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

namespace M423project
{
    public struct MessageInfo
    {
        public DateTime Time;
        public string Message;
        public bool DisplayRequired;
    }
    public class MessageHandler
    {
        private string _lastFileName = string.Empty;
        private StreamWriter _logWriter = null;
        private static MessageHandler _messageHandler = null;
        private Queue<MessageInfo> _messagePool;
        private MainForm _mainForm = null;
        private Thread _thread = null;
        public MessageHandler(MainForm mainForm)
        {
            _messagePool = new Queue<MessageInfo>();
            _mainForm = mainForm;
        }
        public static MessageHandler MessageHandlerInstance
        {
            get
            {
                if (_messageHandler == null)
                    _messageHandler = new MessageHandler(CommonUtil.mainForm);
                return _messageHandler;               
            }
        }

        public void Open()
        {
            _thread = new Thread(Execute);
            _thread.Start();
        }

        public void Close()
        {
            if (_thread != null)
            {
                _thread.Abort();
                _thread.Join();
            }
        }

        public void NewMessage(string logInfo, bool displayRequired = false)
        {
            DateTime dt = DateTime.Now;
            lock(this)
            {
                _messagePool.Enqueue(new MessageInfo() { Message = logInfo, Time = dt, DisplayRequired = displayRequired });
            }
        }

        private void Execute()
        {
            List<MessageInfo> lmi = new List<MessageInfo>();

            try
            {
                while (true)
                {
                    lmi.Clear();
                    lock (this)
                    {
                        while (_messagePool.Count > 0)
                            lmi.Add(_messagePool.Dequeue());
                    }
                    foreach (MessageInfo mi in lmi)
                    {
                        string logFile = CommonUtil.DayDir + @"\log\" + mi.Time.ToString("yyyyMMddHH") + ".log";
                        if (logFile != _lastFileName)
                        {
                            if (_logWriter != null)
                                _logWriter.Close();
                            _logWriter = new StreamWriter(logFile, true);
                            _lastFileName = logFile;
                        }

                        string infoString = string.Format("{0} {1}", mi.Time.ToString("yyyyMMdd HH:mm:ss:ffffff"), mi.Message);
                        _logWriter.WriteLine(infoString);

                        if (mi.DisplayRequired)
                        {
                            if (_mainForm.IsHandleCreated)
                                _mainForm.Invoke(new Action(() =>
                                {
                                    _mainForm.DisplayMessage(infoString);
                                }));
                        }
                        Thread.Sleep(50);
                    }
                    if (lmi.Count > 0)
                        _logWriter.Flush();


                    Thread.Sleep(100);
                }
            }
            catch (ThreadAbortException)
            { }
            catch (Exception)
            { }
            finally
            {
                if (_logWriter != null)
                    _logWriter.Close();
            }
        }
    }
}