[backend/federation] Federate alt text (ISH-55)

Iceshrimp.Backend/Core/Database/Tables/DriveFile.cs

@@ -72,7 +72,6 @@ public class DriveFile : IEntity {
 	///     The comment of the DriveFile.
 	/// </summary>
 	[Column("comment")]
-	[StringLength(8192)]
 	public string? Comment { get; set; }
 
 	/// <summary>

Iceshrimp.Backend/Core/Federation/ActivityPub/NoteRenderer.cs

@@ -56,7 +56,8 @@ public class NoteRenderer(IOptions<Config.InstanceSection> config, MfmConverter
 				          Type      = $"{Constants.ActivityStreamsNs}#Document",
 				          Sensitive = p.IsSensitive,
 				          Url       = new ASObjectBase(p.Url),
-				          MediaType = p.Type
+				          MediaType = p.Type,
+				          Description = p.Comment
 			          })
 			          .Cast<ASAttachment>()
 			          .ToListAsync()

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

@@ -24,6 +24,10 @@ public class ASDocument : ASAttachment {
 	[J("https://www.w3.org/ns/activitystreams#sensitive")]
 	[JC(typeof(ValueObjectConverter))]
 	public bool? Sensitive { get; set; }
+	
+	[J("https://www.w3.org/ns/activitystreams#name")]
+	[JC(typeof(ValueObjectConverter))]
+	public string? Description { get; set; }
 }
 
 public sealed class ASAttachmentConverter : JsonConverter {

Iceshrimp.Backend/Core/Services/DriveService.cs

@@ -23,7 +23,9 @@ public class DriveService(
 	QueueService queueSvc,
 	ILogger<DriveService> logger
 ) {
-	public async Task<DriveFile?> StoreFile(string? uri, User user, bool sensitive) {
+	public async Task<DriveFile?> StoreFile(
+		string? uri, User user, bool sensitive, string? description = null, string? mimeType = null
+	) {
 		if (uri == null) return null;
 
 		logger.LogDebug("Storing file {uri} for user {userId}", uri, user.Id);
@@ -63,7 +65,8 @@ public class DriveService(
 				Uri         = uri,
 				Filename    = new Uri(uri).AbsolutePath.Split('/').LastOrDefault() ?? "",
 				IsSensitive = sensitive,
-				MimeType    = CleanMimeType(res.Content.Headers.ContentType?.MediaType)
+				Comment     = description,
+				MimeType    = CleanMimeType(mimeType ?? res.Content.Headers.ContentType?.MediaType)
 			};
 
 			return await StoreFile(await res.Content.ReadAsStreamAsync(), user, request);

Iceshrimp.Backend/Core/Services/NoteService.cs

@@ -283,7 +283,7 @@ public class NoteService(
 		if (attachments is not { Count: > 0 }) return [];
 		var result = await attachments
 		                   .OfType<ASDocument>()
-		                   .Select(p => driveSvc.StoreFile(p.Url?.Id, user, p.Sensitive ?? sensitive))
+		                   .Select(p => driveSvc.StoreFile(p.Url?.Id, user, p.Sensitive ?? sensitive, p.Description, p.MediaType))
 		                   .AwaitAllNoConcurrencyAsync();
 
 		return result.Where(p => p != null).Cast<DriveFile>().ToList();