AP Undo Like (#3933)

* AP Undo Like

* rename

src/services/note/reaction/delete.ts

@@ -0,0 +1,49 @@
+import { IUser, isLocalUser, isRemoteUser } from '../../../models/user';
+import Note, { INote } from '../../../models/note';
+import Reaction from '../../../models/note-reaction';
+import { publishNoteStream } from '../../../stream';
+import renderLike from '../../../remote/activitypub/renderer/like';
+import renderUndo from '../../../remote/activitypub/renderer/undo';
+import pack from '../../../remote/activitypub/renderer';
+import { deliver } from '../../../queue';
+
+export default async (user: IUser, note: INote) => new Promise(async (res, rej) => {
+	// if already unreacted
+	const exist = await Reaction.findOne({
+		noteId: note._id,
+		userId: user._id,
+		deletedAt: { $exists: false }
+	});
+
+	if (exist === null) {
+		return rej('never reacted');
+	}
+
+	// Delete reaction
+	await Reaction.remove({
+		_id: exist._id
+	});
+
+	res();
+
+	const dec: any = {};
+	dec[`reactionCounts.${exist.reaction}`] = -1;
+
+	// Decrement reactions count
+	Note.update({ _id: note._id }, {
+		$inc: dec
+	});
+
+	publishNoteStream(note._id, 'unreacted', {
+		reaction: exist.reaction,
+		userId: user._id
+	});
+
+	//#region 配信
+	// リアクターがローカルユーザーかつリアクション対象がリモートユーザーの投稿なら配送
+	if (isLocalUser(user) && isRemoteUser(note._user)) {
+		const content = pack(renderUndo(renderLike(user, note, exist.reaction), user));
+		deliver(user, content, note._user.inbox);
+	}
+	//#endregion
+});