using InnovEnergy.Lib.Protocols.DBus.Protocol.Header;
using InnovEnergy.Lib.Protocols.DBus.Transport;

namespace InnovEnergy.Lib.Protocols.DBus.WireFormat;

internal class DBusSocketReader : DBusReader
{
    private BufferedSocketReader BufferedSocketReader { get; }

    public override Int32 BytesRead => BufferedSocketReader.BytesRead;

    public DBusSocketReader(BufferedSocketReader bufferedSocketReader, Boolean swapEndian) : base(swapEndian)
    {
        BufferedSocketReader = bufferedSocketReader;
    }

    public DBusSocketReader(BufferedSocketReader bufferedSocketReader) :
        this(bufferedSocketReader, MessageStart(bufferedSocketReader))
    {
    }

    private static Boolean MessageStart(BufferedSocketReader socketReader)
    {
        Endian PeekEndian() => (Endian) socketReader.PeekByte();

        while (PeekEndian() is not (Endian.Little or Endian.Big))
        {
            socketReader.ReadByte();
        }

        socketReader.Reset();

        return PeekEndian() != Env.Endianness;
    }

    public override Byte ReadByte() => BufferedSocketReader.ReadByte();

    public override ArraySegment<Byte> ReadSegment(Int32 size) => BufferedSocketReader.ReadSegment(size);

}