/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */

/*

 * Copyright (c) 2008,2009 IITP RAS

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation;

 *

 * This program 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 this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 * Author: Kirill Andreev <andreev@iitp.ru>

 */

#ifndef WIFI_TIMING_ELEMENT_H

#define WIFI_TIMING_ELEMENT_H

#include <vector>

#include "ns3/nstime.h"

#include "ns3/wifi-information-element-vector.h"

namespace ns3 {

namespace dot11s {

/**

 * \ingroup dot11s

 * \brief Describes one unit of beacon timing element

 */

class IeBeaconTimingUnit : public SimpleRefCount<IeBeaconTimingUnit>

{

public:

  IeBeaconTimingUnit ();

  void SetAid (uint8_t aid);

  void SetLastBeacon (uint16_t lastBeacon);

  void SetBeaconInterval (uint16_t beaconInterval);

  uint8_t GetAid () const;

  uint16_t GetLastBeacon () const;

  uint16_t GetBeaconInterval () const;

private:

  /// Least significant octet of AID:

  uint8_t m_aid;

  /// Last time we received a beacon in accordance with a local TSF measured in 256 microseconds unit

  uint16_t m_lastBeacon;

  /// Beacon interval of remote mesh point

  uint16_t m_beaconInterval;

  friend bool operator== (const IeBeaconTimingUnit & a, const IeBeaconTimingUnit & b);

};

/**

 * \ingroup dot11s

 * \brief See 7.3.2.89 of 802.11s draft 2.07

 */

class IeBeaconTiming : public WifiInformationElement

{

public:

  /**

   * \ingroup dot11s

   * This type is a list of timing elements obtained from neigbours with their beacons:

   */

  typedef std::vector< Ptr<IeBeaconTimingUnit> > NeighboursTimingUnitsList;

  IeBeaconTiming ();

  /**

   * This methods are needed for beacon collision

   * avoidance module:

   */

  NeighboursTimingUnitsList GetNeighboursTimingElementsList ();

  void AddNeighboursTimingElementUnit (

    uint16_t aid,

    Time last_beacon,

    Time beacon_interval

  );

  void   DelNeighboursTimingElementUnit (

    uint16_t aid,

    Time  last_beacon,

    Time  beacon_interval

  );

  void   ClearTimingElement ();

  /**

   * \name Inherited from WifiInformationElement

   * \{

   */

  virtual WifiElementId ElementId () const;

  virtual uint8_t  GetInformationSize () const;

  virtual void SerializeInformation (Buffer::Iterator i) const;

  virtual uint8_t DeserializeInformation (Buffer::Iterator i, uint8_t length);

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

  ///\}

  bool operator== (WifiInformationElement const & a);

private:

  /**

   * Converters:

   */

  static uint16_t TimestampToU16 (Time x);

  static uint16_t BeaconIntervalToU16 (Time x);

  static uint8_t AidToU8 (uint16_t x);

  NeighboursTimingUnitsList  m_neighbours;

  /**

   * Timing element parameters:

   */

  uint16_t  m_numOfUnits;

};

bool operator== (const IeBeaconTimingUnit & a, const IeBeaconTimingUnit & b);

std::ostream &operator << (std::ostream &os, const IeBeaconTiming &beaconTiming);

} // namespace dot11s

} //namespace ns3

#endif