From c64d3fa19544ab9aeaa82568b7eae1ee966ac8e6 Mon Sep 17 00:00:00 2001
From: Anthony Wang <a@exozy.me>
Date: Sun, 27 Nov 2022 22:30:00 +0000
Subject: [PATCH] Implement commenting on issues from Mastodon

---
 models/issues/comment.go             | 16 ++++++++++++++++
 routers/api/v1/activitypub/create.go |  9 +++++----
 routers/api/v1/activitypub/person.go |  8 ++++++++
 routers/api/v1/activitypub/repo.go   |  2 +-
 services/activitypub/objects.go      |  2 ++
 services/comments/comments.go        |  2 +-
 services/issue/issue.go              |  2 +-
 7 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/models/issues/comment.go b/models/issues/comment.go
index 6877991a9..fe692bd58 100644
--- a/models/issues/comment.go
+++ b/models/issues/comment.go
@@ -26,6 +26,7 @@ import (
 	"code.gitea.io/gitea/modules/markup"
 	"code.gitea.io/gitea/modules/markup/markdown"
 	"code.gitea.io/gitea/modules/references"
+	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
@@ -1549,3 +1550,18 @@ func FixCommentTypeLabelWithOutsideLabels() (int64, error) {
 
 	return res.RowsAffected()
 }
+
+func (c *Comment) GetIRI() string {
+	err := c.LoadIssue()
+	if err != nil {
+		return ""
+	}
+	err = c.Issue.LoadRepo(db.DefaultContext)
+	if err != nil {
+		return ""
+	}
+	if strings.Contains(c.Issue.Repo.OwnerName, "@") {
+		return c.OldTitle
+	}
+	return setting.AppURL + "api/v1/activitypub/note/" + c.Issue.Repo.OwnerName + "/" + c.Issue.Repo.Name + "/" + strconv.FormatInt(c.Issue.Index, 10) + "/" + strconv.FormatInt(c.ID, 10)
+}
diff --git a/routers/api/v1/activitypub/create.go b/routers/api/v1/activitypub/create.go
index eb4f86d59..8a2f77398 100644
--- a/routers/api/v1/activitypub/create.go
+++ b/routers/api/v1/activitypub/create.go
@@ -308,10 +308,11 @@ func createComment(ctx context.Context, note *ap.Note) error {
 		return err
 	}
 	_, err = issues_model.CreateCommentCtx(ctx, &issues_model.CreateCommentOptions{
-		Doer:    user,
-		Repo:    repo,
-		Issue:   issue,
-		Content: note.Content.String(),
+		Doer:     user,
+		Repo:     repo,
+		Issue:    issue,
+		OldTitle: note.GetLink().String(),
+		Content:  note.Content.String(),
 	})
 	return err
 }
diff --git a/routers/api/v1/activitypub/person.go b/routers/api/v1/activitypub/person.go
index 4fbc7f736..4068dfcf6 100644
--- a/routers/api/v1/activitypub/person.go
+++ b/routers/api/v1/activitypub/person.go
@@ -134,6 +134,14 @@ func PersonInbox(ctx *context.APIContext) {
 		err = follow(ctx, activity)
 	case ap.UndoType:
 		err = unfollow(ctx, activity)
+	case ap.CreateType:
+		// TODO: this is kinda a hack
+		err = ap.OnObject(activity.Object, func(n *ap.Note) error {
+			noteIRI := n.InReplyTo.GetLink().String()
+			noteIRISplit := strings.Split(noteIRI, "/")
+			n.Context = ap.IRI(strings.TrimSuffix(noteIRI, "/"+noteIRISplit[len(noteIRISplit)-1]))
+			return createComment(ctx, n)
+		})
 	default:
 		log.Info("Incoming unsupported ActivityStreams type: %s", activity.GetType())
 		ctx.PlainText(http.StatusNotImplemented, "ActivityStreams type not supported")
diff --git a/routers/api/v1/activitypub/repo.go b/routers/api/v1/activitypub/repo.go
index 9f7d93f22..df1e5e233 100644
--- a/routers/api/v1/activitypub/repo.go
+++ b/routers/api/v1/activitypub/repo.go
@@ -140,7 +140,7 @@ func RepoInbox(ctx *context.APIContext) {
 				return createComment(ctx, n)
 			})
 		default:
-			log.Info("Incoming unsupported ActivityStreams object type: %s",  activity.Object.GetType())
+			log.Info("Incoming unsupported ActivityStreams object type: %s", activity.Object.GetType())
 			ctx.PlainText(http.StatusNotImplemented, "ActivityStreams object type not supported")
 			return
 		}
diff --git a/services/activitypub/objects.go b/services/activitypub/objects.go
index ef4e7f3e2..0169194cd 100644
--- a/services/activitypub/objects.go
+++ b/services/activitypub/objects.go
@@ -26,8 +26,10 @@ func Note(comment *issues_model.Comment) (*ap.Note, error) {
 	}
 	note := ap.Note{
 		Type:         ap.NoteType,
+		ID:           ap.IRI(comment.GetIRI()),
 		AttributedTo: ap.IRI(comment.Poster.GetIRI()),
 		Context:      ap.IRI(comment.Issue.GetIRI()),
+		To:           ap.ItemCollection{ap.IRI("https://www.w3.org/ns/activitystreams#Public")},
 	}
 	note.Content = ap.NaturalLanguageValuesNew()
 	err = note.Content.Set("en", ap.Content(comment.Content))
diff --git a/services/comments/comments.go b/services/comments/comments.go
index 8f478c018..d2406ba07 100644
--- a/services/comments/comments.go
+++ b/services/comments/comments.go
@@ -36,7 +36,7 @@ func CreateIssueComment(doer *user_model.User, repo *repo_model.Repository, issu
 		if err != nil {
 			return nil, err
 		}
-		create := activitypub.Create(repo.OriginalURL + "/inbox", note)
+		create := activitypub.Create(repo.OriginalURL+"/inbox", note)
 		err = activitypub.Send(doer, create)
 		if err != nil {
 			return nil, err
diff --git a/services/issue/issue.go b/services/issue/issue.go
index e18e65b5a..e9b44d405 100644
--- a/services/issue/issue.go
+++ b/services/issue/issue.go
@@ -35,7 +35,7 @@ func NewIssue(repo *repo_model.Repository, issue *issues_model.Issue, labelIDs [
 		if err != nil {
 			return err
 		}
-		create := activitypub.Create(repo.OriginalURL + "/inbox", ticket)
+		create := activitypub.Create(repo.OriginalURL+"/inbox", ticket)
 		err = activitypub.Send(issue.Poster, create)
 		if err != nil {
 			return err