feat: update Remove(Context) to use target instead of origin, federate out Move(Context) on topic move between local cids

src/activitypub/inbox.js

@@ -86,14 +86,12 @@ inbox.remove = async (req) => {
 	if (!isContext) {
 		return; // don't know how to handle other types
 	}
-	console.log('isContext?', isContext);
 
 	const mainPid = await activitypub.contexts.getItems(0, object.id, { returnRootId: true });
 	const exists = await posts.exists(mainPid);
 	if (!exists) {
 		return; // post not cached; do nothing.
 	}
-	console.log('mainPid is', mainPid);
 
 	// Ensure that cid is same-origin as the actor
 	const tid = await posts.getPostField(mainPid, 'tid');

src/activitypub/index.js

@@ -533,7 +533,7 @@ ActivityPub.buildRecipients = async function (object, { pid, uid, cid }) {
 	 * - Builds a list of targets for activitypub.send to consume
 	 * - Extends to and cc since the activity can be addressed more widely
 	 * - Optional parameters:
-	 *     - `cid`: includes followers of the passed-in cid (local only)
+	 *     - `cid`: includes followers of the passed-in cid (local only, can also be an array)
 	 *     - `uid`: includes followers of the passed-in uid (local only)
 	 *     - `pid`: includes post announcers and all topic participants
 	 */
@@ -551,12 +551,15 @@ ActivityPub.buildRecipients = async function (object, { pid, uid, cid }) {
 	}
 
 	if (cid) {
+		cid = Array.isArray(cid) ? cid : [cid];
+		await Promise.all(cid.map(async (cid) => {
 			const cidFollowers = await ActivityPub.notes.getCategoryFollowers(cid);
 			followers = followers.concat(cidFollowers);
 			const followersUrl = `${nconf.get('url')}/category/${cid}/followers`;
 			if (!to.has(followersUrl)) {
 				cc.add(followersUrl);
 			}
+		}));
 	}
 
 	const targets = new Set([...followers, ...to, ...cc]);

src/activitypub/out.js

@@ -351,10 +351,9 @@ Out.remove.context = enabledCheck(async (uid, tid) => {
 
 	const { to, cc, targets } = await activitypub.buildRecipients({
 		to: [activitypub._constants.publicAddress],
-		cc: [`${nconf.get('url')}/category/${cid}/followers`],
+		cc: [],
 	}, { cid });
 
-	// Remove(Context)
 	await activitypub.send('uid', uid, Array.from(targets), {
 		id: `${nconf.get('url')}/topic/${tid}#activity/remove/${now.getTime()}`,
 		type: 'Remove',
@@ -362,7 +361,43 @@ Out.remove.context = enabledCheck(async (uid, tid) => {
 		to,
 		cc,
 		object: `${nconf.get('url')}/topic/${tid}`,
-		origin: `${nconf.get('url')}/category/${cid}`,
+		target: `${nconf.get('url')}/category/${cid}`,
+	});
+});
+
+Out.move = {};
+
+Out.move.context = enabledCheck(async (uid, tid) => {
+	// Federates Move(Context); where Context is the tid
+	const now = new Date();
+	const { cid, oldCid } = await topics.getTopicFields(tid, ['cid', 'oldCid']);
+
+	// This check may be revised if inter-community moderation becomes real.
+	const isNotLocal = id => !utils.isNumber(cid) || parseInt(cid, 10) < 1;
+	if ([cid, oldCid].some(isNotLocal)) {
+		return;
+	}
+
+	const allowed = await privileges.categories.can('topics:read', cid, activitypub._constants.uid);
+	if (!allowed) {
+		activitypub.helpers.log(`[activitypub/api] Not federating move of tid ${tid} to the fediverse due to privileges.`);
+		return;
+	}
+
+	const { to, cc, targets } = await activitypub.buildRecipients({
+		to: [activitypub._constants.publicAddress],
+		cc: [],
+	}, { cid: [cid, oldCid] });
+
+	await activitypub.send('uid', uid, Array.from(targets), {
+		id: `${nconf.get('url')}/topic/${tid}#activity/move/${now.getTime()}`,
+		type: 'Move',
+		actor: `${nconf.get('url')}/uid/${uid}`,
+		to,
+		cc,
+		object: `${nconf.get('url')}/topic/${tid}`,
+		origin: `${nconf.get('url')}/category/${oldCid}`,
+		target: `${nconf.get('url')}/category/${cid}`,
 	});
 });
 

src/api/topics.js

@@ -326,7 +326,7 @@ topicsAPI.move = async (caller, { tid, cid }) => {
 					activitypub.out.remove.context(caller.uid, tid);
 					// tbd: activitypubApi.undo.announce?
 				} else {
-					// tbd: activitypubApi.move
+					activitypub.out.move.context(caller.uid, tid);
 					activitypub.out.announce.category(tid);
 				}
 			}