address activitypub notes to the streamer's follower collection (#4314)

* make a new function to generate appropriate to and cc apub objects

* use new addressing function to set "public" message addressing appropriately with the followers collection

* early return from sending federated message if federation is disabled

* cleanup old addressing code, apply new addressing mechanism to live notifications as well

* linter fix

* Update activitypub/outbox/outbox.go

---------

Co-authored-by: Gabe Kangas <gabek@real-ity.com>

activitypub/apmodels/activity.go

@@ -31,6 +31,20 @@ func MakeNotePublic(note vocab.ActivityStreamsNote) vocab.ActivityStreamsNote {
 	return note
 }
 
+func MakeAddressingToFollowers(followers_iri *url.URL, public bool) (vocab.ActivityStreamsToProperty, vocab.ActivityStreamsCcProperty) {
+	to := streams.NewActivityStreamsToProperty()
+	cc := streams.NewActivityStreamsCcProperty()
+
+	if public {
+		public, _ := url.Parse(PUBLIC)
+		to.AppendIRI(public)
+		cc.AppendIRI(followers_iri)
+	} else {
+		to.AppendIRI(followers_iri)
+	}
+	return to, cc
+}
+
 // MakeNoteDirect sets the required properties to make this note seen as a
 // direct message.
 func MakeNoteDirect(note vocab.ActivityStreamsNote, toIRI *url.URL) vocab.ActivityStreamsNote {

activitypub/outbox/outbox.go

@@ -66,11 +66,11 @@ func SendLive() error {
 
 	activity, _, note, noteID := createBaseOutboundMessage(textContent)
 
-	// To the public if we're not treating ActivityPub as "private".
-	if !configRepository.GetFederationIsPrivate() {
-		note = apmodels.MakeNotePublic(note)
-		activity = apmodels.MakeActivityPublic(activity)
-	}
+	to, cc := getAddressingToFollowers()
+	note.SetActivityStreamsTo(to)
+	note.SetActivityStreamsCc(cc)
+	activity.SetActivityStreamsTo(to)
+	activity.SetActivityStreamsCc(cc)
 
 	note.SetActivityStreamsTag(tagProp)
 
@@ -153,8 +153,6 @@ func SendDirectMessageToAccount(textContent, account string) error {
 
 // SendPublicMessage will send a public message to all followers.
 func SendPublicMessage(textContent string) error {
-	configRepository := configrepository.Get()
-
 	originalContent := textContent
 	textContent = utils.RenderSimpleMarkdown(textContent)
 
@@ -177,10 +175,11 @@ func SendPublicMessage(textContent string) error {
 	activity, _, note, noteID := createBaseOutboundMessage(textContent)
 	note.SetActivityStreamsTag(tagProp)
 
-	if !configRepository.GetFederationIsPrivate() {
-		note = apmodels.MakeNotePublic(note)
-		activity = apmodels.MakeActivityPublic(activity)
-	}
+	to, cc := getAddressingToFollowers()
+	note.SetActivityStreamsTo(to)
+	note.SetActivityStreamsCc(cc)
+	activity.SetActivityStreamsTo(to)
+	activity.SetActivityStreamsCc(cc)
 
 	b, err := apmodels.Serialize(activity)
 	if err != nil {
@@ -199,6 +198,18 @@ func SendPublicMessage(textContent string) error {
 	return nil
 }
 
+// if public, cc the followers and to the Public uri, else private, address followers directly.
+func getAddressingToFollowers() (vocab.ActivityStreamsToProperty, vocab.ActivityStreamsCcProperty) {
+	configRepository := configrepository.Get()
+	server_url := configRepository.GetServerURL()
+	followers_iri, _ := url.Parse(server_url)
+	username := configRepository.GetDefaultFederationUsername()
+
+	followers_iri = followers_iri.JoinPath("federation", "user", username, "followers")
+
+	return apmodels.MakeAddressingToFollowers(followers_iri, !configRepository.GetFederationIsPrivate())
+}
+
 // nolint: unparam
 func createBaseOutboundMessage(textContent string) (vocab.ActivityStreamsCreate, string, vocab.ActivityStreamsNote, string) {
 	configRepository := configrepository.Get()

webserver/handlers/admin/federation.go

@@ -16,6 +16,13 @@ func SendFederatedMessage(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	configRepository := configrepository.Get()
+
+	if !configRepository.GetFederationEnabled() {
+		webutils.WriteSimpleResponse(w, false, "Federation is disabled")
+		return
+	}
+
 	configValue, success := getValueFromRequest(w, r)
 	if !success {
 		return