/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2007-2009 Strasbourg University
 *
 * 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: Sebastien Vincent <vincent@clarinet.u-strasbg.fr>
 */

#include "ipv6-end-point-demux.h"
#include "ipv6-end-point.h"
#include "ns3/log.h"

namespace ns3
{

NS_LOG_COMPONENT_DEFINE ("Ipv6EndPointDemux");

Ipv6EndPointDemux::Ipv6EndPointDemux ()
  : m_ephemeral (49152)
{
  NS_LOG_FUNCTION_NOARGS ();
}

Ipv6EndPointDemux::~Ipv6EndPointDemux ()
{
  NS_LOG_FUNCTION_NOARGS ();
  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 
  {
    Ipv6EndPoint *endPoint = *i;
    delete endPoint;
  }
  m_endPoints.clear ();
}

bool Ipv6EndPointDemux::LookupPortLocal (uint16_t port)
{
  NS_LOG_FUNCTION (this << port);
  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 
  {
    if ((*i)->GetLocalPort  () == port) 
    {
      return true;
    }
  }
  return false;
}

bool Ipv6EndPointDemux::LookupLocal (Ipv6Address addr, uint16_t port)
{
  NS_LOG_FUNCTION (this << addr << port);
  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 
  {
    if ((*i)->GetLocalPort () == port &&
        (*i)->GetLocalAddress () == addr) 
    {
      return true;
    }
  }
  return false;
}

Ipv6EndPoint* Ipv6EndPointDemux::Allocate ()
{
  NS_LOG_FUNCTION_NOARGS ();
  uint16_t port = AllocateEphemeralPort ();
  if (port == 0) 
  {
    NS_LOG_WARN ("Ephemeral port allocation failed.");
    return 0;
  }
  Ipv6EndPoint *endPoint = new Ipv6EndPoint (Ipv6Address::GetAny (), port);
  m_endPoints.push_back (endPoint);
  NS_LOG_DEBUG ("Now have >>" << m_endPoints.size () << "<< endpoints.");
  return endPoint;
}

Ipv6EndPoint* Ipv6EndPointDemux::Allocate (Ipv6Address address)
{
  NS_LOG_FUNCTION (this << address);
  uint16_t port = AllocateEphemeralPort ();
  if (port == 0) 
  {
    NS_LOG_WARN ("Ephemeral port allocation failed.");
    return 0;
  }
  Ipv6EndPoint *endPoint = new Ipv6EndPoint (address, port);
  m_endPoints.push_back (endPoint);
  NS_LOG_DEBUG ("Now have >>" << m_endPoints.size () << "<< endpoints.");
  return endPoint;
}

Ipv6EndPoint* Ipv6EndPointDemux::Allocate (uint16_t port)
{
  NS_LOG_FUNCTION (this <<  port);

  return Allocate (Ipv6Address::GetAny (), port);
}

Ipv6EndPoint* Ipv6EndPointDemux::Allocate (Ipv6Address address, uint16_t port)
{
  NS_LOG_FUNCTION (this << address << port);
  if (LookupLocal (address, port)) 
  {
    NS_LOG_WARN ("Duplicate address/port; failing.");
    return 0;
  }
  Ipv6EndPoint *endPoint = new Ipv6EndPoint (address, port);
  m_endPoints.push_back (endPoint);
  NS_LOG_DEBUG ("Now have >>" << m_endPoints.size () << "<< endpoints.");
  return endPoint;
}

Ipv6EndPoint* Ipv6EndPointDemux::Allocate (Ipv6Address localAddress, uint16_t localPort,
    Ipv6Address peerAddress, uint16_t peerPort)
{
  NS_LOG_FUNCTION (this << localAddress << localPort << peerAddress << peerPort);
  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 
  {
    if ((*i)->GetLocalPort () == localPort &&
        (*i)->GetLocalAddress () == localAddress &&
        (*i)->GetPeerPort () == peerPort &&
        (*i)->GetPeerAddress () == peerAddress) 
    {
      NS_LOG_WARN ("No way we can allocate this end-point.");
      /* no way we can allocate this end-point. */
      return 0;
    }
  }
  Ipv6EndPoint *endPoint = new Ipv6EndPoint (localAddress, localPort);
  endPoint->SetPeer (peerAddress, peerPort);
  m_endPoints.push_back (endPoint);

  NS_LOG_DEBUG ("Now have >>" << m_endPoints.size () << "<< endpoints.");

  return endPoint;
}

void Ipv6EndPointDemux::DeAllocate (Ipv6EndPoint *endPoint)
{
  NS_LOG_FUNCTION_NOARGS ();
  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 
  {
    if (*i == endPoint)
    {
      delete endPoint;
      m_endPoints.erase (i);
      break;
    }
  }
}

/*
 * If we have an exact match, we return it.
 * Otherwise, if we find a generic match, we return it.
 * Otherwise, we return 0.
 */
Ipv6EndPointDemux::EndPoints Ipv6EndPointDemux::Lookup (Ipv6Address daddr, uint16_t dport, 
                                                        Ipv6Address saddr, uint16_t sport,
                                                        Ptr<Ipv6Interface> incomingInterface)
{
  NS_LOG_FUNCTION (this << daddr << dport << saddr << sport << incomingInterface);

