[wip] Implement like activity

src/remote/activitypub/act/like.ts

@@ -0,0 +1,63 @@
+import { MongoError } from 'mongodb';
+import Reaction, { IPostReaction } from '../../../models/post-reaction';
+import Post from '../../../models/post';
+import queue from '../../../queue';
+
+export default async (resolver, actor, activity, distribute) => {
+	const id = activity.object.id || activity.object;
+
+	// Transform:
+	// https://misskey.ex/@syuilo/xxxx to
+	// xxxx
+	const postId = id.split('/').pop();
+
+	const post = await Post.findOne({ _id: postId });
+	if (post === null) {
+		throw new Error();
+	}
+
+	if (!distribute) {
+		const { _id } = await Reaction.findOne({
+			userId: actor._id,
+			postId: post._id
+		});
+
+		return {
+			resolver,
+			object: { $ref: 'postPeactions', $id: _id }
+		};
+	}
+
+	const promisedReaction = Reaction.insert({
+		createdAt: new Date(),
+		userId: actor._id,
+		postId: post._id,
+		reaction: 'pudding'
+	}).then(reaction => new Promise<IPostReaction>((resolve, reject) => {
+		queue.create('http', {
+			type: 'reaction',
+			reactionId: reaction._id
+		}).save(error => {
+			if (error) {
+				reject(error);
+			} else {
+				resolve(reaction);
+			}
+		});
+	}), async error => {
+		// duplicate key error
+		if (error instanceof MongoError && error.code === 11000) {
+			return Reaction.findOne({
+				userId: actor._id,
+				postId: post._id
+			});
+		}
+
+		throw error;
+	});
+
+	return promisedReaction.then(({ _id }) => ({
+		resolver,
+		object: { $ref: 'postPeactions', $id: _id }
+	}));
+};