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

namespace DTS.DASLib.Command.Ribeye
{
    public class CommandPacket : CommandPacketBase
    {
        public enum CommandType
        {
            Reserved = 0x00,
            Arm,
            Attribute,
            Diagnostics,
            EventData,
            FirmwareUpdate,
            Information,
            QAandUtility,
            Realtime,
        };

        const int HEADER_SIZE_BYTES = 4;

        public string[] Parameter;
        byte Checksum = 0;

        //public byte[] OriginalBytes;

        public CommandPacket()
        {
            Parameter = new string[0];
            ShouldLog = true;
        }

        public CommandPacket(byte[] Bytes)
        {
            OriginalBytes = Bytes;
            ShouldLog = true;

            int ParameterCount = 0;
            foreach (byte CurrentByte in Bytes)
            {
                if ('#' == CurrentByte)
                {
                    ParameterCount++;
                }
            }

            Parameter = new string[ParameterCount];
            int CurrentParameter = 0;

            StringBuilder sb = new StringBuilder();

            foreach (byte CurrentByte in Bytes)
            {
                if ('#' == CurrentByte)
                {
                    Parameter[CurrentParameter] = sb.ToString();
                    CurrentParameter++;
                    sb = new StringBuilder();
                }
                else if ((byte)'\r' != CurrentByte && (byte)'\n' != CurrentByte)
                {
                    sb.Append((char)CurrentByte);
                }
            }
        }

        public override PacketState VerifyPacket(byte[] Bytes)
        {
            if (Bytes == null || '?' == Bytes[0]) // ? is the error indicator
                return PacketState.Unknown;

            if (Bytes.Length < HEADER_SIZE_BYTES)
                return PacketState.TooShort;

            // Need to check checksum
            if (Bytes[Bytes.Length - 2] == '\r' && Bytes[Bytes.Length - 1] == '\n')
            {
                return PacketState.OK;
            }
            else
            {
                return PacketState.TooShort;
            }
        }

        public override byte[] ToBytes()
        {
            uint Length;
            byte[] CommandBytes;

            Length = 0;

            foreach (string CurrentParameter in Parameter)
            {
                if (null != CurrentParameter)
                {
                    Length += (uint)(CurrentParameter.Length + 1);
                }
            }
            Length += (uint)(Checksum.ToString().Length + 2);
            CommandBytes = new byte[Length];

            int CommandIndex = 0;
            foreach (string CurrentParameter in Parameter)
            {
                foreach (char CurrentChar in CurrentParameter)
                {
                    CommandBytes[CommandIndex] = (byte)CurrentChar;
                    CommandIndex++;
                }
                CommandBytes[CommandIndex] = (byte)'#';
                CommandIndex++;
            }

            foreach (char CurrentChar in Checksum.ToString())
            {
                CommandBytes[CommandIndex] = (byte)CurrentChar;
                CommandIndex++;
            }

            CommandBytes[CommandBytes.Length - 2] = (byte)'\r';
            CommandBytes[CommandBytes.Length - 1] = (byte)'\n';
            OriginalBytes = CommandBytes;

            return CommandBytes;
        }

        private void ComputeChecksum()
        {
            Checksum = 0;

            foreach (string CurrentParameter in Parameter)
            {
                foreach (char CurrentCharacter in CurrentParameter)
                {
                    Checksum += (byte)CurrentCharacter;
                }
                Checksum += (byte)'#';
            }
        }
        public override void ComputeCRCs()
        {
            ComputeChecksum();
        }
        private static System.Globalization.CultureInfo InvariantCulture = new System.Globalization.CultureInfo("");
        public void GetParameter(int Position, out double Value)
        {
            Double.TryParse(Parameter[Position], System.Globalization.NumberStyles.Float, InvariantCulture, out Value);
        }

        public void GetParameter(int Position, out UInt64 Value)
        {
            UInt64.TryParse(Parameter[Position], out Value);
        }

        public void GetParameter(int Position, out Int64 Value)
        {
            Int64.TryParse(Parameter[Position], out Value);
        }

        public void GetParameter(int Position, out Int32 Value)
        {
            Int32.TryParse(Parameter[Position], out Value);
        }

        public void GetParameter(int Position, out UInt32 Value)
        {
            UInt32.TryParse(Parameter[Position], out Value);
        }

        public void GetParameter(int Position, out Int16 Value)
        {
            Int16.TryParse(Parameter[Position], out Value);
        }

        public void GetParameter(int Position, out UInt16 Value)
        {
            UInt16.TryParse(Parameter[Position], out Value);
        }

        public void GetParameter(int Position, out float Value)
        {
            float.TryParse(Parameter[Position], out Value);
        }

