#include <AliKFParticle.h>
#include <KFPTrack.h>
#include <KFPVertex.h>

#include <fstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cstring>

void Example()
{
  std::cout << "Try different constructors" << std::endl<< std::endl;
  
  ///  *****************************************************************************************
  
  std::cout << "1. Construction from Vertex" << std::endl<< std::endl;
  
  KFPVertex vert;
  vert.SetXYZ(0.1, 0.5, -0.8);
  vert.SetCovarianceMatrix( 0.01,
                            0.9e-4,  0.02,
                            1.3e-3, 0.6e-2, 0.1 );
  vert.SetNContributors(2);
  vert.SetChi2(1.01);
  
  AliKFParticle p1(vert);

  std::cout << "	Vertex	Particle" << std::endl;
  for(int i=0; i<3; i++)
    std::cout <<"fP["<<i<<"]	"<< vert.GetParameter(i) << "	" << p1.Parameter(i) << std::endl;
  std::cout << std::endl;
  
  for(int i=0; i<6; i++)
    std::cout <<"fC["<<i<<"]	"<< vert.GetCovariance(i) << "	" << p1.Covariance(i) << std::endl;
  std::cout << std::endl;
  std::cout <<"fNDF	"<< 2*vert.GetNContributors()-3 << "	" << p1.GetNDF() << std::endl;
  std::cout <<"fChi2	"<< vert.GetChi2() << "	" << p1.GetChi2() << std::endl;
  std::cout << std::endl;
   
  ///  *****************************************************************************************
  
  std::cout << "2. Construction from Track" << std::endl<< std::endl;
  
  KFPTrack track;
  track.SetParameters(0.7, 0.1, 0.01, 0.2, 0.5, 1.8);
  double C[21]= { 0.05,
               1.3e-6, 0.01,
               1.3e-4, 1.2e-5, 0.005,
               1.9e-6, 1.1e-7, 1.2e-6, 0.003,
               1.4e-5, 1.3e-6, 1.7e-6, 1.1e-5, 0.001,
               1.1e-7, 1.2e-6, 1.1e-4, 1.3e-6, 1.2e-6, 0.011 };
  track.SetCovarianceMatrix(C);
  track.SetNDF(1);
  track.SetChi2(1.5);
  track.SetID(15);
  track.SetCharge(-1);
  
  AliKFParticle p2(track, 11); // PDG = 11
  
  std::cout << "	Track	Particle" << std::endl;
  for(int i=0; i<6; i++)
    std::cout <<"fP["<<i<<"]	"<< track.GetParameter(i) << "	" << p2.Parameter(i) << std::endl;
  std::cout << std::endl;
  
  for(int i=0; i<21; i++)
    std::cout <<"fC["<<i<<"]	"<< track.GetCovariance(i) << "	" << p2.Covariance(i) << std::endl;
  std::cout << std::endl;
  std::cout <<"fQ	"<< track.Charge() << "	" << p2.GetQ() << std::endl;
  std::cout <<"PDG	"<< "11" << std::endl;
  double M, dM;
  p2.GetMass(M,dM);
  std::cout <<"Mass		" << M << std::endl;
  std::cout << std::endl;
  
  ///  *****************************************************************************************
  
  std::cout << "3. Now we will create one more particle from track and call the construction from these 2 particles" << std::endl<< std::endl;
  
  KFPTrack track2;
  track2.SetParameters(0.7, 0.1, 0.01, 0.2, 0.5, 1.8);
  double C2[21]= { 0.06,
               2.3e-6, 0.02,
               2.3e-5, 2.2e-6, 0.006,
               2.9e-6, 2.2e-7, 2.2e-6, 0.003,
               2.5e-6, 2.3e-6, 2.7e-6, 2.2e-6, 0.002,
               2.2e-7, 2.2e-6, 2.2e-5, 2.3e-6, 2.2e-6, 0.022};
  track2.SetCovarianceMatrix(C2);
  track2.SetNDF(2);
  track2.SetChi2(2.5);
  track2.SetID(25);
  track2.SetCharge(-1);
  
  AliKFParticle p3(track2, 11); // PDG = 11
  
  AliKFParticle p4(p2, p3);
  
  std::cout << "	Particle" << std::endl;
  for(int i=0; i<6; i++)
    std::cout <<"fP["<<i<<"]	"<< p4.Parameter(i) << std::endl;
  std::cout << std::endl;
  
  for(int i=0; i<21; i++)
    std::cout <<"fC["<<i<<"]	" << p4.Covariance(i) << std::endl;
  std::cout << std::endl;
  std::cout <<"fQ	"<< p4.GetQ() << std::endl;
  std::cout <<"Mass	"<< p4.GetMass() << std::endl;
  std::cout << std::endl;

  ///  *****************************************************************************************
  std::cout << "4. Construction with constrained Mass or (and) vertex position values" << std::endl<< std::endl;

/// This is the example of the AliKFParticleBase::Construct function usage.
/// parameter 1 - array of the daughter particles
/// parameter 2 - number of the daughter particles
/// parameter 3 - vertex (it should be the object of the KFParticle class)
/// parameter 4 - the value we force the particle mass to be equial to.

  const AliKFParticle pVertex = p1;
  int NDaughters = 2;
  const AliKFParticle *vDaughters[2] = {&p2, &p3};
  double Mass = 1865.;

  std::cout << "4.1 Construction with constrained Mass, without vertex hipotesis " << std::endl<< std::endl;
/// we assume Mass to be the mass of the constructed particle
  AliKFParticle D0;
  D0.Construct(vDaughters,NDaughters,0,Mass,0);

  std::cout << "4.2 Construction without constrained Mass, with vertex hipotesis " << std::endl<< std::endl;
/// we assume p1 to be the vertex of the constructed particle
  AliKFParticle D0_1;
  D0_1.Construct(vDaughters,NDaughters,&pVertex,-1,0);

  std::cout << "4.3 Construction with constrained Mass, with vertex hipotesis " << std::endl<< std::endl;
///we assume p1 to be the vertex of the constructed particle, Mass to be the mass of the constructed particle
  AliKFParticle D0_2;
  D0_2.Construct(vDaughters,NDaughters,&pVertex,Mass,0);

/// here are examples how to get different particle parameters
  double mass, massErr;
  double length, lengthErr;
  double tau, tauErr;
  double P, PErr;
  double chi2;

  D0.GetMass(mass, massErr);
  D0.GetDecayLength(length, lengthErr);
  D0.GetLifeTime(tau, tauErr);
  D0.GetMomentum(P, PErr);
  chi2 = D0.GetChi2();

  std::cout << std::endl;

}

int main(int argc, char **argv)
{
  Example();
  return 0;
}