using RemoteFrameBuffer.Common;
using System.Text;

namespace RemoteFrameBuffer.Client
{
    public class RemoteFrameBufferClientProtocol_3_3 : RemoteFrameBufferClientProtocol
    {
        public override RfbProtoVersion Version => new(3, 3);

        public RemoteFrameBufferClientProtocol_3_3(Stream s) : base(s)
        {
            this.Phase = RfbClientProtocolPhase.Constructed;
        }

        public override void Handshake(CancellationToken token)
        {
            if (this.Phase != RfbClientProtocolPhase.Constructed)
            {
                throw new InvalidOperationException("In wrong phase when calling Handshake");
            }
            this.Phase = RfbClientProtocolPhase.Handshake;
            Byte[] buf;
            // Request protocol version
            this.vncStream.Write(Encoding.ASCII.GetBytes("RFB 003.003\n"));
            // Read security type
            buf = new Byte[4];
            CancellationTokenSource readTimeout = new CancellationTokenSource(TimeSpan.FromSeconds(5));
            CancellationTokenSource readTokenSource = CancellationTokenSource.CreateLinkedTokenSource(token, readTimeout.Token);
            this.vncStream.ReadExactlyAsync(buf, 0, buf.Length, readTokenSource.Token).AsTask().Wait();
            if (BitConverter.IsLittleEndian)
            {
                Array.Reverse(buf);
            }
            this.SecurityType = (RemoteFramebufferSecurityType)BitConverter.ToUInt32(buf, 0);
            Console.Error.WriteLine($"Server uses security type {this.SecurityType}");
            switch (this.SecurityType)
            {
            case RemoteFramebufferSecurityType.Invalid:
                throw new Exception("Connection failed");
            case RemoteFramebufferSecurityType.None:
                break;// RFB 3.3 straight up jumps to initialization here
            case RemoteFramebufferSecurityType.VncAuthentication:
                throw new NotImplementedException("VNC Authentication is not implemented");
            default:
                throw new NotSupportedException("RFB version 3.3 doesn't support the security type returned by the server");
            }
            this.Phase = RfbClientProtocolPhase.HandshakeDone;
        }
    }
}