#include <list>
#include <cmath>

#include "nlsr.hpp"
#include "nexthop-list.hpp"
#include "fib.hpp"


namespace nlsr {

using namespace std;
using namespace ndn;

static bool
fibEntryNameCompare(const FibEntry& fibEntry, const string& name)
{
  return fibEntry.getName() == name ;
}

void
Fib::cancelScheduledExpiringEvent(Nlsr& pnlsr, EventId eid)
{
  pnlsr.getScheduler().cancelEvent(eid);
}


ndn::EventId
Fib::scheduleEntryRefreshing(Nlsr& pnlsr, const string& name, int32_t feSeqNum,
                             int32_t refreshTime)
{
  std::cout << "Fib::scheduleEntryRefreshing Called" << std::endl;
  std::cout << "Name: " << name << " Seq Num: " << feSeqNum << std::endl;
  return pnlsr.getScheduler().scheduleEvent(ndn::time::seconds(refreshTime),
                                            ndn::bind(&Fib::refreshEntry, this,
                                                      boost::ref(pnlsr), 
                                                      name, feSeqNum));
}

void
Fib::refreshEntry(Nlsr& nlsr, const string& name, int32_t feSeqNum)
{
  std::cout << "Fib::refreshEntry Called" << std::endl;
  std::cout << "Name: " << name << " Seq Num: " << feSeqNum << std::endl;
  std::list<FibEntry>::iterator it = std::find_if(m_table.begin(),
                                                  m_table.end(),
                                                  bind(&fibEntryNameCompare, _1, name));
  if (it != m_table.end())
  {
    std::cout << "Entry found with Seq Num: " << feSeqNum << std::endl;
    if (it->getSeqNo() == feSeqNum)
    {
      std::cout << "Refreshing the FIB entry" << std::endl;
      for (std::list<NextHop>::iterator nhit =
           (*it).getNexthopList().getNextHops().begin();
         nhit != (*it).getNexthopList().getNextHops().end(); nhit++)
      {
        // add entry to NDN-FIB
        registerPrefixInNfd(it->getName(), nhit->getConnectingFace(), std::ceil(nhit->getRouteCost()));
      }
      
      // increase sequence number and schedule refresh again
      it->setSeqNo(feSeqNum + 1);
      it->setExpiringEventId(scheduleEntryRefreshing(nlsr,
                                                     it->getName() ,
                                                     it->getSeqNo(), 
                                                     m_refreshTime));
      
    }
  }
}

void
Fib::remove(Nlsr& pnlsr, const std::string& name)
{
  std::list<FibEntry>::iterator it = std::find_if(m_table.begin(),
                                                  m_table.end(),
                                                  bind(&fibEntryNameCompare, _1, name));
  if (it != m_table.end())
  {
    for (std::list<NextHop>::iterator nhit =
           (*it).getNexthopList().getNextHops().begin();
         nhit != (*it).getNexthopList().getNextHops().end(); nhit++)
    {
      //remove entry from NDN-FIB
      if (!pnlsr.getAdjacencyList().isNeighbor(it->getName()))
      {
        unregisterPrefixFromNfd(it->getName(), nhit->getConnectingFace());
      }
      else
      {
        if(pnlsr.getAdjacencyList().getAdjacent(it->getName()).getConnectingFace() != 
           nhit->getConnectingFace())
        {
          unregisterPrefixFromNfd(it->getName(), nhit->getConnectingFace());
        }
      }
    }
    std::cout << "Cancellling Scheduled event" << std::endl;
    std::cout << "Name: " << name << "Seq num: " << it->getSeqNo() << std::endl;
    cancelScheduledExpiringEvent(pnlsr, (*it).getExpiringEventId());
    m_table.erase(it);
  }
}


void
Fib::update(Nlsr& pnlsr, const string& name, NexthopList& nextHopList)
{
  std::cout << "Fib::updateFib Called" << std::endl;
  int startFace = 0;
  int endFace = getNumberOfFacesForName(nextHopList,
                                        pnlsr.getConfParameter().getMaxFacesPerPrefix());
  std::list<FibEntry>::iterator it = std::find_if(m_table.begin(),
                                                  m_table.end(),
                                                  bind(&fibEntryNameCompare, _1, name));
  if (it == m_table.end())
  {
    if (nextHopList.getSize() > 0)
    {
      nextHopList.sort();
      FibEntry newEntry(name);
      std::list<NextHop> nhl = nextHopList.getNextHops();
      std::list<NextHop>::iterator nhit = nhl.begin();
      for (int i = startFace; i < endFace && nhit != nhl.end(); ++nhit, i++)
      {
        newEntry.getNexthopList().addNextHop((*nhit));
        //Add entry to NDN-FIB
        registerPrefixInNfd(name, nhit->getConnectingFace(), std::ceil(nhit->getRouteCost()));
      }
      newEntry.getNexthopList().sort();
      newEntry.setTimeToRefresh(m_refreshTime);
      newEntry.setSeqNo(1);
      newEntry.setExpiringEventId(scheduleEntryRefreshing(pnlsr,
                                                          name , 1, m_refreshTime));
      m_table.push_back(newEntry);
    }
  }
  else
  {
    std::cout << "Old FIB Entry" << std::endl;
    if (nextHopList.getSize() > 0)
    {
      nextHopList.sort();
      if (!it->isEqualNextHops(nextHopList))
      {
        std::list<NextHop> nhl = nextHopList.getNextHops();
        std::list<NextHop>::iterator nhit = nhl.begin();
        // Add first Entry to NDN-FIB
        registerPrefixInNfd(name, nhit->getConnectingFace(), std::ceil(nhit->getRouteCost()));
        removeHop(pnlsr, it->getNexthopList(), nhit->getConnectingFace(), name);
        it->getNexthopList().reset();
        it->getNexthopList().addNextHop((*nhit));
        ++startFace;
        ++nhit;
        for (int i = startFace; i < endFace && nhit != nhl.end(); ++nhit, i++)
        {
          it->getNexthopList().addNextHop((*nhit));
          //Add Entry to NDN_FIB
          registerPrefixInNfd(name, nhit->getConnectingFace(), std::ceil(nhit->getRouteCost()));
        }
      }
      it->setTimeToRefresh(m_refreshTime);
      std::cout << "Cancellling Scheduled event" << std::endl;
      std::cout << "Name: " << name << "Seq num: " << it->getSeqNo() << std::endl;
      cancelScheduledExpiringEvent(pnlsr, it->getExpiringEventId());
      it->setSeqNo(it->getSeqNo() + 1);
      (*it).setExpiringEventId(scheduleEntryRefreshing(pnlsr,
                                                       it->getName() ,
                                                       it->getSeqNo(), m_refreshTime));
    }
    else
    {
      remove(pnlsr, name);
    }
  }
}


