#pragma once

#include "envoy/config/typed_config.h"

#include "envoy/network/address.h"

#include "envoy/protobuf/message_validator.h"

#include "envoy/server/factory_context.h"

#include "absl/container/flat_hash_set.h"

namespace Envoy {

namespace Geolocation {

// Actual result of the lookup. Each entry in the map represents the geolocation header (entry key)

// for which the lookup was invoked mapped to a lookup result from the database.

using LookupResult = const absl::flat_hash_map<std::string, std::string>;

// Async callbacks used for geolocation provider lookups.

using LookupGeoHeadersCallback = std::function<void(LookupResult&&)>;

class LookupRequest {

public:

  LookupRequest(Network::Address::InstanceConstSharedPtr&& remote_address)

private:

  Network::Address::InstanceConstSharedPtr remote_address_;

};

class Driver {

public:

  /**

   *  Performs asynchronous lookup in the geolocation database.

   *

   *  @param request containing geolocation headers to lookup in the database.

   *  @param cb supplies the filter callbacks to notify when lookup is complete.

   */

  virtual void lookup(LookupRequest&& request, LookupGeoHeadersCallback&& cb) const PURE;

};

using DriverSharedPtr = std::shared_ptr<Driver>;

/**

 * Implemented by each geolocation provider and registered via Registry::registerFactory() or the

 * convenience class RegisterFactory.

 */

class GeoipProviderFactory : public Config::TypedFactory {

public:

  /**

   * Create a particular geolocation provider implementation. If the implementation is unable to

   * produce a geolocation provider with the provided parameters, it should throw an EnvoyException

   * in the case of general error or a Json::Exception if the json configuration is erroneous. The

   * returned pointer should always be valid.

   *

   *

   * @param config supplies the proto configuration for the geolocation provider

   * @param context supplies the factory context

   */

  virtual DriverSharedPtr

  createGeoipProviderDriver(const Protobuf::Message& config, const std::string& stat_prefix,

                            Server::Configuration::FactoryContext& context) PURE;

};

} // namespace Geolocation

} // namespace Envoy