#include "source/extensions/filters/network/thrift_proxy/framed_transport_impl.h"

#include "envoy/common/exception.h"

#include "source/extensions/filters/network/thrift_proxy/buffer_helper.h"

namespace Envoy {

namespace Extensions {

namespace NetworkFilters {

namespace ThriftProxy {

bool FramedTransportImpl::decodeFrameStart(Buffer::Instance& buffer, MessageMetadata& metadata) {

  UNREFERENCED_PARAMETER(metadata);

  if (buffer.length() < 4) {

    return false;

  }

  int32_t thrift_size = buffer.peekBEInt<int32_t>();

  if (thrift_size <= 0 || thrift_size > MaxFrameSize) {

    throw EnvoyException(absl::StrCat("invalid thrift framed transport frame size ", thrift_size));

  }

  buffer.drain(4);

  metadata.setFrameSize(static_cast<uint32_t>(thrift_size));

  return true;

}

bool FramedTransportImpl::decodeFrameEnd(Buffer::Instance&) { return true; }

void FramedTransportImpl::encodeFrame(Buffer::Instance& buffer, const MessageMetadata& metadata,

                                      Buffer::Instance& message) {

  UNREFERENCED_PARAMETER(metadata);

  uint64_t size = message.length();

  if (size == 0 || size > MaxFrameSize) {

    throw EnvoyException(absl::StrCat("invalid thrift framed transport frame size ", size));

  }

  int32_t thrift_size = static_cast<int32_t>(size);

  buffer.writeBEInt<int32_t>(thrift_size);

  buffer.move(message);

}

class FramedTransportConfigFactory : public TransportFactoryBase<FramedTransportImpl> {

public:

  FramedTransportConfigFactory() : TransportFactoryBase(TransportNames::get().FRAMED) {}

};

/**

 * Static registration for the framed transport. @see RegisterFactory.

 */

REGISTER_FACTORY(FramedTransportConfigFactory, NamedTransportConfigFactory);

} // namespace ThriftProxy

} // namespace NetworkFilters

} // namespace Extensions

} // namespace Envoy