class Program
{
    public X509Certificate2 cert = new X509Certificate2("server.pfx", "enote");

    static void Main(string[] args)
    {
        var url = "http://192.168.0.61:8080/";
        using (WebApp.Start<Startup>(url))
        {
            Console.WriteLine($"Статус: Сервер запущен. Адрес: {url}");
            Console.ReadLine();
        }
    }

}

public class Startup
{
    public void Configuration(IAppBuilder app)
    {
        app.UseCors(CorsOptions.AllowAll);
        app.MapSignalR("/enote", new HubConfiguration());
    }
}

public interface IClient
    {
        void ParticipantDisconnection(string name);
        void ParticipantReconnection(string name);
        void ParticipantLogin(User client);
        void ParticipantLogout(string name);
        void BroadcastMessage(string sender, string message);
        void UnicastMessage(string sender, string message);
    }

public class ChatHub : Hub<IClient>
    {
        private static ConcurrentDictionary<string, User> ChatClients = new ConcurrentDictionary<string, User>();

        public override Task OnDisconnected(bool stopCalled)
        {
            var userName = ChatClients.SingleOrDefault((c) => c.Value.ID == Context.ConnectionId).Key;
            if (userName != null)
            {
                Clients.Others.ParticipantDisconnection(userName);
                Console.WriteLine($"<> {userName} отключен");
            }
            return base.OnDisconnected(stopCalled);
        }

        public override Task OnReconnected()
        {
            var userName = ChatClients.SingleOrDefault((c) => c.Value.ID == Context.ConnectionId).Key;
            if (userName != null)
            {
                Clients.Others.ParticipantReconnection(userName);
                Console.WriteLine($"== {userName} переподключен");
            }
            return base.OnReconnected();
        }

        public List<User> Login(string name, string password, byte[] photo)
        {
            if (!ChatClients.ContainsKey(name))
            {
                Console.WriteLine($"++ {name} выходит в сеть");
                List<User> users = new List<User>(ChatClients.Values);
                User newUser = new User { Name = name, Password = password, ID = Context.ConnectionId, Photo = photo };
                var added = ChatClients.TryAdd(name, newUser);
                if (!added) return null;
                Clients.CallerState.UserName = name;
                Clients.Others.ParticipantLogin(newUser);
                return users;
            }
            return null;
        }

        public void Logout()
        {
            var name = Clients.CallerState.UserName;
            if (!string.IsNullOrEmpty(name))
            {
                User client = new User();
                ChatClients.TryRemove(name, out client);
                Clients.Others.ParticipantLogout(name);
                Console.WriteLine($"-- {name} ушел из сети");
            }
        }

        public void BroadcastChat(string message)
        {
            var name = Clients.CallerState.UserName;
            if (!string.IsNullOrEmpty(name) && !string.IsNullOrEmpty(message))
            {
                Clients.Others.BroadcastMessage(name, message);
            }
        }

        public void UnicastChat(string recepient, string message)
        {
            var sender = Clients.CallerState.UserName;
            if (!string.IsNullOrEmpty(sender) && recepient != sender &&
                !string.IsNullOrEmpty(message) && ChatClients.ContainsKey(recepient))
            {
                User client = new User();
                ChatClients.TryGetValue(recepient, out client);
                Clients.Client(client.ID).UnicastMessage(sender, message);
            }
        }
    }