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

/*

 * Copyright (c) 2006, 2009 INRIA

 * 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: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

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

 */

#ifndef EDCA_TXOP_N_H

#define EDCA_TXOP_N_H

#include "ns3/object.h"

#include "ns3/mac48-address.h"

#include "ns3/packet.h"

#include "wifi-mode.h"

#include "wifi-mac.h"

#include "wifi-mac-header.h"

#include "qos-utils.h"

#include "dcf.h"

#include "ctrl-headers.h"

#include <map>

#include <list>

namespace ns3 {

class DcfState;

class DcfManager;

class MacLow;

class MacTxMiddle;

class WifiMacParameters;

class WifiMacQueue;

class RandomStream;

class QosBlockedDestinations;

class MsduAggregator;

class MgtAddBaResponseHeader;

class BlockAckManager;

class MgtDelBaHeader;

/* This queue contains packets for a particular access class.

 * possibles access classes are:

 *   

 *   -AC_VO : voice, tid = 6,7         ^

 *   -AC_VI : video, tid = 4,5         |

 *   -AC_BE : best-effort, tid = 0,3   |  priority  

 *   -AC_BK : background, tid = 1,2    |

 * 

 * For more details see section 9.1.3.1 in 802.11 standard.

 */

enum TypeOfStation

{

  STA,

  AP,

  ADHOC_STA

};

class EdcaTxopN : public Dcf

{

public:

  typedef Callback <void, const WifiMacHeader&> TxOk;

  typedef Callback <void, const WifiMacHeader&> TxFailed;

  static TypeId GetTypeId (void);

  EdcaTxopN ();

  virtual ~EdcaTxopN ();

  void DoDispose ();

  void SetLow (Ptr<MacLow> low);

  void SetTxMiddle (MacTxMiddle *txMiddle);

  void SetManager (DcfManager *manager);

  void SetTxOkCallback (TxOk callback);

  void SetTxFailedCallback (TxFailed callback);

  void SetWifiRemoteStationManager (Ptr<WifiRemoteStationManager> remoteManager);

  void SetTypeOfStation (enum TypeOfStation type);

  enum TypeOfStation GetTypeOfStation (void) const;

  void SetMaxQueueSize (uint32_t size);

  void SetMaxQueueDelay (Time delay);

  virtual void SetMinCw (uint32_t minCw);

  virtual void SetMaxCw (uint32_t maxCw);

  virtual void SetAifsn (uint32_t aifsn);

  virtual uint32_t GetMinCw (void) const;

  virtual uint32_t GetMaxCw (void) const;

  virtual uint32_t GetAifsn (void) const;

  Ptr<MacLow> Low (void);

  Ptr<MsduAggregator> GetMsduAggregator (void) const;

  /* dcf notifications forwarded here */

  bool NeedsAccess (void) const;

  void NotifyAccessGranted (void);

  void NotifyInternalCollision (void);

  void NotifyCollision (void);

  /**

  * When a channel switching occurs, enqueued packets are removed.

  */

  void NotifyChannelSwitching (void);

  /*event handlers*/

  void GotCts (double snr, WifiMode txMode);

  void MissedCts (void);

  void GotAck (double snr, WifiMode txMode);

  void GotBlockAck (const CtrlBAckResponseHeader *blockAck, Mac48Address recipient);

  void MissedBlockAck (void);

  void GotAddBaResponse (const MgtAddBaResponseHeader *respHdr, Mac48Address recipient);

  void GotDelBaFrame (const MgtDelBaHeader *delBaHdr, Mac48Address recipient);

  void MissedAck (void);

  void StartNext (void);

  void Cancel (void);

  void RestartAccessIfNeeded (void);

  void StartAccessIfNeeded (void);

  bool NeedRts (void);

  bool NeedRtsRetransmission (void);

  bool NeedDataRetransmission (void);

  bool NeedFragmentation (void) const;

  uint32_t GetNextFragmentSize (void);

  uint32_t GetFragmentSize (void);

  uint32_t GetFragmentOffset (void);

  bool IsLastFragment (void) const;

  void NextFragment (void);

