feat: accept and undo support

src/activitypub/inbox.js

@@ -2,6 +2,7 @@
 
 const db = require('../database');
 const user = require('../user');
+const activitypub = require('.');
 
 const helpers = require('./helpers');
 
@@ -24,8 +25,8 @@ inbox.isFollowed = async (actorId, uid) => {
 
 async function handleFollow(type, actorId, objectId) {
 	// Sanity checks
-	const actorExists = await helpers.query(actorId);
-	if (!actorId || !actorExists) {
+	const from = await helpers.query(actorId);
+	if (!actorId || !from) {
 		throw new Error('[[error:invalid-uid]]'); // should probably be AP specific
 	}
 
@@ -46,13 +47,64 @@ async function handleFollow(type, actorId, objectId) {
 		}
 		const now = Date.now();
 		await db.sortedSetAdd(`followersRemote:${localUid}`, now, actorId);
+		await activitypub.send(localUid, actorId, {
+			type: 'Accept',
+			object: {
+				type: 'Follow',
+				actor: from.actorUri,
+			},
+		});
 	} else {
 		if (!isFollowed) {
 			throw new Error('[[error:not-following]]');
 		}
 		await db.sortedSetRemove(`followersRemote:${localUid}`, actorId);
+		await activitypub.send(localUid, actorId, {
+			type: 'Undo',
+			object: {
+				type: 'Follow',
+				actor: from.actorUri,
+			},
+		});
 	}
 
 	const followerRemoteCount = await db.sortedSetCard(`followersRemote:${localUid}`);
 	await user.setUserField(localUid, 'followerRemoteCount', followerRemoteCount);
 }
+
+inbox.accept = async (req) => {
+	const { actor, object } = req.body;
+	const { type } = object;
+
+	if (type === 'Follow') {
+		// todo: should check that actor and object.actor are the same person?
+		const uid = await helpers.resolveLocalUid(object.actor);
+		if (!uid) {
+			throw new Error('[[error:invalid-uid]]');
+		}
+
+		const now = Date.now();
+		await Promise.all([
+			db.sortedSetAdd(`followingRemote:${uid}`, now, actor.name),
+			db.incrObjectField(`user:${uid}`, 'followingRemoteCount'),
+		]);
+	}
+};
+
+inbox.undo = async (req) => {
+	const { actor, object } = req.body;
+	const { type } = object;
+
+	if (type === 'Follow') {
+		// todo: should check that actor and object.actor are the same person?
+		const uid = await helpers.resolveLocalUid(object.actor);
+		if (!uid) {
+			throw new Error('[[error:invalid-uid]]');
+		}
+
+		await Promise.all([
+			db.sortedSetRemove(`followingRemote:${uid}`, actor.name),
+			db.decrObjectField(`user:${uid}`, 'followingRemoteCount'),
+		]);
+	}
+};

src/activitypub/index.js

@@ -178,12 +178,10 @@ ActivityPub.send = async (uid, targets, payload) => {
 	const inboxes = await ActivityPub.resolveInboxes(targets);
 
 	payload = {
-		...{
-			'@context': 'https://www.w3.org/ns/activitystreams',
-			actor: {
-				type: 'Person',
-				name: `${userslug}@${nconf.get('url_parsed').host}`,
-			},
+		'@context': 'https://www.w3.org/ns/activitystreams',
+		actor: {
+			type: 'Person',
+			name: `${userslug}@${nconf.get('url_parsed').host}`,
 		},
 		...payload,
 	};

src/controllers/activitypub/index.js

@@ -113,6 +113,21 @@ Controller.postInbox = async (req, res) => {
 			await activitypub.inbox.unfollow(req.body.actor.name, req.body.object.name);
 			break;
 		}
+
+		case 'Accept': {
+			await activitypub.inbox.accept(req);
+			break;
+		}
+
+		case 'Undo': {
+			await activitypub.inbox.undo(req);
+			break;
+		}
+
+		default: {
+			console.log('Unhandled Activity!!!');
+			console.log(req.body);
+		}
 	}
 
 	res.sendStatus(201);