users.js

const users = [];

const addUser = ({ id, name, room }) => {
	name = name.trim().toLowerCase();
	room = room.trim().toLowerCase();

	const existingUser = users.find(
		user => user.room === room && user.name === name
	);

	if (!name || !room) return { error: "Username and room are required." };
	if (existingUser) {
		return { error: "This username is already taken!" };
	}

	const user = { id, name, room };

	users.push(user);

	return { user };
};

const removeUser = id => {
	const index = users.findIndex(user => user.id === id);

	if (index !== -1) return users.splice(index, 1)[0];
};

const getUser = id => {
	for (let i = 0; i < users.length; i++) {
		if (users[i].id == id) return users[i];
	}
};

const getUsersInRoom = room => users.filter(user => user.room === room);

module.exports = { addUser, removeUser, getUser, getUsersInRoom };