using CliWrap;

namespace InnovEnergy.Lib.Channels.V2.Pipes;

public class ChannelPipeSource : PipeSource
{
    private readonly IStreamChannel _StreamChannel;
    private Byte[]? _Buffer;

    private ChannelPipeSource(IStreamChannel streamChannel)
    {
        _StreamChannel = streamChannel;
    }

    public static ChannelPipeSource FromStreamChannel(IStreamChannel streamChannel)
    {
        return new ChannelPipeSource(streamChannel);
    }


    public override async Task CopyToAsync(Stream destination, CancellationToken cancellationToken = new CancellationToken())
    {
        var rx = await _StreamChannel.Read();

        if (rx is Byte[] ba)
        {
            await destination.WriteAsync(ba, 0, ba.Length, cancellationToken);
            return;
        }
        
        if (_Buffer is null || _Buffer.Length < rx.Count )
        {
            _Buffer = rx.ToArray();
        }
        else
        {
            var i = 0;
            foreach (var b in _Buffer)
                _Buffer[i++] = b;
        }
        
        await destination.WriteAsync(_Buffer, 0, rx.Count, cancellationToken);
    }
}