using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Sockets;

namespace Sog
{
    /// <summary>
    /// session的轮询管理
    /// </summary>
    public class AcceptedWebSessionUpdateAsyncMode
    {
        private Dictionary<Socket, NetSession> m_sessionDict = new Dictionary<Socket, NetSession>();

        private WebSessionListener m_listener;

        //临时存放所有出错的socket
        private List<Socket> m_needCloseList = new List<Socket>();
        private object m_needCloseListLocker = new object();

        //临时存放所有检查发送关闭帧超时的socket
        private List<Socket> m_needCheckSendCloseTimeOutList = new List<Socket>();
        private object m_needCheckSendCloseTimeOutListLocker = new object();

        private long m_lastCheckSendKeepAliveTime;

        private List<NetSession> m_asyncAddedSessions = new List<NetSession>();
        private object m_asyncAddedSessionsLocker = new object();

        public AcceptedWebSessionUpdateAsyncMode(WebSessionListener listener)
        {
            m_listener = listener;
        }

        public int GetSessionCount()
        {
            return m_sessionDict.Count + m_asyncAddedSessions.Count;
        }

        public void AddAsync(NetSession session)
        {
            if (session.WorkSocket == null)
            {
                return;
            }

            lock (m_asyncAddedSessionsLocker)
            {
                m_asyncAddedSessions.Add(session);
            }
        }

        public void Close()
        {
            m_sessionDict.Clear();
            m_asyncAddedSessions.Clear();
        }

        public void Update(long nowMs)
        {
            if (nowMs - m_lastCheckSendKeepAliveTime >= 10000)
            {
                m_lastCheckSendKeepAliveTime = nowMs;

                //keep alive
                foreach (var pair in m_sessionDict)
                {
                    NetSession session = pair.Value;

                    if (session.IsSocketClosed == false )
                    {
                        session.StartSendAsync();
                    }
                }
            }

            foreach (var pair in m_sessionDict)
            {
                WebSession session = pair.Value as WebSession;
                Socket socket = pair.Key;

                if (session.IsSocketClosed)
                {
                    AddSocketToNeedClose(socket);
                }
                if (session.IsSendingClose)
                {
                    AddSocketToNeedCheckSendCloseTimeOut(socket);
                }
            }
            CloseNeedCloseSocket();
            CheckSendCloseTimeOut();

            //异步添加的session在这里放到dict里去
            if (m_asyncAddedSessions.Count > 0)
            {
                lock (m_asyncAddedSessionsLocker)
                {
                    foreach (var session in m_asyncAddedSessions)
                    {
                        if (session.WorkSocket != null)
                        {
                            m_sessionDict.Add(session.WorkSocket, session);
                        }
                    }

                    m_asyncAddedSessions.Clear();
                }
            }
        }

        public void ForceAsyncCloseSession(NetSession session)
        {
            AddSocketToNeedClose(session.WorkSocket);
        }

        private void AddSocketToNeedClose(Socket socket)
        {
            if (socket == null)
            {
                return;
            }
            lock (m_needCloseListLocker)
            {
                m_needCloseList.Add(socket);
            }
        }

        private void AddSocketToNeedCheckSendCloseTimeOut(Socket socket)
        {
            if (socket == null)
            {
                return;
            }
            lock (m_needCheckSendCloseTimeOutListLocker)
            {
                m_needCheckSendCloseTimeOutList.Add(socket);
            }
        }

        private void CloseNeedCloseSocket()
        {
            if (m_needCloseList.Count == 0)
            {
                return;
            }

            List<Socket> closeSocket;
            lock (m_needCloseListLocker)
            {
                closeSocket = m_needCloseList.ToList();
                m_needCloseList.Clear();
            }

            foreach (Socket socket in closeSocket)
            {
                if (m_sessionDict.ContainsKey(socket))
                {
                    WebSession session = m_sessionDict[socket] as WebSession;
                    if (session.IsSocketClosed)
                    {
                        m_sessionDict.Remove(socket);
                        SessionEventArgs e = new SessionEventArgs();
                        e.Session = session;
                        session.Close();
                        TraceLog.Trace("AcceptedWebSessionUpdateAsyncMode.process_close_result Close session {0}", session.SessionID);
                        m_listener.OnDisconnected(e);
                    }
                    else if (!session.IsSendingClose)// websocket已经连接的关闭前需要发送关闭帧
                    {
                        TraceLog.Trace("AcceptedWebSessionUpdateAsyncMode.process_close_result CloseWebSocket session {0}", session.SessionID);
                        session.CloseWebSocket();
                    }
                }
            }
        }

        private void CheckSendCloseTimeOut()
        {
            if (m_needCheckSendCloseTimeOutList.Count == 0)
            {
                return;
            }

            List<Socket> closeSocket;
            lock (m_needCheckSendCloseTimeOutListLocker)
            {
                closeSocket = m_needCheckSendCloseTimeOutList.ToList();
                m_needCheckSendCloseTimeOutList.Clear();
            }

            foreach (Socket socket in closeSocket)
            {
                if (m_sessionDict.ContainsKey(socket))
                {
                    WebSession session = m_sessionDict[socket] as WebSession;
                    if (!session.IsSendingClose)// websocket已经连接的关闭前需要发送关闭帧
                    {
                        session.CheckSendCloseFrameTimeOut();
                    }
                }
            }
        }

    }
}