using System;
using Microsoft.SPOT;

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

using Microsoft.SPOT.Hardware;
using Microsoft.SPOT.IO;

using GHI.Hardware.EMX;

namespace miniCPF
{
    class SBE41
    {
        private static OutputPort DR = new OutputPort(Pin.IO15, false);
        private static OutputPort SPM = new OutputPort(Pin.IO46, true);
        private static OutputPort serialTX;

        private static double pressure = Double.NaN;
        private static byte[] pressureBytes = new byte[16];
        private static int pressureBytesIndex = 0;

        private static int portBytesToRead;
        private static byte[] portReadBytes = new byte[1024];
        private static byte[] portInBytes = new byte[240];
        private static int portInBytesIndex = -1;

        private static int messageNum;
        private static SerialPort SBE41Port = new SerialPort("com4", 9600, Parity.None, 8, StopBits.One);

        private static Timer SBE41Timer = null;
        private static int timerState = 0;

        private static StringBuilder sbTemp = new StringBuilder(256);

        private static Object SBE41Lock = new Object();

        private static int parserI = 0;
        private static byte token = 32;         //token (separator) = space
        private static byte CR = 13;
        private static byte LF = 10;
        private static byte comma = 44;
        private static int inArrayLength = 0;

        private static byte[] header = UTF8Encoding.UTF8.GetBytes("CTD ");
        private static byte[] message = new byte[256];

        public static void Init()
        {
            SBE41Port.DataReceived += new SerialDataReceivedEventHandler(portDataReceivedHandler);

            //Initialize();
            SBE41Port.ReadTimeout = 5000;
            SBE41Port.WriteTimeout = 20;
            SBE41Port.Open();

            //ReleaseWakeUp();
            DR.Write(false);
            SPM.Write(true);

            SBE41Timer = new Timer(new TimerCallback(SBE41TimerCallback), null, 500, 2000);
            //Stop the timer by set SBE41Timer = null

            Array.Copy(header, message, header.Length);
        }

        private static void SBE41TimerCallback(object state)
        {
            switch (timerState)
            {
                case 0:
                    SBE41Port.Close();
                    serialTX = new OutputPort(Pin.IO6, true);
                    DR.Write(true);
                    SPM.Write(false);
                    // Debug.Print(DateTime.Now + "." + DateTime.Now.TimeOfDay.Milliseconds.ToString() + "  SBE41 State 0  DR = true   SM = false   TX = true");
                    timerState = 1;
                    SBE41Timer.Change(0, 50);
                    break;
                case 1:
                    DR.Write(false);
                    // Debug.Print(DateTime.Now + "." + DateTime.Now.TimeOfDay.Milliseconds.ToString() + "  SBE41 State 1  DR = false  SM = false   TX = true");
                    timerState = 2;
                    SBE41Timer.Change(0, 150);
                    break;
                case 2:
                    serialTX.Write(false);
                    // Debug.Print(DateTime.Now + "." + DateTime.Now.TimeOfDay.Milliseconds.ToString() + "  SBE41 State 2  DR = false  SM = false   TX = false");
                    timerState = 3;
                    SBE41Timer.Change(0, 150);
                    break;
                case 3:
                    SPM.Write(true);
                    serialTX.Write(true);
                    //Debug.Print(DateTime.Now + "." + DateTime.Now.TimeOfDay.Milliseconds.ToString() + "  SBE41 State 3  DR = false  SM = true    TX = true");
                    timerState = 4;
                    SBE41Timer.Change(0, 50);
                    break;
                case 4:
                    serialTX.Dispose();
                    SBE41Port.Open();
                    //Debug.Print(DateTime.Now + "." + DateTime.Now.TimeOfDay.Milliseconds.ToString() + "  SBE41 State 3  DR = false  SM = true    TX = true");
                    timerState = 0;
                    SBE41Timer.Change(0, 1600);
                    break;
            }
        }

        private static void portDataReceivedHandler(object sender, SerialDataReceivedEventArgs e)
        {
            portBytesToRead = SBE41Port.BytesToRead;

            try
            {
                SBE41Port.Read(portReadBytes, 0, portBytesToRead);

            }
            catch
            {
                Debug.Print("SBE41 Read Exception");          //TODO do something smarter here
            }

            for (int i = 0; i < portBytesToRead; i++)
            {
                if (portInBytesIndex == -1)    //Check to make sure first character is = LF
                {
                    if (portReadBytes[i] == LF)  //only move on to byte index 1 after we get a LF
                    {
                        portInBytesIndex = portInBytesIndex + 1;
                    }
                }
                else
                {
                    portInBytes[portInBytesIndex] = portReadBytes[i];
                    if (portInBytes[portInBytesIndex] == CR)
                    {
                        messageNum = messageNum + 1;

                        Array.Copy(portInBytes, 1, message, header.Length, portInBytesIndex);
                        lock (SBE41Lock) { Program.MessageQueue.Enqueue(message); }
                     
                        Array.Clear(portReadBytes, 0, portReadBytes.Length);
                        Array.Clear(portInBytes, 0, portInBytes.Length);
                        portInBytesIndex = -1;
                    }
                    else
                    {
                        portInBytesIndex = portInBytesIndex + 1;
                    }
                }
            }
        }

        public static double parse(byte[] inArray)          
        {
            inArrayLength = Array.IndexOf(inArray, 0);

            parserI = Array.IndexOf(inArray, token);

            while ((inArray[parserI] != CR) && (inArray[parserI] != comma) && (parserI < inArrayLength))
            {
                pressureBytes[pressureBytesIndex] = inArray[parserI];
                pressureBytesIndex = pressureBytesIndex + 1;
                parserI = parserI + 1;
            }
            sbTemp.Clear();
            sbTemp.Append(UTF8Encoding.UTF8.GetChars(pressureBytes));
            pressure = double.Parse(sbTemp.ToString());
            Array.Clear(pressureBytes, 0, pressureBytes.Length);
            pressureBytesIndex = 0;
            return (pressure);
        }
    }
}