/* -*- 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

 *

 */

#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-header.h"

#include "wifi-remote-station-manager.h"

#include "qos-utils.h"

#include "dcf.h"

#include "ctrl-headers.h"

#include "block-ack-manager.h"

#include <map>

#include <list>

namespace ns3 {

class DcfState;

class DcfManager;

class MacLow;

class MacTxMiddle;

class WifiMac;

class WifiMacParameters;

class WifiMacQueue;

class RandomStream;

class QosBlockedDestinations;

class MsduAggregator;

class MgtAddBaResponseHeader;

class BlockAckManager;

class MgtDelBaHeader;

/**

 * Enumeration for type of station

 */

enum TypeOfStation

{

  STA,

  AP,

  ADHOC_STA,

  MESH,

  HT_STA,

  HT_AP,

  HT_ADHOC_STA,

  OCB

};

/**

 * \ingroup wifi

 * 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.

 */

class EdcaTxopN : public Dcf

{

public:

  /**

   * typedef for a callback to invoke when a

   * packet transmission was completed successfully.

   */

  typedef Callback <void, const WifiMacHeader&> TxOk;

  /**

   * typedef for a callback to invoke when a

   * packet transmission was failed.

   */

  typedef Callback <void, const WifiMacHeader&> TxFailed;

  static TypeId GetTypeId (void);

  EdcaTxopN ();

  virtual ~EdcaTxopN ();

  void DoDispose ();

  /**

   * Set MacLow associated with this EdcaTxopN.

   *

   * \param low MacLow

   */

  void SetLow (Ptr<MacLow> low);

  void SetTxMiddle (MacTxMiddle *txMiddle);

  /**

   * Set DcfManager this EdcaTxopN is associated to.

   *

   * \param manager DcfManager

   */

  void SetManager (DcfManager *manager);

  /**

   * \param callback the callback to invoke when a

   * packet transmission was completed successfully.

   */

  void SetTxOkCallback (TxOk callback);

  /**

   * \param callback the callback to invoke when a

   * packet transmission was completed unsuccessfully.

   */

  void SetTxFailedCallback (TxFailed callback);

  /**

   * Set WifiRemoteStationsManager this EdcaTxopN is associated to.

   *

   * \param remoteManager WifiRemoteStationManager

   */

  void SetWifiRemoteStationManager (Ptr<WifiRemoteStationManager> remoteManager);

  /**

   * Set type of station with the given type.

   *

   * \param type

   */

  void SetTypeOfStation (enum TypeOfStation type);

  /**

   * Return type of station.

   *

   * \return type of station

   */

  enum TypeOfStation GetTypeOfStation (void) const;

  /**

   * Return the packet queue associated with this EdcaTxopN.

   *

   * \return WifiMacQueue

   */

  Ptr<WifiMacQueue > GetEdcaQueue () const;

  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;

  /**

   * Return the MacLow associated with this EdcaTxopN.

   *

   * \return MacLow

   */

  Ptr<MacLow> Low (void);

  Ptr<MsduAggregator> GetMsduAggregator (void) const;

  /**

   * \param recipient address of the peer station

   * \param tid traffic ID.

   * \return true if a block ack agreement exists, false otherwise

   *

   * Checks if a block ack agreement exists with station addressed by

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

   */

  bool GetBaAgreementExists (Mac48Address address, uint8_t tid);

  /**

   * \param recipient address of peer station involved in block ack mechanism.

   * \param tid traffic ID.

   * \return the number of packets buffered for a specified agreement

   *

   */

  uint32_t GetNOutstandingPacketsInBa (Mac48Address address, uint8_t tid);

  /**

   * \param recipient address of peer station involved in block ack mechanism.

   * \param tid traffic ID.

   * \return the number of packets for a specific agreement that need retransmission

   *

   * Returns number of packets for a specific agreement that need retransmission.

   */

  uint32_t GetNRetryNeededPackets (Mac48Address recipient, uint8_t tid) const;

  /**

   * \param recipient address of peer station involved in block ack mechanism.

   * \param tid Ttraffic ID of transmitted packet.

   *

   * This function resets the status of OriginatorBlockAckAgreement after the transfer

   * of an A-MPDU with ImmediateBlockAck policy (i.e. no BAR is scheduled)

   */

  /* dcf notifications forwarded here */

  /**

   * Check if the EDCAF requires access.

   *

   * \return true if the EDCAF requires access,

   *         false otherwise

   */

  bool NeedsAccess (void) const;

  /**

   * Notify the EDCAF that access has been granted.

   */

  void NotifyAccessGranted (void);

  /**

   * Notify the EDCAF that internal collision has occurred.

   */

  void NotifyInternalCollision (void);

  /**

   * Notify the EDCAF that collision has occurred.

   */

  void NotifyCollision (void);

  /**

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

   */

  void NotifyChannelSwitching (void);

  /**

   * When sleep operation occurs, re-insert pending packet into front of the queue

   */

  void NotifySleep (void);

  /**

   * When wake up operation occurs, restart channel access

   */

  void NotifyWakeUp (void);

  /* Event handlers */

  /**

   * Event handler when a CTS is received.

   *

   * \param snr

   * \param txMode

   */

  void GotCts (double snr, WifiMode txMode);

  /**

   * Event handler when a CTS timeout has occurred.

   */

  void MissedCts (void);

  /**

   * Event handler when an ACK is received.

   *

   * \param snr

   * \param txMode

   */

  void GotAck (double snr, WifiMode txMode);

  /**

   * Event handler when a Block ACK is received.

