Implement unfollow by remote account

src/processor/http/perform-activitypub.ts

@@ -1,5 +1,6 @@
 import User from '../../models/user';
 import act from '../../remote/activitypub/act';
+import Resolver from '../../remote/activitypub/resolver';
 
 export default ({ data }) => User.findOne({ _id: data.actor })
-	.then(actor => act(actor, data.outbox, false));
+	.then(actor => act(new Resolver(), actor, data.outbox));

src/processor/http/process-inbox.ts

@@ -3,6 +3,7 @@ import parseAcct from '../../acct/parse';
 import User, { IRemoteUser } from '../../models/user';
 import act from '../../remote/activitypub/act';
 import resolvePerson from '../../remote/activitypub/resolve-person';
+import Resolver from '../../remote/activitypub/resolver';
 
 export default async ({ data }) => {
 	const keyIdLower = data.signature.keyId.toLowerCase();
@@ -34,5 +35,5 @@ export default async ({ data }) => {
 		throw 'signature verification failed';
 	}
 
-	await act(user, data.inbox, true);
+	await act(new Resolver(), user, data.inbox, true);
 };

src/remote/activitypub/act/follow.ts

@@ -1,6 +1,6 @@
 import { MongoError } from 'mongodb';
 import parseAcct from '../../../acct/parse';
-import Following from '../../../models/following';
+import Following, { IFollowing } from '../../../models/following';
 import User from '../../../models/user';
 import config from '../../../config';
 import queue from '../../../queue';
@@ -8,7 +8,7 @@ import context from '../renderer/context';
 import renderAccept from '../renderer/accept';
 import request from '../../request';
 
-export default async (actor, activity) => {
+export default async (resolver, actor, activity, distribute) => {
 	const prefix = config.url + '/@';
 	const id = activity.object.id || activity.object;
 
@@ -26,33 +26,52 @@ export default async (actor, activity) => {
 		throw new Error();
 	}
 
+	if (!distribute) {
+		const { _id } = await Following.findOne({
+			followerId: actor._id,
+			followeeId: followee._id
+		})
+
+		return {
+			resolver,
+			object: { $ref: 'following', $id: _id }
+		};
+	}
+
+	const promisedFollowing = Following.insert({
+		createdAt: new Date(),
+		followerId: actor._id,
+		followeeId: followee._id
+	}).then(following => new Promise((resolve, reject) => {
+		queue.create('http', {
+			type: 'follow',
+			following: following._id
+		}).save(error => {
+			if (error) {
+				reject(error);
+			} else {
+				resolve(following);
+			}
+		});
+	}) as Promise<IFollowing>, async error => {
+		// duplicate key error
+		if (error instanceof MongoError && error.code === 11000) {
+			return Following.findOne({
+				followerId: actor._id,
+				followeeId: followee._id
+			});
+		}
+
+		throw error;
+	});
+
 	const accept = renderAccept(activity);
 	accept['@context'] = context;
 
-	await Promise.all([
-		request(followee, actor.account.inbox, accept),
+	await request(followee, actor.account.inbox, accept);
 
-		Following.insert({
-			createdAt: new Date(),
-			followerId: actor._id,
-			followeeId: followee._id
-		}).then(following => new Promise((resolve, reject) => {
-			queue.create('http', { type: 'follow', following: following._id }).save(error => {
-				if (error) {
-					reject(error);
-				} else {
-					resolve();
-				}
-			});
-		}), error => {
-			// duplicate key error
-			if (error instanceof MongoError && error.code === 11000) {
-				return;
-			}
-
-			throw error;
-		})
-	]);
-
-	return null;
+	return promisedFollowing.then(({ _id }) => ({
+		resolver,
+		object: { $ref: 'following', $id: _id }
+	}));
 };

src/remote/activitypub/act/index.ts

@@ -1,23 +1,26 @@
 import create from './create';
 import follow from './follow';
+import undo from './undo';
 import createObject from '../create';
-import Resolver from '../resolver';
 
-export default (actor, value, distribute) => {
-	return new Resolver().resolve(value).then(resolved => Promise.all(resolved.map(async promisedResult => {
-		const { resolver, object } = await promisedResult;
-		const created = await (await createObject(resolver, actor, [object], distribute))[0];
+export default (resolver, actor, value, distribute?: boolean) => {
+	return resolver.resolve(value).then(resolved => Promise.all(resolved.map(async promisedResult => {
+		const result = await promisedResult;
+		const created = await (await createObject(result.resolver, actor, [result.object], distribute))[0];
 
 		if (created !== null) {
 			return created;
 		}
 
-		switch (object.type) {
+		switch (result.object.type) {
 		case 'Create':
-			return create(resolver, actor, object, distribute);
+			return create(result.resolver, actor, result.object, distribute);
 
 		case 'Follow':
-			return follow(actor, object);
+			return follow(result.resolver, actor, result.object, distribute);
+
+		case 'Undo':
+			return undo(result.resolver, actor, result.object);
 
 		default:
 			return null;

src/remote/activitypub/act/undo/index.ts

@@ -0,0 +1,23 @@
+import act from '../../act';
+import unfollow from './unfollow';
+
+export default async (resolver, actor, activity) => {
+	if ('actor' in activity && actor.account.uri !== activity.actor) {
+		throw new Error();
+	}
+
+	const results = await act(resolver, actor, activity.object);
+
+	await Promise.all(results.map(async result => {
+		if (result === null) {
+			return;
+		}
+
+		switch (result.object.$ref) {
+		case 'following':
+			await unfollow(result.resolver, result.object);
+		}
+	}));
+
+	return null;
+};

src/remote/activitypub/act/undo/unfollow.ts

@@ -0,0 +1,24 @@
+import FollowedLog from '../../../../models/followed-log';
+import Following from '../../../../models/following';
+import FollowingLog from '../../../../models/following-log';
+import User from '../../../../models/user';
+
+export default async (resolver, { $id }) => {
+	const following = await Following.findOneAndDelete({ _id: $id });
+	if (following === null) {
+		return;
+	}
+
+	await Promise.all([
+		User.update({ _id: following.followerId }, { $inc: { followingCount: -1 } }),
+		User.findOne({ _id: following.followerId }).then(({ followingCount }) => FollowingLog.insert({
+			userId: following.followerId,
+			count: followingCount - 1
+		})),
+		User.update({ _id: following.followeeId }, { $inc: { followersCount: -1 } }),
+		User.findOne({ _id: following.followeeId }).then(({ followersCount }) => FollowedLog.insert({
+			userId: following.followeeId,
+			count: followersCount - 1
+		})),
+	]);
+};