/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
 * Copyright (c) 2011-2015  Regents of the University of California.
 *
 * This file is part of ndnSIM. See AUTHORS for complete list of ndnSIM authors and
 * contributors.
 *
 * ndnSIM is free software: you can redistribute it and/or modify it under the terms
 * of the GNU General Public License as published by the Free Software Foundation,
 * either version 3 of the License, or (at your option) any later version.
 *
 * ndnSIM is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE.  See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * ndnSIM, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
 **/

#ifndef L2_RATE_TRACER_H
#define L2_RATE_TRACER_H

#include "l2-tracer.hpp"

#include "ns3/nstime.h"
#include "ns3/event-id.h"

#include <tuple>
#include <map>

namespace ns3 {

/**
 * @ingroup ndn-tracers
 * @brief Tracer to collect link-layer rate information about links
 *
 * @todo Finish implementation
 */
class L2RateTracer : public L2Tracer {
public:
  /**
   * @brief Network layer tracer constructor
   */
  L2RateTracer(std::shared_ptr<std::ostream> os, Ptr<Node> node);
  virtual ~L2RateTracer();

  /**
   * @brief Helper method to install tracers on all simulation nodes
   *
   * @param file File to which traces will be written
   * @param averagingPeriod Defines averaging period for the rate calculation,
   *        as well as how often data will be written into the trace file (default, every half
   *second)
   *
   * @returns a tuple of reference to output stream and list of tracers. !!! Attention !!! This
   *tuple needs to be preserved
   *          for the lifetime of simulation, otherwise SEGFAULTs are inevitable
   *
   */
  static void
  InstallAll(const std::string& file, Time averagingPeriod = Seconds(0.5));

  /**
   * @brief Explicit request to remove all statically created tracers
   *
   * This method can be helpful if simulation scenario contains several independent run,
   * or if it is desired to do a postprocessing of the resulting data
   */
  static void
  Destroy();

  void
  SetAveragingPeriod(const Time& period);

  virtual void
  PrintHeader(std::ostream& os) const;

  virtual void
  Print(std::ostream& os) const;

  virtual void
  Drop(Ptr<const Packet>);

private:
  void
  PeriodicPrinter();

  void
  Reset();

private:
  std::shared_ptr<std::ostream> m_os;
  Time m_period;
  EventId m_printEvent;

  mutable std::tuple<Stats, Stats, Stats, Stats> m_stats;
};

} // namespace ns3

#endif // L2_RATE_TRACER_H