[backend/federation] Correctly serialize value types

Iceshrimp.Backend/Controllers/Mastodon/Renderers/NoteRenderer.cs

@@ -103,8 +103,8 @@ public class NoteRenderer(
 			Renote         = renote,
 			Quote          = quote,
 			ContentType    = "text/x.misskeymarkdown",
-			CreatedAt      = note.CreatedAt.ToStringMastodon(),
+			CreatedAt      = note.CreatedAt.ToStringIso8601Like(),
-			EditedAt       = note.UpdatedAt?.ToStringMastodon(),
+			EditedAt       = note.UpdatedAt?.ToStringIso8601Like(),
 			RepliesCount   = note.RepliesCount,
 			RenoteCount    = note.RenoteCount,
 			FavoriteCount  = likeCount,

Iceshrimp.Backend/Controllers/Mastodon/Renderers/NotificationRenderer.cs

@@ -37,7 +37,7 @@ public class NotificationRenderer(NoteRenderer noteRenderer, UserRenderer userRe
 			Type      = NotificationEntity.EncodeType(notification.Type),
 			Note      = note,
 			Notifier  = notifier,
-			CreatedAt = notification.CreatedAt.ToStringMastodon()
+			CreatedAt = notification.CreatedAt.ToStringIso8601Like()
 		};
 
 		return res;

Iceshrimp.Backend/Controllers/Mastodon/Renderers/UserRenderer.cs

@@ -26,7 +26,7 @@ public class UserRenderer(IOptions<Config.InstanceSection> config, MfmConverter
 			Acct               = acct,
 			FullyQualifiedName = $"{user.Username}@{user.Host ?? config.Value.AccountDomain}",
 			IsLocked           = user.IsLocked,
-			CreatedAt          = user.CreatedAt.ToStringMastodon(),
+			CreatedAt          = user.CreatedAt.ToStringIso8601Like(),
 			FollowersCount     = user.FollowersCount,
 			FollowingCount     = user.FollowingCount,
 			StatusesCount      = user.NotesCount,

Iceshrimp.Backend/Core/Configuration/Constants.cs

@@ -5,6 +5,7 @@ public static class Constants
 	public const           string   ActivityStreamsNs = "https://www.w3.org/ns/activitystreams";
 	public const           string   W3IdSecurityNs    = "https://w3id.org/security";
 	public const           string   PurlDcNs          = "http://purl.org/dc/terms";
+	public const           string   XsdNs             = "http://www.w3.org/2001/XMLSchema";
 	public static readonly string[] SystemUsers       = ["instance.actor", "relay.actor"];
 
 	public static readonly string[] BrowserSafeMimeTypes =

Iceshrimp.Backend/Core/Extensions/DateTimeExtensions.cs

@@ -2,7 +2,7 @@ namespace Iceshrimp.Backend.Core.Extensions;
 
 public static class DateTimeExtensions
 {
-	public static string ToStringMastodon(this DateTime dateTime)
+	public static string ToStringIso8601Like(this DateTime dateTime)
 	{
 		return dateTime.ToString("yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fffK");
 	}

Iceshrimp.Backend/Core/Federation/ActivityStreams/Types/ASCollection.cs

@@ -20,7 +20,7 @@ public class ASCollection<T>() : ASObjectBase where T : ASObject
 
 	[J($"{Constants.ActivityStreamsNs}#totalItems")]
 	[JC(typeof(VC))]
-	public long? TotalItems { get; set; }
+	public uint? TotalItems { get; set; }
 }
 
 public sealed class ASCollectionConverter : ASSerializer.ListSingleObjectConverter<ASCollection<ASObject>>;

Iceshrimp.Backend/Core/Federation/ActivityStreams/Types/LDValueObject.cs

@@ -1,3 +1,5 @@
+using Iceshrimp.Backend.Core.Configuration;
+using Iceshrimp.Backend.Core.Extensions;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 using J = Newtonsoft.Json.JsonPropertyAttribute;
@@ -12,7 +14,7 @@ public class LDValueObject<T>
 
 public class ValueObjectConverter : JsonConverter
 {
-	public override bool CanWrite => false;
+	public override bool CanWrite => true;
 
 	public override bool CanConvert(Type objectType)
 	{
@@ -43,6 +45,28 @@ public class ValueObjectConverter : JsonConverter
 
 	public override void WriteJson(JsonWriter writer, object? value, JsonSerializer serializer)
 	{
-		throw new NotImplementedException();
+		writer.WriteStartObject();
+
+		switch (value)
+		{
+			case DateTime dt:
+				writer.WritePropertyName("@type");
+				writer.WriteValue($"{Constants.XsdNs}#dateTime");
+				writer.WritePropertyName("@value");
+				writer.WriteValue(dt.ToStringIso8601Like());
+				break;
+			case uint ui:
+				writer.WritePropertyName("@type");
+				writer.WriteValue($"{Constants.XsdNs}#nonNegativeInteger");
+				writer.WritePropertyName("@value");
+				writer.WriteValue(ui);
+				break;
+			default:
+				writer.WritePropertyName("@value");
+				writer.WriteValue(value);
+				break;
+		}
+
+		writer.WriteEndObject();
 	}
 }

Iceshrimp.Backend/Core/Services/QueueService.cs

@@ -219,7 +219,7 @@ public class JobQueue<T>(
 			else
 			{
 				logger.LogTrace("Job in queue {queue} completed after {duration} ms, has been queued since {time}",
-				                name, job.Duration, job.QueuedAt.ToStringMastodon());
+				                name, job.Duration, job.QueuedAt.ToStringIso8601Like());
 			}
 		}
 
@@ -236,8 +236,8 @@ public class JobQueue<T>(
 			job.DelayedUntil ??= DateTime.Now;
 			var logger = scope.ServiceProvider.GetRequiredService<ILogger<QueueService>>();
 			logger.LogTrace("Job in queue {queue} was delayed to {time} after {duration} ms, has been queued since {time}",
-			                name, job.DelayedUntil.Value.ToStringMastodon(), job.Duration,
+			                name, job.DelayedUntil.Value.ToStringIso8601Like(), job.Duration,
-			                job.QueuedAt.ToStringMastodon());
+			                job.QueuedAt.ToStringIso8601Like());
 
 			var timestamp = (long)job.DelayedUntil.Value.Subtract(DateTime.UnixEpoch).TotalSeconds;
 			await _redisDb.SortedSetAddAsync(targetQueue, RedisValue.Unbox(RedisHelpers.Serialize(job)), timestamp);