Добавьте файлы проекта.

PlaylistShared.Api/Services/TrackAdditionLogService.cs

@@ -0,0 +1,44 @@
+using Microsoft.EntityFrameworkCore;
+using PlaylistShared.Api.Data;
+using PlaylistShared.Api.Entities;
+
+namespace PlaylistShared.Api.Services;
+
+public class TrackAdditionLogService
+{
+    private readonly ApplicationDbContext _db;
+
+    public TrackAdditionLogService(ApplicationDbContext db)
+    {
+        _db = db;
+    }
+
+    public async Task LogAdditionAsync(Guid sharedPlaylistId, string trackId, Guid addedByUserId)
+    {
+        var log = new TrackAdditionLogEntity
+        {
+            Id = Guid.NewGuid(),
+            SharedPlaylistId = sharedPlaylistId,
+            TrackId = trackId,
+            AddedByUserId = addedByUserId,
+            AddedAtUtc = DateTime.UtcNow
+        };
+        _db.TrackAdditionLogs.Add(log);
+        await _db.SaveChangesAsync();
+    }
+
+    public async Task<bool> IsTrackAddedByUserAsync(Guid sharedPlaylistId, string trackId, Guid userId)
+    {
+        return await _db.TrackAdditionLogs
+            .AnyAsync(l => l.SharedPlaylistId == sharedPlaylistId && l.TrackId == trackId && l.AddedByUserId == userId);
+    }
+
+    public async Task RemoveLogsForTrackAsync(Guid sharedPlaylistId, string trackId)
+    {
+        var logs = await _db.TrackAdditionLogs
+            .Where(l => l.SharedPlaylistId == sharedPlaylistId && l.TrackId == trackId)
+            .ToListAsync();
+        _db.TrackAdditionLogs.RemoveRange(logs);
+        await _db.SaveChangesAsync();
+    }
+}