#pragma once

#include <memory>

#include "envoy/common/pure.h"

#include "envoy/rds/config.h"

#include "envoy/server/factory_context.h"

#include "source/common/protobuf/protobuf.h"

namespace Envoy {

namespace Rds {

/**

 * Traits of the protocol specific route configuration and proto.

 * The generic rds classes will call the methods of this interface

 * to get information which is not visible for them directly.

 */

class ProtoTraits {

public:

  /**

   * Give the full name of the route configuration proto description.

   * For example 'envoy.config.route.v3.RouteConfiguration'

   */

  virtual const std::string& resourceType() const PURE;

  /**

   * Gives back the name field tag number of the route configuration proto.

   */

  virtual int resourceNameFieldNumber() const PURE;

  /**

   * Create an empty route configuration proto object.

   */

  virtual ProtobufTypes::MessagePtr createEmptyProto() const PURE;

};

class ConfigTraits {

public:

  /**

   * Create a dummy config object without actual route configuration.

   * This object will be used before the first valid route configuration is fetched.

   */

  virtual ConfigConstSharedPtr createNullConfig() const PURE;

  /**

   * Create a config object based on a route configuration.

   * The full name of the type of the parameter message is

   * guaranteed to match with the return value of ProtoTraits::resourceType.

   * Both dynamic or static cast can be applied to downcast the message

   * to the corresponding route configuration class.

   * @param rc supplies the RouteConfiguration.

   * @param context supplies the context of the server factory.

   * @param validate_clusters_default specifies whether the clusters that the route

   *    table refers to will be validated by the cluster manager. Currently thrift

   *    route config provider manager validates the clusters for static route config

   *    by default but doesn't validate the clusters for TRDS.

   * @throw EnvoyException if the new config can't be applied of.

   */

  virtual ConfigConstSharedPtr createConfig(const Protobuf::Message& rc,

                                            Server::Configuration::ServerFactoryContext& context,

                                            bool validate_clusters_default) const PURE;

};

} // namespace Rds

} // namespace Envoy