#pragma once

#include "envoy/server/tracer_config.h"

#include "envoy/singleton/instance.h"

#include "envoy/tracing/tracer_manager.h"

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

#include "source/common/tracing/tracer_config_impl.h"

#include "source/common/tracing/tracer_impl.h"

namespace Envoy {

namespace Tracing {

/**

 * TracerManager implementation that manages the tracers. This should be used as a singleton except

 * in tests.

 */

class TracerManagerImpl : public TracerManager,

                          public Singleton::Instance,

                          Logger::Loggable<Logger::Id::tracing> {

public:

  TracerManagerImpl(Server::Configuration::TracerFactoryContextPtr factory_context);

  // TracerManager

  TracerSharedPtr getOrCreateTracer(const envoy::config::trace::v3::Tracing_Http* config) override;

  // Take a peek into the cache of HttpTracers. This should only be used in tests.

  static std::shared_ptr<TracerManager> singleton(Server::Configuration::FactoryContext& context);

private:

  void removeExpiredCacheEntries();

  Server::Configuration::TracerFactoryContextPtr factory_context_;

  const TracerSharedPtr null_tracer_{std::make_shared<Tracing::NullTracer>()};

  // HttpTracers indexed by the hash of their configuration.

  absl::flat_hash_map<std::size_t, std::weak_ptr<Tracer>> tracers_;

};

} // namespace Tracing

} // namespace Envoy