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

namespace TTTCore
{
    class ListenersContainer
    {
        private readonly Dictionary<Type, List<MessageHandler>> listeners;

        public ListenersContainer()
        {
            listeners = new Dictionary<Type, List<MessageHandler>>();
        }

        public void Add(Type messageType, MessageHandler handler)
        {
            lock (listeners)
            {
                if (!listeners.ContainsKey(messageType))
                {
                    listeners[messageType] = new List<MessageHandler>();
                }
                listeners[messageType].Add(handler);
            }
        }

        public bool Remove(Type messageType, MessageHandler handler)
        {
            lock (listeners)
            {
                return listeners.ContainsKey(messageType) && listeners[messageType].Remove(handler);
            }
        }

        public IEnumerable<MessageHandler> GetListeners(Type type, bool returnSubtypes = true)
        {
            List<MessageHandler> handlers = new List<MessageHandler>();
            lock (listeners)
            {
                foreach (var kvp in listeners)
                {
                    if (type.Equals(kvp.Key) || (returnSubtypes && type.IsSubclassOf(kvp.Key)))
                    {
                        handlers.AddRange(kvp.Value);
                    }
                }
            }
            return handlers;
        }
    }
}