  Ptr<Packet> GetFragmentPacket (WifiMacHeader *hdr);

  void SetAccessClass (enum AccessClass ac);

  void Queue (Ptr<const Packet> packet, const WifiMacHeader &hdr);

  void SetMsduAggregator (Ptr<MsduAggregator> aggr);

  void PushFront (Ptr<const Packet> packet, const WifiMacHeader &hdr);

  void CompleteConfig (void);

  void SetBlockAckThreshold (uint8_t threshold);

  uint8_t GetBlockAckThreshold (void) const;

  void SendDelbaFrame (Mac48Address addr, uint8_t tid, bool byOriginator);

private:

  void DoStart ();

  /**

   * This functions are used only to correctly set addresses in a-msdu subframe.

   * If aggregating sta is a STA (in an infrastructured network):

   *   SA = Address2

   *   DA = Address3

   * If aggregating sta is an AP

   *   SA = Address3

   *   DA = Address1

   */

  Mac48Address MapSrcAddressForAggregation (const WifiMacHeader &hdr);

  Mac48Address MapDestAddressForAggregation (const WifiMacHeader &hdr);

  EdcaTxopN &operator = (const EdcaTxopN &);

  EdcaTxopN (const EdcaTxopN &);

  /* If number of packets in the queue reaches m_blockAckThreshold value, an ADDBARequest frame

   * is sent to destination in order to setup a block ack.

   */

  bool SetupBlockAckIfNeeded ();

  /* Sends an ADDBARequest to establish a block ack agreement with sta

   * addressed by <i>recipient</i> for tid <i>tid</i>.

   */

  void SendAddBaRequest (Mac48Address recipient, uint8_t tid, uint16_t startSeq,

                         uint16_t timeout, bool immediateBAck);

  /* After that all packets, for which a block ack agreement was established, have been

   * transmitted, we have to send a block ack request.

   */

  void SendBlockAckRequest (const struct Bar &bar);

  /* For now is typically invoked to complete transmission of a packets sent with ack policy

   * Block Ack: the packet is buffered and dcf is reset.

   */

  void CompleteTx (void);

  /* Verifies if dequeued packet has to be transmitted with ack policy Block Ack. This happens

   * if an established block ack agreement exists with the receiver.

   */

  void VerifyBlockAck (void);

  AccessClass m_ac;

  class Dcf;

  class TransmissionListener;

  class BlockAckEventListener;

  friend class Dcf;

  friend class TransmissionListener;

  Dcf *m_dcf;

  DcfManager *m_manager;

  Ptr<WifiMacQueue> m_queue;

  TxOk m_txOkCallback;

  TxFailed m_txFailedCallback;

  Ptr<MacLow> m_low;

  MacTxMiddle *m_txMiddle;

  TransmissionListener *m_transmissionListener;

  BlockAckEventListener *m_blockAckListener;

  RandomStream *m_rng;

  Ptr<WifiRemoteStationManager> m_stationManager;

  uint8_t m_fragmentNumber;

  /* current packet could be a simple MSDU or, if an aggregator for this queue is

     present, could be an A-MSDU.

   */

  Ptr<const Packet> m_currentPacket;

  WifiMacHeader m_currentHdr;

  Ptr<MsduAggregator> m_aggregator;

  TypeOfStation m_typeOfStation;

  QosBlockedDestinations *m_qosBlockedDestinations;

  BlockAckManager *m_baManager;

  /*

   */

  uint8_t m_blockAckThreshold;

  enum BlockAckType m_blockAckType;

  Time m_currentPacketTimestamp;

  uint16_t m_blockAckInactivityTimeout;

};

}  //namespace ns3

#endif /* EDCA_TXOP_N_H */