   *

   * \param blockAck

   * \param recipient

   * \param txMode

   */

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

  /**

   * Event handler when a Block ACK timeout has occurred.

   */

  void MissedBlockAck (void);

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

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

  /**

   * Event handler when an ACK is received.

   */

  void MissedAck (void);

  /**

   * Start transmission for the next fragment.

   * This is called for fragment only.

   */

  void StartNext (void);

  /**

   * Cancel the transmission.

   */

  void Cancel (void);

  /**

   * Event handler when a transmission that

   * does not require an ACK has completed.

   */

  void EndTxNoAck (void);

  /**

   * Restart access request if needed.

   */

  void RestartAccessIfNeeded (void);

  /**

   * Request access from DCF manager if needed.

   */

  void StartAccessIfNeeded (void);

  /**

   * Check if the current packet should be sent with a RTS protection.

   *

   */

  bool NeedRts (void);

  /**

   * Check if RTS should be re-transmitted if CTS was missed.

   *

   */

  bool NeedRtsRetransmission (void);

  /**

   * Check if DATA should be re-transmitted if ACK was missed.

   *

   */

  bool NeedDataRetransmission (void);

  /**

   * Check if Block ACK Request should be re-transmitted.

   *

   */

  bool NeedBarRetransmission (void);

  /**

   * Check if the current packet should be fragmented.

   *

   * \return true if the current packet should be fragmented,

   *         false otherwise

   */

  bool NeedFragmentation (void) const;

  /**

   * Calculate the size of the next fragment.

   *

   * \return the size of the next fragment

   */

  uint32_t GetNextFragmentSize (void);

  /**

   * Calculate the size of the current fragment.

   *

   * \return the size of the current fragment

   */

  uint32_t GetFragmentSize (void);

  /**

   * Calculate the offset for the current fragment.

   *

   * \return the offset for the current fragment

   */

  uint32_t GetFragmentOffset (void);

  /**

   * Check if the current fragment is the last fragment.

   *

   * \return true if the current fragment is the last fragment,

   *         false otherwise

   */

  bool IsLastFragment (void) const;

  /**

   * Continue to the next fragment. This method simply

   * increments the internal variable that keep track

   * of the current fragment number.

   */

  void NextFragment (void);

  /**

   * Get the next fragment from the packet with

   * appropriate Wifi header for the fragment.

   *

   * \param hdr

   * \return the fragment with the current fragment number

   */

  Ptr<Packet> GetFragmentPacket (WifiMacHeader *hdr);

  /**

   * Set the access category of this EDCAF.

   *

   * \param ac

   */

  void SetAccessCategory (enum AcIndex ac);

  /**

   * \param packet packet to send

   * \param hdr header of packet to send.

   *

   * Store the packet in the internal queue until it

   * can be sent safely.

   */

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

  void SetMsduAggregator (Ptr<MsduAggregator> aggr);

  /**

   * \param packet packet to send

   * \param hdr header of packet to send.

   *

   * Store the packet in the front of the internal queue until it

   * can be sent safely.

   */

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

  /**

   * Complete block ACK configuration.

   */

  void CompleteConfig (void);

  /**

   * Set threshold for block ACK mechanism. If number of packets in the

   * queue reaches the threshold, block ACK mechanism is used.

   *

   * \param threshold

   */

  void SetBlockAckThreshold (uint8_t threshold);

  /**

   * Return the current threshold for block ACK mechanism.

   *

   * \return the current threshold for block ACK mechanism

   */

  uint8_t GetBlockAckThreshold (void) const;

  void SetBlockAckInactivityTimeout (uint16_t timeout);

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

  void CompleteMpduTx (Ptr<const Packet> packet, WifiMacHeader hdr, Time tstamp);

  bool GetAmpduExist (void);

  void SetAmpduExist (bool ampdu);

  /**

   * Return the next sequence number for the given header.

   *

   * \param hdr Wi-Fi header

   * \return the next sequence number

   */

  uint16_t GetNextSequenceNumberfor (WifiMacHeader *hdr);

  /**

   * Return the next sequence number for the Traffic ID and destination, but do not pick it (i.e. the current sequence number remains unchanged).

   *

   * \param hdr Wi-Fi header

   * \return the next sequence number

   */

  uint16_t PeekNextSequenceNumberfor (WifiMacHeader *hdr);

  /**

   * Remove a packet after you peek in the retransmit queue and get it

   */

  void RemoveRetransmitPacket (uint8_t tid, Mac48Address recipient, uint16_t seqnumber);

  /*

   * Peek in retransmit queue and get the next packet without removing it from the queue

   */

  Ptr<const Packet> PeekNextRetransmitPacket (WifiMacHeader &header, Mac48Address recipient, uint8_t tid, Time *timestamp);

  /**

   * The packet we sent was successfully received by the receiver

   *

   * \param hdr the header of the packet that we successfully sent

   */

  void BaTxOk (const WifiMacHeader &hdr);

  /**

   * The packet we sent was successfully received by the receiver

   *

   * \param hdr the header of the packet that we failed to sent

   */

  void BaTxFailed (const WifiMacHeader &hdr);

  int64_t AssignStreams (int64_t stream);

private:

  void DoInitialize ();

  /**

   * 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

   *

   * \param hdr

   * \return Mac48Address

   */

  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 ADDBA Request frame

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

   *

   * \return true if we tried to set up block ACK, false otherwise

   */

  bool SetupBlockAckIfNeeded ();