using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using static LibrarySDR.Helpers.BinaryHexHelper;

namespace LibrarySDR.Requests
{
    public class Header
    {
        private static int sendingCounter = 0;
        public static int SendingCounter
        {
            get
            {
                // rest counter to value 0 after max value inside a byte
                if (sendingCounter > 255)
                    sendingCounter = 0;

                return sendingCounter++;
            }
        }

        private static int MagicNumber = 0xA5;

        private Int16 length;
        public Int16 Length { get { return length; } }

        private Int16 counter;
        public Int16 Counter { get { return counter;  } }

        public Header(string hexHeader)
        {
            int i = 0;
            int prevIdx = 0;
            Int16 magicNumber = 0;

            // get magic number
            String hex = LittleToBigEndianHexString(hexHeader.Substring(i = i + prevIdx, prevIdx = 2));
            Int16.TryParse(hex, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out magicNumber);

            // get counter 
            hex = LittleToBigEndianHexString(hexHeader.Substring(i = i + prevIdx, prevIdx = 2));
            //i = i + 2;
            Int16.TryParse(hex, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out counter);

            // get length
            hex = LittleToBigEndianHexString(hexHeader.Substring(i = i + prevIdx, prevIdx = 2 * 2));
            //i = i + 4;
            Int16.TryParse(hex, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out length);
        }


        public static String GetHeader(int length)
        {
            StringBuilder sb = new StringBuilder("");

            // get the binary data for the header
            sb.Append(GetHeaderBinary(length));

            // generate the hex command
            String headerHex = BinaryStringToHexString(sb.ToString(), Padding.RIGHT);

            return headerHex;
        }

        public static String GetHeaderBinary(int length)
        {
            StringBuilder sb = new StringBuilder("");

            // Magic Number (8 bits)
            sb.Append(GetBits(MagicNumber, 8));

            // Counter (8 bits)
            sb.Append(GetBits(SendingCounter, 8));

            // Length of the following message (16 bits)
            sb.Append(GetBits(length, 16));

            return sb.ToString();
        }


        public static void ResetCounter()
        {
            sendingCounter = 0;
        }

    }
}