//******************************************************************************************************//  Commands.cs - Gbtc////  Copyright © 2020, Grid Protection Alliance.  All Rights Reserved.////  Licensed to the Grid Protection Alliance (GPA) under one or more contributor license agreements. See//  the NOTICE file distributed with this work for additional information regarding copyright ownership.//  The GPA licenses this file to you under the MIT License (MIT), the "License"; you may not use this//  file except in compliance with the License. You may obtain a copy of the License at:////      http://opensource.org/licenses/MIT////  Unless agreed to in writing, the subject software distributed under the License is distributed on an//  "AS-IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Refer to the//  License for the specific language governing permissions and limitations.////  Code Modification History://  ----------------------------------------------------------------------------------------------------//  05/12/2020 - J. Ritchie Carroll//       Generated original version of source code.////****************************************************************************************************** #region [ Contributor License Agreements ] //*******************************************************************************************************////   Code based on the following project://        https://github.com/Callisto82/tftp.net//  //   Copyright © 2011, Michael Baer////******************************************************************************************************* #endregion using System.Collections.Generic; namespace GSF.Net.TFtp.Commands{    internal interface ITFtpCommand    {        void Visit(ITFtpCommandVisitor visitor);    }     internal interface ITFtpCommandVisitor    {        void OnReadRequest(ReadRequest command);        void OnWriteRequest(WriteRequest command);        void OnData(Data command);        void OnAcknowledgement(Acknowledgement command);        void OnError(Error command);        void OnOptionAcknowledgement(OptionAcknowledgement command);    }     internal abstract class ReadOrWriteRequest    {        protected ReadOrWriteRequest(ushort opCode, string filename, TFtpTransferMode mode, IEnumerable<TransferOption> options)        {            TargetOpCode = opCode;            Filename = filename;            Mode = mode;            Options = options;        }         public ushort TargetOpCode { get; }         public string Filename { get; }         public TFtpTransferMode Mode { get; }         public IEnumerable<TransferOption> Options { get; }    }     internal class ReadRequest : ReadOrWriteRequest, ITFtpCommand    {        public const ushort OpCode = 1;         public ReadRequest(string filename, TFtpTransferMode mode, IEnumerable<TransferOption> options)            : base(OpCode, filename, mode, options)        {        }         public void Visit(ITFtpCommandVisitor visitor)        {            visitor.OnReadRequest(this);        }    }     internal class WriteRequest : ReadOrWriteRequest, ITFtpCommand    {        public const ushort OpCode = 2;         public WriteRequest(string filename, TFtpTransferMode mode, IEnumerable<TransferOption> options)            : base(OpCode, filename, mode, options)        {        }         public void Visit(ITFtpCommandVisitor visitor)        {            visitor.OnWriteRequest(this);        }    }     internal class Data : ITFtpCommand    {        public const ushort OpCode = 3;         public Data(ushort blockNumber, byte[] data)        {            BlockNumber = blockNumber;            Bytes = data;        }         public ushort BlockNumber { get; }         public byte[] Bytes { get; }         public void Visit(ITFtpCommandVisitor visitor)        {            visitor.OnData(this);        }    }     internal class Acknowledgement : ITFtpCommand    {        public const ushort OpCode = 4;         public Acknowledgement(ushort blockNumber)        {            BlockNumber = blockNumber;        }         public ushort BlockNumber { get; }         public void Visit(ITFtpCommandVisitor visitor)        {            visitor.OnAcknowledgement(this);        }    }     internal class Error : ITFtpCommand    {        public const ushort OpCode = 5;         public Error(ushort errorCode, string message)        {            ErrorCode = errorCode;            Message = message;        }         public ushort ErrorCode { get; }         public string Message { get; }         public void Visit(ITFtpCommandVisitor visitor)        {            visitor.OnError(this);        }    }     internal class OptionAcknowledgement : ITFtpCommand    {        public const ushort OpCode = 6;         public OptionAcknowledgement(IEnumerable<TransferOption> options)        {            Options = options;        }         public IEnumerable<TransferOption> Options { get; }         public void Visit(ITFtpCommandVisitor visitor)        {            visitor.OnOptionAcknowledgement(this);        }    }}