From cc3704c3e94db4eb6f7e46bec2f68d19a7b0252e Mon Sep 17 00:00:00 2001
From: Akihiko Odaki <nekomanma@pixiv.co.jp>
Date: Tue, 3 Apr 2018 12:07:29 +0900
Subject: [PATCH] Accept remote follow

---
 src/remote/activitypub/act/follow.ts      | 49 +++++++++++++----------
 src/remote/activitypub/renderer/accept.ts |  4 ++
 2 files changed, 32 insertions(+), 21 deletions(-)
 create mode 100644 src/remote/activitypub/renderer/accept.ts

diff --git a/src/remote/activitypub/act/follow.ts b/src/remote/activitypub/act/follow.ts
index ec9e080dfc..d7ea15fa36 100644
--- a/src/remote/activitypub/act/follow.ts
+++ b/src/remote/activitypub/act/follow.ts
@@ -4,11 +4,13 @@ import Following from '../../../models/following';
 import User from '../../../models/user';
 import config from '../../../config';
 import queue from '../../../queue';
+import context from '../renderer/context';
+import renderAccept from '../renderer/accept';
+import request from '../../request';
 
 export default async (actor, activity) => {
 	const prefix = config.url + '/@';
 	const id = activity.object.id || activity.object;
-	let following;
 
 	if (!id.startsWith(prefix)) {
 		return null;
@@ -24,28 +26,33 @@ export default async (actor, activity) => {
 		throw new Error();
 	}
 
-	try {
-		following = await Following.insert({
+	const accept = renderAccept(activity);
+	accept['@context'] = context;
+
+	await Promise.all([
+		request(followee, actor.account.inbox, accept),
+
+		Following.insert({
 			createdAt: new Date(),
 			followerId: actor._id,
 			followeeId: followee._id
-		});
-	} catch (exception) {
-		// duplicate key error
-		if (exception instanceof MongoError && exception.code === 11000) {
-			return null;
-		}
-
-		throw exception;
-	}
-
-	await new Promise((resolve, reject) => {
-		queue.create('http', { type: 'follow', following: following._id }).save(error => {
-			if (error) {
-				reject(error);
-			} else {
-				resolve(null);
+		}).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;
 };
diff --git a/src/remote/activitypub/renderer/accept.ts b/src/remote/activitypub/renderer/accept.ts
new file mode 100644
index 0000000000..00c76883a9
--- /dev/null
+++ b/src/remote/activitypub/renderer/accept.ts
@@ -0,0 +1,4 @@
+export default object => ({
+	type: 'Accept',
+	object
+});