/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2010
 *
 * 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: Nicola Baldo <nbaldo@cttc.es>
 */

#ifndef ALOHA_NOACK_NET_DEVICE_H
#define ALOHA_NOACK_NET_DEVICE_H

#include <string.h>
#include <ns3/node.h>
#include <ns3/address.h>
#include <ns3/net-device.h>
#include <ns3/callback.h>
#include <ns3/packet.h>
#include <ns3/traced-callback.h>
#include <ns3/nstime.h>
#include <ns3/ptr.h>
#include <ns3/mac48-address.h>
#include <ns3/generic-phy.h>

namespace ns3 {


class SpectrumChannel;
class Channel;
class SpectrumErrorModel;
class Queue;



/**
 * \ingroup spectrum
 *
 * This devices implements the following features:
 *  - layer 3 protocol multiplexing
 *  - MAC addressing
 *  - Aloha MAC:
 *    + packets transmitted as soon as possible
 *    + a new packet is queued if previous one is still being transmitted
 *    + no acknowledgements, hence no retransmissions
 *  - can support any PHY layer compatible with the API defined in generic-phy.h
 *
 */
class AlohaNoackNetDevice : public NetDevice
{
public:
  enum State
  {
    IDLE, TX, RX
  };

  static TypeId GetTypeId (void);

  AlohaNoackNetDevice ();
  virtual ~AlohaNoackNetDevice ();


  /**
   * set the queue which is going to be used by this device
   *
   * @param queue
   */
  virtual void SetQueue (Ptr<Queue> queue);


  /**
   * Notify the MAC that the PHY has finished a previously started transmission
   *
   */
  void NotifyTransmissionEnd (Ptr<const Packet>);

  /**
   * Notify the MAC that the PHY has started a reception
   *
   */
  void NotifyReceptionStart ();


  /**
   * Notify the MAC that the PHY finished a reception with an error
   *
   */
  void NotifyReceptionEndError ();

  /**
   * Notify the MAC that the PHY finished a reception successfully
   *
   * @param p the received packet
   */
  void NotifyReceptionEndOk (Ptr<Packet> p);


  /**
   * This class doesn't talk directly with the underlying channel (a
   * dedicated PHY class is expected to do it), however the NetDevice
   * specification features a GetChannel() method. This method here
   * is therefore provide to allow AlohaNoackNetDevice::GetChannel() to have
   * something meaningful to return.
   *
   * @param c the underlying channel
   */
  void SetChannel (Ptr<Channel> c);


  /**
   * set the callback used to instruct the lower layer to start a TX
   *
   * @param c
   */
  void SetGenericPhyTxStartCallback (GenericPhyTxStartCallback c);



  /**
   * Set the Phy object which is attached to this device.
   * This object is needed so that we can set/get attributes and
   * connect to trace sources of the PHY from the net device.
   *
   * @param phy the Phy object attached to the device.  Note that the
   * API between the PHY and the above (this NetDevice which also
   * implements the MAC) is implemented entirely by
   * callbacks, so we do not require that the PHY inherits by any
   * specific class.
   */
  void SetPhy (Ptr<Object> phy);

  /**
   * @return a reference to the PHY object embedded in this NetDevice.
   */
  Ptr<Object> GetPhy () const;



  // inherited from NetDevice
  virtual void SetIfIndex (const uint32_t index);
  virtual uint32_t GetIfIndex (void) const;
  virtual Ptr<Channel> GetChannel (void) const;
  virtual bool SetMtu (const uint16_t mtu);
  virtual uint16_t GetMtu (void) const;
  virtual void SetAddress (Address address);
  virtual Address GetAddress (void) const;
  virtual bool IsLinkUp (void) const;
  virtual void AddLinkChangeCallback (Callback<void> callback);
  virtual bool IsBroadcast (void) const;
  virtual Address GetBroadcast (void) const;
  virtual bool IsMulticast (void) const;
  virtual bool IsPointToPoint (void) const;
  virtual bool IsBridge (void) const;
  virtual bool Send (Ptr<Packet> packet, const Address& dest,
                     uint16_t protocolNumber);
  virtual bool SendFrom (Ptr<Packet> packet, const Address& source, const Address& dest,
                         uint16_t protocolNumber);
  virtual Ptr<Node> GetNode (void) const;
  virtual void SetNode (Ptr<Node> node);
  virtual bool NeedsArp (void) const;
  virtual void SetReceiveCallback (NetDevice::ReceiveCallback cb);
  virtual Address GetMulticast (Ipv4Address addr) const;
  virtual Address GetMulticast (Ipv6Address addr) const;
  virtual void SetPromiscReceiveCallback (PromiscReceiveCallback cb);
  virtual bool SupportsSendFrom (void) const;





private:
  void NotifyGuardIntervalEnd ();
  virtual void DoDispose (void);

  /**
   * start the transmission of a packet by contacting the PHY layer
   *
   */
  void StartTransmission ();


  Ptr<Queue> m_queue;

  TracedCallback<Ptr<const Packet> > m_macTxTrace;
  TracedCallback<Ptr<const Packet> > m_macTxDropTrace;
  TracedCallback<Ptr<const Packet> > m_macPromiscRxTrace;
  TracedCallback<Ptr<const Packet> > m_macRxTrace;

  Ptr<Node>    m_node;
  Ptr<Channel> m_channel;

  Mac48Address m_address;

  NetDevice::ReceiveCallback m_rxCallback;
  NetDevice::PromiscReceiveCallback m_promiscRxCallback;

  GenericPhyTxStartCallback m_phyMacTxStartCallback;

  /**
   * List of callbacks to fire if the link changes state (up or down).
   */
  TracedCallback<> m_linkChangeCallbacks;


  uint32_t m_ifIndex;
  mutable uint32_t m_mtu;
  bool m_linkUp;


  State m_state;

  Ptr<Packet> m_currentPkt;

  Ptr<Object> m_phy;
};


} // namespace ns3

#endif // ALOHA_NOACK_NET_DEVICE_H