where(mix => mix.UserId == userId)
-            .ToListAsync(cancellationToken);
-
-        if (previousMixes.Count > 0)
-        {
-            database.Mixes.RemoveRange(previousMixes);
-        }
-
-        for (var position = 0; position < drafts.Count; position++)
-        {
-            var draft = drafts[position];
-            var mix = new Mix
+            if (libraryTrackIds.Count == 0)
             {
-                UserId = userId,
-                Kind = draft.Kind,
-                Position = position
-            };
+                logger.LogInformation("User {UserId} has no tracks yet, skipping mix generation", userId);
+                return new Success();
+            }
 
-            await database.Mixes.AddAsync(mix, cancellationToken);
+            var historyTrackIds = await database.ListeningHistories
+                .AsNoTracking()
+                .Where(history => history.UserId == userId && history.IsCounted)
+                .Select(history => history.TrackId)
+                .Distinct()
+                .ToListAsync(cancellationToken);
 
-            for (var itemPosition = 0; itemPosition < draft.TrackIds.Count; itemPosition++)
+            var historySet = new HashSet<Guid>(historyTrackIds);
+            var unheardTrackIds = libraryTrackIds.Where(id => !historySet.Contains(id)).ToList();
+
+            var drafts = new List<MixDraft>();
+
+            var discovery = Take(Shuffle(unheardTrackIds));
+            if (discovery.Count > 0)
             {
-                await database.MixItems.AddAsync(new MixItem
+                drafts.Add(new MixDraft(
+                    "Descubrimiento",
+                    "Canciones de tu biblioteca que todavía no has escuchado.",
+                    discovery));
+            }
+
+            var daily = Take(Interleave(Shuffle(historyTrackIds), Shuffle(unheardTrackIds)));
+            if (daily.Count > 0)
+            {
+                drafts.Add(new MixDraft(
+                    "Tu mezcla diaria",
+                    "Lo que más escuchas, con alguna sorpresa de tu biblioteca.",
+                    daily));
+            }
+
+            if (drafts.Count == 0)
+            {
+                logger.LogInformation("No candidate songs found for user {UserId}, skipping mix generation", userId);
+                return new Success();
+            }
+
+            await ReplaceMixesAsync(userId, drafts, cancellationToken);
+
+            try
+            {
+                await database.SaveChangesAsync(cancellationToken);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to generate mixes for user {UserId}", userId);
+                return Error.Failure(description: $"Failed to generate mixes for user {userId}");
+            }
+
+            logger.LogInformation("Generated {Count} mixes for user {UserId}", drafts.Count, userId);
+            return new Success();
+        }
+
+        private List<Guid> Take(IEnumerable<Guid> trackIds) =>
+            [.. trackIds.Take(mixConfiguration.ItemsPerMix)];
+
+        private static List<Guid> Shuffle(IEnumerable<Guid> trackIds) =>
+            [.. trackIds.OrderBy(_ => Guid.NewGuid())];
+
+        private static List<Guid> Interleave(IReadOnlyList<Guid> first, IReadOnlyList<Guid> second)
+        {
+            var merged = new List<Guid>(first.Count + second.Count);
+            for (var index = 0; index < Math.Max(first.Count, second.Count); index++)
+            {
+                if (index < first.Count)
+                    merged.Add(first[index]);
+                if (index < second.Count)
+                    merged.Add(second[index]);
+            }
+
+            return merged;
+        }
+
+        private async Task ReplaceMixesAsync(long userId, IReadOnlyList<MixDraft> drafts, CancellationToken cancellationToken)
+        {
+            var previousMixes = await database.Mixes
+                .Where(mix => mix.UserId == userId)
+                .ToListAsync(cancellationToken);
+
+            if (previousMixes.Count > 0)
+            {
+                var previousIds = previousMixes.Select(mix => mix.Id).ToList();
+                var previousItems = await database.MixItems
+                    .Where(item => previousIds.Contains(item.MixId))
+                    .ToListAsync(cancellationToken);
+
+                database.MixItems.RemoveRange(previousItems);
+                database.Mixes.RemoveRange(previousMixes);
+            }
+
+            for (var position = 0; position < drafts.Count; position++)
+            {
+                var draft = drafts[position];
+                var mix = new Mix
                 {
-                    MixId = mix.Id,
-                    Position = itemPosition,
-                    TrackId = draft.TrackIds[itemPosition]
-                }, cancellationToken);
+                    UserId = userId,
+                    Title = draft.Title,
+                    Subtitle = draft.Subtitle,
+                    Position = position
+                };
+
+                await database.Mixes.AddAsync(mix, cancellationToken);
+
+                for (var itemPosition = 0; itemPosition < draft.TrackIds.Count; itemPosition++)
+                {
+                    await database.MixItems.AddAsync(new MixItem
+                    {
+                        MixId = mix.Id,
+                        Position = itemPosition,
+                        TrackId = draft.TrackIds[itemPosition]
+                    }, cancellationToken);
+                }
             }
         }
     }

backend/Core/Musify.Application/Mixes/GetMixById.cs

@@ -3,29 +3,29 @@ using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Musify.Application.Contracts;
 using Musify.Application.Mixes.Responses;
-using Musify.Application.Shared;
 
-namespace Musify.Application.Mixes;
-
-public record GetMixByIdQuery(long UserId, Guid MixId)
-    : IQuery<ErrorOr<MixApplicationResponse>>;
-
-public class GetMixByIdQueryHandler(IDatabase database)
-    : IQueryHandler<GetMixByIdQuery, ErrorOr<MixApplicationResponse>>
+namespace Musify.Application.Mixes
 {
-    public async ValueTask<ErrorOr<MixApplicationResponse>> Handle(GetMixByIdQuery request, CancellationToken cancellationToken)
+    public record GetMixByIdQuery(long UserId, Guid MixId)
+        : IQuery<ErrorOr<MixApplicationResponse>>;
+
+    public class GetMixByIdQueryHandler(IDatabase database)
+        : IQueryHandler<GetMixByIdQuery, ErrorOr<MixApplicationResponse>>
     {
-        var mix = await database.Mixes
-            .AsNoTracking()
-            .Include(mix => mix.Items)
-            .SingleOrDefaultAsync(mix => mix.Id == request.MixId && mix.UserId == request.UserId, cancellationToken);
+        public async ValueTask<ErrorOr<MixApplicationResponse>> Handle(GetMixByIdQuery request, CancellationToken cancellationToken)
+        {
+            var mix = await database.Mixes
+                .AsNoTracking()
+                .Include(mix => mix.Items)
+                .SingleOrDefaultAsync(mix => mix.Id == request.MixId && mix.UserId == request.UserId, cancellationToken);
 
-        if (mix == null)
-            return AppErrors.NotFound("Mix", request.MixId);
+            if (mix == null)
+                return Error.NotFound(description: $"Mix {request.MixId} was not found");
 
-        var orderedItems = mix.Items.OrderBy(item => item.Position).ToList();
-        var items = await MixItemMapper.ToResponsesAsync(database, orderedItems, cancellationToken);
+            var orderedItems = mix.Items.OrderBy(item => item.Position).ToList();
+            var items = await MixItemMapper.ToResponsesAsync(database, orderedItems, cancellationToken);
 
-        return new MixApplicationResponse(mix.Id, mix.Kind, items.Count, items);
+            return new MixApplicationResponse(mix.Id, mix.Title, mix.Subtitle, items.Count, items);
+        }
     }
 }

backend/Core/Musify.Application/Mixes/GetMixesByUserId.cs

@@ -1,50 +1,37 @@
+using ErrorOr;
 using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Musify.Application.Contracts;
 using Musify.Application.Mixes.Responses;
 
-namespace Musify.Application.Mixes;
-
-public record GetMixesByUserIdQuery(long UserId)
-    : IQuery<IReadOnlyList<MixApplicationResponse>>;
-
-public class GetMixesByUserIdQueryHandler(IDatabase database)
-    : IQueryHandler<GetMixesByUserIdQuery, IReadOnlyList<MixApplicationResponse>>
+namespace Musify.Application.Mixes
 {
-    public async ValueTask<IReadOnlyList<MixApplicationResponse>> Handle(GetMixesByUserIdQuery request, CancellationToken cancellationToken)
+    public record GetMixesByUserIdQuery(long UserId)
+        : IQuery<ErrorOr<IReadOnlyList<MixApplicationResponse>>>;
+
+    public class GetMixesByUserIdQueryHandler(IDatabase database)
+        : IQueryHandler<GetMixesByUserIdQuery, ErrorOr<IReadOnlyList<MixApplicationResponse>>>
     {
-        var mixes = await database.Mixes
-            .AsNoTracking()
-            .Where(mix => mix.UserId == request.UserId)
-            .Include(mix => mix.Items)
-            .OrderBy(mix => mix.Position)
-            .ThenBy(mix => mix.Id)
-            .ToListAsync(cancellationToken);
-
-        var orderedItemsByMix = mixes.ToDictionary(
-            mix => mix.Id,
-            mix => mix.Items.OrderBy(item => item.Position).ToList());
-
-        var coverItems = orderedItemsByMix.Values
-            .SelectMany(items => items.Take(MixApplicationResponse.CoverItemCount))
-            .ToList();
-        var coverResponses = (await MixItemMapper.ToResponsesAsync(database, coverItems, cancellationToken))
-            .GroupBy(response => response.TrackId)
-            .ToDictionary(group => group.Key, group => group.First());
-
-        var responses = new List<MixApplicationResponse>(mixes.Count);
-        foreach (var mix in mixes)
+        public async ValueTask<ErrorOr<IReadOnlyList<MixApplicationResponse>>> Handle(GetMixesByUserIdQuery request, CancellationToken cancellationToken)
         {
-            var orderedItems = orderedItemsByMix[mix.Id];
-            var covers = orderedItems
-                .Take(MixApplicationResponse.CoverItemCount)
-                .Where(item => coverResponses.ContainsKey(item.TrackId))
-                .Select(item => coverResponses[item.TrackId])
-                .ToList();
+            var mixes = await database.Mixes
+                .AsNoTracking()
+                .Where(mix => mix.UserId == request.UserId)
+                .Include(mix => mix.Items)
+                .OrderBy(mix => mix.Position)
+                .ToListAsync(cancellationToken);
 
