using System.Collections;
using System.Collections.Generic;
using System.Text;
using System;
using System.Linq;


namespace Rokojori
{   
  public class EventSlot<T>
  {
    protected List<Action<T>> _actions = new List<Action<T>>();
    List<Action<T>> _once = new List<Action<T>>();

    public bool hasListeners => _once.Count > 0 || _actions.Count > 0;

    public void AddAction( Action<T> action )
    {
      _actions.Add( action );
    }

    public void RemoveAction( Action<T> action )
    {
      _actions.Remove( action );
    }

    public void Once( Action<T> action )
    {
      _actions.Add( action );
      _once.Add( action );
    }

    protected void _ClearOnceActions()
    {
      _once.ForEach( a => { _actions.Remove( a ); } );
      _once.Clear();
    } 

    public void DispatchEvent( T t )
    {
      _actions.ForEach( a => { if ( a != null ){ a( t ); } } );
      
      _ClearOnceActions();

    }
  }
  
}