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

/*

 * Copyright (c) 2005,2006,2007 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 PROPAGATION_DELAY_MODEL_H

#define PROPAGATION_DELAY_MODEL_H

#include "ns3/ptr.h"

#include "ns3/object.h"

#include "ns3/nstime.h"

namespace ns3 {

class MobilityModel;

class RandomVariable;

/**

 * \brief calculate a propagation delay.

 */

class PropagationDelayModel : public Object

{

public:

  virtual ~PropagationDelayModel ();

  /**

   * \param a the source

   * \param b the destination

   * \returns the calculated propagation delay

   *

   * Calculate the propagation delay between the specified

   * source and destination.

   */

  virtual Time GetDelay (Ptr<MobilityModel> a, Ptr<MobilityModel> b) const = 0;

  /**

   * \returns the default propagation loss model as specified

   * by the PropagationDelayModelType ns3::DefaultValue.

   */

  static Ptr<PropagationDelayModel> CreateDefault (void);

};

/**

 * \brief the propagation delay is random

 */

class RandomPropagationDelayModel : public PropagationDelayModel

{

public:

  /**

   * Use the default parameters from PropagationDelayRandomDistribution.

   */

  RandomPropagationDelayModel ();

  /**

   * \param variable the random distribution to use for this

   * instance

   */

  RandomPropagationDelayModel (const RandomVariable &variable);

  virtual ~RandomPropagationDelayModel ();

  virtual Time GetDelay (Ptr<MobilityModel> a, Ptr<MobilityModel> b) const;

private:

  RandomVariable *m_variable;

};

/**

 * \brief the propagation speed is constant

 */

class ConstantSpeedPropagationDelayModel : public PropagationDelayModel

{

public:

  /**

   * Use the default parameters from PropagationDelayConstantSpeed.

   */

  ConstantSpeedPropagationDelayModel ();

  /**

   * \param speed the speed (m/s) of the propagation to use for this

   * instance

   */

  ConstantSpeedPropagationDelayModel (double speed);

  virtual Time GetDelay (Ptr<MobilityModel> a, Ptr<MobilityModel> b) const;

  /**

   * \param speed the new speed (m/s)

   */

  void SetSpeed (double speed);

  /**

   * \returns the current propagation speed (m/s).

   */

  double GetSpeed (void) const;

private:

  double m_speed;

};

} // namespace ns3

#endif /* PROPAGATION_DELAY_MODEL_H */