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

/*

 * Copyright (c) 2005,2006 INRIA

 *

 * 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>

 */

#ifndef WIFI_PHY_STATE_HELPER_H

#define WIFI_PHY_STATE_HELPER_H

#include "wifi-phy.h"

#include "ns3/traced-callback.h"

#include "ns3/object.h"

#include <vector>

namespace ns3 {

/**

 * \ingroup wifi

 *

 * This objects implements the PHY state machine of the Wifi device.

 */

class WifiPhyStateHelper : public Object

{

public:

  static TypeId GetTypeId (void);

  WifiPhyStateHelper ();

  /**

   * Set a callback for a successful reception.

   *

   * \param callback

   */

  void SetReceiveOkCallback (WifiPhy::RxOkCallback callback);

  /**

   * Set a callback for a failed reception.

   *

   * \param callback

   */

  void SetReceiveErrorCallback (WifiPhy::RxErrorCallback callback);

  /**

   * Register WifiPhyListener to this WifiPhyStateHelper.

   *

   * \param listener

   */

  void RegisterListener (WifiPhyListener *listener);

  /**

   * Return the current state of WifiPhy.

   *

   * \return the current state of WifiPhy

   */

  enum WifiPhy::State GetState (void);

  /**

   * Check whether the current state is CCA busy.

   *

   * \return true if the current state is CCA busy, false otherwise

   */

  bool IsStateCcaBusy (void);

  /**

   * Check whether the current state is IDLE.

   *

   * \return true if the current state is IDLE, false otherwise

   */

  bool IsStateIdle (void);

  /**

   * Check whether the current state is not IDLE.

   *

   * \return true if the current state is not IDLE, false otherwise

   */

  bool IsStateBusy (void);

  /**

   * Check whether the current state is RX.

   *

   * \return true if the current state is RX, false otherwise

   */

  bool IsStateRx (void);

  /**

   * Check whether the current state is TX.

   *

   * \return true if the current state is TX, false otherwise

   */

  bool IsStateTx (void);

  /**

   * Check whether the current state is SWITCHING.

   *

   * \return true if the current state is SWITCHING, false otherwise

   */

  bool IsStateSwitching (void);

  /**

   * Return the elapsed time of the current state.

   *

   * \return the elapsed time of the current state

   */

  Time GetStateDuration (void);

  /**

   * Return the time before the state is back to IDLE.

   *

   * \return the delay before the state is back to IDLE

   */

  Time GetDelayUntilIdle (void);

  /**

   * Return the time the last RX start.

   *

   * \return the time the last RX start.

   */

  Time GetLastRxStartTime (void) const;

  /**

   * Switch state to TX for the given duration.

   *

   * \param txDuration the duration of the TX

   * \param packet the packet

   * \param preamble the preamble of the packet

   */

  /**

   * Switch state to RX for the given duration.

   *

   * \param rxDuration the duration of the RX

   */

  void SwitchToRx (Time rxDuration);

  /**

   * Switch state to channel switching for the given duration.

   *

   * \param switchingDuration the duration of required to switch the channel

   */

  void SwitchToChannelSwitching (Time switchingDuration);

  /**

   * Switch from RX after the reception was successful.

   *

   * \param packet the successfully received packet

   * \param snr the SNR of the received packet

   * \param mode the transmission mode of the packet

   * \param preamble the preamble of the received packet

   */

  void SwitchFromRxEndOk (Ptr<Packet> packet, double snr, WifiMode mode, enum WifiPreamble preamble);

  /**

   * Switch from RX after the reception failed.

   *

   * \param packet the packet that we failed to received

   * \param snr the SNR of the received packet

   */

  void SwitchFromRxEndError (Ptr<const Packet> packet, double snr);

  /**

   * Switch to CCA busy.

   *

   * \param duration the duration of CCA busy state

   */

  void SwitchMaybeToCcaBusy (Time duration);

  TracedCallback<Time,Time,enum WifiPhy::State> m_stateLogger;

private:

  /**

   * typedef for a list of WifiPhyListeners

   */

  typedef std::vector<WifiPhyListener *> Listeners;

  /**

   * Log the ideal and CCA states.

   */

  void LogPreviousIdleAndCcaBusyStates (void);

  /**

   * Notify all WifiPhyListener that the transmission has started for the given duration.

   *

   * \param duration the duration of the transmission

   */

  /**

   * Notify all WifiPhyListener that the reception has started for the given duration.

   *

   * \param duration the duration of the reception

   */

  void NotifyRxStart (Time duration);

  /**

   * Notify all WifiPhyListener that the reception was successful.

   */

  void NotifyRxEndOk (void);

  /**

   * Notify all WifiPhyListener that the reception was not successful.

   */

  void NotifyRxEndError (void);

  /**

   * Notify all WifiPhyListener that the CCA has started for the given duration.

   *

   * \param duration the duration of the CCA state

   */

  void NotifyMaybeCcaBusyStart (Time duration);

  /**

   * Notify all WifiPhyListener that we are switching channel with the given channel

   * switching delay.

   *

   * \param duration the delay to switch the channel

   */

  void NotifySwitchingStart (Time duration);

  /**

   * Switch the state from RX.

   */

  void DoSwitchFromRx (void);

  bool m_rxing;

  Time m_endTx;

  Time m_endRx;

  Time m_endCcaBusy;

  Time m_endSwitching;

  Time m_startTx;

  Time m_startRx;

  Time m_startCcaBusy;

  Time m_startSwitching;

  Time m_previousStateChangeTime;

  Listeners m_listeners;

  TracedCallback<Ptr<const Packet>, double, WifiMode, enum WifiPreamble> m_rxOkTrace;

  TracedCallback<Ptr<const Packet>, double> m_rxErrorTrace;

  TracedCallback<Ptr<const Packet>,WifiMode,WifiPreamble,uint8_t> m_txTrace;

  WifiPhy::RxOkCallback m_rxOkCallback;

  WifiPhy::RxErrorCallback m_rxErrorCallback;

};

} // namespace ns3

#endif /* WIFI_PHY_STATE_HELPER_H */