////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2014-2023, Lawrence Livermore National Security, LLC.
// Produced at the Lawrence Livermore National Laboratory.
// Written by the LBANN Research Team (B. Van Essen, et al.) listed in
// the CONTRIBUTORS file. <lbann-dev@llnl.gov>
//
// LLNL-CODE-697807.
// All rights reserved.
//
// This file is part of LBANN: Livermore Big Artificial Neural Network
// Toolkit. For details, see http://software.llnl.gov/LBANN or
// https://github.com/LLNL/LBANN.
//
// Licensed under the Apache License, Version 2.0 (the "Licensee"); you
// may not use this file except in compliance with the License.  You may
// obtain a copy of the License at:
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
// implied. See the License for the specific language governing
// permissions and limitations under the license.
//
// print_statistics .hpp .cpp - Callback hooks to print information
////////////////////////////////////////////////////////////////////////////////

#ifndef LBANN_CALLBACKS_CALLBACK_PRINT_STATISTICS_HPP_INCLUDED
#define LBANN_CALLBACKS_CALLBACK_PRINT_STATISTICS_HPP_INCLUDED

#include "lbann/callbacks/callback.hpp"

namespace lbann {
namespace callback {

/** Periodically print computational results.
 *  Prints average objective function value and metric scores after
 *  each training epoch and evaluation.
 */
class print_statistics : public callback_base
{
public:
  print_statistics(int batch_interval = 1, bool print_global_stat_only = false)
    : callback_base(batch_interval),
      m_print_global_stat_only(print_global_stat_only)
  {}
  print_statistics(const print_statistics&) = default;
  print_statistics& operator=(const print_statistics&) = default;
  print_statistics* copy() const override
  {
    return new print_statistics(*this);
  }
  void setup(model* m) override;
  void on_epoch_begin(model* m) override;
  void on_epoch_end(model* m) override;
  void on_validation_end(model* m) override;
  void on_test_end(model* m) override;
  std::string name() const override { return "print_statistics"; }

  /** @name Serialization */
  ///@{

  /** @brief Store state to archive for checkpoint and restart */
  template <class Archive>
  void serialize(Archive& ar);

  ///@}

private:
  /** Add callback specific data to prototext */
  void write_specific_proto(lbann_data::Callback& proto) const final;

  /** Print objective function and metrics to standard output. */
  void report_results(model* m);
  bool m_print_global_stat_only;
};

// Builder function
std::unique_ptr<callback_base> build_print_statistics_callback_from_pbuf(
  const google::protobuf::Message&,
  std::shared_ptr<lbann_summary> const&);

} // namespace callback
} // namespace lbann

#endif // LBANN_CALLBACKS_CALLBACK_PRINT_STATISTICS_HPP_INCLUDED
