/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2011 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: Marco Miozzo <marco.miozzo@cttc.es>
 *         Nicola Baldo <nbaldo@cttc.es>
 */

#include <ns3/simulator.h>
#include <ns3/log.h>
#include <ns3/hybrid-buildings-propagation-loss-model.h>
#include <ns3/string.h>
#include <ns3/double.h>
#include <ns3/building.h>
#include <ns3/enum.h>
#include <ns3/buildings-helper.h>
#include <ns3/mobility-model.h>
#include <ns3/mobility-building-info.h>
#include <ns3/constant-position-mobility-model.h>

#include "buildings-shadowing-test.h"

NS_LOG_COMPONENT_DEFINE ("BuildingsShadowingTest");


namespace ns3 {



/**
* Test 1.1 Shadowing compound test
*/

/**
* This TestSuite tests the shadowing model of BuildingPathlossModel 
* by reproducing several communication scenarios 
*/


BuildingsShadowingTestSuite::BuildingsShadowingTestSuite ()
  : TestSuite ("buildings-shadowing-test", SYSTEM)
{

  LogComponentEnable ("BuildingsShadowingTest", LOG_LEVEL_ALL);

  // Test #1 Outdoor Model
  AddTestCase (new BuildingsShadowingTestCase (1, 2, 148.86, 7.0, "Outdoor Shadowing"), TestCase::QUICK);

  // Test #2 Indoor model
  AddTestCase (new BuildingsShadowingTestCase (5, 6, 88.5724, 8.0, "Indoor Shadowing"), TestCase::QUICK);

  // Test #3 Indoor -> Outdoor
  AddTestCase (new BuildingsShadowingTestCase (9, 10, 85.0012, 8.6, "Indoor -> Outdoor Shadowing"), TestCase::QUICK);

}

static BuildingsShadowingTestSuite buildingsShadowingTestSuite;


/**
* TestCase
*/

BuildingsShadowingTestCase::BuildingsShadowingTestCase ( uint16_t m1, uint16_t m2, double refValue, double sigmaRef, std::string name)
  : TestCase ("SHADOWING calculation: " + name),
    m_mobilityModelIndex1 (m1),
    m_mobilityModelIndex2 (m2),
    m_lossRef (refValue),
    m_sigmaRef (sigmaRef)
{
}

BuildingsShadowingTestCase::~BuildingsShadowingTestCase ()
{
}

void
BuildingsShadowingTestCase::DoRun (void)
{
  NS_LOG_FUNCTION (this);

  // the building basically occupies the negative x plane, so any node
  // in this area will fall in the building 
  Ptr<Building> building1 = CreateObject<Building> ();
  building1->SetBoundaries (Box (-3000, -1, -4000, 4000.0, 0.0, 12));
  building1->SetBuildingType (Building::Residential);
  building1->SetExtWallsType (Building::ConcreteWithWindows);
  building1->SetNFloors (3);
  
  Ptr<HybridBuildingsPropagationLossModel> propagationLossModel = CreateObject<HybridBuildingsPropagationLossModel> ();
  
  std::vector<double> loss;
  double sum = 0.0;
  double sumSquared = 0.0;
  int samples = 1000;
  for (int i = 0; i < samples; i++)
    {
      Ptr<MobilityModel> mma = CreateMobilityModel (m_mobilityModelIndex1);
      Ptr<MobilityModel> mmb = CreateMobilityModel (m_mobilityModelIndex2);
      double shadowingLoss = propagationLossModel->DoCalcRxPower (0.0, mma, mmb) + m_lossRef;
      double shadowingLoss2 = propagationLossModel->DoCalcRxPower (0.0, mma, mmb) + m_lossRef;
      NS_TEST_ASSERT_MSG_EQ_TOL (shadowingLoss, shadowingLoss2, 0.001, 
                                 "Shadowing is not constant for the same mobility model pair!");
      loss.push_back (shadowingLoss);
      sum += shadowingLoss;
      sumSquared += (shadowingLoss * shadowingLoss);
    }
  double sampleMean = sum / samples;
  double sampleVariance = (sumSquared - (sum * sum / samples)) / (samples - 1);
  double sampleStd = std::sqrt (sampleVariance);

