feat: follow/unfollow logic and receipt

src/activitypub/helpers.js

@@ -3,9 +3,11 @@
 const request = require('request-promise-native');
 const { generateKeyPairSync } = require('crypto');
 const winston = require('winston');
+const nconf = require('nconf');
 
 const db = require('../database');
 const ttl = require('../cache/ttl');
+const user = require('../user');
 
 const webfingerCache = ttl({ ttl: 1000 * 60 * 60 * 24 }); // 24 hours
 
@@ -65,3 +67,13 @@ Helpers.generateKeys = async (uid) => {
 	await db.setObject(`uid:${uid}:keys`, { publicKey, privateKey });
 	return { publicKey, privateKey };
 };
+
+Helpers.resolveLocalUid = async (id) => {
+	const [slug, host] = id.split('@');
+
+	if (id.indexOf('@') === -1 || host !== nconf.get('url_parsed').host) {
+		throw new Error('[[activitypub:invalid-id]]');
+	}
+
+	return await user.getUidByUserslug(slug);
+};

src/activitypub/inbox.js

@@ -0,0 +1,61 @@
+'use strict';
+
+const db = require('../database');
+const user = require('../user');
+
+const helpers = require('./helpers');
+
+const inbox = module.exports;
+
+inbox.follow = async (actorId, objectId) => {
+	await handleFollow('follow', actorId, objectId);
+};
+
+inbox.unfollow = async (actorId, objectId) => {
+	await handleFollow('unfollow', actorId, objectId);
+};
+
+inbox.isFollowed = async (actorId, uid) => {
+	if (actorId.indexOf('@') === -1 || parseInt(uid, 10) <= 0) {
+		return false;
+	}
+	return await db.isSortedSetMember(`followersRemote:${uid}`, actorId);
+};
+
+async function handleFollow(type, actorId, objectId) {
+	// Sanity checks
+	const actorExists = await helpers.query(actorId);
+	if (!actorId || !actorExists) {
+		throw new Error('[[error:invalid-uid]]'); // should probably be AP specific
+	}
+
+	if (!objectId) {
+		throw new Error('[[error:invalid-uid]]'); // should probably be AP specific
+	}
+
+	const localUid = await helpers.resolveLocalUid(objectId);
+	if (!localUid) {
+		throw new Error('[[error:invalid-uid]]');
+	}
+
+	// matches toggleFollow() in src/user/follow.js
+	const isFollowed = await inbox.isFollowed(actorId, localUid);
+	if (type === 'follow') {
+		if (isFollowed) {
+			throw new Error('[[error:already-following]]');
+		}
+		const now = Date.now();
+		await db.sortedSetAdd(`followersRemote:${localUid}`, now, actorId);
+	} else {
+		if (!isFollowed) {
+			throw new Error('[[error:not-following]]');
+		}
+		await db.sortedSetRemove(`followersRemote:${localUid}`, actorId);
+	}
+
+	const [followerCount, followerRemoteCount] = await Promise.all([
+		db.sortedSetCard(`followers:${localUid}`),
+		db.sortedSetCard(`followersRemote:${localUid}`),
+	]);
+	await user.setUserField(localUid, 'followerCount', followerCount + followerRemoteCount);
+}

src/activitypub/index.js

@@ -12,6 +12,8 @@ const actorCache = ttl({ ttl: 1000 * 60 * 60 * 24 }); // 24 hours
 const ActivityPub = module.exports;
 
 ActivityPub.helpers = require('./helpers');
+ActivityPub.inbox = require('./inbox');
+ActivityPub.outbox = require('./outbox');
 
 ActivityPub.getActor = async (id) => {
 	if (actorCache.has(id)) {

src/activitypub/outbox.js

@@ -0,0 +1,13 @@
+'use strict';
+
+const db = require('../database');
+
+const outbox = module.exports;
+
+outbox.isFollowing = async (uid, actorId) => {
+	if (parseInt(uid, 10) <= 0 || actorId.indexOf('@') === -1) {
+		return false;
+	}
+	return await db.isSortedSetMember(`followingRemote:${uid}`, actorId);
+};
+

src/controllers/activitypub/index.js

@@ -2,8 +2,10 @@
 
 const nconf = require('nconf');
 
