Rocket.Chat/app/livechat/server/lib/QueueManager.js

import { Meteor } from 'meteor/meteor';
import { Match, check } from 'meteor/check';

import { LivechatRooms, LivechatInquiry } from '../../../models/server';
import { checkServiceStatus, createLivechatRoom, createLivechatInquiry } from './Helper';
import { callbacks } from '../../../callbacks/server';
import { RoutingManager } from './RoutingManager';

export const QueueManager = {
	async requestRoom({ guest, message, roomInfo, agent, extraData }) {
		check(message, Match.ObjectIncluding({
			rid: String,
		}));
		check(guest, Match.ObjectIncluding({
			_id: String,
			username: String,
			status: Match.Maybe(String),
			department: Match.Maybe(String),
		}));

		if (!checkServiceStatus({ guest, agent })) {
			throw new Meteor.Error('no-agent-online', 'Sorry, no online agents');
		}

		const { rid } = message;
		const name = (roomInfo && roomInfo.fname) || guest.name || guest.username;

		const room = LivechatRooms.findOneById(createLivechatRoom(rid, name, guest, roomInfo, extraData));
		let inquiry = LivechatInquiry.findOneById(createLivechatInquiry({ rid, name, guest, message, extraData }));

		LivechatRooms.updateRoomCount();

		if (!agent) {
			agent = RoutingManager.getMethod().delegateAgent(agent, inquiry);
		}

		inquiry = await callbacks.run('livechat.beforeRouteChat', inquiry, agent);
		if (inquiry.status === 'ready') {
			return RoutingManager.delegateInquiry(inquiry, agent);
		}

		if (inquiry.status === 'queued') {
			Meteor.defer(() => callbacks.run('livechat.chatQueued', room));
		}

		return room;
	},
};