#pragma once

#include "envoy/config/typed_config.h"

#include "envoy/network/address.h"

#include "envoy/network/listen_socket.h"

#include "envoy/server/factory_context.h"

#include "source/common/quic/envoy_quic_packet_writer.h"

#include "quiche/quic/core/quic_path_validator.h"

namespace Envoy {

namespace Quic {

// An extension interface to creating customized UDP sockets and creating

// QUIC packet writers for upstream connections based on such sockets.

class QuicClientPacketWriterFactory {

public:

  struct CreationResult {

    // Not null.

    std::unique_ptr<EnvoyQuicPacketWriter> writer_;

    // Not null but can be a bad socket if creation goes wrong.

    Network::ConnectionSocketPtr socket_;

  };

  /**

   * Creates a socket and a QUIC packet writer associated with it.

   * @param server_addr The server address to connect to.

   * @param network The network to bind the socket to.

   * @param local_addr The local address to bind if not nullptr and if the network is invalid. Will

   * be set to the actual local address of the created socket.

   * @param options The socket options to apply.

   * @return A struct containing the created socket and writer objects.

   */

  virtual CreationResult

  createSocketAndQuicPacketWriter(Network::Address::InstanceConstSharedPtr server_addr,

                                  quic::QuicNetworkHandle network,

                                  Network::Address::InstanceConstSharedPtr& local_addr,

                                  const Network::ConnectionSocket::OptionsSharedPtr& options) PURE;

};

using QuicClientPacketWriterFactoryPtr = std::shared_ptr<QuicClientPacketWriterFactory>;

class QuicClientPacketWriterConfigFactory : public Config::TypedFactory {

public:

  /**

   * Returns a packet writer factory based on the given config.

   */

  virtual QuicClientPacketWriterFactoryPtr

  createQuicClientPacketWriterFactory(const Protobuf::Message& config,

                                      Event::Dispatcher& dispatcher,

                                      ProtobufMessage::ValidationVisitor& validation_visitor) PURE;

};

} // namespace Quic

} // namespace Envoy