using System;
using System.Diagnostics;
using System.Threading;
using System.IO.Ports;
using System.Text.RegularExpressions;

namespace RfidClass
{
    public class RFIDReaderClass
    {
        private Thread t;
        private SerialPort s;
        private long id;
        private bool _stop;
        private Exception e;
        public RFIDReaderClass(string com)
        {
            this.t = new Thread(this.reader);
            s = new SerialPort(com, 115200, Parity.None, 8, StopBits.One);
        }

        private void reader()
        {
            while (!_stop)
            {
                Process r = new Process();
                r.StartInfo.FileName = "librfid-tool.exe";
                r.StartInfo.Arguments = "-s";
                r.StartInfo.UseShellExecute = false;
                r.StartInfo.RedirectStandardOutput = true;
                r.StartInfo.RedirectStandardError = true;
                try
                {
                    r.Start();
                }
                catch (Exception exeption)
                {
                    this.e = exeption;
                    return;
                }
                string a = r.StandardOutput.ReadToEnd();
                string err = r.StandardError.ReadToEnd();
                if (err.Contains("No OpenPCD found either"))
                {
                    this.e = new Exception("No OpenPCD found");
                    return;
                }
                if (a.Contains("Layer 2 success") && a.Contains("Protocol success"))
                {
                    string ids = a.Substring(a.IndexOf("):")+2,13);
                    ids = Regex.Replace(ids.Trim(), @"[^0-9a-fA-F]", "");
                    try
                    {
                        this.id = Int64.Parse(ids, System.Globalization.NumberStyles.HexNumber);
                    }
                    catch (Exception exeption)
                    {
                        this.e = exeption;
                        return;
                    }
                }
                Thread.Sleep(1000);
            }
        }

        public long readKey()
        {
            this.e = null;
            this.t = new Thread(this.reader);
            this.id = 0;
            this._stop = false;
            try
            {
                if(!s.IsOpen)
                    this.s.Open();
            }
            catch (Exception exeption)
            {
                throw exeption;
            }
            this.t.Start();
            while (!this.t.IsAlive) ;
            while (this.t.IsAlive)
            {
                if (this.id != 0 || this.e != null)
                {
                    this._stop = true;
                }
                Thread.Sleep(10);
            }
            if (this.e != null)
            {
                throw this.e;
            }
            return this.id;
        }

        public void abort()
        {
            this._stop = true;
            this.reset();
            this.s.Close();
        }

        public void reset()
        {
            if (s.IsOpen)
                this.s.Write("9");
        }
    }
}