misskey/src/services/following/create.ts

import User, { isLocalUser, isRemoteUser, pack as packUser, IUser } from '../../models/user';
import Following from '../../models/following';
import FollowingLog from '../../models/following-log';
import FollowedLog from '../../models/followed-log';
import event from '../../publishers/stream';
import notify from '../../publishers/notify';
import pack from '../../remote/activitypub/renderer';
import renderFollow from '../../remote/activitypub/renderer/follow';
import renderAccept from '../../remote/activitypub/renderer/accept';
import { deliver } from '../../queue';

export default async function(follower: IUser, followee: IUser, activity?) {
	const following = await Following.insert({
		createdAt: new Date(),
		followerId: follower._id,
		followeeId: followee._id
	});

	//#region Increment following count
	User.update({ _id: follower._id }, {
		$inc: {
			followingCount: 1
		}
	});

	FollowingLog.insert({
		createdAt: following.createdAt,
		userId: follower._id,
		count: follower.followingCount + 1
	});
	//#endregion

	//#region Increment followers count
	User.update({ _id: followee._id }, {
		$inc: {
			followersCount: 1
		}
	});
	FollowedLog.insert({
		createdAt: following.createdAt,
		userId: followee._id,
		count: followee.followersCount + 1
	});
	//#endregion

	// Publish follow event
	if (isLocalUser(follower)) {
		packUser(followee, follower).then(packed => event(follower._id, 'follow', packed));
	}

	// Publish followed event
	if (isLocalUser(followee)) {
		packUser(follower, followee).then(packed => event(followee._id, 'followed', packed)),

		// 通知を作成
		notify(followee._id, follower._id, 'follow');
	}

	if (isLocalUser(follower) && isRemoteUser(followee)) {
		const content = pack(renderFollow(follower, followee));
		deliver(follower, content, followee.inbox);
	}

	if (isRemoteUser(follower) && isLocalUser(followee)) {
		const content = pack(renderAccept(activity));
		deliver(followee, content, follower.inbox);
	}
}