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

/*

 * Copyright (c) 2013

 *

 * 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: Ghada Badawy <gbadawy@gmail.com>

 */

#ifndef MPDU_AGGREGATOR_H

#define MPDU_AGGREGATOR_H

#include "ns3/ptr.h"

#include "ns3/packet.h"

#include "ns3/object.h"

#include "ampdu-subframe-header.h"

#include <list>

namespace ns3 {

class WifiMacHeader;

/**

 * \brief Abstract class that concrete mpdu aggregators have to implement

 * \ingroup wifi

 */

class MpduAggregator : public Object

{

public:

  /**

   * A list of deaggregated packets and their A-MPDU subframe headers.

   */

  typedef std::list<std::pair<Ptr<Packet>, AmpduSubframeHeader> > DeaggregatedMpdus;

  /**

   * A constant iterator for a list of deaggregated packets and their A-MPDU subframe headers.

   */

  typedef std::list<std::pair<Ptr<Packet>, AmpduSubframeHeader> >::const_iterator DeaggregatedMpdusCI;

  static TypeId GetTypeId (void);

  /**

   * \param packet Packet we have to insert into <i>aggregatedPacket</i>.

   * \param aggregatedPacket Packet that will contain <i>packet</i>, if aggregation is possible.

   *

   * \return true if <i>packet</i> can be aggregated to <i>aggregatedPacket</i>, false otherwise.

   *

   * Adds <i>packet</i> to <i>aggregatedPacket</i>. In concrete aggregator's implementation is

   * specified how and if <i>packet</i> can be added to <i>aggregatedPacket</i>.

   */

  virtual bool Aggregate (Ptr<const Packet> packet, Ptr<Packet> aggregatedPacket) = 0;

  /**

   * Adds A-MPDU subframe header and padding to each MPDU that is part of an A-MPDU before it is sent.

   */

  /**

   * \param packetSize size of the packet we want to insert into <i>aggregatedPacket</i>.

   * \param aggregatedPacket packet that will contain the packet of size <i>packetSize</i>, if aggregation is possible.

   * \param blockAckSize size of the piggybacked block ack request

   *

   * \return true if the packet of size <i>packetSize</i> can be aggregated to <i>aggregatedPacket</i>, false otherwise.

   *

   * This method is used to determine if a packet could be aggregated to an A-MPDU without exceeding the maximum packet size.

   */

  virtual bool CanBeAggregated (uint32_t packetSize, Ptr<Packet> aggregatedPacket, uint8_t blockAckSize) = 0;

  /**

   * \return padding that must be added to the end of an aggregated packet

   *

   * Calculates how much padding must be added to the end of an aggregated packet, after that a new packet is added.

   * Each A-MPDU subframe is padded so that its length is multiple of 4 octets.

   */

  virtual uint32_t CalculatePadding (Ptr<const Packet> packet) = 0;

  /**

   * Deaggregates an A-MPDU by removing the A-MPDU subframe header and padding.

   *

   * \return list of deaggragted packets and their A-MPDU subframe headers

   */

  static DeaggregatedMpdus Deaggregate (Ptr<Packet> aggregatedPacket);

};

}  //namespace ns3

#endif /* MPDU_AGGREGATOR_H */