server/src/socket/room.ts

import { generateSessionToken } from "../helpers";
import { User } from "./hapticLinkServer";

// User data that is safe to reveal to users
export interface UserData {
    username: string;
    id: string;
    online: boolean;
    lastOnline: number;
}

export class Room {
    static roomIdLength: number = 6;
    id: string;
    users: User[];

    /**
     * @constructor
     * @param roomId Optional, a secure one will be generated
     */
    constructor(roomId?: string) {
        this.id = roomId || generateSessionToken(Room.roomIdLength);
        this.users = [];
    }

    /**
     * Add a user to room, broadcasts message to all room users
     * when user if user is successfully added. Won't add user
     * if they are alreadu part of it
     * @param {User} user
     * @returns 
     */
    addUser(user: User) {
        if (this.users.includes(user)) return;
        this.users.push(user);
        this.updateRoom();
    }

    /**
     * Removed user from an ID 
     * @param {string} id User's ID
     * @returns {boolean} true/false whether the user was deleted or not
     */
    removeUserById(id: string): boolean {
        const oldSize = this.users.length;
        this.users = this.users.filter((user) => user.id != id);
        this.updateRoom();
        return oldSize > this.users.length;
    }

    /**
     * Used to check if a room contains a user 
     * @param {string} id User's ID
     * @returns {boolean} true/false whether the room has that user
     */
    hasUser(id: string): boolean {
        return this.users.some((user) => user.id == id);
    }

    /**
     * Broadcasts a message to every user in room
     * @param {string} message Message to send to users
     * @param {string[]} filter Array of user ID to ignore when sending
     **/
    broadcast(message: string, filter: string[] = []) {
        this.users.forEach((user) => {
            if (filter.includes(user.id)) return;
            user.socket.send(message);
        });
    }

    /**
     * Broadcasts the user list of the current room.
     * Should be used when a user is added or removed.
     */
    updateRoom() {
        const usersData: UserData[] = [];
        this.users.forEach((user) => {
            usersData.push({
                username: user.username || "Unknown",
                id: user.id,
                online: true,
                lastOnline: 0,
            });
        });

        this.broadcast(
            JSON.stringify({
                message: "room_update",
                roomId: this.id,
                users: usersData,
            })
        );
    }
}