/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2011-2019 Centre Tecnologic de Telecomunicacions de Catalunya (CTTC)
 *
 * 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: Jaume Nin <jnin@cttc.es>
 *         Nicola Baldo <nbaldo@cttc.es>
 *         Manuel Requena <manuel.requena@cttc.es>
 */

#include <iomanip>

#include "ns3/log.h"
#include "ns3/string.h"
#include "ns3/lte-enb-net-device.h"
#include "ns3/lte-enb-rrc.h"
#include "ns3/epc-x2.h"
#include "ns3/emu-fd-net-device-helper.h"
#include "ns3/emu-epc-helper.h"

namespace ns3 {

NS_LOG_COMPONENT_DEFINE ("EmuEpcHelper");

NS_OBJECT_ENSURE_REGISTERED (EmuEpcHelper);


EmuEpcHelper::EmuEpcHelper ()
  : NoBackhaulEpcHelper ()
{
  NS_LOG_FUNCTION (this);
  // To access the attribute value within the constructor
  ObjectBase::ConstructSelf (AttributeConstructionList ());

  // Create EmuFdNetDevice for SGW
  EmuFdNetDeviceHelper emu;
  NS_LOG_LOGIC ("SGW device: " << m_sgwDeviceName);
  emu.SetDeviceName (m_sgwDeviceName);

  Ptr<Node> sgw = GetSgwNode ();
  NetDeviceContainer sgwDevices = emu.Install (sgw);
  Ptr<NetDevice> sgwDevice = sgwDevices.Get (0);
  NS_LOG_LOGIC ("SGW MAC address: " << m_sgwMacAddress);
  sgwDevice->SetAttribute ("Address", Mac48AddressValue (m_sgwMacAddress.c_str ()));

  // Address of the SGW: 10.0.0.1
  m_epcIpv4AddressHelper.SetBase ("10.0.0.0", "255.255.255.0", "0.0.0.1");
  m_sgwIpIfaces = m_epcIpv4AddressHelper.Assign (sgwDevices);

  // Address of the first eNB: 10.0.0.101
  m_epcIpv4AddressHelper.SetBase ("10.0.0.0", "255.255.255.0", "0.0.0.101");
}

EmuEpcHelper::~EmuEpcHelper ()
{
  NS_LOG_FUNCTION (this);
}

TypeId
EmuEpcHelper::GetTypeId (void)
{
  static TypeId tid = TypeId ("ns3::EmuEpcHelper")
    .SetParent<EpcHelper> ()
    .SetGroupName("Lte")
    .AddConstructor<EmuEpcHelper> ()
    .AddAttribute ("SgwDeviceName",
                   "The name of the device used for the S1-U interface of the SGW",
                   StringValue ("veth0"),
                   MakeStringAccessor (&EmuEpcHelper::m_sgwDeviceName),
                   MakeStringChecker ())
    .AddAttribute ("EnbDeviceName",
                   "The name of the device used for the S1-U interface of the eNB",
                   StringValue ("veth1"),
                   MakeStringAccessor (&EmuEpcHelper::m_enbDeviceName),
                   MakeStringChecker ())
    .AddAttribute ("SgwMacAddress",
                   "MAC address used for the SGW",
                   StringValue ("00:00:00:59:00:aa"),
                   MakeStringAccessor (&EmuEpcHelper::m_sgwMacAddress),
                   MakeStringChecker ())
    .AddAttribute ("EnbMacAddressBase",
                   "First 5 bytes of the eNB MAC address base",
                   StringValue ("00:00:00:eb:00"),
                   MakeStringAccessor (&EmuEpcHelper::m_enbMacAddressBase),
                   MakeStringChecker ())
    ;
  return tid;
}

TypeId
EmuEpcHelper::GetInstanceTypeId () const
{
  return GetTypeId ();
}

void
EmuEpcHelper::DoDispose ()
{
  NS_LOG_FUNCTION (this);
  NoBackhaulEpcHelper::DoDispose ();
}


void
EmuEpcHelper::AddEnb (Ptr<Node> enb, Ptr<NetDevice> lteEnbNetDevice, uint16_t cellId)
{
  NS_LOG_FUNCTION (this << enb << lteEnbNetDevice << cellId);

  NoBackhaulEpcHelper::AddEnb (enb, lteEnbNetDevice, cellId);

  // Create an EmuFdNetDevice for the eNB to connect with the SGW and other eNBs
  EmuFdNetDeviceHelper emu;
  NS_LOG_LOGIC ("eNB cellId: " << cellId);
  NS_LOG_LOGIC ("eNB device: " << m_enbDeviceName);
  emu.SetDeviceName (m_enbDeviceName);
  NetDeviceContainer enbDevices = emu.Install (enb);