void
Fib::clean(Nlsr& pnlsr)
{
  for (std::list<FibEntry>::iterator it = m_table.begin(); it != m_table.end();
       ++it)
  {
    std::cout << "Cancellling Scheduled event" << std::endl;
    std::cout << "Name: " << it->getName() << "Seq num: " << it->getSeqNo() << std::endl;
    cancelScheduledExpiringEvent(pnlsr, (*it).getExpiringEventId());
    for (std::list<NextHop>::iterator nhit =
           (*it).getNexthopList().getNextHops().begin();
         nhit != (*it).getNexthopList().getNextHops().end(); nhit++)
    {
      //Remove entry from NDN-FIB
      if (!pnlsr.getAdjacencyList().isNeighbor(it->getName()))
      {
        unregisterPrefixFromNfd(it->getName(), nhit->getConnectingFace());
      }
      else
      {
        if(pnlsr.getAdjacencyList().getAdjacent(it->getName()).getConnectingFace() != 
           nhit->getConnectingFace())
        {
          unregisterPrefixFromNfd(it->getName(), nhit->getConnectingFace());
        }
      }
    }
  }
  if (m_table.size() > 0)
  {
    m_table.clear();
  }
}

int
Fib::getNumberOfFacesForName(NexthopList& nextHopList, uint32_t maxFacesPerPrefix)
{
  int endFace = 0;
  if ((maxFacesPerPrefix == 0) || (nextHopList.getSize() <= maxFacesPerPrefix))
  {
    return nextHopList.getSize();
  }
  else
  {
    return maxFacesPerPrefix;
  }
  return endFace;
}

void
Fib::removeHop(Nlsr& pnlsr, NexthopList& nl, uint32_t doNotRemoveHopFaceId,
               const std::string& name)
{
  for (std::list<NextHop>::iterator it = nl.getNextHops().begin();
       it != nl.getNextHops().end();   ++it)
  {
    if (it->getConnectingFace() != doNotRemoveHopFaceId)
    {
      //Remove FIB Entry from NDN-FIB
      if (!pnlsr.getAdjacencyList().isNeighbor(name))
      {
        unregisterPrefixFromNfd(name, it->getConnectingFace());
      }
      else
      {
        if(pnlsr.getAdjacencyList().getAdjacent(name).getConnectingFace() != 
           it->getConnectingFace())
        {
          unregisterPrefixFromNfd(name, it->getConnectingFace());
        }
      }
    }
  }
}

void
Fib::registerPrefixInNfd(const std::string& namePrefix, uint64_t faceId, uint64_t faceCost)
{
  ndn::nfd::ControlParameters controlParameters;
  controlParameters
    .setName(namePrefix)
    .setCost(faceCost)
    .setFaceId(faceId)
    .setExpirationPeriod(ndn::time::milliseconds(m_refreshTime*1000))
    .setOrigin(128);

  m_controller.start<ndn::nfd::RibRegisterCommand>(controlParameters,
                                                   ndn::bind(&Fib::onSuccess, this, _1,
                                                             "Successful in name registration"),
                                                   ndn::bind(&Fib::onFailure, this, _1, _2,
                                                             "Failed in name registration"));
}
  
void
Fib::unregisterPrefixFromNfd(const std::string& namePrefix, uint64_t faceId)
{
  ndn::nfd::ControlParameters controlParameters;
  controlParameters
    .setName(namePrefix)
    .setFaceId(faceId)
    .setOrigin(128);

  m_controller.start<ndn::nfd::RibUnregisterCommand>(controlParameters,
                                                     ndn::bind(&Fib::onSuccess, this, _1,
                                                               "Successful in unregistering name"),
                                                     ndn::bind(&Fib::onFailure, this, _1, _2,
                                                               "Failed in unregistering name"));
}

void
Fib::onSuccess(const ndn::nfd::ControlParameters& commandSuccessResult, const std::string& message)
{
  std::cout << message << ": " << commandSuccessResult << std::endl;
}

void
Fib::onFailure(uint32_t code, const std::string& error, const std::string& message)
{
  std::cout << message << ": " << error << " (code: " << code << ")";
}


void
Fib::print()
{
  cout << "-------------------FIB-----------------------------" << endl;
  for (std::list<FibEntry>::iterator it = m_table.begin(); it != m_table.end();
       ++it)
  {
    cout << (*it);
  }
}

} //namespace nlsr