  // test whether the sample mean falls in the 99% confidence interval
  const double zn995 = 2.575829303549; // 99.5 quantile of the normal distribution
  double ci = (zn995 * sampleStd) / std::sqrt (samples);
  NS_LOG_INFO ("SampleMean from simulation " << sampleMean << ", sampleStd " << sampleStd << ", reference value " << m_sigmaRef << ", CI(99%) " << ci);
  NS_TEST_ASSERT_MSG_EQ_TOL (std::fabs (sampleMean), 0.0, ci, "Wrong shadowing distribution !");

  // test whether the sample variance falls in the 99% confidence interval
  // since the shadowing is gaussian, its sample variance follows the 
  // chi2 distribution with samples-1 degrees of freedom
  double chi2 = (samples - 1) *  sampleVariance / (m_sigmaRef*m_sigmaRef);
  const double zchi2_005 = 887.621135217515;  //  0.5% quantile of the chi2 distribution 
  const double zchi2_995 = 1117.89045267865;  // 99.5% quantile of the chi2 distribution
  NS_TEST_ASSERT_MSG_GT (chi2, zchi2_005, "sample variance lesser than expected");
  NS_TEST_ASSERT_MSG_LT (chi2, zchi2_995, "sample variance greater than expected");

  Simulator::Destroy ();
}



Ptr<MobilityModel>
BuildingsShadowingTestCase::CreateMobilityModel (uint16_t index)
{

  /*
   * The purpose of this method is to defer the creation of the
   * MobilityModel instances to when DoRun() is called. In a previous
   * version, MobilityModel instances where created directly in the
   * constructor of the test suite, which caused subtle bugs due to
   * "static initialization order fiasco". An example of such a subtle
   * bug is that logging via NS_LOG failed for some modules.
   * 
   */

  double hm = 1;
  double hb = 30;
  double henbHeight = 10.0;

  Ptr<MobilityModel> mm;
  
  switch (index)
    {
    case 1:
      mm = CreateObject<ConstantPositionMobilityModel> ();
      mm->SetPosition (Vector (0.0, 0.0, hb));
      break;

    case 2:
      mm = CreateObject<ConstantPositionMobilityModel> ();
      mm->SetPosition (Vector (2000, 0.0, hm));
      break;

    case 3:
      mm = CreateObject<ConstantPositionMobilityModel> ();
      mm->SetPosition (Vector (100, 0.0, hm));
      break;

    case 4:
      mm = CreateObject<ConstantPositionMobilityModel> ();
      mm->SetPosition (Vector (900, 0.0, hm));
      break;

    case 5:
      mm = CreateObject<ConstantPositionMobilityModel> ();
      mm->SetPosition (Vector (-5, 0.0, hm));
      break;

    case 6:
      mm = CreateObject<ConstantPositionMobilityModel> ();
      mm->SetPosition (Vector (-5, 30, henbHeight));
      break;

    case 7:
      mm = CreateObject<ConstantPositionMobilityModel> ();
      mm->SetPosition (Vector (-2000, 0.0, hm));
      break;

    case 8:
      mm = CreateObject<ConstantPositionMobilityModel> ();
      mm->SetPosition (Vector (-100, 0.0, hm));
      break;

    case 9:
      mm = CreateObject<ConstantPositionMobilityModel> ();
      mm->SetPosition (Vector (0, 0.0, hm));
      break;

    case 10:
      mm = CreateObject<ConstantPositionMobilityModel> ();
      mm->SetPosition (Vector (-100, 0.0, henbHeight));
      break;

    case 11:
      mm = CreateObject<ConstantPositionMobilityModel> ();
      mm->SetPosition (Vector (-500, 0.0, henbHeight));
      break;

    default:
      mm = 0;
      break;
    }
  Ptr<MobilityBuildingInfo> buildingInfo = CreateObject<MobilityBuildingInfo> ();
  mm->AggregateObject (buildingInfo); // operation usually done by BuildingsHelper::Install
  BuildingsHelper::MakeConsistent (mm); 
  return mm;
}




} // namespace ns3