+const db = require('../../database');
 const user = require('../../user');
 const activitypub = require('../../activitypub');
+const helpers = require('../helpers');
 
 const Controller = module.exports;
 
@@ -99,7 +101,17 @@ Controller.getInbox = async (req, res) => {
 };
 
 Controller.postInbox = async (req, res) => {
-	console.log('received', req.body);
+	switch (req.body.type) {
+		case 'Follow': {
+			await activitypub.inbox.follow(req.body.actor.name, req.body.object.name);
+			break;
+		}
+
+		case 'Unfollow': {
+			await activitypub.inbox.unfollow(req.body.actor.name, req.body.object.name);
+			break;
+		}
+	}
 
 	res.sendStatus(201);
 };
@@ -109,18 +121,50 @@ Controller.postInbox = async (req, res) => {
  */
 
 Controller.follow = async (req, res) => {
-	await activitypub.send(req.uid, req.params.uid, {
-		type: 'Follow',
-		object: {
-			type: 'Person',
-			name: req.params.uid,
-		},
-	});
-
-	res.sendStatus(201);
+	try {
+		const { uid: objectId } = req.params;
+		await activitypub.send(req.uid, objectId, {
+			type: 'Follow',
+			object: {
+				type: 'Person',
+				name: objectId,
+			},
+		});
+
+		const now = Date.now();
+		await db.sortedSetAdd(`followingRemote:${req.uid}`, now, objectId);
+		await recountFollowing(req.uid);
+
+		helpers.formatApiResponse(200, res);
+	} catch (e) {
+		helpers.formatApiResponse(400, res, e);
+	}
 };
 
 Controller.unfollow = async (req, res) => {
-	console.log('got here');
-	res.sendStatus(201);
+	try {
+		const { uid: objectId } = req.params;
+		await activitypub.send(req.uid, objectId, {
+			type: 'Unfollow',
+			object: {
+				type: 'Person',
+				name: objectId,
+			},
+		});
+
+		await db.sortedSetRemove(`followingRemote:${req.uid}`, objectId);
+		await recountFollowing(req.uid);
+
+		helpers.formatApiResponse(200, res);
+	} catch (e) {
+		helpers.formatApiResponse(400, res, e);
+	}
 };
+
+async function recountFollowing(uid) {
+	const [followingCount, followingRemoteCount] = await Promise.all([
+		db.sortedSetCard(`following:${uid}`),
+		db.sortedSetCard(`followingRemote:${uid}`),
+	]);
+	await user.setUserField(uid, 'followingCount', followingCount + followingRemoteCount);
+}

src/controllers/activitypub/profiles.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const { getActor } = require('../../activitypub');
+const { getActor, outbox } = require('../../activitypub');
 
 const controller = module.exports;
 
@@ -11,6 +11,8 @@ controller.get = async function (req, res, next) {
 		return next();
 	}
 	const { preferredUsername, published, icon, image, name, summary, hostname } = actor;
+	const isFollowing = await outbox.isFollowing(req.uid, uid);
+
 	const payload = {
 		uid,
 		username: `${preferredUsername}@${hostname}`,
@@ -23,6 +25,8 @@ controller.get = async function (req, res, next) {
 		'cover:position': '50% 50%',
 		aboutme: summary,
 		aboutmeParsed: summary,
+
+		isFollowing,
 	};
 
 	res.render('account/profile', payload);

src/user/follow.js

@@ -49,13 +49,15 @@ module.exports = function (User) {
 			]);
 		}
 
-		const [followingCount, followerCount] = await Promise.all([
+		const [followingCount, followingRemoteCount, followerCount, followerRemoteCount] = await Promise.all([
 			db.sortedSetCard(`following:${uid}`),
+			db.sortedSetCard(`followingRemote:${uid}`),
 			db.sortedSetCard(`followers:${theiruid}`),
+			db.sortedSetCard(`followersRemote:${theiruid}`),
 		]);
 		await Promise.all([
-			User.setUserField(uid, 'followingCount', followingCount),
-			User.setUserField(theiruid, 'followerCount', followerCount),
+			User.setUserField(uid, 'followingCount', followingCount + followingRemoteCount),
+			User.setUserField(theiruid, 'followerCount', followerCount + followerRemoteCount),
 		]);
 	}