整理した

src/models/channel.ts

@@ -0,0 +1,75 @@
+import * as mongo from 'mongodb';
+import deepcopy = require('deepcopy');
+import { IUser } from './user';
+import Watching from './channel-watching';
+import db from '../db/mongodb';
+
+const Channel = db.get<IChannel>('channels');
+export default Channel;
+
+export type IChannel = {
+	_id: mongo.ObjectID;
+	createdAt: Date;
+	title: string;
+	userId: mongo.ObjectID;
+	index: number;
+	watchingCount: number;
+};
+
+/**
+ * Pack a channel for API response
+ *
+ * @param channel target
+ * @param me? serializee
+ * @return response
+ */
+export const pack = (
+	channel: string | mongo.ObjectID | IChannel,
+	me?: string | mongo.ObjectID | IUser
+) => new Promise<any>(async (resolve, reject) => {
+
+	let _channel: any;
+
+	// Populate the channel if 'channel' is ID
+	if (mongo.ObjectID.prototype.isPrototypeOf(channel)) {
+		_channel = await Channel.findOne({
+			_id: channel
+		});
+	} else if (typeof channel === 'string') {
+		_channel = await Channel.findOne({
+			_id: new mongo.ObjectID(channel)
+		});
+	} else {
+		_channel = deepcopy(channel);
+	}
+
+	// Rename _id to id
+	_channel.id = _channel._id;
+	delete _channel._id;
+
+	// Remove needless properties
+	delete _channel.userId;
+
+	// Me
+	const meId: mongo.ObjectID = me
+	? mongo.ObjectID.prototype.isPrototypeOf(me)
+		? me as mongo.ObjectID
+		: typeof me === 'string'
+			? new mongo.ObjectID(me)
+			: (me as IUser)._id
+	: null;
+
+	if (me) {
+		//#region Watchしているかどうか
+		const watch = await Watching.findOne({
+			userId: meId,
+			channelId: _channel.id,
+			deletedAt: { $exists: false }
+		});
+
+		_channel.isWatching = watch !== null;
+		//#endregion
+	}
+
+	resolve(_channel);
+});