#pragma once

#include <chrono>

#include <memory>

#include "envoy/config/grpc_mux.h"

#include "envoy/config/subscription.h"

#include "envoy/event/dispatcher.h"

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

#include "xds/core/v3/resource_locator.pb.h"

namespace Envoy {

namespace Config {

/**

 * Adapter from typed Subscription to untyped GrpcMux. Also handles per-xDS API stats/logging.

 */

class GrpcSubscriptionImpl : public Subscription,

                             protected SubscriptionCallbacks,

                             Logger::Loggable<Logger::Id::config> {

public:

  GrpcSubscriptionImpl(GrpcMuxSharedPtr grpc_mux, SubscriptionCallbacks& callbacks,

                       OpaqueResourceDecoderSharedPtr resource_decoder, SubscriptionStats stats,

                       absl::string_view type_url, Event::Dispatcher& dispatcher,

                       std::chrono::milliseconds init_fetch_timeout, bool is_aggregated,

                       const SubscriptionOptions& options);

  // Config::Subscription

  void start(const absl::flat_hash_set<std::string>& resource_names) override;

  void

  updateResourceInterest(const absl::flat_hash_set<std::string>& update_to_these_names) override;

  void requestOnDemandUpdate(const absl::flat_hash_set<std::string>& add_these_names) override;

  // Config::SubscriptionCallbacks (all pass through to callbacks_!)

  absl::Status onConfigUpdate(const std::vector<Config::DecodedResourceRef>& resources,

                              const std::string& version_info) override;

  absl::Status onConfigUpdate(const std::vector<Config::DecodedResourceRef>& added_resources,

                              const Protobuf::RepeatedPtrField<std::string>& removed_resources,

                              const std::string& system_version_info) override;

  void onConfigUpdateFailed(ConfigUpdateFailureReason reason, const EnvoyException* e) override;

  ScopedResume pause();

private:

  void disableInitFetchTimeoutTimer();

  GrpcMuxSharedPtr grpc_mux_;

  SubscriptionCallbacks& callbacks_;

  OpaqueResourceDecoderSharedPtr resource_decoder_;

  SubscriptionStats stats_;

  const std::string type_url_;

  GrpcMuxWatchPtr watch_;

  Event::Dispatcher& dispatcher_;

  // NOTE: if another subscription of the same type_url has already been started, this value will be

  // ignored in favor of the other subscription's.

  std::chrono::milliseconds init_fetch_timeout_;

  Event::TimerPtr init_fetch_timeout_timer_;

  const bool is_aggregated_;

  const SubscriptionOptions options_;

  struct ResourceNameFormatter {

  };

};

using GrpcSubscriptionImplPtr = std::unique_ptr<GrpcSubscriptionImpl>;

using GrpcSubscriptionImplSharedPtr = std::shared_ptr<GrpcSubscriptionImpl>;

class GrpcCollectionSubscriptionImpl : public GrpcSubscriptionImpl {

public:

  GrpcCollectionSubscriptionImpl(const xds::core::v3::ResourceLocator& collection_locator,

                                 GrpcMuxSharedPtr grpc_mux, SubscriptionCallbacks& callbacks,

                                 OpaqueResourceDecoderSharedPtr resource_decoder,

                                 SubscriptionStats stats, Event::Dispatcher& dispatcher,

                                 std::chrono::milliseconds init_fetch_timeout, bool is_aggregated,

                                 const SubscriptionOptions& options);

  void start(const absl::flat_hash_set<std::string>& resource_names) override;

private:

  xds::core::v3::ResourceLocator collection_locator_;

};

} // namespace Config

} // namespace Envoy