#define ALLOW_LOG_CLEARING // when defined will allow the log to be cleared
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Reflection;

namespace RomCheater.Logging
{
    public partial class LogWriter : UserControl
    {
        private static string LOG_PATH { get { return string.Format(@"{0}\{1}", typeof(LogWriter).Assembly.Location.Replace("RomCheater.Logging.dll", ""), LoggingConstants.AppLogFile); } }

        private delegate string OnGetLogText();
        private delegate void OnSetLogText(string value);
        private delegate void GenericVoidDelegate();

        private OnGetLogText HandleGetLogText = null;
        private OnSetLogText HandleSetLogText = null;
        private GenericVoidDelegate delegate_EndLogUpdate = null;

        public LogWriter() : this(false) { }
        public LogWriter(bool redirectConsole)
        {
            InitializeComponent();
            this.Log = new LogStream(this);
            HandleGetLogText += new OnGetLogText(GetLogText);
            HandleSetLogText += new OnSetLogText(SetLogText);

            delegate_EndLogUpdate += new GenericVoidDelegate(EndLogUpdate);

            this.RedirectConsoleOutput = redirectConsole;
            toolTip1.SetToolTip(btnClearLog, "Clears the Log");
            toolTip1.SetToolTip(btnCopyLogToClipboard, "Copies the Log to the Clipboard");

            ms = new MemoryStream();
            sw = new StreamWriter(ms);
            sw.AutoFlush = true;
            sr = new StreamReader(ms);
        }
        private LogStream _Log;
        public LogStream Log { get { return _Log; } private set { _Log = value; } }


        private MemoryStream ms;
        private StreamWriter sw;
        private StreamReader sr;
        private bool _AutoScroll;
        new public bool AutoScroll { get { return _AutoScroll; } set { _AutoScroll = value; autoscroll_timer.Enabled = value; } }

        private bool _RedirectConsoleOutput;
        public bool RedirectConsoleOutput
        {
            get { return _RedirectConsoleOutput; }
            set
            {
                _RedirectConsoleOutput = value;
                if (value) { Console.SetOut(this.Log); }
                else
                {
                    Stream stream = Console.OpenStandardOutput(0x100);
                    TextWriter writer = null;
                    if (stream == Stream.Null) { writer = TextWriter.Synchronized(StreamWriter.Null); }
                    Encoding encoding = this.Log.Encoding;
                    StreamWriter writer2 = new StreamWriter(stream, encoding, 0x100);
                    //writer2.HaveWrittenPreamble = true;
                    writer2.AutoFlush = true;
                    writer = TextWriter.Synchronized(writer2);
                    Console.SetOut(writer);
                }
            }
        }

        private void btnClearLog_Click(object sender, EventArgs e) { this.Clear(true); }
        private void btnCopyLogToClipboard_Click(object sender, EventArgs e) { Clipboard.SetText(GetLogText()); }


        private string PreserveLineEndings(string text) { return text.Replace("\n", System.Environment.NewLine); }


        private bool BeginUpdate;
        public void BeginLogUpdate()
        {
            BeginUpdate = true;
        }
        public void EndLogUpdate()
        {
            if (txtLog.InvokeRequired)
            {
                this.Invoke(delegate_EndLogUpdate);
            }
            else
            {
                StringReader _sr = new StringReader(GetLogText());
                List<string> lines = new List<string>();
                string line = "";
                while ((line = _sr.ReadLine()) != null)
                {
                    lines.Add(line);
                }
                txtLog.Lines = lines.ToArray();
                BeginUpdate = false;
            }
        }
        private string StreamToString()
        {
            try
            {
                string value = "";
                sr = new StreamReader(ms);
                sr.BaseStream.Seek(0, SeekOrigin.Begin);
                value = sr.ReadToEnd();
                return value;
            }
            catch (Exception ex)
            {
                return "";
            }
        }
        public string GetLogText()
        {
            //if (txtLog.InvokeRequired)
            //{
            //    return (string)this.Invoke(HandleGetLogText, new object[] { });
            //}
            //else
            //{
            return PreserveLineEndings(StreamToString());
            //}