-            responses.Add(new MixApplicationResponse(mix.Id, mix.Kind, orderedItems.Count, covers));
+            var responses = new List<MixApplicationResponse>(mixes.Count);
+            foreach (var mix in mixes)
+            {
+                var orderedItems = mix.Items.OrderBy(item => item.Position).ToList();
+                var coverItems = await MixItemMapper.ToResponsesAsync(
+                    database, orderedItems.Take(MixApplicationResponse.CoverItemCount).ToList(), cancellationToken);
+
+                responses.Add(new MixApplicationResponse(mix.Id, mix.Title, mix.Subtitle, orderedItems.Count, coverItems));
+            }
+
+            return responses;
         }
-
-        return responses;
     }
 }

backend/Core/Musify.Application/Mixes/MixItemMapper.cs

@@ -2,39 +2,39 @@ using Microsoft.EntityFrameworkCore;
 using Musify.Application.Contracts;
 using Musify.Application.Mixes.Responses;
 using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
 
-namespace Musify.Application.Mixes;
-
-
-internal static class MixItemMapper
+namespace Musify.Application.Mixes
 {
-    public static async Task<List<MixItemApplicationResponse>> ToResponsesAsync(
-        IDatabase database,
-        IReadOnlyList<MixItem> orderedItems,
-        CancellationToken cancellationToken)
+
+    internal static class MixItemMapper
     {
-        var trackIds = orderedItems.Select(item => item.TrackId).Distinct().ToList();
+        public static async Task<List<MixItemApplicationResponse>> ToResponsesAsync(
+            IDatabase database,
+            IReadOnlyList<MixItem> orderedItems,
+            CancellationToken cancellationToken)
+        {
+            var trackIds = orderedItems.Select(item => item.TrackId).Distinct().ToList();
 
-        var tracksById = await database.Tracks
-            .AsNoTracking()
-            .Include(track => track.Owner)
-            .Where(track => trackIds.Contains(track.Id) && track.LifeCycleStatus == LifeCycleStatus.Active)
-            .Select(track => new { Track = track, ListensCount = track.ListeningHistories.Count(l => l.IsCounted) })
-            .ToDictionaryAsync(x => x.Track.Id, cancellationToken);
+            var tracksById = await database.Tracks
+                .AsNoTracking()
+                .Include(track => track.Owner)
+                .Where(track => trackIds.Contains(track.Id))
+                .Select(track => new { Track = track, ListensCount = track.ListeningHistories.Count(l => l.IsCounted) })
+                .ToDictionaryAsync(x => x.Track.Id, cancellationToken);
 
-        return orderedItems
-            .Where(item => tracksById.ContainsKey(item.TrackId))
-            .Select(item =>
-            {
-                var entry = tracksById[item.TrackId];
-                return new MixItemApplicationResponse(
-                    item.TrackId,
-                    entry.Track.Title,
-                    entry.Track.Owner.Name,
-                    entry.Track.DurationSeconds,
-                    entry.ListensCount);
-            })
-            .ToList();
+            return orderedItems
+                .Where(item => tracksById.ContainsKey(item.TrackId))
+                .Select(item =>
+                {
+                    var entry = tracksById[item.TrackId];
+                    return new MixItemApplicationResponse(
+                        item.TrackId,
+                        entry.Track.Title,
+                        entry.Track.Owner.Name,
+                        entry.Track.DurationSeconds,
+                        entry.ListensCount);
+                })
+                .ToList();
+        }
     }
 }

backend/Core/Musify.Application/Mixes/Responses/MixApplicationResponse.cs

@@ -1,12 +1,12 @@
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Mixes.Responses;
-
-public record MixApplicationResponse(
-    Guid Id,
-    MixKind Kind,
-    int ItemCount,
-    IReadOnlyList<MixItemApplicationResponse> Items)
+namespace Musify.Application.Mixes.Responses
 {
-    public const int CoverItemCount = 4;
+    public record MixApplicationResponse(
+        Guid Id,
+        string Title,
+        string? Subtitle,
+        int ItemCount,
+        IReadOnlyList<MixItemApplicationResponse> Items)
+    {
+        public const int CoverItemCount = 4;
+    }
 }

backend/Core/Musify.Application/Mixes/Responses/MixItemApplicationResponse.cs

@@ -1,8 +1,9 @@
-namespace Musify.Application.Mixes.Responses;
-
-public record MixItemApplicationResponse(
-    Guid TrackId,
-    string Title,
-    string? Artist,
-    double DurationSeconds,
-    int ListensCount);
+namespace Musify.Application.Mixes.Responses
+{
+    public record MixItemApplicationResponse(
+        Guid TrackId,
+        string Title,
+        string? Artist,
+        double DurationSeconds,
+        int ListensCount);
+}

backend/Core/Musify.Application/Pictures/GetCover.cs

@@ -1,75 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using MimeMapping;
-using Musify.Application.Configuration;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Pictures;
-
-public enum CoverOwner
-{
-    Track,
-    Album,
-    PlayList
-}
-
-public record GetCoverQuery(CoverOwner Owner, Guid Id, PictureSize Size = PictureSize.Medium)
-    : IQuery<ErrorOr<CoverLocation>>;
-
-public record CoverLocation(string Bucket, string Key, string ContentType);
-
-public class GetCoverQueryHandler(
-    IDatabase database,
-    ApplicationStorageConfiguration storageConfiguration,
-    TrackConfiguration trackConfiguration,
-    AlbumConfiguration albumConfiguration,
-    PlayListConfiguration playListConfiguration)
-    : IQueryHandler<GetCoverQuery, ErrorOr<CoverLocation>>
-{
-    private sealed record CoverSource(long OwnerUserId, string? Original, string? Small, string? Medium, string? Large);
-
-    public async ValueTask<ErrorOr<CoverLocation>> Handle(GetCoverQuery request, CancellationToken cancellationToken)
-    {
-        var (source, routes) = request.Owner switch
-        {
-            CoverOwner.Track => (await database.Tracks.AsNoTracking()
-                .Where(t => t.Id == request.Id && t.LifeCycleStatus == LifeCycleStatus.Active)
-                .Select(t => new CoverSource(t.OwnerUserId, t.Pictures.OriginalName, t.Pictures.SmallName, t.Pictures.MediumName, t.Pictures.LargeName))
-                .SingleOrDefaultAsync(cancellationToken), trackConfiguration.Routes),
-            CoverOwner.Album => (await database.Albums.AsNoTracking()
-                .Where(a => a.Id == request.Id && a.LifeCycleStatus == LifeCycleStatus.Active && a.Pictures != null)
-                .Select(a => new CoverSource(a.OwnerUserId, a.Pictures!.OriginalName, a.Pictures.SmallName, a.Pictures.MediumName, a.Pictures.LargeName))
-                .SingleOrDefaultAsync(cancellationToken), albumConfiguration.Routes),
-            _ => (await database.PlayLists.AsNoTracking()
-                .Where(p => p.Id == request.Id && p.LifeCycleStatus == LifeCycleStatus.Active && p.Pictures != null)
-                .Select(p => new CoverSource(p.OwnerUserId, p.Pictures!.OriginalName, p.Pictures.SmallName, p.Pictures.MediumName, p.Pictures.LargeName))
-                .SingleOrDefaultAsync(cancellationToken), playListConfiguration.Routes)
-        };
-
-        var entity = request.Owner.ToString();
-        if (source == null)
-            return AppErrors.NotFound($"{entity}Cover", request.Id);
-
-        var resizedName = request.Size switch
-        {
-            PictureSize.Small => source.Small,
-            PictureSize.Large => source.Large,
-            _ => source.Medium
-        };
-
-        // The resized files only exist once processing has finished; until then serve the original.
-        var (name, key) = !string.IsNullOrEmpty(resizedName)
-            ? (resizedName, routes.BuildPicturePath(request.Size, resizedName))
-            : !string.IsNullOrEmpty(source.Original)
-                ? (source.Original, routes.BuildOriginalPicturePath(source.OwnerUserId, source.Original))
-                : (null, null);
-
-        if (name == null || key == null)
-            return AppErrors.NotFound($"{entity}Cover", request.Id);
-
-        return new CoverLocation(storageConfiguration.Bucket, key, MimeUtility.GetMimeMapping(name));
-    }
-}

