package com.university.chat.Server;

import java.util.concurrent.ConcurrentHashMap;

public class UserManager {

    private final ConcurrentHashMap<String, ClientSession> users = new ConcurrentHashMap<>();

    public boolean addUser(String username, ClientSession session) {
        return users.putIfAbsent(username, session) == null;
    }

    public void removeUser(String username) {
        users.remove(username);
    }

    public ClientSession getUser(String username) {
        return users.get(username);
    }

    public String listUsers() {
        return users.keySet().toString();
    }

    public Iterable<ClientSession> getAllSessions() {
        return users.values();
    }
}