        }
        public void SetLogText(string value)
        {
            FileStream fs = new FileStream(LOG_PATH, FileMode.Append, FileAccess.Write, FileShare.ReadWrite);
            StreamWriter writer = new StreamWriter(fs);
            writer.AutoFlush = true;
            if (value == Log.NewLine) { writer.Write(System.Environment.NewLine); }
            else { writer.Write(value); }
            writer.Close();
            //string text = value.Replace(System.Environment.NewLine,"");
            string text = value.Replace(System.Environment.NewLine, Log.NewLine);
            //if (text.StartsWith(Log.NewLine))
            //{
            //    text = text.Remove(0, Log.NewLine.Length);
            //}
            sw.Write(text);
            Application.DoEvents();
        }

        new public string Text
        {
            get
            {
                throw new InvalidOperationException("Please use GetLogText()");
            }
            private set
            {
                throw new InvalidOperationException("Please use SetLogText(string value)");
            }
        }
        public void CreateNewLog(bool delete)
        {
            if (delete)
            {
                FileInfo fi = new FileInfo(LOG_PATH);
                if (fi.Exists)
                    fi.Delete();
            }
            Log.WriteLine("{0} ({2} v{3} {4}) created on {1}", LoggingConstants.AppLogFile, DateTime.Now.ToString(), LoggingConstants.AppName, LoggingConstants.AppVersion, LoggingConstants.AppBuild);     
        }
        public void Clear()
        {
            Clear(false);
        }
        private void Clear(bool force)
        {
            bool allow_log_clearing = false;
#if ALLOW_LOG_CLEARING
            allow_log_clearing = true;
#endif
            if (force || allow_log_clearing)
            {

                txtLog.Clear();
                ms = new MemoryStream();
                sw = new StreamWriter(ms);
                sw.AutoFlush = true;
                sr = new StreamReader(ms);
            }
        }
        #region sub-classes
        public class LogStream : TextWriter
        {
            private StringBuilder strMessage = new StringBuilder();
            public LogStream() : this(null) { }
            public LogStream(LogWriter text) : base() { _text_writer = text; this.NewLine = "\n"; }
            private LogWriter _text_writer;
            private void _write(string message)
            {
                if (_text_writer == null) return;

                if (message.EndsWith("\n"))
                {
                    //_text_writer.SetLogText(string.Format("{0}", strMessage.ToString()));
                    while (_text_writer.logupdater.IsBusy)
                    {
                        Application.DoEvents();
                    }
                    _text_writer.logupdater.RunWorkerAsync((string.Format("{0}", strMessage.ToString())));
                    strMessage = new StringBuilder();
                }
                strMessage.Append(message);
            }
            #region Overriden Methods
            public override Encoding Encoding { get { return Encoding.UTF8; } }
            public override void Write(char value) { base.Write(value); _write(value.ToString()); if (!_text_writer.BeginUpdate) _text_writer.EndLogUpdate(); }
            #endregion
        }
        #endregion

        private void autoscroll_timer_Tick(object sender, EventArgs e)
        {           
            try
            {
                if (this.DesignMode) { return; }
                ////txtLog.ScrollToEnd();
                //txtLog.SelectionStart = txtLog.Text.Length - 100;
                //txtLog.ScrollToCaret();
                //txtLog.Refresh();

                //txtLog.SelectionStart = 0;
                //txtLog.ScrollToCaret();
                //txtLog.Refresh();

                //int last_line_position = -1;
                //int position = -1;
                int len = txtLog.Text.Length;
                //StringReader sr = new StringReader(this.StreamToString());
                //string line = "";
                //while ((line = sr.ReadLine()) != null)
                //{
                //    position += (line.Length * 2);
                //    last_line_position = (line.Length * 2);
                //    //if (line.EndsWith("/n"))
                //    //{
                //    //    position++;
                //    //}
                //    //logger.VerboseDebug.WriteLine("current line: {0}", line);
                //}
                txtLog.SelectionStart = len;
                txtLog.ScrollToCaret();
                txtLog.Refresh();
                //autoscroll_timer.Enabled = false;
            }
            catch { }

        }

        private void logupdater_DoWork(object sender, DoWorkEventArgs e)
        {
            string message = e.Argument.ToString();
            SetLogText(string.Format("{0}", message));
        }

        private void logupdater_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {

        }
    }
}