CS2-SuperPowers/Players/PlayerHud.cs

using CounterStrikeSharp.API;
using CounterStrikeSharp.API.Core;

namespace Cs2SuperPowers.Players;

public class PlayerHud : IPlayerHud
{
    private readonly Dictionary<CCSPlayerController, DisposableMessage> _playerMessages = new();
    private readonly List<Delegate> _registeredDelegates = new();

    public void Initialize(BasePlugin pluginRef)
    {
        Listeners.OnTick onTickListener = OnTick;
        _registeredDelegates.Add(onTickListener);
        pluginRef.RegisterListener(onTickListener);
    }

    public void ShowMessage(CCSPlayerController player, string message, TimeSpan? duration = null)
    {
        duration ??= TimeSpan.FromSeconds(10);
        if (_playerMessages.ContainsKey(player))
        {
            _playerMessages.Remove(player);
        }
        _playerMessages.Add(player, new DisposableMessage(message, DateTime.UtcNow.Add(duration.Value)));
    }
    
    private void OnTick()
    {
        var toRemove = new List<CCSPlayerController>();
        
        foreach (var playerMessage in _playerMessages.ToList())
        {
            if (playerMessage.Value.DisplayUntil >= DateTime.UtcNow)
            {
                playerMessage.Key.PrintToCenterHtml(playerMessage.Value.Message);
            }
            else
            {
                toRemove.Add(playerMessage.Key);
            }
        }

        foreach (var player in toRemove)
        {
            Action? wrappedCallback = null;
            wrappedCallback = () =>
            {
                _playerMessages.Remove(player);
                if (wrappedCallback != null)
                {
                    _registeredDelegates.Remove(wrappedCallback);
                }
            };
            _registeredDelegates.Add(wrappedCallback);
            Server.NextFrame(wrappedCallback);
        }
    }
}

record DisposableMessage(string Message, DateTime DisplayUntil);