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

namespace GuruClient
{
    public interface IEventData
    {
        string Name { get; }
        object Sender { get; }

    }

    public class BaseIEventData : IEventData
    {
        public string Name
        {
            get
            {
                return GetType().FullName;
            }
        }

        public object Sender
        {
            get; private set;
        }

        public BaseIEventData()
        {

        }

        public BaseIEventData(object sender)
        {
            Sender = sender;
        }

    }

    public class EventData : BaseIEventData
    {
        private readonly string _data;
        public string Data { get { return _data; } }

        public EventData(string data)
        {
            _data = data;
        }
    }

    public delegate void MyEventHandler(IEventData data);

    /// <summary>
    /// 全局事件管理器
    /// </summary>
    public class EventManager
    {
        #region 单例
        private static readonly EventManager _instance = new EventManager();

        internal static void AddListenner(string uI_SignIn_SignHandler1, string uI_SignIn_SignHandler2)
        {
            throw new NotImplementedException();
        }
        #endregion

        #region 静态公共接口
        /// <summary>
        /// 为指定事件注册一个处理函数
        /// </summary>
        /// <param name="eventName"></param>
        /// <param name="handler"></param>
        public static void AddListenner(string eventName, MyEventHandler handler)
        {
            _instance.AddEventHandler(eventName, handler);
        }

        /// <summary>
        /// 取消指定事件的指定处理函数
        /// </summary>
        /// <param name="eventName"></param>
        /// <param name="handler"></param>
        public static void RemoveListenner(string eventName, MyEventHandler handler)
        {
            _instance.RemoveEventHandler(eventName, handler);
        }

        /// <summary>
        /// 取消指定事件的所有处理函数
        /// </summary>
        /// <param name="eventName"></param>
        public static void ClearEvent(string eventName)
        {
            _instance.ClearEventHandler(eventName);
        }

        /// <summary>
        /// 取消所有事件监听
        /// </summary>
        public static void Clear()
        {
            _instance.ClearAllEvent();
        }

        /// <summary>
        /// 激发一个事件
        /// </summary>
        /// <param name="eventName"></param>
        /// <param name="data"></param>
        public static void Dispatch(string eventName, IEventData data)
        {
            _instance.FireEvent(eventName, data);
        }

        public static void Dispatch(string eventName)
        {
            Dispatch(eventName, null);
        }

        #endregion

        private readonly Dictionary<string, MyEventHandler> _handlerDict = new Dictionary<string, MyEventHandler>();

        /// <summary>
        /// 为指定事件注册一个处理函数
        /// </summary>
        /// <param name="eventName"></param>
        /// <param name="handler"></param>
        private void AddEventHandler(string eventName, MyEventHandler handler)
        {
            if (handler == null)
            {
                return;
            }
            if (_handlerDict.ContainsKey(eventName))
            {
                _handlerDict[eventName] += handler;
            }
            else
            {
                _handlerDict.Add(eventName, handler);
            }
        }

        /// <summary>
        /// 取消指定事件的指定处理函数
        /// </summary>
        /// <param name="eventName"></param>
        /// <param name="handler"></param>
        private void RemoveEventHandler(string eventName, MyEventHandler handler)
        {
            if (_handlerDict.ContainsKey(eventName))
            {
                _handlerDict[eventName] -= handler;
            }
        }

        private void ClearEventHandler(string eventName)
        {
            if (_handlerDict.ContainsKey(eventName))
            {
                _handlerDict.Remove(eventName);
            }
        }

        private void ClearAllEvent()
        {
            _handlerDict.Clear();
        }

        /// <summary>
        /// 激发一个事件
        /// </summary>
        /// <param name="eventName"></param>
        /// <param name="data"></param>
        private void FireEvent(string eventName, IEventData data)
        {
            if (_handlerDict.ContainsKey(eventName))
            {
                var handler = _handlerDict[eventName];
                if (handler != null)
                {
                    handler.Invoke(data);
                }
            }
        }
    }
}