backend/Core/Musify.Application/Pictures/PictureSourceChange.cs

@@ -1,35 +0,0 @@
-using ErrorOr;
-using Musify.Application.Configuration;
-using Musify.Application.Services;
-using Musify.Application.Shared;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.Pictures;
-
-/// <summary>What an album or playlist needs to switch to a freshly uploaded picture.</summary>
-public sealed record PreparedPicture(UploadIntent Intent, EntityPictures Pictures, string FinalKey, ImageSizes Sizes);
-
-public static class PictureSourceChange
-{
-    public static async Task<ErrorOr<PreparedPicture>> PrepareAsync(
-        UploadIntentValidator uploadIntentValidator,
-        Guid intentId,
-        long userId,
-        UploadIntentPurpose purpose,
-        IPictureOwnerConfiguration owner,
-        CancellationToken cancellationToken)
-    {
-        var validation = await uploadIntentValidator.ValidateAndLoadAsync(intentId, userId, purpose, cancellationToken);
-        if (validation.IsError)
-            return validation.Errors;
-
-        var intent = validation.Value;
-
-        return new PreparedPicture(
-            intent,
-            EntityPictures.Pending(intent.ObjectName),
-            owner.Routes.BuildOriginalPicturePath(userId, intent.ObjectName),
-            owner.PicturesSizes.ToImageSizes(owner.Routes));
-    }
-}

backend/Core/Musify.Application/Pictures/Responses/PictureUploadResponse.cs

@@ -1,10 +0,0 @@
-namespace Musify.Application.Pictures.Responses;
-
-public record PictureUploadResponse(
-    Guid IntentId,
-    string Bucket,
-    string Key,
-    string PictureName,
-    string ContentType,
-    int ExpiresInSeconds,
-    string UploadUrl);

backend/Core/Musify.Application/PlayLists/AddAlbumToPlayList.cs

@@ -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);
+        }
+    }
+}

backend/Core/Musify.Application/PlayLists/AddTrackToPlayList.cs

@@ -0,0 +1,75 @@
+using ErrorOr;
+using Mediator;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+using Musify.Application.Contracts;
+using Musify.Domain.Entities;
+
+namespace Musify.Application.PlayLists
+{
+    public record AddTrackToPlayListCommand(long UserId, Guid PlayListId, Guid TrackId)
+        : ICommand<ErrorOr<Success>>;
+
+    public class AddTrackToPlayListCommandHandler(
+        IDatabase database,
+        ILogger<AddTrackToPlayListCommandHandler> logger)
+        : ICommandHandler<AddTrackToPlayListCommand, ErrorOr<Success>>
+    {
+        public async ValueTask<ErrorOr<Success>> Handle(AddTrackToPlayListCommand 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 trackExists = await database.Tracks
+                .AsNoTracking()
+                .AnyAsync(t => t.Id == request.TrackId, cancellationToken);
+            if (!trackExists)
+            {
+                logger.LogInformation("Track {TrackId} not found", request.TrackId);
+                return Error.NotFound(description: $"Track {request.TrackId} not found");
+            }
+
+            var alreadyAdded = await database.PlayListHasTracks
+                .AsNoTracking()
+                .AnyAsync(plt => plt.PlayListId == request.PlayListId && plt.TrackId == request.TrackId, cancellationToken);
+            if (alreadyAdded)
+            {
+                logger.LogInformation("Track {TrackId} already in playlist {PlayListId}", request.TrackId, request.PlayListId);
+                return Error.Conflict(description: "Track is already in the playlist.");
+            }
+
+            var playListTracksQuery = database.PlayListHasTracks
+                .Where(plt => plt.PlayListId == request.PlayListId);
+
+            var hasTracks = await playListTracksQuery.AnyAsync(cancellationToken);
+            var nextPosition = hasTracks
+                ? await playListTracksQuery.MaxAsync(plt => plt.Position, cancellationToken) + 1
+                : 0;
+
+            await database.PlayListHasTracks.AddAsync(new PlayListHasTrack
+            {
+                PlayListId = request.PlayListId,
+                TrackId = request.TrackId,
+                Position = nextPosition
+            }, cancellationToken);
+
+            await database.SaveChangesAsync(cancellationToken);
+
+            logger.LogInformation("Added track {TrackId} to playlist {PlayListId} at position {Position}",
+                request.TrackId, request.PlayListId, nextPosition);
+
+            return new Success();
+        }
+    }
+}

backend/Core/Musify.Application/PlayLists/AddTracksToPlayList.cs

@@ -1,73 +0,0 @@
-using ErrorOr;
-using Mediator;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
-using Musify.Application.Contracts;
-using Musify.Application.Shared;
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.PlayLists;
-
-/// <summary>Appends tracks to a playlist in the given order, skipping the ones it already has.</summary>
-public record AddTracksToPlayListCommand(long UserId, Guid PlayListId, IReadOnlyList<Guid> TrackIds)
-    : ICommand<ErrorOr<Success>>;
-
-public class AddTracksToPlayListCommandHandler(
-    IDatabase database,
-    ILogger<AddTracksToPlayListCommandHandler> logger)
-    : ICommandHandler<AddTracksToPlayListCommand, ErrorOr<Success>>
-{
-    public async ValueTask<ErrorOr<Success>> Handle(AddTracksToPlayListCommand request, CancellationToken cancellationToken)
-    {
-        var playList = await database.PlayLists.FindOwnedAsync(request.PlayListId, request.UserId, cancellationToken);
-        if (playList.IsError)
-            return playList.Errors;
-
-        var requestedIds = request.TrackIds.Distinct().ToList();
-
-        var existingIds = await database.Tracks
-            .AsNoTracking()
-            .Where(track => requestedIds.Contains(track.Id) && track.LifeCycleStatus == LifeCycleStatus.Active)
-            .Select(track => track.Id)
-            .ToListAsync(cancellationToken);
-
-        var missing = requestedIds.FirstOrDefault(id => !existingIds.Contains(id));
-        if (missing != Guid.Empty)
-            return AppErrors.NotFound("Track", missing);
-
-        var alreadyInPlayList = await database.PlayListHasTracks
-            .AsNoTracking()
-            .Where(link => link.PlayListId == request.PlayListId && requestedIds.Contains(link.TrackId))
-            .Select(link => link.TrackId)
-            .ToListAsync(cancellationToken);
-
-        var toAdd = requestedIds.Where(id => !alreadyInPlayList.Contains(id)).ToList();
-        if (toAdd.Count == 0)
-            return Result.Success;
-
-        // Playlist positions are internal indexes, so they start at 0.
-        var nextPosition = (await database.PlayListHasTracks
-            .Where(link => link.PlayListId == request.PlayListId)
-            .MaxAsync(link => (int?)link.Position, cancellationToken) ?? -1) + 1;
-
-        foreach (var trackId in toAdd)
-        {
-            await database.PlayListHasTracks.AddAsync(new PlayListHasTrack
-            {
-                PlayListId = request.PlayListId,
-                TrackId = trackId,
-                Position = nextPosition++
-            }, cancellationToken);
-        }
-
-        var saved = await database.TrySaveChangesAsync(
-            AppErrors.Conflict("PlayList.ConcurrentChange", "The playlist changed while adding tracks. Try again."), cancellationToken);
-        if (saved.IsError)
-            return saved;
-
-        logger.LogInformation("Added {Count} tracks to playlist {PlayListId}", toAdd.Count, request.PlayListId);
-
-        return Result.Success;
-    }
-}

backend/Core/Musify.Application/PlayLists/CreatePlayList.cs

@@ -3,76 +3,144 @@ using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using Musify.Application.Configuration;
-using Musify.Application.Contracts;
+using Musify.Application.Shared;
 using Musify.Application.Events;
-using Musify.Application.Pictures;
 using Musify.Application.PlayLists.Responses;
 using Musify.Application.Services;
-using Musify.Application.Shared;
 using Musify.Domain.Entities;
 using Musify.Domain.ValueObjects;
+using Musify.Application.Contracts;
 
-namespace Musify.Application.PlayLists;
-
-public record CreatePlayListCommand(
-    long UserId,
-    string Name,
-    string? Description,
-    Guid? PictureIntentId,
-    PlayListVisibility Visibility = PlayListVisibility.Private)
-    : ICommand<ErrorOr<PlayListApplicationResponse>>;
-
-public class CreatePlayListCommandHandler(
-    IEventBus eventBus,
-    IDatabase database,
-    UploadIntentValidator uploadIntentValidator,
-    ILogger<CreatePlayListCommandHandler> logger,
-    PlayListConfiguration playListConfiguration)
-    : ICommandHandler<CreatePlayListCommand, ErrorOr<PlayListApplicationResponse>>
+namespace Musify.Application.PlayLists
 {
-    public async ValueTask<ErrorOr<PlayListApplicationResponse>> Handle(CreatePlayListCommand request, CancellationToken cancellationToken)
+    public record CreatePlayListCommand(
+        long UserId,
+        string Name,
+        string? Description,
+        Guid? PictureIntentId,
+        PlaylistVisibility Visibility = PlaylistVisibility.Private)
+        : ICommand<ErrorOr<PlayListApplicationResponse>>;
+
+    public class CreatePlayListCommandHandler(
+        IEventBus eventBus,
+        IDatabase database,
+        UploadIntentValidator uploadIntentValidator,
+        ILogger<CreatePlayListCommandHandler> logger,
+        ApplicationStorageConfiguration storageConfiguration,
+        PlayListConfiguration playListConfiguration,
+        UploadIntentConfiguration uploadIntentConfiguration)
+        : ICommandHandler<CreatePlayListCommand, ErrorOr<PlayListApplicationResponse>>
     {
-        var userExists = await database.Users
-            .AsNoTracking()
-            .AnyAsync(u => u.Id == request.UserId, cancellationToken);
-        if (!userExists)
-            return AppErrors.NotFound("User", request.UserId);
+        private sealed record ResolvedPlayListPictures(PlayListPictures? Pictures, UploadIntent? Intent);
 
