#pragma once

#include "envoy/event/dispatcher.h"

#include "envoy/service/load_stats/v3/lrs.pb.h"

#include "envoy/stats/scope.h"

#include "envoy/stats/stats_macros.h"

#include "envoy/upstream/cluster_manager.h"

#include "envoy/upstream/load_stats_reporter.h"

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

#include "source/common/grpc/async_client_impl.h"

#include "source/common/grpc/typed_async_client.h"

namespace Envoy {

namespace Upstream {

class LoadStatsReporterImpl

    : public LoadStatsReporter,

      public Grpc::AsyncStreamCallbacks<envoy::service::load_stats::v3::LoadStatsResponse>,

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

public:

  LoadStatsReporterImpl(const LocalInfo::LocalInfo& local_info, ClusterManager& cluster_manager,

                        Stats::Scope& scope, Grpc::RawAsyncClientSharedPtr async_client,

                        Event::Dispatcher& dispatcher);

  ~LoadStatsReporterImpl() override;

  // Grpc::AsyncStreamCallbacks

  void onCreateInitialMetadata(Http::RequestHeaderMap& metadata) override;

  void onReceiveInitialMetadata(Http::ResponseHeaderMapPtr&& metadata) override;

  void onReceiveMessage(

      std::unique_ptr<envoy::service::load_stats::v3::LoadStatsResponse>&& message) override;

  void onReceiveTrailingMetadata(Http::ResponseTrailerMapPtr&& metadata) override;

  void onRemoteClose(Grpc::Status::GrpcStatus status, const std::string& message) override;

  // Upstream::LoadStatsReporter

  // TODO(htuch): Make this configurable or some static.

  const uint32_t RETRY_DELAY_MS = 5000;

private:

  void setRetryTimer();

  void establishNewStream();

  void sendLoadStatsRequest();

  void handleFailure();

  void startLoadReportPeriod();

  ClusterManager& cm_;

  LoadReporterStats stats_;

  Grpc::AsyncClient<envoy::service::load_stats::v3::LoadStatsRequest,

                    envoy::service::load_stats::v3::LoadStatsResponse>

      async_client_;

  Grpc::AsyncStream<envoy::service::load_stats::v3::LoadStatsRequest> stream_{};

  const Protobuf::MethodDescriptor& service_method_;

  Event::TimerPtr retry_timer_;

  Event::TimerPtr response_timer_;

  const envoy::service::load_stats::v3::LoadStatsRequest request_template_;

  std::unique_ptr<envoy::service::load_stats::v3::LoadStatsResponse> message_;

  // Map from cluster name to start of measurement interval.

  absl::node_hash_map<std::string, std::chrono::steady_clock::duration> clusters_;

  TimeSource& time_source_;

};

} // namespace Upstream

} // namespace Envoy