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

/*

 * Copyright (c) 2009 MIRKO BANCHI

 *

 * 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: Mirko Banchi <mk.banchi@gmail.com>

 */

#ifndef CTRL_HEADERS_H

#define CTRL_HEADERS_H

#include "ns3/header.h"

namespace ns3 {

/** Headers for Block ack request and response.

 *  802.11n standard includes three types of block ack:

 *    - Basic block ack (unique type in 802.11e)

 *    - Compressed block ack

 *    - Multi-TID block ack

 *  For now only basic block ack and compressed block ack 

 *  are supported.

 *  Basic block ack is also default variant.

 */

enum BlockAckType

{

  BASIC_BLOCK_ACK,

  COMPRESSED_BLOCK_ACK,

  MULTI_TID_BLOCK_ACK

};

class CtrlBAckRequestHeader : public Header {

public:

  CtrlBAckRequestHeader ();

  ~CtrlBAckRequestHeader ();

  static TypeId GetTypeId (void);

  virtual TypeId GetInstanceTypeId (void) const;

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

  virtual uint32_t GetSerializedSize (void) const;

  virtual void Serialize (Buffer::Iterator start) const;

  virtual uint32_t Deserialize (Buffer::Iterator start);

  void SetHtImmediateAck (bool immediateAck);

  void SetType (enum BlockAckType type);

  void SetTidInfo (uint8_t tid);

  void SetStartingSequence (uint16_t seq);

  bool MustSendHtImmediateAck (void) const;

  uint8_t GetTidInfo (void) const;

  uint16_t GetStartingSequence (void) const;

  bool IsBasic (void) const;

  bool IsCompressed (void) const;

  bool IsMultiTid (void) const;

  uint16_t GetStartingSequenceControl (void) const;

private:

  void SetStartingSequenceControl (uint16_t seqControl);

  uint16_t GetBarControl (void) const;

  void SetBarControl (uint16_t bar);

  /**

   * The lsb bit of the BAR control field is used only for the

   * HT (High Throughput) delayed block ack configuration.

   * For now only non HT immediate block ack is implemented so this field

   * is here only for a future implementation of HT delayed variant.

   */

  bool m_barAckPolicy;

  bool m_multiTid;

  bool m_compressed;

  uint16_t m_tidInfo;

  uint16_t m_startingSeq;

};

class CtrlBAckResponseHeader : public Header {

public:

  CtrlBAckResponseHeader ();

  ~CtrlBAckResponseHeader ();

  static TypeId GetTypeId (void);

  virtual TypeId GetInstanceTypeId (void) const;

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

  virtual uint32_t GetSerializedSize (void) const;

  virtual void Serialize (Buffer::Iterator start) const;

  virtual uint32_t Deserialize (Buffer::Iterator start);

  void SetHtImmediateAck (bool immeadiateAck);

  void SetType (enum BlockAckType type);

  void SetTidInfo (uint8_t tid);

  void SetStartingSequence (uint16_t seq);

  bool MustSendHtImmediateAck (void) const;

  uint8_t GetTidInfo (void) const;

  uint16_t GetStartingSequence (void) const;

  bool IsBasic (void) const;

  bool IsCompressed (void) const;

  bool IsMultiTid (void) const;

  void SetReceivedPacket (uint16_t seq);

  void SetReceivedFragment (uint16_t seq, uint8_t frag);

  bool IsPacketReceived (uint16_t seq) const;

  bool IsFragmentReceived (uint16_t seq, uint8_t frag) const;

  uint16_t GetStartingSequenceControl (void) const;

  void SetStartingSequenceControl (uint16_t seqControl);

private:

  uint16_t GetBaControl (void) const;

  void SetBaControl (uint16_t bar);

  Buffer::Iterator SerializeBitmap (Buffer::Iterator start) const;

  Buffer::Iterator DeserializeBitmap (Buffer::Iterator start);

  /**

   * This function is used to correctly index in both bitmap

   * and compressed bitmap, one bit or one block of 16 bits respectly.

   * If we are using basic block ack, return value represents index of 

   * block of 16 bits for packet having sequence number equals to <i>seq</i>.

   * If we are using compressed block ack, return value represents bit 

   * to set to 1 in the compressed bitmap to indicate that packet having 

   * sequence number equals to <i>seq</i> was correctly received.

   *

   * for more details see 7.2.1.8 in IEEE 802.11n/D4.00

   */

  uint8_t IndexInBitmap (uint16_t seq) const;

  /**

   * The lsb bit of the BA control field is used only for the

   * HT (High Throughput) delayed block ack configuration.

   * For now only non HT immediate block ack is implemented so this field

   * is here only for a future implementation of HT delayed variant.

   */

  bool m_baAckPolicy;

  bool m_multiTid;

  bool m_compressed;

  uint16_t m_tidInfo;

  uint16_t m_startingSeq;

  union {

    uint16_t m_bitmap[64];

    uint64_t m_compressedBitmap;

  } bitmap;

};

} //namespace ns3

#endif /* CTRL_HEADERS_H */