//******************************************************************************************************
//  SendWriteRequest.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 GSF.Net.TFtp.Commands;

namespace GSF.Net.TFtp.Transfer.States
{
    internal class SendWriteRequest : StateWithNetworkTimeout
    {
        public override void OnStateEnter()
        {
            base.OnStateEnter();
            SendRequest();
        }

        private void SendRequest()
        {
            WriteRequest request = new WriteRequest(Context.Filename, Context.TransferMode, Context.ProposedOptions.ToOptionList());
            SendAndRepeat(request);
        }

        public override void OnCommand(ITFtpCommand command, System.Net.EndPoint endpoint)
        {
            switch (command)
            {
                case OptionAcknowledgement optionAcknowledgement:
                {
                    TransferOptionSet acknowledged = new TransferOptionSet(optionAcknowledgement.Options);
                    Context.FinishOptionNegotiation(acknowledged);
                    BeginSendingTo(endpoint);
                    break;
                }
                
                case Acknowledgement acknowledgement when acknowledgement.BlockNumber == 0:
                    Context.FinishOptionNegotiation(TransferOptionSet.NewEmptySet());
                    BeginSendingTo(endpoint);
                    break;
                
                case Error error:
                    // The server denied our request
                    Context.SetState(new ReceivedError(error));
                    break;
                
                default:
                    base.OnCommand(command, endpoint);
                    break;
            }
        }

        private void BeginSendingTo(System.Net.EndPoint endpoint)
        {
            // Switch to the endpoint that we received from the server
            Context.GetConnection().RemoteEndpoint = endpoint;

            // Start sending packets
            Context.SetState(new Sending());
        }

        public override void OnCancel(TFtpErrorPacket reason)
        {
            Context.SetState(new CancelledByUser(reason));
        }
    }
}