/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2011-2012 University of California, Los Angeles
 *
 * 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: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
 */

// custom-app.cc

#include "custom-app.h"
#include "ns3/ptr.h"
#include "ns3/log.h"
#include "ns3/simulator.h"
#include "ns3/packet.h"

#include "ns3/ndn-app-face.hpp"
#include "ns3/ndn-interest.hpp"
#include "ns3/ndn-data.hpp"

#include "ns3/ndn-fib.hpp"
#include "ns3/random-variable.h"

NS_LOG_COMPONENT_DEFINE("CustomApp");

namespace ns3 {

NS_OBJECT_ENSURE_REGISTERED(CustomApp);

// register NS-3 type
TypeId
CustomApp::GetTypeId()
{
  static TypeId tid = TypeId("CustomApp").SetParent<ndn::App>().AddConstructor<CustomApp>();
  return tid;
}

// Processing upon start of the application
void
CustomApp::StartApplication()
{
  // initialize ndn::App
  ndn::App::StartApplication();

  // Create a name components object for name ``/prefix/sub``
  Ptr<ndn::Name> prefix = Create<ndn::Name>(); // now prefix contains ``/``
  prefix->append("prefix");                    // now prefix contains ``/prefix``
  prefix->append("sub");                       // now prefix contains ``/prefix/sub``

  /////////////////////////////////////////////////////////////////////////////
  // Creating FIB entry that ensures that we will receive incoming Interests //
  /////////////////////////////////////////////////////////////////////////////

  // Get FIB object
  Ptr<ndn::Fib> fib = GetNode()->GetObject<ndn::Fib>();

  // Add entry to FIB
  // Note that ``m_face`` is cretaed by ndn::App
  Ptr<ndn::fib::Entry> fibEntry = fib->Add(*prefix, m_face, 0);

  Simulator::Schedule(Seconds(1.0), &CustomApp::SendInterest, this);
}

// Processing when application is stopped
void
CustomApp::StopApplication()
{
  // cleanup ndn::App
  ndn::App::StopApplication();
}

void
CustomApp::SendInterest()
{
  /////////////////////////////////////
  // Sending one Interest packet out //
  /////////////////////////////////////

  Ptr<ndn::Name> prefix = Create<ndn::Name>("/prefix/sub"); // another way to create name

  // Create and configure ndn::Interest
  Ptr<ndn::Interest> interest = Create<ndn::Interest>();
  UniformVariable rand(0, std::numeric_limits<uint32_t>::max());
  interest->SetNonce(rand.GetValue());
  interest->SetName(prefix);
  interest->SetInterestLifetime(Seconds(1.0));

  NS_LOG_DEBUG("Sending Interest packet for " << *prefix);

  // Call trace (for logging purposes)
  m_transmittedInterests(interest, this, m_face);

  m_face->ReceiveInterest(interest);
}

// Callback that will be called when Interest arrives
void
CustomApp::OnInterest(Ptr<const ndn::Interest> interest)
{
  ndn::App::OnInterest(interest);

  NS_LOG_DEBUG("Received Interest packet for " << interest->GetName());

  // Create and configure ndn::Data and ndn::DataTail
  // (header is added in front of the packet, tail is added at the end of the packet)

  // Note that Interests send out by the app will not be sent back to the app !

  Ptr<ndn::Data> data = Create<ndn::Data>(Create<Packet>(1024));
  data->SetName(
    Create<ndn::Name>(interest->GetName())); // data will have the same name as Interests

  NS_LOG_DEBUG("Sending Data packet for " << data->GetName());

  // Call trace (for logging purposes)
  m_transmittedDatas(data, this, m_face);

  m_face->ReceiveData(data);
}

// Callback that will be called when Data arrives
void
CustomApp::OnData(Ptr<const ndn::Data> contentObject)
{
  NS_LOG_DEBUG("Receiving Data packet for " << contentObject->GetName());

  std::cout << "DATA received for name " << contentObject->GetName() << std::endl;
}

} // namespace ns3