-        PreparedPicture? picture = null;
-        if (request.PictureIntentId is { } intentId)
+        public async ValueTask<ErrorOr<PlayListApplicationResponse>> Handle(CreatePlayListCommand request, CancellationToken cancellationToken)
         {
-            var prepared = await PictureSourceChange.PrepareAsync(
-                uploadIntentValidator, intentId, request.UserId, UploadIntentPurpose.PlayListPicture, playListConfiguration, cancellationToken);
-            if (prepared.IsError)
-                return prepared.Errors;
+            var userExists = await database.Users
+                .AsNoTracking()
+                .AnyAsync(u => u.Id == request.UserId, cancellationToken);
+            if (!userExists)
+            {
+                logger.LogWarning("User {UserId} not found", request.UserId);
+                return Error.NotFound(description: $"User {request.UserId} not found");
+            }
 
-            picture = prepared.Value;
+            var picturesResult = await ResolvePicturesAsync(request, cancellationToken);
+            if (picturesResult.IsError)
+                return picturesResult.Errors;
+
+            var resolvedPictures = picturesResult.Value;
+
+            var playList = new PlayList
+            {
+                UserId = request.UserId,
+                Name = request.Name,
+                NormalizedName = request.Name.Trim().ToUpperInvariant(),
+                Description = string.IsNullOrWhiteSpace(request.Description) ? null : request.Description.Trim(),
+                Pictures = resolvedPictures.Pictures,
+                Visibility = request.Visibility
+            };
+            await database.PlayLists.AddAsync(playList, cancellationToken);
+
+            if (resolvedPictures.Intent != null)
+            {
+                var finalPictureKey = playListConfiguration.Routes.BuildOriginalPicturePath(request.UserId, resolvedPictures.Pictures!.OriginalName);
+                var publishResult = await PublishCreatePlayListEventAsync(playList.Id, resolvedPictures.Intent, finalPictureKey, cancellationToken);
+                if (publishResult.IsError)
+                    return publishResult.Errors;
+            }
+
+            try
+            {
+                await database.SaveChangesAsync(cancellationToken);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to save playlist for user {UserId}", request.UserId);
+                return Error.Failure(description: $"Failed to create playlist for user {request.UserId}");
+            }
+
+            logger.LogInformation("Created playlist {PlayListId} for user {UserId}", playList.Id, request.UserId);
+            return PlayListApplicationResponse.FromEntity(playList);
         }
 
-        var name = request.Name.Trim();
-        var playList = new PlayList
+        private async ValueTask<ErrorOr<ResolvedPlayListPictures>> ResolvePicturesAsync(
+            CreatePlayListCommand request, CancellationToken cancellationToken)
         {
-            OwnerUserId = request.UserId,
-            Name = name,
-            NormalizedName = TextNormalizer.Normalize(name),
-            Description = string.IsNullOrWhiteSpace(request.Description) ? null : request.Description.Trim(),
-            Pictures = picture?.Pictures,
-            Visibility = request.Visibility
-        };
-        await database.PlayLists.AddAsync(playList, cancellationToken);
+            if (!request.PictureIntentId.HasValue)
+            {
+                return new ResolvedPlayListPictures(null, null);
+            }
 
-        if (picture != null)
-        {
-            await eventBus.PublishAsync(
-                new CreatePlayListResourcesEvent(
-                    playList.Id, picture.Intent.Id, picture.Intent.Bucket, picture.Intent.Key, picture.FinalKey, picture.Sizes),
-                cancellationToken);
+            var validation = await uploadIntentValidator.ValidateAndLoadAsync(
+                uploadIntentConfiguration, request.PictureIntentId.Value, request.UserId, cancellationToken);
+
+            if (validation.IsError)
+                return validation.Errors;
+
+            return new ResolvedPlayListPictures(new PlayListPictures
+            {
+                OriginalName = validation.Value.ObjectName,
+                SmallName = validation.Value.ObjectName,
+                MediumName = validation.Value.ObjectName,
+                LargeName = validation.Value.ObjectName
+            }, validation.Value);
         }
 
-        await database.SaveChangesAsync(cancellationToken);
-
-        logger.LogInformation("Created playlist {PlayListId} for user {UserId}", playList.Id, request.UserId);
-
-        return PlayListApplicationResponse.FromEntity(playList);
+        private async Task<ErrorOr<Success>> PublishCreatePlayListEventAsync(
+            Guid playListId,
+            UploadIntent pictureIntent,
+            string finalPictureKey,
+            CancellationToken cancellationToken)
+        {
+            try
+            {
+                await eventBus.PublishAsync(
+                    new CreatePlayListResourcesEvent(
+                        playListId,
+                        pictureIntent.Id,
+                        storageConfiguration.Bucket,
+                        pictureIntent.Key,
+                        finalPictureKey,
+                        new ImageSize(
+                            playListConfiguration.Routes.SmallPicturesPath,
+                            playListConfiguration.PicturesSizes.SmallPictureWidth,
+                            playListConfiguration.PicturesSizes.SmallPictureHeight),
+                        new ImageSize(
+                            playListConfiguration.Routes.MediumPicturesPath,
+                            playListConfiguration.PicturesSizes.MediumPictureWidth,
+                            playListConfiguration.PicturesSizes.MediumPictureHeight),
+                        new ImageSize(
+                            playListConfiguration.Routes.LargePicturesPath,
+                            playListConfiguration.PicturesSizes.LargePictureWidth,
+                            playListConfiguration.PicturesSizes.LargePictureHeight)),
+                    cancellationToken);
+                return new Success();
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to publish create playlist event for playlist {PlayListId}", playListId);
+                return Error.Failure(description: $"Failed to publish create playlist event for playlist {playListId}");
+            }
+        }
     }
 }

backend/Core/Musify.Application/PlayLists/DeletePlayList.cs

@@ -1,36 +1,62 @@
 using ErrorOr;
 using Mediator;
+using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using Musify.Application.Contracts;
 using Musify.Application.Events;
-using Musify.Application.Shared;
 using Musify.Domain.ValueObjects;
 
-namespace Musify.Application.PlayLists;
-
-public record DeletePlayListCommand(long UserId, Guid PlayListId)
-    : ICommand<ErrorOr<Success>>;
-
-public class DeletePlayListCommandHandler(
-    IDatabase database,
-    IEventBus eventBus,
-    ILogger<DeletePlayListCommandHandler> logger)
-    : ICommandHandler<DeletePlayListCommand, ErrorOr<Success>>
+namespace Musify.Application.PlayLists
 {
-    public async ValueTask<ErrorOr<Success>> Handle(DeletePlayListCommand request, CancellationToken cancellationToken)
+    public record DeletePlayListCommand(long UserId, Guid PlayListId)
+        : ICommand<ErrorOr<Success>>;
+
+    public class DeletePlayListCommandHandler(
+        IDatabase database,
+        IEventBus eventBus,
+        ILogger<DeletePlayListCommandHandler> logger)
+        : ICommandHandler<DeletePlayListCommand, ErrorOr<Success>>
     {
-        var found = await database.PlayLists.FindOwnedAsync(request.PlayListId, request.UserId, cancellationToken);
-        if (found.IsError)
-            return found.Errors;
+        public async ValueTask<ErrorOr<Success>> Handle(DeletePlayListCommand request, CancellationToken cancellationToken)
+        {
+            var playList = await database.PlayLists.SingleOrDefaultAsync(p => p.Id == request.PlayListId, cancellationToken);
+            if (playList == null)
+            {
+                logger.LogDebug("Playlist {PlayListId} not found", request.PlayListId);
+                return Error.NotFound();
+            }
 
-        var playList = found.Value;
-        playList.LifeCycleStatus = LifeCycleStatus.Removing;
+            if (playList.UserId != request.UserId)
+            {
+                logger.LogWarning("Playlist {PlayListId} does not belong to user {UserId}", request.PlayListId, request.UserId);
+                return Error.Unauthorized();
+            }
 
-        await eventBus.PublishAsync(new DeletePlayListEvent(playList.Id, request.UserId), cancellationToken);
-        await database.SaveChangesAsync(cancellationToken);
+            playList.LifeCycleStatus = LifeCycleStatus.Removing;
 
-        logger.LogInformation("Marked playlist {PlayListId} as removing", request.PlayListId);
+            try
+            {
+                await eventBus.PublishAsync(
+                    new DeletePlayListEvent(playList.Id, request.UserId),
+                    cancellationToken);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to publish delete playlist event for playlist {PlayListId}", request.PlayListId);
+                return Error.Failure(description: $"Failed to delete playlist {request.PlayListId}");
+            }
 
-        return Result.Success;
+            try
+            {
+                await database.SaveChangesAsync(cancellationToken);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to mark playlist {PlayListId} as removing", request.PlayListId);
+                return Error.Failure(description: $"Failed to delete playlist {request.PlayListId}");
+            }
+
+            return new Success();
+        }
     }
 }

backend/Core/Musify.Application/PlayLists/GetPlayListById.cs

@@ -1,30 +1,44 @@
 using ErrorOr;
-using Mediator;
 using Microsoft.EntityFrameworkCore;
-using Musify.Application.Contracts;
 using Musify.Application.PlayLists.Responses;
-using Musify.Application.Shared;
+using Mediator;
+using Musify.Application.Contracts;
+using Musify.Domain.ValueObjects;
 
