/// <summary>
/// 遊戲事件分發器，用於監聽、廣播遊戲事件。
/// </summary>
public static class EventDispatcher
{
    public delegate void EventListener(Dictionary<string, object> args);

    /// <summary>
    /// 廣播指定事件。
    /// </summary>
    /// <param name="eventId">事件編號</param>
    /// <param name="args">事件引數</param>
    public static void Dispatch(int eventId, Dictionary<string, object> args = null)
    {
        var luaListeners = getLuaEventListener(eventId);
        for (var i = 0; i < luaListeners.Count; i++)
        {
            var listener = luaListeners[i];
            listener.Function.Call(listener.Self, args);
        }


        var listeners = getEventListeners(eventId);
        for (var i = 0; i < listeners.Count; i++)
            listeners[i].Invoke(args);
    }

    /// <summary>
    /// 新增對指定事件的監聽。
    /// </summary>
    /// <param name="eventId">事件編號</param>
    /// <param name="listener">回撥委託</param>
    [NoToLua]
    public static void AddListener(int eventId, EventListener listener)
    {
        var listeners = getEventListeners(eventId);
        listeners.Add(listener);
    }

    /// <summary>
    /// 移除對指定事件的監聽。
    /// </summary>
    /// <param name="eventId">事件編號</param>
    /// <param name="listenerToBeRemoved">回撥委託</param>
    [NoToLua]
    public static void RemoveListener(int eventId, EventListener listenerToBeRemoved)
    {
        var listeners = getEventListeners(eventId);
        for (var i = 0; i < listeners.Count; i++)
        {
            var listener = listeners[i];
            if (listener == listenerToBeRemoved)
            {
                listeners.RemoveAt(i);
                break;
            }
        }
    }


    /// <summary>
    /// 清除所有的事件監聽器。
    /// </summary>
    public static void Clear()
    {
        _listeners.Clear();
        _luaListeners.Clear();
    }


    private static List<EventListener> getEventListeners(int eventId)
    {
        List<EventListener> ret;
        if (_listeners.TryGetValue(eventId, out ret))
            return ret;
        ret = new List<EventListener>();
        _listeners.Add(eventId, ret);
        return ret;
    }

    private static readonly Dictionary<int, List<EventListener>> _listeners = new Dictionary<int, List<EventListener>>();
}