//-----------------------------------------------------------
// File and Version Information:
// $Id$
//
// Description:
//     Implementation of TpcLaser.
//
// Environment:
//      Software developed for the PANDA Detector at FAIR.
//
// Author List:
//      Felix Boehmer        TUM            (original author)
//
//
//-----------------------------------------------------------


// This class' header
#include "TpcLaser.h"

// Collaborating class headers
#include "TError.h"
#include <cmath>
#include <iostream>
#include "TpcPoint.h"
#include "TpcPrimaryCluster.h"
#include "LinearInterpolPolicy.h"
#include "TRandom.h"


TpcLaser::TpcLaser() {
  fEval = false;
  fId = false;
}

TpcLaser::TpcLaser(unsigned int id, const TVector3& start, const TVector3& direction,
		   double iondens, double width, double time, bool dirisend)
{
  fstart=start;
  fId=id;
  if(direction.Mag()!=0)
  {
    if(dirisend==false){
      fdir = direction;
      fdir.SetMag(1.);  //normalize
      fend = TVector3(0,0,0);}
    else {
      fend = direction;
      fdir = TVector3(0,0,0); }
  }
  fionDens = iondens; 
  fwidth = width;
  ftime = time;
  frMin=15.5;
  frMax=41.5;
  fzMin=-39.5;
  fzMax=109.5;
  fEval = false;

  evalGeometry();
}


TpcLaser::TpcLaser(unsigned int id, double rMin, double rMax, double zMin, double zMax,
		   const TVector3& start, const TVector3& direction,
		   double iondens, double width, double time, bool dirisend)
{
  fstart=start;
  fId = id;
  if(direction.Mag()!=0)
  {
    if(dirisend==false){
      fdir = direction;
      fdir.SetMag(1.);  //normalize
      fend = TVector3(0,0,0);
    }
    else {
      fend = direction;
      fdir = TVector3(0,0,0); 
    }
  }
  fionDens = iondens; 
  fwidth = width;
  ftime = time;
  frMin=rMin;
  frMax=rMax;
  fzMin=zMin;
  fzMax=zMax;
  fEval = false;

  evalGeometry();
}


TpcLaser::~TpcLaser()
{
  ;
}

void
TpcLaser::evalGeometry()
{
  if(fEval)
    return;
  if(fdir.Mag() < 1.E-5 && fend.Mag() < 1.E-5)
    Error("TpcLaser::evalGeometry()", "geometry not set! supply direction or end");

  if(fend.Mag() < 1.E-5)    //direction is given, standard case
  {
    fdir.SetMag(1.);
    double stepsize = 0.1;  //1 mm, should be small enough
    fend = fstart;
    //determine the end-point
    //the correction +0.05 guarantees that we don't lie outside due to
    //rounding errors
    int count = 0;
    while(fend.Perp() >= (frMin-0.05) &&
	  fend.Perp() <= (frMax+0.05) && 
	  fend.Z() >= (fzMin-0.05) && fend.Z() <= (fzMax+0.05))
    {
      fend += (fdir*stepsize);
      count++;
      
    }
    
  }  
    
  if(fdir.Mag() < 1.E-5)    //end-point is given
  {
    fdir = fend - fstart;
    fdir.SetMag(1.);
  }
  fEval = true;
}

TClonesArray*
TpcLaser::activate()
{
  if(!fEval)
    evalGeometry();
  double trackLength = (fend - fstart).Mag();
  //total number of electrons
  ftotalNE = (unsigned int)std::floor(fionDens*trackLength);
  TClonesArray* laserArray = new TClonesArray("TpcPrimaryCluster");
  for (int i=0; i<ftotalNE; i++){
    TpcPrimaryCluster *clus= new((*laserArray)[i]) TpcPrimaryCluster(ftime, 1, TVector3(0,0,0), 1, 1);
    clus->setIndex(i);
  }
  
  TpcPoint* startPoint = new TpcPoint(1, 1, fstart, TVector3(0,0,0),
				      ftime, 0, 0);
  TpcPoint* endPoint = new TpcPoint(1, 1, fend, TVector3(0,0,0),
				      ftime, 0, 0);

  //arrange the created "clusters" along a straight line, the beam
  LinearInterpolPolicy().Interpolate(startPoint,endPoint,laserArray,0,ftotalNE);
  
  // Gauss-profile ... smear them
  double dx, dy, dz;
  TpcPrimaryCluster* cluster;
  TVector3 pos;
  int size = laserArray->GetEntriesFast();
  
  for(int j=0; j<size; j++)
  {   
    cluster = (TpcPrimaryCluster*) laserArray->At(j);
    pos = cluster->pos();
    dx = gRandom->Gaus(0,fwidth);
    dy = gRandom->Gaus(0,fwidth);
    dz = gRandom->Gaus(0,fwidth);
    TVector3 tempPos(pos.X()+dx, pos.Y()+dy, pos.Z()+dz);
    if(tempPos.Perp() < frMin)
      tempPos.SetPerp(frMin+0.001);
    if(tempPos.Perp() > frMax)
      tempPos.SetPerp(frMax-0.001);
    cluster->setpos(tempPos.X(),tempPos.Y(),tempPos.Z());
  }
  return laserArray;
}

void
TpcLaser::print() 
{
  if(!fEval)
    evalGeometry();
  std::cout<<"\nId: "<<fId;
  std::cout<<"\nStart("<<fstart.X()<<", "<<fstart.Y()<<", "<<fstart.Z()<<"), ";
  std::cout<<"direction("<<fdir.X()<<", "<<fdir.Y()<<", "<<fdir.Z()<<"), ";
  std::cout<<"\nend("<<fend.X()<<", "<<fend.Y()<<", "<<fend.Z()<<")";
  std::cout<<"\nIon density: "<<fionDens<<", width: "<<fwidth<<", time: "
	   <<ftime<<std::endl;
}
  
  
//ClasssImp(TpcLaser)