-namespace Musify.Application.PlayLists;
-
-public record GetPlayListByIdQuery(Guid Id, long? RequestingUserId = null)
-    : IQuery<ErrorOr<PlayListApplicationResponse>>;
-
-public class GetPlayListByIdQueryHandler(IDatabase database)
-    : IQueryHandler<GetPlayListByIdQuery, ErrorOr<PlayListApplicationResponse>>
+namespace Musify.Application.PlayLists
 {
-    public async ValueTask<ErrorOr<PlayListApplicationResponse>> Handle(GetPlayListByIdQuery request, CancellationToken cancellationToken)
-    {
-        var playList = await database.PlayLists
-            .AsNoTracking()
-            .Active()
-            .VisibleTo(request.RequestingUserId)
-            .Where(p => p.Id == request.Id)
-            .SelectResponse()
-            .SingleOrDefaultAsync(cancellationToken);
+    public record GetPlayListByIdQuery(Guid Id, long? RequestingUserId = null)
+        : IQuery<ErrorOr<PlayListApplicationResponse>>;
 
-        return playList == null
-            ? AppErrors.NotFound("PlayList", request.Id)
-            : playList;
+    public class GetPlayListByIdQueryHandler(IDatabase database)
+        : IQueryHandler<GetPlayListByIdQuery, ErrorOr<PlayListApplicationResponse>>
+    {
+        public async ValueTask<ErrorOr<PlayListApplicationResponse>> Handle(GetPlayListByIdQuery request, CancellationToken cancellationToken)
+        {
+            var entry = await database.PlayLists
+                .AsNoTracking()
+                .Where(p => p.Id == request.Id)
+                .Select(p => new
+                {
+                    PlayList = p,
+                    TrackCount = p.PlayListTracks.Count,
+                    DurationSeconds = p.PlayListTracks.Sum(plt => (double?)plt.Track.DurationSeconds) ?? 0,
+                    CoverTrackIds = p.PlayListTracks
+                        .OrderBy(plt => plt.Position)
+                        .Take(PlayListApplicationResponse.CoverTrackCount)
+                        .Select(plt => plt.TrackId)
+                        .ToList()
+                })
+                .SingleOrDefaultAsync(cancellationToken);
+
+            if (entry == null)
+                return Error.NotFound();
+
+            if (entry.PlayList.Visibility == PlaylistVisibility.Private
+                && entry.PlayList.UserId != request.RequestingUserId)
+                return Error.NotFound();
+
+            return PlayListApplicationResponse.FromEntity(entry.PlayList, entry.TrackCount, entry.DurationSeconds, entry.CoverTrackIds);
+        }
     }
 }

backend/Core/Musify.Application/PlayLists/GetPlayListCover.cs

@@ -0,0 +1,49 @@
+using ErrorOr;
+using Mediator;
+using Microsoft.EntityFrameworkCore;
+using MimeMapping;
+using Musify.Application.Configuration;
+using Musify.Application.Contracts;
+
+namespace Musify.Application.PlayLists
+{
+    public record GetPlayListCoverQuery(Guid PlayListId, string Size)
+        : IQuery<ErrorOr<PlayListCoverLocation>>;
+
+    public record PlayListCoverLocation(string Bucket, string Key, string ContentType);
+
+    public class GetPlayListCoverQueryHandler(
+        IDatabase database,
+        ApplicationStorageConfiguration storageConfiguration,
+        PlayListConfiguration playListConfiguration)
+        : IQueryHandler<GetPlayListCoverQuery, ErrorOr<PlayListCoverLocation>>
+    {
+        public async ValueTask<ErrorOr<PlayListCoverLocation>> Handle(GetPlayListCoverQuery request, CancellationToken cancellationToken)
+        {
+            var pictures = await database.PlayLists.AsNoTracking()
+                .Where(p => p.Id == request.PlayListId)
+                .Select(p => p.Pictures)
+                .SingleOrDefaultAsync(cancellationToken);
+
+            if (pictures == null)
+                return Error.NotFound();
+
+            var routes = playListConfiguration.Routes;
+            var (name, key) = request.Size.ToLowerInvariant() switch
+            {
+                "small" => (pictures.SmallName, BuildKey(routes.BuildSmallPicturePath, pictures.SmallName)),
+                "large" => (pictures.LargeName, BuildKey(routes.BuildLargePicturePath, pictures.LargeName)),
+                _ => (pictures.MediumName, BuildKey(routes.BuildMediumPicturePath, pictures.MediumName))
+            };
+
+            if (string.IsNullOrEmpty(name) || string.IsNullOrEmpty(key))
+                return Error.NotFound();
+
+            var contentType = MimeUtility.GetMimeMapping(name);
+            return new PlayListCoverLocation(storageConfiguration.Bucket, key, contentType);
+        }
+
+        private static string? BuildKey(Func<string, string> builder, string? name)
+            => string.IsNullOrEmpty(name) ? null : builder(name);
+    }
+}

backend/Core/Musify.Application/PlayLists/GetPlayListTracks.cs

@@ -2,40 +2,48 @@ using ErrorOr;
 using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Musify.Application.Contracts;
-using Musify.Application.PlayLists.Responses;
 using Musify.Application.Shared;
 using Musify.Application.Tracks.Responses;
-using Musify.Domain.ValueObjects;
+using X.PagedList;
+using X.PagedList.EF;
 
-namespace Musify.Application.PlayLists;
-
-public record GetPlayListTracksQuery(
-    Guid PlayListId,
-    int PageNumber,
-    int PageSize,
-    long? ViewerId = null)
-    : IQuery<ErrorOr<PaginatedResponse<TrackApplicationResponse>>>;
-
-public class GetPlayListTracksQueryHandler(IDatabase database)
-    : IQueryHandler<GetPlayListTracksQuery, ErrorOr<PaginatedResponse<TrackApplicationResponse>>>
+namespace Musify.Application.PlayLists
 {
-    public async ValueTask<ErrorOr<PaginatedResponse<TrackApplicationResponse>>> Handle(GetPlayListTracksQuery request, CancellationToken cancellationToken)
-    {
-        var playListVisible = await database.PlayLists
-            .AsNoTracking()
-            .Active()
-            .VisibleTo(request.ViewerId)
-            .AnyAsync(playList => playList.Id == request.PlayListId, cancellationToken);
-        if (!playListVisible)
-            return AppErrors.NotFound("PlayList", request.PlayListId);
+    public record GetPlayListTracksQuery(
+        Guid PlayListId,
+        int PageNumber,
+        int PageSize)
+        : IQuery<ErrorOr<PaginatedResponse<TrackApplicationResponse>>>;
 
-        return await database.PlayListHasTracks
-            .AsNoTracking()
-            .Where(playListTrack => playListTrack.PlayListId == request.PlayListId && playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active)
-            .OrderBy(playListTrack => playListTrack.Position)
-            .ThenBy(playListTrack => playListTrack.Id)
-            .Select(playListTrack => playListTrack.Track)
-            .SelectResponse()
-            .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
+    public class GetPlayListTracksQueryHandler(IDatabase database)
+        : IQueryHandler<GetPlayListTracksQuery, ErrorOr<PaginatedResponse<TrackApplicationResponse>>>
+    {
+        public async ValueTask<ErrorOr<PaginatedResponse<TrackApplicationResponse>>> Handle(GetPlayListTracksQuery request, CancellationToken cancellationToken)
+        {
+            var playListExists = await database.PlayLists
+                .AsNoTracking()
+                .AnyAsync(p => p.Id == request.PlayListId, cancellationToken);
+            if (!playListExists)
+                return Error.NotFound();
+
+            var tracksQuery = database.PlayListHasTracks
+                .AsNoTracking()
+                .Include(plt => plt.Track.Owner)
+                .Include(plt => plt.Track.Tags)
+                .Where(plt => plt.PlayListId == request.PlayListId);
+
+            var totalCount = await tracksQuery.CountAsync(cancellationToken);
+
+            var pagedEntities = await tracksQuery
+                .OrderBy(plt => plt.Position)
+                .Select(plt => new { plt.Track, ListensCount = plt.Track.ListeningHistories.Count(l => l.IsCounted) })
+                .ToPagedListAsync(request.PageNumber, request.PageSize, totalCount, cancellationToken);
+
+            var pagedTracks = new StaticPagedList<TrackApplicationResponse>(
+                pagedEntities.Select(x => TrackApplicationResponse.FromEntity(x.Track, x.ListensCount)),
+                pagedEntities.PageNumber, pagedEntities.PageSize, pagedEntities.TotalItemCount);
+
+            return PaginatedResponse<TrackApplicationResponse>.FromPagedList(pagedTracks);
+        }
     }
 }

backend/Core/Musify.Application/PlayLists/GetPlayLists.cs

@@ -0,0 +1,45 @@
+using ErrorOr;
+using Microsoft.EntityFrameworkCore;
+using Musify.Application.Shared;
+using Musify.Application.PlayLists.Responses;
+using X.PagedList;
+using X.PagedList.EF;
+using Mediator;
+using Musify.Application.Contracts;
+
+namespace Musify.Application.PlayLists
+{
+    public record GetPlayListsQuery(int PageNumber, int PageSize)
+        : IQuery<ErrorOr<PaginatedResponse<PlayListApplicationResponse>>>;
+
+    public class GetPlayListsQueryHandler(IDatabase database)
+        : IQueryHandler<GetPlayListsQuery, ErrorOr<PaginatedResponse<PlayListApplicationResponse>>>
+    {
+        public async ValueTask<ErrorOr<PaginatedResponse<PlayListApplicationResponse>>> Handle(GetPlayListsQuery request, CancellationToken cancellationToken)
+        {
+            var totalCount = await database.PlayLists.CountAsync(cancellationToken);
+
+            var pagedEntities = await database.PlayLists
+                .AsNoTracking()
+                .OrderBy(p => p.Id)
+                .Select(p => new
+                {
+                    PlayList = p,
+                    TrackCount = p.PlayListTracks.Count,
+                    DurationSeconds = p.PlayListTracks.Sum(plt => (double?)plt.Track.DurationSeconds) ?? 0,
+                    CoverTrackIds = p.PlayListTracks
+                        .OrderBy(plt => plt.Position)
+                        .Take(PlayListApplicationResponse.CoverTrackCount)
+                        .Select(plt => plt.TrackId)
+                        .ToList()
+                })
+                .ToPagedListAsync(request.PageNumber, request.PageSize, totalCount, cancellationToken);
+
+            var pagedPlayLists = new StaticPagedList<PlayListApplicationResponse>(
+                pagedEntities.Select(entry => PlayListApplicationResponse.FromEntity(entry.PlayList, entry.TrackCount, entry.DurationSeconds, entry.CoverTrackIds)),
+                pagedEntities.PageNumber, pagedEntities.PageSize, pagedEntities.TotalItemCount);
+
+            return PaginatedResponse<PlayListApplicationResponse>.FromPagedList(pagedPlayLists);
+        }
+    }
+}

backend/Core/Musify.Application/PlayLists/GetPlayListsByUserId.cs

@@ -1,40 +1,66 @@
+using ErrorOr;
 using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Musify.Application.Contracts;
 using Musify.Application.PlayLists.Responses;
 using Musify.Application.Shared;
+using Musify.Domain.ValueObjects;
+using X.PagedList;
+using X.PagedList.EF;
 
