#pragma once

#include "envoy/extensions/load_balancing_policies/least_request/v3/least_request.pb.h"

#include "envoy/extensions/load_balancing_policies/least_request/v3/least_request.pb.validate.h"

#include "envoy/upstream/load_balancer.h"

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

#include "source/extensions/load_balancing_policies/common/factory_base.h"

namespace Envoy {

namespace Extensions {

namespace LoadBalancingPolicies {

namespace LeastRequest {

using LeastRequestLbProto =

    envoy::extensions::load_balancing_policies::least_request::v3::LeastRequest;

using ClusterProto = envoy::config::cluster::v3::Cluster;

using CommonLbConfigProto = envoy::config::cluster::v3::Cluster::CommonLbConfig;

using LegacyLeastRequestLbProto = envoy::config::cluster::v3::Cluster::LeastRequestLbConfig;

/**

 * Load balancer config that used to wrap the least request config.

 */

class TypedLeastRequestLbConfig : public Upstream::LoadBalancerConfig {

public:

  TypedLeastRequestLbConfig(const LeastRequestLbProto& lb_config);

  TypedLeastRequestLbConfig(const CommonLbConfigProto& common_lb_config,

                            const LegacyLeastRequestLbProto& lb_config);

  LeastRequestLbProto lb_config_;

};

struct LeastRequestCreator : public Logger::Loggable<Logger::Id::upstream> {

  Upstream::LoadBalancerPtr operator()(Upstream::LoadBalancerParams params,

                                       OptRef<const Upstream::LoadBalancerConfig> lb_config,

                                       const Upstream::ClusterInfo& cluster_info,

                                       const Upstream::PrioritySet& priority_set,

                                       Runtime::Loader& runtime, Random::RandomGenerator& random,

                                       TimeSource& time_source);

};

class Factory : public Common::FactoryBase<LeastRequestLbProto, LeastRequestCreator> {

public:

  absl::StatusOr<Upstream::LoadBalancerConfigPtr>

  loadConfig(Server::Configuration::ServerFactoryContext&,

  absl::StatusOr<Upstream::LoadBalancerConfigPtr>

};

DECLARE_FACTORY(Factory);

} // namespace LeastRequest

} // namespace LoadBalancingPolicies

} // namespace Extensions

} // namespace Envoy