backend/Musify.Api/Endpoints/PlayListEndpoints.cs

@@ -3,6 +3,7 @@ using Musify.Application.PlayLists;
 using Musify.Application.PlayLists.Responses;
 using Musify.Application.Tracks.Responses;
 using Musify.Application.Shared;
+using Musify.Application.Contracts;
 using Musify.Api.Authentication;
 using Musify.Api.DataTransferObjects.PlayLists;
 using Musify.Api.Extensions;
@@ -39,6 +40,12 @@ public static class PlayListEndpoints
             .Produces<PaginatedResponse<TrackApplicationResponse>>()
             .Produces(StatusCodes.Status404NotFound);
 
+        group.MapGet("/{id}/cover", GetPlayListCover)
+            .WithName("GetPlayListCover")
+            .WithSummary("Get A PlayList Cover Image.")
+            .Produces(StatusCodes.Status200OK)
+            .Produces(StatusCodes.Status404NotFound);
+
         group.MapPost("/", CreatePlayList)
             .WithName("CreatePlayList")
             .WithSummary("Create A New PlayList.")
@@ -139,14 +146,36 @@ public static class PlayListEndpoints
         return result.ToHttpResult();
     }
 
+    private static async Task<IResult> GetPlayListCover(
+        IMediator mediator,
+        IStorageService storageService,
+        HttpResponse response,
+        Guid id,
+        CancellationToken cancellationToken,
+        string size = "medium")
+    {
+        var result = await mediator.Send(new GetPlayListCoverQuery(id, size), cancellationToken);
+        if (result.IsError)
+            return Results.NotFound();
+
+        var location = result.Value;
+        var stream = await storageService.GetFileAsync(location.Bucket, location.Key, cancellationToken);
+        response.Headers.CacheControl = "public, max-age=31536000, immutable";
+        return Results.Stream(stream, location.ContentType);
+    }
+
     private static async Task<IResult> CreatePlayList(
         IMediator mediator,
         CurrentUser currentUser,
         CreatePlayListRequest request,
         CancellationToken cancellationToken)
     {
+        var description = string.IsNullOrWhiteSpace(request.Description)
+            ? "No description was provided."
+            : request.Description;
+
         var result = await mediator.Send(
-            new CreatePlayListCommand(currentUser.RequiredId, request.Name, request.Description, request.PictureIntentId),
+            new CreatePlayListCommand(currentUser.RequiredId, request.Name, description, request.PictureIntentId),
             cancellationToken);
 
         return result.ToCreatedResult(playList => $"/playlists/{playList.Id}");

backend/Musify.Api/Validators/PlayLists/CreatePlayListRequestValidator.cs

@@ -12,7 +12,6 @@ public sealed class CreatePlayListRequestValidator : AbstractValidator<CreatePla
             .MaximumLength(50);
 
         RuleFor(x => x.Description)
-            .NotEmpty()
             .MaximumLength(256);
     }
 }

backend/Musify.Api/Validators/PlayLists/UpdatePlayListRequestValidator.cs

@@ -13,7 +13,6 @@ public sealed class UpdatePlayListRequestValidator : AbstractValidator<UpdatePla
             .When(x => x.NewName is not null);
 
         RuleFor(x => x.NewDescription)
-            .NotEmpty()
             .MaximumLength(256)
             .When(x => x.NewDescription is not null);
     }

backend/Musify.Application/Musify.Application.csproj

@@ -13,6 +13,7 @@
     <PackageReference Include="Microsoft.Extensions.Configuration.Binder" />
     <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>

backend/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 playList = await database.PlayLists.AsNoTracking()
+                .Where(p => p.Id == request.PlayListId)
+                .Select(p => new { p.SmallPictureName, p.MediumPictureName, p.LargePictureName })
+                .SingleOrDefaultAsync(cancellationToken);
+
+            if (playList == null)
+                return Error.NotFound();
+
+            var routes = playListConfiguration.Routes;
+            var (name, key, presetName) = request.Size.ToLowerInvariant() switch
+            {
+                "small" => (playList.SmallPictureName, BuildKey(routes.BuildSmallPicturePath, playList.SmallPictureName), routes.PresetSmallPicture),
+                "large" => (playList.LargePictureName, BuildKey(routes.BuildLargePicturePath, playList.LargePictureName), routes.PresetLargePicture),
+                _ => (playList.MediumPictureName, BuildKey(routes.BuildMediumPicturePath, playList.MediumPictureName), routes.PresetMediumPicture)
+            };
+
+            if (string.IsNullOrEmpty(name) || string.IsNullOrEmpty(key) || name == presetName)
+                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);
+    }
+}