-namespace Musify.Application.PlayLists;
-
-public record GetPlayListsByUserIdQuery(
-    long UserId,
-    string? Name,
-    int PageNumber,
-    int PageSize,
-    long? ViewerId = null)
-    : IQuery<PaginatedResponse<PlayListApplicationResponse>>;
-
-public class GetPlayListsByUserIdQueryHandler(IDatabase database)
-    : IQueryHandler<GetPlayListsByUserIdQuery, PaginatedResponse<PlayListApplicationResponse>>
+namespace Musify.Application.PlayLists
 {
-    public async ValueTask<PaginatedResponse<PlayListApplicationResponse>> Handle(GetPlayListsByUserIdQuery request, CancellationToken cancellationToken)
+    public record GetPlayListsByUserIdQuery(
+        long UserId,
+        string? Name,
+        int PageNumber,
+        int PageSize,
+        bool OnlyPublic = false)
+        : IQuery<ErrorOr<PaginatedResponse<PlayListApplicationResponse>>>;
+
+    public class GetPlayListsByUserIdQueryHandler(IDatabase database)
+        : IQueryHandler<GetPlayListsByUserIdQuery, ErrorOr<PaginatedResponse<PlayListApplicationResponse>>>
     {
-        var playListsQuery = database.PlayLists
-            .AsNoTracking()
-            .Active()
-            .VisibleTo(request.ViewerId)
-            .Where(playList => playList.OwnerUserId == request.UserId);
-
-        if (!string.IsNullOrWhiteSpace(request.Name))
+        public async ValueTask<ErrorOr<PaginatedResponse<PlayListApplicationResponse>>> Handle(GetPlayListsByUserIdQuery request, CancellationToken cancellationToken)
         {
-            var normalizedName = TextNormalizer.Normalize(request.Name);
-            playListsQuery = playListsQuery.Where(playList => playList.NormalizedName.Contains(normalizedName));
-        }
+            var playListsQuery = database.PlayLists
+                .AsNoTracking()
+                .Where(p => p.UserId == request.UserId);
 
-        return await playListsQuery
-            .OrderBy(playList => playList.CreatedAt)
-            .ThenBy(playList => playList.Id)
-            .SelectResponse()
-            .ToPaginatedAsync(new PageRequest(request.PageNumber, request.PageSize), cancellationToken);
+            if (request.OnlyPublic)
+            {
+                playListsQuery = playListsQuery.Where(p => p.Visibility == PlaylistVisibility.Public);
+            }
+
+            if (!string.IsNullOrEmpty(request.Name))
+            {
+                var normalizedName = request.Name.Trim().ToUpperInvariant();
+                playListsQuery = playListsQuery.Where(p => p.NormalizedName.Contains(normalizedName));
+            }
+
+            var totalCount = await playListsQuery.CountAsync(cancellationToken);
+
+            var pagedEntities = await playListsQuery
+                .OrderBy(p => p.CreatedAt)
+                .Where(p => p.LifeCycleStatus == LifeCycleStatus.Active)
+                .Select(p => new
+                {
+                    PlayList = p,
+                    TrackCount = p.PlayListTracks.Count,
+                    DurationSeconds = p.PlayListTracks.Sum(plt => (double?)plt.Track.DurationSeconds) ?? 0,
+                    CoverTrackIds = p.PlayListTracks
+                        .OrderBy(plt => plt.Position)
+                        .Take(PlayListApplicationResponse.CoverTrackCount)
+                        .Select(plt => plt.TrackId)
+                        .ToList()
+                })
+                .ToPagedListAsync(request.PageNumber, request.PageSize, totalCount, cancellationToken);
+
+            var pagedPlayLists = new StaticPagedList<PlayListApplicationResponse>(
+                pagedEntities.Select(entry => PlayListApplicationResponse.FromEntity(entry.PlayList, entry.TrackCount, entry.DurationSeconds, entry.CoverTrackIds)),
+                pagedEntities.PageNumber, pagedEntities.PageSize, pagedEntities.TotalItemCount);
+
+            return PaginatedResponse<PlayListApplicationResponse>.FromPagedList(pagedPlayLists);
+        }
     }
 }

backend/Core/Musify.Application/PlayLists/RemoveTrackFromPlayList.cs

@@ -3,43 +3,47 @@ using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using Musify.Application.Contracts;
-using Musify.Application.Shared;
 
-namespace Musify.Application.PlayLists;
-
-public record RemoveTrackFromPlayListCommand(long UserId, Guid PlayListId, Guid TrackId)
-    : ICommand<ErrorOr<Success>>;
-
-public class RemoveTrackFromPlayListCommandHandler(
-    IDatabase database,
-    ILogger<RemoveTrackFromPlayListCommandHandler> logger)
-    : ICommandHandler<RemoveTrackFromPlayListCommand, ErrorOr<Success>>
+namespace Musify.Application.PlayLists
 {
-    public async ValueTask<ErrorOr<Success>> Handle(RemoveTrackFromPlayListCommand request, CancellationToken cancellationToken)
+    public record RemoveTrackFromPlayListCommand(long UserId, Guid PlayListId, Guid TrackId)
+        : ICommand<ErrorOr<Success>>;
+
+    public class RemoveTrackFromPlayListCommandHandler(
+        IDatabase database,
+        ILogger<RemoveTrackFromPlayListCommandHandler> logger)
+        : ICommandHandler<RemoveTrackFromPlayListCommand, ErrorOr<Success>>
     {
-        var playList = await database.PlayLists.FindOwnedAsync(request.PlayListId, request.UserId, cancellationToken);
-        if (playList.IsError)
-            return playList.Errors;
+        public async ValueTask<ErrorOr<Success>> Handle(RemoveTrackFromPlayListCommand 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();
+            }
 
-        var playListTracks = await database.PlayListHasTracks
-            .Where(plt => plt.PlayListId == request.PlayListId)
-            .OrderBy(plt => plt.Position)
-            .ToListAsync(cancellationToken);
+            if (playList.UserId != request.UserId)
+            {
+                logger.LogWarning("User {UserId} is not the owner of playlist {PlayListId}", request.UserId, request.PlayListId);
+                return Error.Unauthorized();
+            }
 
-        var link = playListTracks.SingleOrDefault(plt => plt.TrackId == request.TrackId);
-        if (link == null)
-            return Error.NotFound("PlayList.TrackNotFound", "Track is not in the playlist.");
+            var link = await database.PlayListHasTracks
+                .SingleOrDefaultAsync(plt => plt.PlayListId == request.PlayListId && plt.TrackId == request.TrackId, cancellationToken);
+            if (link == null)
+            {
+                logger.LogInformation("Track {TrackId} not in playlist {PlayListId}", request.TrackId, request.PlayListId);
+                return Error.NotFound(description: "Track is not in the playlist.");
+            }
 
-        database.PlayListHasTracks.Remove(link);
+            database.PlayListHasTracks.Remove(link);
+            await database.SaveChangesAsync(cancellationToken);
 
-        var position = 0;
-        foreach (var remaining in playListTracks.Where(plt => plt.Id != link.Id))
-            remaining.Position = position++;
+            logger.LogInformation("Removed track {TrackId} from playlist {PlayListId}", request.TrackId, request.PlayListId);
 
-        await database.SaveChangesAsync(cancellationToken);
-
-        logger.LogInformation("Removed track {TrackId} from playlist {PlayListId}", request.TrackId, request.PlayListId);
-
-        return Result.Success;
+            return new Success();
+        }
     }
 }

backend/Core/Musify.Application/PlayLists/RequestPlayListPictureUpload.cs

@@ -1,24 +1,105 @@
 using ErrorOr;
 using Mediator;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
 using Musify.Application.Configuration;
-using Musify.Application.Pictures.Responses;
+using Musify.Application.PlayLists.Responses;
 using Musify.Application.Services;
+using Musify.Domain.Entities;
 using Musify.Domain.ValueObjects;
+using Musify.Application.Contracts;
 
