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

// Written by Michael Oborne

namespace ArdupilotMega
{
    class ArduinoSTKv2 : SerialPort,ArduinoComms
    {
        public event ProgressEventHandler Progress;

        public byte[] genstkv2packet(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++;

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

            byte[] ret = readpacket();

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

            return ret;
        }

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

            this.ReadTimeout = 1000;

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

            count++;

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

            //Console.WriteLine(this.BytesToRead);

            return mes;
        }


        /// <summary>
        /// Used to start initial connecting after serialport.open
        /// </summary>
        /// <returns>true = passed, false = failed</returns>
        public bool connectAP()
        {
            if (!this.IsOpen)
            {
                return false;
            }

            Thread.Sleep(100);

            int a = 0;
            while (a < 5)
            {
                byte[] temp = new byte[] { 0x6, 0,0,0,0};
                temp = this.genstkv2packet(temp);
                a++;
                Thread.Sleep(50);

                try
                {
                    if (temp[0] == 6 && temp[1] == 0 && temp.Length == 2)
                    {
                        return true;
                    }
                }
                catch { }
            }
            return false;
        }

        /// <summary>
        /// Used to keep alive the connection
        /// </summary>
        /// <returns>true = passed, false = lost connection</returns>
        public bool keepalive()
        {
            return connectAP();
        }
        /// <summary>
        /// Syncs after a private command has been sent
        /// </summary>
        /// <returns>true = passed, false = failed</returns>
        public bool sync()
        {
            if (!this.IsOpen)
            {
                return false;
            }
            return true;
        }
        /// <summary>
        /// Downloads the eeprom with the given length - set Address first
        /// </summary>
        /// <param name="length">eeprom length</param>
        /// <returns>downloaded data</returns>
        public byte[] download(short length)
        {
            if (!this.IsOpen)
            {
                throw new Exception();
            }
            byte[] data = new byte[length];

            byte[] temp = new byte[] { 0x16, (byte)((length >> 8) & 0xff), (byte)((length >> 0) & 0xff) };
            temp = this.genstkv2packet(temp);

            Array.Copy(temp, 2, data, 0, length);

            return data;
        }

        public byte[] downloadflash(short length)
        {
            if (!this.IsOpen)
            {
                throw new Exception("Port Closed");
            }
            byte[] data = new byte[length];

            byte[] temp = new byte[] { 0x14, (byte)((length >> 8) & 0xff), (byte)((length >> 0) & 0xff) };
            temp = this.genstkv2packet(temp);

            Array.Copy(temp, 2, data, 0, length);

            return data;
        }

        public bool uploadflash(byte[] data, int startfrom, int length, int startaddress)
        {
            if (!this.IsOpen)
            {
                return false;
            }
            int loops = (length / 0x100);
            int totalleft = length;
            int sending = 0;

            for (int a = 0; a <= loops; a++)
            {
                if (totalleft > 0x100)
                {
                    sending = 0x100;
                }
                else
                {
                    sending = totalleft;
                }

                //startaddress = 256;
                if (sending == 0)
                    return true;

                setaddress(startaddress);
                startaddress += sending;

                // 0x13          

                byte[] command = new byte[] { (byte)0x13, (byte)(sending >> 8), (byte)(sending & 0xff) };

                Console.WriteLine((startfrom + (length - totalleft)) + " - " + sending);

                Array.Resize<byte>(ref command, sending + 10); // sending + head

                Array.Copy(data, startfrom + (length - totalleft), command, 10, sending);

                command = this.genstkv2packet(command);

                totalleft -= sending;


                if (Progress != null)
                    Progress((int)(((float)startaddress / (float)length) * 100));

                if (command[1] != 0)
                {
                    Console.WriteLine("No Sync");
                    return false;
                }
            }
            return true;
        }

        /// <summary>
        /// Sets the eeprom start read or write address
        /// </summary>
        /// <param name="address">address, must be eaven number</param>
        /// <returns>true = passed, false = failed</returns>
        public bool setaddress(int address)
        {
            if (!this.IsOpen)
            {
                return false;
            }

            if (address % 2 == 1)
            {
                throw new Exception("Address must be an even number");
            }
                
            Console.WriteLine("Sending address   " + ((address / 2)));

            int tempstart = address / 2; // words
            byte[] temp = new byte[] { 0x6, (byte)((tempstart >> 24) & 0xff), (byte)((tempstart >> 16) & 0xff), (byte)((tempstart >> 8) & 0xff), (byte)((tempstart >> 0) & 0xff) };
            temp = this.genstkv2packet(temp);

            if (temp[1] == 0)
            {
                return true;
            }
            return false;
        }
        /// <summary>
        /// Upload data at preset address
        /// </summary>
        /// <param name="data">array to read from</param>
        /// <param name="startfrom">start array index</param>
        /// <param name="length">length to send</param>
        /// <param name="startaddress">sets eeprom start programing address</param>
        /// <returns>true = passed, false = failed</returns>
        public bool upload(byte[] data,short startfrom,short length, short startaddress)
        {
            if (!this.IsOpen)
            {
                return false;
            }
            int loops = (length / 0x100);
            int totalleft = length;
            int sending = 0;

            for (int a = 0; a <= loops; a++)
            {
                if (totalleft > 0x100)
                {
                    sending = 0x100;
                }
                else
                {
                    sending = totalleft;
                }

                //startaddress = 256;
                if (sending == 0)
                    return true;

                setaddress(startaddress);
                startaddress += (short)sending;

                // 0x13          

                byte[] command = new byte[] { (byte)0x15, (byte)(sending >> 8), (byte)(sending & 0xff) };

                Console.WriteLine((startfrom + (length - totalleft)) + " - " + sending);

                Array.Resize<byte>(ref command, sending + 10); // sending + head

                Array.Copy(data, startfrom + (length - totalleft), command, 10, sending);

                command = this.genstkv2packet(command);

                totalleft -= sending;


                if (Progress != null)
                    Progress((int)(((float)startaddress / (float)length) * 100));

                if (command[1] != 0)
                {
                    Console.WriteLine("No Sync");
                    return false;
                }
            }
            return true;
        }

        public new bool Close() {

            try
            {
                byte[] command = new byte[] { (byte)0x11 };
                genstkv2packet(command);
            }
            catch { }

            if (base.IsOpen)
                base.Close();
            this.DtrEnable = false;
            return true;
        }
    }
}