feat: recommend server-generated mixes from Musify and YouTube Music

Mixes are their own concept, not playlists: they live in their own Mixes/MixItems tables, cannot be edited and never show up among the user's playlists. Each item is either a Musify track or a YouTube Music reference, so YouTube songs stream directly instead of being downloaded. A daily Hangfire job seeds the mixes from the listening history: one discovery mix, one daily mix and one per top artist. The per-user YouTube filler query was already in the working tree and rides along here because it shares files with this change.
2026-07-21 18:13:07 +02:00
parent 2cb51f540e
commit 90e842d084
36 changed files with 2667 additions and 13 deletions
@@ -0,0 +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<ErrorOr<IReadOnlyList<MixApplicationResponse>>>;
+
+    public class GetMixesByUserIdQueryHandler(IDatabase database)
+        : IQueryHandler<GetMixesByUserIdQuery, ErrorOr<IReadOnlyList<MixApplicationResponse>>>
+    {
+        public async ValueTask<ErrorOr<IReadOnlyList<MixApplicationResponse>>> Handle(GetMixesByUserIdQuery request, CancellationToken cancellationToken)
+        {
+            var entries = await database.Mixes
+                .AsNoTracking()
+                .Where(mix => mix.UserId == request.UserId)
+                .OrderBy(mix => mix.Position)
+                .Select(mix => new
+                {
+                    Mix = mix,
+                    ItemCount = mix.Items.Count,
+                    CoverItems = mix.Items
+                        .OrderBy(item => item.Position)
+                        .Take(MixApplicationResponse.CoverItemCount)
+                        .ToList()
+                })
+                .ToListAsync(cancellationToken);
+
+            return entries
+                .Select(entry => MixApplicationResponse.FromEntity(entry.Mix, entry.ItemCount, entry.CoverItems))
+                .ToList();
+        }
+    }
+}