-namespace Musify.Application.PlayLists;
-
-public record RequestPlayListPictureUploadCommand(
-    long UserId,
-    string FileType,
-    string ContentType,
-    long? ExpectedSizeBytes = null)
-    : ICommand<ErrorOr<PictureUploadResponse>>;
-
-public class RequestPlayListPictureUploadCommandHandler(UploadIntentIssuer issuer, PlayListConfiguration playListConfiguration)
-    : ICommandHandler<RequestPlayListPictureUploadCommand, ErrorOr<PictureUploadResponse>>
+namespace Musify.Application.PlayLists
 {
-    public async ValueTask<ErrorOr<PictureUploadResponse>> Handle(RequestPlayListPictureUploadCommand request, CancellationToken cancellationToken) =>
-        await issuer.IssuePictureAsync(
-            request.UserId, UploadIntentPurpose.PlayListPicture, playListConfiguration,
-            request.FileType, request.ContentType, request.ExpectedSizeBytes, cancellationToken);
+    public record RequestPlayListPictureUploadCommand(
+        long UserId,
+        string FileType,
+        string ContentType,
+        long? ExpectedSizeBytes = null)
+        : ICommand<ErrorOr<PlayListPictureUploadResponse>>;
+
+    public class RequestPlayListPictureUploadCommandHandler(
+        IDatabase database,
+        UploadIntentValidator uploadIntentValidator,
+        IStorageService storageService,
+        ILogger<RequestPlayListPictureUploadCommandHandler> logger,
+        ApplicationStorageConfiguration storageConfiguration,
+        PlayListConfiguration playListConfiguration,
+        UploadIntentConfiguration uploadIntentConfiguration)
+        : ICommandHandler<RequestPlayListPictureUploadCommand, ErrorOr<PlayListPictureUploadResponse>>
+    {
+        public async ValueTask<ErrorOr<PlayListPictureUploadResponse>> Handle(RequestPlayListPictureUploadCommand request, CancellationToken cancellationToken)
+        {
+            var userExists = await database.Users
+                .AsNoTracking()
+                .AnyAsync(u => u.Id == request.UserId, cancellationToken);
+            if (!userExists)
+            {
+                logger.LogWarning("User {UserId} not found", request.UserId);
+                return Error.NotFound(description: $"User {request.UserId} not found");
+            }
+
+            var effectiveSizeBytes = request.ExpectedSizeBytes
+                ?? uploadIntentConfiguration.DefaultExpectedPictureSizeBytes;
+
+            var objectName = $"{Guid.NewGuid()}.{request.FileType.TrimStart('.').ToLowerInvariant()}";
+
+            var tempKey = playListConfiguration.Routes.BuildTempPicturePath(
+                uploadIntentConfiguration.TemporalRootPrefix, request.UserId, objectName);
+
+            try
+            {
+                var uploadUrl = await storageService.GetUploadUrlAsync(
+                    storageConfiguration.Bucket,
+                    tempKey,
+                    request.ContentType,
+                    TimeSpan.FromSeconds(uploadIntentConfiguration.UploadUrlExpiresInSeconds),
+                    cancellationToken);
+
+                await using var transaction = await database.BeginTransactionAsync(
+                    System.Data.IsolationLevel.Serializable, cancellationToken);
+
+                var quotaCheck = await uploadIntentValidator.CheckQuotaAsync(
+                    uploadIntentConfiguration,
+                    request.UserId, effectiveSizeBytes, 1, cancellationToken);
+                if (quotaCheck.IsError)
+                {
+                    logger.LogWarning("User {UserId} failed upload intent quota check", request.UserId);
+                    return quotaCheck.Errors;
+                }
+
+                var intent = new UploadIntent
+                {
+                    UserId = request.UserId,
+                    Bucket = storageConfiguration.Bucket,
+                    Key = tempKey,
+                    ObjectName = objectName,
+                    ContentType = request.ContentType,
+                    ExpectedSizeBytes = effectiveSizeBytes,
+                    Purpose = UploadIntentPurpose.PlayListPicture,
+                    ExpiresAt = DateTime.UtcNow.AddSeconds(uploadIntentConfiguration.UploadUrlExpiresInSeconds),
+                };
+
+                await database.UploadIntents.AddAsync(intent, cancellationToken);
+                await database.SaveChangesAsync(cancellationToken);
+                await transaction.CommitAsync(cancellationToken);
+
+                logger.LogInformation("Issued upload intent {IntentId} for user {UserId} (PlayListPicture, temp key: {Key})", intent.Id, request.UserId, tempKey);
+
+                return new PlayListPictureUploadResponse(
+                    intent.Id,
+                    storageConfiguration.Bucket,
+                    tempKey,
+                    objectName,
+                    request.ContentType,
+                    uploadIntentConfiguration.UploadUrlExpiresInSeconds,
+                    uploadUrl);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to generate playlist picture upload URL for user {UserId}", request.UserId);
+                return Error.Failure(description: "Failed to generate upload URL");
+            }
+        }
+    }
 }

backend/Core/Musify.Application/PlayLists/Responses/AddAlbumToPlayListResponse.cs

@@ -0,0 +1,4 @@
+namespace Musify.Application.PlayLists.Responses
+{
+    public record AddAlbumToPlayListResponse(int AddedCount);
+}

backend/Core/Musify.Application/PlayLists/Responses/PlayListApplicationResponse.cs

@@ -1,45 +1,47 @@
+using System.Text.Json.Serialization;
+using Musify.Application.Serialization;
 using Musify.Domain.Entities;
 using Musify.Domain.ValueObjects;
 
-
-namespace Musify.Application.PlayLists.Responses;
-
-public record PlayListApplicationResponse(
-    Guid Id,
-    string Name,
-    string? Description,
-    string? SmallImageKeyName,
-    string? MediumImageKeyName,
-    string? LargeImageKeyName,
-    PlayListVisibility Visibility,
-    DateTime CreatedAt,
-    DateTime UpdatedAt,
-    IReadOnlyList<Guid> CoverTrackIds,
-    long OwnerUserId,
-    int TrackCount,
-    double DurationSeconds)
+namespace Musify.Application.PlayLists.Responses
 {
-    public const int CoverTrackCount = PlayListProjections.CoverTrackCount;
-
-    public static PlayListApplicationResponse FromEntity(
-        PlayList playList,
-        IReadOnlyList<Guid>? coverTrackIds = null,
-        int trackCount = 0,
-        double durationSeconds = 0)
+    public record PlayListApplicationResponse(
+        Guid Id,
+        string Name,
+        string? Description,
+        string? SmallImageKeyName,
+        string? MediumImageKeyName,
+        string? LargeImageKeyName,
+        [property: JsonConverter(typeof(LongAsStringConverter))] long OwnerUserId,
+        PlaylistVisibility Visibility,
+        int TrackCount,
+        double DurationSeconds,
+        DateTime CreatedAt,
+        DateTime UpdatedAt,
+        IReadOnlyList<Guid> CoverTrackIds)
     {
-        return new PlayListApplicationResponse(
-            playList.Id,
-            playList.Name,
-            playList.Description,
-            playList.Pictures?.SmallName,
-            playList.Pictures?.MediumName,
-            playList.Pictures?.LargeName,
-            playList.Visibility,
-            playList.CreatedAt,
-            playList.UpdatedAt,
-            coverTrackIds ?? [],
-            playList.OwnerUserId,
-            trackCount,
-            durationSeconds);
+        public const int CoverTrackCount = 4;
+
+        public static PlayListApplicationResponse FromEntity(
+            PlayList playList,
+            int trackCount = 0,
+            double durationSeconds = 0,
+            IReadOnlyList<Guid>? coverTrackIds = null)
+        {
+            return new PlayListApplicationResponse(
+                playList.Id,
+                playList.Name,
+                playList.Description,
+                playList.Pictures?.SmallName,
+                playList.Pictures?.MediumName,
+                playList.Pictures?.LargeName,
+                playList.UserId,
+                playList.Visibility,
+                trackCount,
+                durationSeconds,
+                playList.CreatedAt,
+                playList.UpdatedAt,
+                coverTrackIds ?? []);
+        }
     }
 }

backend/Core/Musify.Application/PlayLists/Responses/PlayListPictureUploadResponse.cs

@@ -0,0 +1,11 @@
+namespace Musify.Application.PlayLists.Responses
+{
+    public record PlayListPictureUploadResponse(
+        Guid IntentId,
+        string Bucket,
+        string Key,
+        string PictureName,
+        string ContentType,
+        int ExpiresInSeconds,
+        string UploadUrl);
+}

backend/Core/Musify.Application/PlayLists/Responses/PlayListProjections.cs

@@ -1,37 +0,0 @@
-using Musify.Domain.Entities;
-using Musify.Domain.ValueObjects;
-
-namespace Musify.Application.PlayLists.Responses;
-
-public static class PlayListProjections
-{
-    public const int CoverTrackCount = 4;
-
-    public static IQueryable<PlayList> Active(this IQueryable<PlayList> query) =>
-        query.Where(playList => playList.LifeCycleStatus == LifeCycleStatus.Active);
-
-    public static IQueryable<PlayList> VisibleTo(this IQueryable<PlayList> query, long? viewerId) =>
-        query.Where(playList => playList.Visibility == PlayListVisibility.Public || playList.OwnerUserId == viewerId);
-
-    public static IQueryable<PlayListApplicationResponse> SelectResponse(this IQueryable<PlayList> query) =>
-        query.Select(playList => new PlayListApplicationResponse(
-            playList.Id,
-            playList.Name,
-            playList.Description,
-            playList.Pictures!.SmallName,
-            playList.Pictures!.MediumName,
-            playList.Pictures!.LargeName,
-            playList.Visibility,
-            playList.CreatedAt,
-            playList.UpdatedAt,
-            playList.PlayListTracks
-                .OrderBy(playListTrack => playListTrack.Position)
-                .Take(CoverTrackCount)
-                .Select(playListTrack => playListTrack.TrackId)
-                .ToList(),
-            playList.OwnerUserId,
-            playList.PlayListTracks.Count(playListTrack => playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active),
-            playList.PlayListTracks
-                .Where(playListTrack => playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active)
-                .Sum(playListTrack => playListTrack.Track.DurationSeconds)));
-}

backend/Core/Musify.Application/PlayLists/UpdatePlayList.cs

@@ -3,78 +3,168 @@ using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using Musify.Application.Configuration;
-using Musify.Application.Contracts;
+using Musify.Application.Shared;
 using Musify.Application.Events;
-using Musify.Application.Pictures;
 using Musify.Application.PlayLists.Responses;
 using Musify.Application.Services;
-using Musify.Application.Shared;
+using Musify.Domain.Entities;
 using Musify.Domain.ValueObjects;
+using Musify.Application.Contracts;
 