  NS_ABORT_IF ((cellId == 0) || (cellId > 255));
  std::ostringstream enbMacAddress;
  enbMacAddress << m_enbMacAddressBase << ":" << std::hex << std::setfill ('0') << std::setw (2) << cellId;
  NS_LOG_LOGIC ("eNB MAC address: " << enbMacAddress.str ());
  Ptr<NetDevice> enbDev = enbDevices.Get (0);
  enbDev->SetAttribute ("Address", Mac48AddressValue (enbMacAddress.str ().c_str ()));

  //emu.EnablePcap ("enbDevice", enbDev);

  NS_LOG_LOGIC ("number of Ipv4 ifaces of the eNB after installing emu dev: " << enb->GetObject<Ipv4> ()->GetNInterfaces ());
  Ipv4InterfaceContainer enbIpIfaces = m_epcIpv4AddressHelper.Assign (enbDevices);
  NS_LOG_LOGIC ("number of Ipv4 ifaces of the eNB after assigning Ipv4 addr to S1 dev: " << enb->GetObject<Ipv4> ()->GetNInterfaces ());

  Ipv4Address enbAddress = enbIpIfaces.GetAddress (0);
  Ipv4Address sgwAddress = m_sgwIpIfaces.GetAddress (0);

  NoBackhaulEpcHelper::AddS1Interface (enb, enbAddress, sgwAddress, cellId);
}


void
EmuEpcHelper::AddX2Interface (Ptr<Node> enb1, Ptr<Node> enb2)
{
  NS_LOG_FUNCTION (this << enb1 << enb2);

  NS_LOG_WARN ("X2 support still untested");


  // for X2, we reuse the same device and IP address of the S1-U interface
  Ptr<Ipv4> enb1Ipv4 = enb1->GetObject<Ipv4> ();
  Ptr<Ipv4> enb2Ipv4 = enb2->GetObject<Ipv4> ();
  NS_LOG_LOGIC ("number of Ipv4 ifaces of the eNB #1: " << enb1Ipv4->GetNInterfaces ());
  NS_LOG_LOGIC ("number of Ipv4 ifaces of the eNB #2: " << enb2Ipv4->GetNInterfaces ());
  NS_LOG_LOGIC ("number of NetDevices of the eNB #1: " << enb1->GetNDevices ());
  NS_LOG_LOGIC ("number of NetDevices of the eNB #2: " << enb2->GetNDevices ());

  // 0 is the LTE device, 1 is localhost, 2 is the EPC NetDevice
  Ptr<NetDevice> enb1EpcDev = enb1->GetDevice (2);
  Ptr<NetDevice> enb2EpcDev = enb2->GetDevice (2);

  int32_t enb1Interface =  enb1Ipv4->GetInterfaceForDevice (enb1EpcDev);
  int32_t enb2Interface =  enb2Ipv4->GetInterfaceForDevice (enb2EpcDev);
  NS_ASSERT (enb1Interface >= 0);
  NS_ASSERT (enb2Interface >= 0);
  NS_ASSERT (enb1Ipv4->GetNAddresses (enb1Interface) == 1);
  NS_ASSERT (enb2Ipv4->GetNAddresses (enb2Interface) == 1);
  Ipv4Address enb1Addr = enb1Ipv4->GetAddress (enb1Interface, 0).GetLocal (); 
  Ipv4Address enb2Addr = enb2Ipv4->GetAddress (enb2Interface, 0).GetLocal (); 
  NS_LOG_LOGIC (" eNB 1 IP address: " << enb1Addr); 
  NS_LOG_LOGIC (" eNB 2 IP address: " << enb2Addr);
  
  // Add X2 interface to both eNBs' X2 entities
  Ptr<EpcX2> enb1X2 = enb1->GetObject<EpcX2> ();
  Ptr<LteEnbNetDevice> enb1LteDev = enb1->GetDevice (0)->GetObject<LteEnbNetDevice> ();
  uint16_t enb1CellId = enb1LteDev->GetCellId ();
  NS_LOG_LOGIC ("LteEnbNetDevice #1 = " << enb1LteDev << " - CellId = " << enb1CellId);

  Ptr<EpcX2> enb2X2 = enb2->GetObject<EpcX2> ();
  Ptr<LteEnbNetDevice> enb2LteDev = enb2->GetDevice (0)->GetObject<LteEnbNetDevice> ();
  uint16_t enb2CellId = enb2LteDev->GetCellId ();
  NS_LOG_LOGIC ("LteEnbNetDevice #2 = " << enb2LteDev << " - CellId = " << enb2CellId);

  enb1X2->AddX2Interface (enb1CellId, enb1Addr, enb2CellId, enb2Addr);
  enb2X2->AddX2Interface (enb2CellId, enb2Addr, enb1CellId, enb1Addr);

  enb1LteDev->GetRrc ()->AddX2Neighbour (enb2LteDev->GetCellId ());
  enb2LteDev->GetRrc ()->AddX2Neighbour (enb1LteDev->GetCellId ());
}

} // namespace ns3
