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

namespace ArdupilotMega
{
    class ArduinoDetect
    {
        /// <summary>
        /// detects a 1280 or a 2560 board
        /// </summary>
        /// <param name="port">comportname</param>
        /// <returns>string either (1280/2560) or "" for none</returns>
        public static string DetectVersion(string port)
        {
            SerialPort serialPort = new SerialPort();
            serialPort.PortName = port;

            if (serialPort.IsOpen)
                serialPort.Close();

            serialPort.DtrEnable = true;
            serialPort.BaudRate = 57600;
            serialPort.Open();

            System.Threading.Thread.Sleep(100);

            int a = 0;
            while (a < 20) // 20 * 50 = 1 sec
            {
                //Console.WriteLine("write " + DateTime.Now.Millisecond);
                serialPort.DiscardInBuffer();
                serialPort.Write(new byte[] { (byte)'0', (byte)' ' }, 0, 2);
                a++;
                System.Threading.Thread.Sleep(50);

                //Console.WriteLine("btr {0}", serialPort.BytesToRead);
                if (serialPort.BytesToRead >= 2)
                {
                    byte b1 = (byte)serialPort.ReadByte();
                    byte b2 = (byte)serialPort.ReadByte();
                    if (b1 == 0x14 && b2 == 0x10)
                    {
                        serialPort.Close();
                        return "1280";
                    }
                }
            }

            serialPort.Close();

            Console.WriteLine("Not a 1280");

            System.Threading.Thread.Sleep(500);

            serialPort.DtrEnable = true;
            serialPort.BaudRate = 115200;
            serialPort.Open();

            System.Threading.Thread.Sleep(100);

            a = 0;
            while (a < 4)
            {
                byte[] temp = new byte[] { 0x6, 0, 0, 0, 0 };
                temp = ArduinoDetect.genstkv2packet(serialPort, temp);
                a++;
                System.Threading.Thread.Sleep(50);

                try
                {
                    if (temp[0] == 6 && temp[1] == 0 && temp.Length == 2)
                    {
                        serialPort.Close();
                        return "2560";
                    }
                }
                catch { }
            }

            serialPort.Close();
            Console.WriteLine("Not a 2560");
            return "";
        }

        public static int decodeApVar(string comport, string version)
        {
            ArduinoComms port = new ArduinoSTK();
            if (version == "1280")
            {
                port = new ArduinoSTK();
                port.BaudRate = 57600;
            }
            else if (version == "2560")
            {
                port = new ArduinoSTKv2();
                port.BaudRate = 115200;
            }
            else { return -1; }
            port.PortName = comport;
            port.DtrEnable = true;
            port.Open();
            port.connectAP();
            byte[] buffer = port.download(1024 * 4);
            port.Close();

            if (buffer[0] != 'A' || buffer[1] != 'P') // this is the apvar header
            {
                return -1;
            }
            else
            {
                if (buffer[0] == 'A' && buffer[1] == 'P' && buffer[2] == 2)
                { // apvar header and version
                    int pos = 4;
                    byte key = 0;
                    while (pos < (1024 * 4))
                    {
                        int size = buffer[pos] & 63;
                        pos++;
                        key = buffer[pos];
                        pos++;

                        Console.Write("{0:X4}: key {1} size {2}\n ", pos - 2, key, size + 1);

                        if (key == 0xff)
                        {
                            Console.WriteLine("end sentinal at {0}", pos - 2);
                            break;
                        }

                        if (key == 0)
                        {
                            //Array.Reverse(buffer, pos, 2);
                            return BitConverter.ToUInt16(buffer,pos);
                        }

                        
                        for (int i = 0; i <= size; i++)
                        {
                            Console.Write(" {0:X2}", buffer[pos]);
                            pos++;
                        }
                        Console.WriteLine();
                    }
                }
            }
            return -1;
        }

        static byte[] genstkv2packet(SerialPort serialPort, byte[] message)
        {
            byte[] data = new byte[300];
            byte ck = 0;

            data[0] = 0x1b;
            ck ^= data[0];
            data[1] = 0x1;
            ck ^= data[1];
            data[2] = (byte)((message.Length >> 8) & 0xff);
            ck ^= data[2];
            data[3] = (byte)(message.Length & 0xff);
            ck ^= data[3];
            data[4] = 0xe;
            ck ^= data[4];

            int a = 5;
            foreach (byte let in message)
            {
                data[a] = let;
                ck ^= let;
                a++;
            }
            data[a] = ck;
            a++;

            serialPort.Write(data, 0, a);
            //Console.WriteLine("about to read packet");

            byte[] ret = ArduinoDetect.readpacket(serialPort);

            //if (ret[1] == 0x0)
            {
                //Console.WriteLine("received OK");
            }

            return ret;
        }

        static byte[] readpacket(SerialPort serialPort)
        {
            byte[] temp = new byte[4000];
            byte[] mes = new byte[2] { 0x0, 0xC0 }; // fail
            int a = 7;
            int count = 0;

            serialPort.ReadTimeout = 1000;

            while (count < a)
            {
                //Console.WriteLine("count {0} a {1} mes leng {2}",count,a,mes.Length);
                try
                {
                    temp[count] = (byte)serialPort.ReadByte();
                }
                catch { break; }


                //Console.Write("{1}", temp[0], (char)temp[0]);

                if (temp[0] != 0x1b)
                {
                    count = 0;
                    continue;
                }

                if (count == 3)
                {
                    a = (temp[2] << 8) + temp[3];
                    mes = new byte[a];
                    a += 5;
                }

                if (count >= 5)
                {
                    mes[count - 5] = temp[count];
                }

                count++;
            }

            //Console.WriteLine("read ck");
            try
            {
                temp[count] = (byte)serialPort.ReadByte();
            }
            catch { }

            count++;

            Array.Resize<byte>(ref temp, count);

            //Console.WriteLine(this.BytesToRead);

            return mes;
        }
    }
}
