[DB] Auto update datetimes on entities

Manager.Data/Contexts/LibraryDbContext.cs

@@ -1,3 +1,4 @@
+using Manager.Data.Entities;
 using Manager.Data.Entities.LibraryContext;
 using Manager.Data.Entities.LibraryContext.Join;
 using Microsoft.EntityFrameworkCore;
@@ -99,4 +100,31 @@ public sealed class LibraryDbContext : DbContext
         
         base.OnModelCreating(modelBuilder);
     }
+
+    public override int SaveChanges()
+    {
+        UpdateEntryDates();
+        return base.SaveChanges();
+    }
+
+    public override Task<int> SaveChangesAsync(bool acceptAllChangesOnSuccess, CancellationToken cancellationToken = new())
+    {
+        UpdateEntryDates();
+        return base.SaveChangesAsync(acceptAllChangesOnSuccess, cancellationToken);
+    }
+
+    private void UpdateEntryDates()
+    {
+        var entries = ChangeTracker.Entries().Where(x => x is { Entity: DateTimeBase, State: EntityState.Added or EntityState.Modified });
+
+        foreach (var entity in entries)
+        {
+            ((DateTimeBase)entity.Entity).LastModifiedUtc = DateTime.UtcNow;
+
+            if (entity.State == EntityState.Added)
+            {
+                ((DateTimeBase)entity.Entity).CreatedAtUtc = DateTime.UtcNow;
+            }
+        }
+    }
 }