-namespace Musify.Application.PlayLists;
-
-public record UpdatePlayListCommand(
-    long UserId,
-    Guid PlayListId,
-    string? NewName,
-    string? NewDescription,
-    Guid? NewPictureIntentId,
-    PlayListVisibility? NewVisibility = null)
-    : ICommand<ErrorOr<PlayListApplicationResponse>>;
-
-public class UpdatePlayListCommandHandler(
-    IEventBus eventBus,
-    IDatabase database,
-    UploadIntentValidator uploadIntentValidator,
-    ILogger<UpdatePlayListCommandHandler> logger,
-    PlayListConfiguration playListConfiguration)
-    : ICommandHandler<UpdatePlayListCommand, ErrorOr<PlayListApplicationResponse>>
+namespace Musify.Application.PlayLists
 {
-    public async ValueTask<ErrorOr<PlayListApplicationResponse>> Handle(UpdatePlayListCommand request, CancellationToken cancellationToken)
+    public record UpdatePlayListCommand(
+        long UserId,
+        Guid PlayListId,
+        string? NewName,
+        string? NewDescription,
+        Guid? NewPictureIntentId,
+        PlaylistVisibility? NewVisibility = null)
+        : ICommand<ErrorOr<PlayListApplicationResponse>>;
+
+    public class UpdatePlayListCommandHandler(
+        IEventBus eventBus,
+        IDatabase database,
+        UploadIntentValidator uploadIntentValidator,
+        ILogger<UpdatePlayListCommandHandler> logger,
+        ApplicationStorageConfiguration storageConfiguration,
+        PlayListConfiguration playListConfiguration,
+        UploadIntentConfiguration uploadIntentConfiguration)
+        : ICommandHandler<UpdatePlayListCommand, ErrorOr<PlayListApplicationResponse>>
     {
-        var found = await database.PlayLists.FindOwnedAsync(request.PlayListId, request.UserId, cancellationToken);
-        if (found.IsError)
-            return found.Errors;
-
-        var playList = found.Value;
-
-        if (!string.IsNullOrWhiteSpace(request.NewName))
+        public async ValueTask<ErrorOr<PlayListApplicationResponse>> Handle(UpdatePlayListCommand request, CancellationToken cancellationToken)
         {
-            playList.Name = request.NewName.Trim();
-            playList.NormalizedName = TextNormalizer.Normalize(request.NewName);
+            var playListEntity = await database.PlayLists.SingleOrDefaultAsync(pl => pl.Id == request.PlayListId, cancellationToken);
+            if (playListEntity == null)
+            {
+                logger.LogInformation("Playlist {PlayListId} not found", request.PlayListId);
+                return Error.NotFound();
+            }
+
+            if (playListEntity.UserId != request.UserId)
+            {
+                logger.LogWarning("User {UserId} is not the owner of playlist {PlayListId}", request.UserId, request.PlayListId);
+                return Error.Unauthorized();
+            }
+
+            if (!string.IsNullOrWhiteSpace(request.NewName))
+            {
+                playListEntity.Name = request.NewName;
+                playListEntity.NormalizedName = request.NewName.Trim().ToUpperInvariant();
+            }
+
+            if (!string.IsNullOrWhiteSpace(request.NewDescription))
+            {
+                playListEntity.Description = request.NewDescription;
+            }
+
+            if (request.NewVisibility.HasValue)
+            {
+                playListEntity.Visibility = request.NewVisibility.Value;
+            }
+
+            UploadIntent? pictureIntent = null;
+            string? finalPictureKey = null;
+
+            if (request.NewPictureIntentId.HasValue)
+            {
+                var validation = await uploadIntentValidator.ValidateAndLoadAsync(
+                    uploadIntentConfiguration,
+                    request.NewPictureIntentId.Value, request.UserId, cancellationToken);
+                if (validation.IsError)
+                    return validation.Errors;
+
+                pictureIntent = validation.Value;
+                playListEntity.Pictures = new PlayListPictures
+                {
+                    OriginalName = pictureIntent.ObjectName,
+                    SmallName = pictureIntent.ObjectName,
+                    MediumName = pictureIntent.ObjectName,
+                    LargeName = pictureIntent.ObjectName
+                };
+                finalPictureKey = playListConfiguration.Routes.BuildOriginalPicturePath(request.UserId, pictureIntent.ObjectName);
+            }
+
+            if (pictureIntent != null && finalPictureKey != null)
+            {
+                var publishResult = await PublishUpdatePlayListPictureSourceEventAsync(
+                    playListEntity.Id, pictureIntent, finalPictureKey, cancellationToken);
+                if (publishResult.IsError)
+                    return publishResult.Errors;
+            }
+
+            try
+            {
+                await database.SaveChangesAsync(cancellationToken);
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to update playlist {PlayListId}", playListEntity.Id);
+                return Error.Failure(description: $"Failed to update playlist {playListEntity.Id}");
+            }
+
+            var coverTrackIds = await database.PlayListHasTracks
+                .AsNoTracking()
+                .Where(plt => plt.PlayListId == playListEntity.Id)
+                .OrderBy(plt => plt.Position)
+                .Take(PlayListApplicationResponse.CoverTrackCount)
+                .Select(plt => plt.TrackId)
+                .ToListAsync(cancellationToken);
+
+            logger.LogInformation("Updated playlist {PlayListId}", playListEntity.Id);
+            var totals = await database.PlayListHasTracks
+                .AsNoTracking()
+                .Where(plt => plt.PlayListId == playListEntity.Id)
+                .GroupBy(plt => plt.PlayListId)
+                .Select(group => new
+                {
+                    TrackCount = group.Count(),
+                    DurationSeconds = group.Sum(plt => plt.Track.DurationSeconds)
+                })
+                .SingleOrDefaultAsync(cancellationToken);
+
+            return PlayListApplicationResponse.FromEntity(
+                playListEntity,
+                totals?.TrackCount ?? 0,
+                totals?.DurationSeconds ?? 0,
+                coverTrackIds);
         }
 
-        // null means "unchanged"; a blank description clears it.
-        if (request.NewDescription != null)
-            playList.Description = string.IsNullOrWhiteSpace(request.NewDescription) ? null : request.NewDescription.Trim();
-
-        if (request.NewVisibility is { } visibility)
-            playList.Visibility = visibility;
-
-        if (request.NewPictureIntentId is { } intentId)
+        private async Task<ErrorOr<Success>> PublishUpdatePlayListPictureSourceEventAsync(
+            Guid playListId,
+            UploadIntent pictureIntent,
+            string finalPictureKey,
+            CancellationToken cancellationToken)
         {
-            var prepared = await PictureSourceChange.PrepareAsync(
-                uploadIntentValidator, intentId, request.UserId, UploadIntentPurpose.PlayListPicture, playListConfiguration, cancellationToken);
-            if (prepared.IsError)
-                return prepared.Errors;
-
-            var picture = prepared.Value;
-            playList.Pictures = picture.Pictures;
-
-            await eventBus.PublishAsync(
-                new UpdatePlayListPictureSourceEvent(
-                    playList.Id, picture.Intent.Id, picture.Intent.Bucket, picture.Intent.Key, picture.FinalKey, picture.Sizes),
-                cancellationToken);
+            try
+            {
+                await eventBus.PublishAsync(
+                    new UpdatePlayListPictureSourceEvent(
+                        playListId,
+                        pictureIntent.Id,
+                        storageConfiguration.Bucket,
+                        pictureIntent.Key,
+                        finalPictureKey,
+                        new ImageSize(
+                            playListConfiguration.Routes.SmallPicturesPath,
+                            playListConfiguration.PicturesSizes.SmallPictureWidth,
+                            playListConfiguration.PicturesSizes.SmallPictureHeight),
+                        new ImageSize(
+                            playListConfiguration.Routes.MediumPicturesPath,
+                            playListConfiguration.PicturesSizes.MediumPictureWidth,
+                            playListConfiguration.PicturesSizes.MediumPictureHeight),
+                        new ImageSize(
+                            playListConfiguration.Routes.LargePicturesPath,
+                            playListConfiguration.PicturesSizes.LargePictureWidth,
+                            playListConfiguration.PicturesSizes.LargePictureHeight)),
+                    cancellationToken);
+                return new Success();
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Failed to publish update playlist picture source event for playlist {PlayListId}", playListId);
+                return Error.Failure(description: $"Failed to publish update playlist picture source event for playlist {playListId}");
+            }
         }
-
-        await database.SaveChangesAsync(cancellationToken);
-
-        logger.LogInformation("Updated playlist {PlayListId}", playList.Id);
-
-        return await database.PlayLists
-            .AsNoTracking()
-            .Where(p => p.Id == playList.Id)
-            .SelectResponse()
-            .SingleAsync(cancellationToken);
     }
 }