        public void GetParameter(int Position, out string Value)
        {
            Value = Parameter[Position];
        }

        public void SetParameter(int Position, double Value)
        {
            Parameter[Position] = Value.ToString();
        }

        public void SetParameter(int Position, Int64 Value)
        {
            Parameter[Position] = Value.ToString();
        }

        public void SetParameter(int Position, UInt64 Value)
        {
            Parameter[Position] = Value.ToString();
        }

        public void SetParameter(int Position, Int32 Value)
        {
            Parameter[Position] = Value.ToString();
        }

        public void SetParameter(int Position, UInt32 Value)
        {
            Parameter[Position] = Value.ToString();
        }

        public void SetParameter(int Position, Int16 Value)
        {
            Parameter[Position] = Value.ToString();
        }

        public void SetParameter(int Position, UInt16 Value)
        {
            Parameter[Position] = Value.ToString();
        }

        public void SetParameter(int Position, float Value)
        {
            Parameter[Position] = Value.ToString();
        }

        public void SetParameter(int Position, string Value)
        {
            Parameter[Position] = Value;
        }
        public override object ConvertByteToCommandType(byte b)
        {
            return (CommandType)b;
        }
        private static UInt16 GlobalSequenceNumber = 0;
        private static object GlobalSequenceNumberLock = new object();
        public override void GetNextSequenceNumber()
        {
            lock (GlobalSequenceNumberLock)
            {
                SequenceNumber = GlobalSequenceNumber;
                GlobalSequenceNumber++;
            }
        }
    }

    public class DownloadPacket : CommandPacket
    {
        public byte[] Data;
        public DownloadPacket(byte[] Bytes)
        {
            OriginalBytes = Bytes;
            ShouldLog = true;

            int ParameterCount = 0;
            foreach (byte CurrentByte in Bytes)
            {
                if ('#' == CurrentByte)
                {
                    ParameterCount++;
                }
                if ('\r' == CurrentByte)
                {
                    break;
                }
            }

            Parameter = new string[ParameterCount];
            int CurrentParameter = 0;

            StringBuilder sb = new StringBuilder();

            uint ByteOffset = 0;
            foreach (byte CurrentByte in Bytes)
            {
                if ('#' == CurrentByte)
                {
                    Parameter[CurrentParameter] = sb.ToString();
                    CurrentParameter++;
                    sb = new StringBuilder();
                }
                else if ((byte)'\n' == CurrentByte)
                {
                    break;
                }
                else
                {
                    sb.Append((char)CurrentByte);
                }
                ByteOffset++;
            }
            ByteOffset++;
            uint DataLength = (uint)(Bytes.Length - ByteOffset);
            Data = new byte[DataLength];
            Array.Copy(Bytes, ByteOffset, Data, 0, DataLength);
        }

        public static PacketState VerifyPacket(byte[] Bytes, ref uint BytesExpected)
        {
            if (Bytes == null)
                return PacketState.Unknown;

            if (0 == BytesExpected)
            {
                string[] Parameter = new string[3];
                uint CurrentParameter = 0;
                StringBuilder sb = new StringBuilder();

                // Look for initial header
                foreach (byte CurrentByte in Bytes)
                {
                    try
                    {
                        if ('#' == CurrentByte)
                        {
                            Parameter[CurrentParameter] = sb.ToString();
                            CurrentParameter++;
                            sb = new StringBuilder();
                        }
                        else if ((byte)'\r' == CurrentByte || (byte)'\n' == CurrentByte)
                        {
                            break;
                        }
                        else
                        {
                            sb.Append((char)CurrentByte);
                        }
                    }
                    catch (Exception)
                    {
                        return PacketState.Unknown;
                    }

                }

                if (3 != CurrentParameter)
                {
                    return PacketState.TooShort;
                }
                else
                {
                    // Parameter 1 = number of channels
                    // Parameter 2 = number of samples
                    // + 1 is for checksum on each sample
                    // * 2 is for 2 bytes per sample
                    try
                    {
                        BytesExpected = (uint)((UInt16.Parse(Parameter[1]) * 2 + 1) * UInt16.Parse(Parameter[2]) + Bytes.Length);
                    }
                    catch (Exception)
                    {
                        return PacketState.Unknown;
                    }

                    if (Bytes.Length >= BytesExpected)
                    {
                        return PacketState.OK;
                    }
                    else
                    {
                        return PacketState.TooShort;
                    }
                }
            }
            else
            {
                if (Bytes.Length >= BytesExpected)
                {
                    return PacketState.OK;
                }
                else
                {
                    return PacketState.TooShort;
                }
            }
        }
    }
}