  EndPoints retval1; /* Matches exact on local port, wildcards on others */
  EndPoints retval2; /* Matches exact on local port/adder, wildcards on others */
  EndPoints retval3; /* Matches all but local address */
  EndPoints retval4; /* Exact match on all 4 */

  NS_LOG_DEBUG ("Looking up endpoint for destination address " << daddr);
  for (EndPointsI i = m_endPoints.begin (); i != m_endPoints.end (); i++) 
  {
    Ipv6EndPoint* endP = *i;
    NS_LOG_DEBUG ("Looking at endpoint dport=" << endP->GetLocalPort ()
        << " daddr=" << endP->GetLocalAddress ()
        << " sport=" << endP->GetPeerPort ()
        << " saddr=" << endP->GetPeerAddress ());
    if (endP->GetLocalPort () != dport) 
    {
      NS_LOG_LOGIC ("Skipping endpoint " << &endP
          << " because endpoint dport "
          << endP->GetLocalPort ()
          << " does not match packet dport " << dport);
      continue;
    }

/*    Ipv6Address incomingInterfaceAddr = incomingInterface->GetAddress (); */
    NS_LOG_DEBUG ("dest addr " << daddr);

    bool localAddressMatchesWildCard = endP->GetLocalAddress () == Ipv6Address::GetAny ();
    bool localAddressMatchesExact = endP->GetLocalAddress () == daddr;
    bool localAddressMatchesAllRouters = endP->GetLocalAddress () == Ipv6Address::GetAllRoutersMulticast ();

    /* if no match here, keep looking */
    if (!(localAddressMatchesExact || localAddressMatchesWildCard))
      continue; 
    bool remotePeerMatchesExact = endP->GetPeerPort () == sport;
    bool remotePeerMatchesWildCard = endP->GetPeerPort () == 0;
    bool remoteAddressMatchesExact = endP->GetPeerAddress () == saddr;
    bool remoteAddressMatchesWildCard = endP->GetPeerAddress () == Ipv6Address::GetAny ();

    /* If remote does not match either with exact or wildcard,i
       skip this one */
    if (!(remotePeerMatchesExact || remotePeerMatchesWildCard))
      continue;
    if (!(remoteAddressMatchesExact || remoteAddressMatchesWildCard))
      continue;

    /* Now figure out which return list to add this one to */
    if (localAddressMatchesWildCard &&
        remotePeerMatchesWildCard && 
        remoteAddressMatchesWildCard)
    { /* Only local port matches exactly */
      retval1.push_back (endP);
    }
    if ((localAddressMatchesExact || (localAddressMatchesAllRouters))&&
        remotePeerMatchesWildCard &&
        remoteAddressMatchesWildCard)
    { /* Only local port and local address matches exactly */
      retval2.push_back (endP);
    }
    if (localAddressMatchesWildCard &&
        remotePeerMatchesExact &&
        remoteAddressMatchesExact)
    { /* All but local address */
      retval3.push_back (endP);
    }
    if (localAddressMatchesExact &&
        remotePeerMatchesExact &&
        remoteAddressMatchesExact)
    { /* All 4 match */
      retval4.push_back (endP);
    }
  }

  /* Here we find the most exact match */
  if (!retval4.empty ()) return retval4;
  if (!retval3.empty ()) return retval3;
  if (!retval2.empty ()) return retval2;
  return retval1;  /* might be empty if no matches */
}

Ipv6EndPoint* Ipv6EndPointDemux::SimpleLookup (Ipv6Address dst, uint16_t dport, Ipv6Address src, uint16_t sport)
{
  uint32_t genericity = 3;
  Ipv6EndPoint *generic = 0;

  for (EndPointsI i = m_endPoints.begin () ; i != m_endPoints.end () ; i++)
  {
    uint32_t tmp = 0;

    if ((*i)->GetLocalPort () != dport)
    {
      continue;
    }

    if ((*i)->GetLocalAddress () == dst && (*i)->GetPeerPort () == sport &&
        (*i)->GetPeerAddress () == src)
    {
      /* this is an exact match. */
      return *i;
    }

    if ((*i)->GetLocalAddress () == Ipv6Address::GetAny ())
    {
      tmp ++;
    }

    if ((*i)->GetPeerAddress () == Ipv6Address::GetAny ())
    {
      tmp ++;
    }

    if (tmp < genericity)
    {
      generic = (*i);
      genericity = tmp;
    }
  }
  return generic;
}

uint16_t Ipv6EndPointDemux::AllocateEphemeralPort ()
{
  NS_LOG_FUNCTION_NOARGS ();
  uint16_t port = m_ephemeral;
  do 
  {
    port++;
    if (port == 65535) 
    {
      port = 49152;
    }
    if (!LookupPortLocal (port)) 
    {
      return port;
    }
  } while (port != m_ephemeral);
  return 0;
}

Ipv6EndPointDemux::EndPoints Ipv6EndPointDemux::GetEndPoints () const
{
  return m_endPoints;
}

} /* namespace ns3 */