#include "source/extensions/tracers/opencensus/config.h"

#include "envoy/config/trace/v3/opencensus.pb.h"

#include "envoy/config/trace/v3/opencensus.pb.validate.h"

#include "envoy/registry/registry.h"

#include "source/extensions/tracers/opencensus/opencensus_tracer_impl.h"

namespace Envoy {

namespace Extensions {

namespace Tracers {

namespace OpenCensus {

OpenCensusTracerFactory::OpenCensusTracerFactory() : FactoryBase("envoy.tracers.opencensus") {}

Tracing::DriverSharedPtr OpenCensusTracerFactory::createTracerDriverTyped(

    const envoy::config::trace::v3::OpenCensusConfig& proto_config,

    Server::Configuration::TracerFactoryContext& context) {

  // Since OpenCensus can only support a single tracing configuration per entire process,

  // we need to make sure that it is configured at most once.

  if (driver_) {

    if (Envoy::Protobuf::util::MessageDifferencer::Equals(config_, proto_config)) {

      return driver_;

    } else {

      throw EnvoyException("Opencensus has already been configured with a different config.");

    }

  }

  driver_ = std::make_shared<Driver>(proto_config, context.serverFactoryContext());

  config_ = proto_config;

  return driver_;

}

/**

 * Static registration for the OpenCensus tracer. @see RegisterFactory.

 */

REGISTER_FACTORY(OpenCensusTracerFactory, Server::Configuration::TracerFactory);

} // namespace OpenCensus

} // namespace Tracers

} // namespace Extensions

} // namespace Envoy