Replies a post's author approves (FEP-5624), checked live with PeerTube

PeerTube puts canReply on a video whose comments wait for approval, and answers each comment with ApproveReply. A
persona's reply to such a post now waits (privapub.approval: pending), its Create going to the author alone; the
author's ApproveReply, signed by the author and naming the post answered, lets it out to its audience with
replyApproval, and RejectReply leaves it ours. A null canReply (PeerTube's open comments) says nothing; an empty one
refuses. The PeerTube scenario holds a comment for review and approves it through PeerTube's API (28 checks).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

PrivaPub/Federation/Inbox/Handlers/ReplyApprovalHandler.cs

@@ -0,0 +1,35 @@
+using PrivaPub.Domain.Statuses;
+using PrivaPub.Models.User;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Federation.Inbox.Handlers
+{
+	// FEP-5624 (PeerTube): the author of a post whose canReply asks it to approve each reply lets one of ours in, which then
+	// goes to its audience carrying the approval (replyApproval)
+	public class ReplyApprovalHandler : IActivityHandler
+	{
+		readonly IInteractionApprovals _approvals;
+
+		public ReplyApprovalHandler(IInteractionApprovals approvals) => _approvals = approvals;
+
+		public virtual string Type => "ApproveReply";
+
+		protected virtual bool Approves => true;
+
+		public async Task Handle(JsonNode activity, ForeignAvatar actor, CancellationToken token) =>
+			await _approvals.Answered(activity, actor, Approves, token);
+	}
+
+	// and refuses one, which stays ours alone
+	public class ReplyRejectionHandler : ReplyApprovalHandler
+	{
+		public ReplyRejectionHandler(IInteractionApprovals approvals) : base(approvals)
+		{
+		}
+
+		public override string Type => "RejectReply";
+
+		protected override bool Approves => false;
+	}
+}

PrivaPub/Federation/Inbox/RemoteEdits.cs

@@ -33,6 +33,7 @@ namespace PrivaPub.Federation.Inbox
 			post.ReplyPolicy = note.ReplyPolicy;
 			post.LikePolicy = note.LikePolicy;
 			post.AnnouncePolicy = note.AnnouncePolicy;
+			post.ReplyApprovals = note.ReplyApprovals;
 			post.Video = note.Video ?? post.Video;
 			post.Audio = note.Audio ?? post.Audio;
 			post.Event = note.Event ?? post.Event;

PrivaPub/Federation/Inbox/RemotePosts.cs

@@ -110,6 +110,7 @@ namespace PrivaPub.Federation.Inbox
 				ReplyPolicy = note.ReplyPolicy,
 				LikePolicy = note.LikePolicy,
 				AnnouncePolicy = note.AnnouncePolicy,
+				ReplyApprovals = note.ReplyApprovals,
 				Emojis = note.Emojis.ToList(),
 				CoverURL = note.CoverURL,
 				Link = note.Link,

PrivaPub/Federation/Objects/NoteParser.cs

@@ -44,6 +44,7 @@ namespace PrivaPub.Federation.Objects
 		public InteractionRule ReplyPolicy { get; init; }
 		public InteractionRule LikePolicy { get; init; }
 		public InteractionRule AnnouncePolicy { get; init; }
+		public InteractionRule ReplyApprovals { get; init; }//FEP-5624's canReply: who may reply, each reply then approved or refused
 		public IReadOnlyList<CustomEmoji> Emojis { get; init; } = Array.Empty<CustomEmoji>();
 		public string CoverURL { get; init; }
 		public PostLink Link { get; init; }
@@ -122,6 +123,7 @@ namespace PrivaPub.Federation.Objects
 				ReplyPolicy = ObjectShapes.Policy(note, "canReply"),
 				LikePolicy = ObjectShapes.Policy(note, "canLike"),
 				AnnouncePolicy = ObjectShapes.Policy(note, "canAnnounce"),
+				ReplyApprovals = ObjectShapes.ReplyApprovals(note),
 				Emojis = ObjectShapes.Emojis(note["tag"]),
 				CoverURL = ObjectShapes.Cover(note),
 				Link = ObjectShapes.Link(note),

PrivaPub/Federation/Objects/ObjectShapes.cs

@@ -102,16 +102,23 @@ namespace PrivaPub.Federation.Objects
 
 		// one rule of a post's interactionPolicy (GoToSocial, FEP-044f): who may, automatically or once asked; the old names
 		// (always, approvalRequired) too. A rule left out means anyone, automatically
+		static List<string> Who(JsonNode node) => node switch
+		{
+			JsonArray array => array.Select(Id).Where(id => id != default).Take(MaxAudience).ToList(),
+			JsonNode single when Id(single) is { } id => new List<string> { id },
+			_ => new List<string>()
+		};
+
+		// FEP-5624's canReply (PeerTube's, on a video whose comments wait for approval): who may reply, each reply then
+		// approved by the author with an ApproveReply, or refused with a RejectReply; null when the post states none (PeerTube
+		// sends null for a video whose comments are open, and an empty list where they are closed)
+		public static InteractionRule ReplyApprovals(JsonObject note) =>
+			note["canReply"] is { } canReply ? new InteractionRule { Manual = Who(canReply) } : default;
+
 		public static InteractionRule Policy(JsonObject note, string rule)
 		{
 			if (note["interactionPolicy"] is not JsonObject policy || policy[rule] is not JsonObject allowed)
 				return default;
-			static List<string> Who(JsonNode node) => node switch
-			{
-				JsonArray array => array.Select(Id).Where(id => id != default).Take(MaxAudience).ToList(),
-				JsonNode single when Id(single) is { } id => new List<string> { id },
-				_ => new List<string>()
-			};
 			return new InteractionRule
 			{
 				Automatic = Who(allowed["automaticApproval"] ?? allowed["always"]),

PrivaPub/Federation/Rendering/ActivityPubRenderer.cs

@@ -63,6 +63,7 @@ namespace PrivaPub.Federation.Rendering
 				["AnnounceAuthorization"] = "gts:AnnounceAuthorization",
 				["likeAuthorization"] = new JsonObject { ["@id"] = "gts:likeAuthorization", ["@type"] = "@id" },
 				["replyAuthorization"] = new JsonObject { ["@id"] = "gts:replyAuthorization", ["@type"] = "@id" },
+				["replyApproval"] = new JsonObject { ["@id"] = "toot:replyApproval", ["@type"] = "@id" },
 				["announceAuthorization"] = new JsonObject { ["@id"] = "gts:announceAuthorization", ["@type"] = "@id" },
 				["litepub"] = "http://litepub.social/ns#",
 				["EmojiReact"] = "litepub:EmojiReact",
@@ -408,6 +409,8 @@ namespace PrivaPub.Federation.Rendering
 			// the parent's author let this reply in (GoToSocial's interaction policies)
 			if (!string.IsNullOrEmpty(inReplyTo) && !string.IsNullOrEmpty(post.ApprovalURI))
 				note["replyAuthorization"] = post.ApprovalURI;
+			if (!string.IsNullOrEmpty(inReplyTo) && !string.IsNullOrEmpty(post.ReplyApprovalURI))
+				note["replyApproval"] = post.ReplyApprovalURI;
 			if (post.EditedAt.HasValue)
 				note["updated"] = Timestamp(post.EditedAt.Value);
 			return note;