feat(backend): expose the first cover track ids of playlists and albums

backend/Musify.Application/PlayLists/GetPlayListById.cs

@@ -14,16 +14,24 @@ namespace Musify.Application.PlayLists
     {
         public async ValueTask<ErrorOr<PlayListApplicationResponse>> Handle(GetPlayListByIdQuery request, CancellationToken cancellationToken)
         {
-            var playList = await database.PlayLists
+            var entry = await database.PlayLists
                 .AsNoTracking()
                 .Where(p => p.Id == request.Id)
-                .Select(p => PlayListApplicationResponse.FromEntity(p))
+                .Select(p => new
+                {
+                    PlayList = p,
+                    CoverTrackIds = p.PlayListTracks
+                        .OrderBy(plt => plt.Position)
+                        .Take(PlayListApplicationResponse.CoverTrackCount)
+                        .Select(plt => plt.TrackId)
+                        .ToList()
+                })
                 .SingleOrDefaultAsync(cancellationToken);
 
-            if (playList is null)
+            if (entry is null)
                 return Error.NotFound();
 
-            return playList;
+            return PlayListApplicationResponse.FromEntity(entry.PlayList, entry.CoverTrackIds);
         }
     }
 }

backend/Musify.Application/PlayLists/GetPlayLists.cs

@@ -2,6 +2,7 @@ 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;
@@ -18,12 +19,24 @@ namespace Musify.Application.PlayLists
         {
             var totalCount = await database.PlayLists.CountAsync(cancellationToken);
 
-            var pagedPlayLists = await database.PlayLists
+            var pagedEntities = await database.PlayLists
                 .AsNoTracking()
                 .OrderBy(p => p.Id)
-                .Select(p => PlayListApplicationResponse.FromEntity(p))
+                .Select(p => new
+                {
+                    PlayList = p,
+                    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.CoverTrackIds)),
+                pagedEntities.PageNumber, pagedEntities.PageSize, pagedEntities.TotalItemCount);
+
             return PaginatedResponse<PlayListApplicationResponse>.FromPagedList(pagedPlayLists);
         }
     }

backend/Musify.Application/PlayLists/GetPlayListsByUserId.cs

@@ -2,6 +2,7 @@ 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;
@@ -32,11 +33,23 @@ namespace Musify.Application.PlayLists
 
             var totalCount = await playListsQuery.CountAsync(cancellationToken);
 
-            var pagedPlayLists = await playListsQuery
+            var pagedEntities = await playListsQuery
                 .OrderBy(p => p.CreatedAt)
-                .Select(p => PlayListApplicationResponse.FromEntity(p))
+                .Select(p => new
+                {
+                    PlayList = p,
+                    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.CoverTrackIds)),
+                pagedEntities.PageNumber, pagedEntities.PageSize, pagedEntities.TotalItemCount);
+
             return PaginatedResponse<PlayListApplicationResponse>.FromPagedList(pagedPlayLists);
         }
     }

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

@@ -1,4 +1,4 @@
-using Musify.Domain.Entities;
+using Musify.Domain.Entities;
 
 namespace Musify.Application.PlayLists.Responses
 {
@@ -10,9 +10,14 @@ namespace Musify.Application.PlayLists.Responses
         string? MediumImageKeyName,
         string? LargeImageKeyName,
         DateTime CreatedAt,
-        DateTime UpdatedAt)
+        DateTime UpdatedAt,
+        IReadOnlyList<Guid> CoverTrackIds)
     {
-        public static PlayListApplicationResponse FromEntity(PlayList playList)
+        public const int CoverTrackCount = 4;
+
+        public static PlayListApplicationResponse FromEntity(
+            PlayList playList,
+            IReadOnlyList<Guid>? coverTrackIds = null)
         {
             return new PlayListApplicationResponse(
                 playList.Id,
@@ -22,7 +27,8 @@ namespace Musify.Application.PlayLists.Responses
                 playList.Pictures?.MediumName,
                 playList.Pictures?.LargeName,
                 playList.CreatedAt,
-                playList.UpdatedAt);
+                playList.UpdatedAt,
+                coverTrackIds ?? []);
         }
     }
-}
+}

backend/Musify.Application/PlayLists/UpdatePlayList.cs

@@ -93,8 +93,16 @@ namespace Musify.Application.PlayLists
                 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);
-            return PlayListApplicationResponse.FromEntity(playListEntity);
+            return PlayListApplicationResponse.FromEntity(playListEntity, coverTrackIds);
         }
 
         async Task<ErrorOr<Success>> PublishUpdatePlayListPictureSourceEventAsync(