#include "AliRICHParam.h"
#include "AliRICHConst.h"
#include <TMath.h>
#include <TRandom.h>
 
ClassImp(AliRICHParam)

// RICH main parameters manipulator
//__________________________________________________________________________________________________
AliRICHParam::AliRICHParam()
{//defines the default parameters
  Segmentation         (144,160);           //nx,ny  for the whole chamber
  DeadZone             (3*cm);              //spacer between PC planes
  PadSize              (8.4*mm,8.0*mm);     
  fWirePitch=PadSizeX()/2;
  
  Size                 (132.6*cm,26*cm,136.7*cm);  //full length, not GEANT half notation
  AngleRot             (60);                       //rotation of the whole RICH around Z, deg
  Angles               (20,19.5);                  //XY angle, YZ angle  deg  
  Offset               (490*cm+1.267*cm);          //1.267???????cm distance from IP to the center of module 
  GapThickness         (8*cm);              
  ProximityGapThickness(0.4*cm);            
  QuartzLength         (133*cm);            
  QuartzWidth          (127.9*cm);          
  QuartzThickness      (0.5*cm);            
  OuterFreonLength     (133*cm);            
  OuterFreonWidth      (41.3*cm);           
  InnerFreonLength     (133*cm);            
  InnerFreonWidth      (41.3*cm);           
  FreonThickness       (1.5*cm);            
  RadiatorToPads       (80*mm);                 
  
  ChargeSlope(27.);
  ChargeSpreadX(0.18);ChargeSpreadY(0.18);
  SigmaIntegration(5.);
  MaxAdc(4096);
  AlphaFeedback(0.036);
  EIonisation(26.e-9);
  SqrtKx3(0.77459667);
  Kx2(0.962);
  Kx4(0.379);
  SqrtKy3(0.77459667);
  Ky2(0.962);
  Ky4(0.379);
  Pitch(0.25);
  WireSag(1);		      // 1->On, 0->Off
  Voltage(2150);	      // Should only be 2000, 2050, 2100 or 2150  
  
  Recalc();
}//AliRICHParam::named ctor 
//__________________________________________________________________________________________________
void AliRICHParam::Recalc()
{//recalculate  
  fPcSizeX=Nx()*fPadSizeX+2*fDeadZone;
  fPcSizeY=Ny()*fPadSizeY+fDeadZone;
  fSectorSizeX=(fPcSizeX-2*fDeadZone)/3;
  fSectorSizeY=(fPcSizeY-fDeadZone)/2;  
}//void AliRICHParam::Recalc()
//__________________________________________________________________________________________________
Int_t AliRICHParam::Sector(Float_t x, Float_t y)const
{//Calculate in which sector is the hit    
  if(TMath::Abs(x)>fPcSizeX/2 || TMath::Abs(y)>fPcSizeY/2){
    Error("Sector","given position is out of active PC area");
    return kBad;
  }  
  Int_t sector=kBad;  
  if(x<=-fSectorSizeX/2-fDeadZone)            sector=1;
  if(x>=-fSectorSizeX/2 && x<=fSectorSizeX/2) sector=2;
  if(x>= fSectorSizeX/2+fDeadZone)            sector=3;  
  if(y>= fDeadZone/2)
    return sector;
  else if(y<=-fDeadZone/2)      
    return -sector;
  else
    return kBad;
}//Int_t AliRICHParam::Sector(Float_t x, Float_t y)
//__________________________________________________________________________________________________
Int_t AliRICHParam::L2P(Float_t x, Float_t y, Int_t &iPadX, Int_t &iPadY)const
{//returns pad numbers (iPadX,iPadY) for given point in local coordinates (x,y)
//
// Please check origin of pad numbering !!!
  iPadX=kBad;
  iPadY=kBad;
  Int_t sector=Sector(x,y);
  switch(sector){
    case -3:
      iPadX = Int_t ((x-fDeadZone)/fPadSizeX);
      iPadY = Int_t ((y+fDeadZone/2)/fPadSizeY)-1;
     break;
    case 3:
      iPadX = Int_t ((x-fDeadZone)/fPadSizeX);
      iPadY = Int_t ((y-fDeadZone/2)/fPadSizeY);
     break;
    case -2:
      iPadX = (x>=0)? iPadX = Int_t (x/fPadSizeX) : iPadX = Int_t (x/fPadSizeX)-1;
      iPadY = Int_t ((y+fDeadZone/2)/fPadSizeY)-1;
     break;
    case 2:
      iPadX = (x>=0)? iPadX = Int_t (x/fPadSizeX) : iPadX = Int_t (x/fPadSizeX)-1;
      iPadY = Int_t ((y-fDeadZone/2)/fPadSizeY);
     break;
    case -1:
      iPadX = Int_t ((x+fDeadZone)/fPadSizeX)-1;
      iPadY = Int_t ((y+fDeadZone/2)/fPadSizeY)-1;
     break;
    case 1:
      iPadX = Int_t ((x+fDeadZone)/fPadSizeX)-1;
      iPadY = Int_t ((y-fDeadZone/2)/fPadSizeY);
     break;
  }//switch  

  if(iPadY> Ny()) iPadY= Ny();
  if(iPadY<-Ny()) iPadY=-Ny();
  if(iPadX> Nx()) iPadX= Nx();
  if(iPadX<-Nx()) iPadX=-Nx();
  return sector;
}//void AliRICHParam::L2P(Float_t x, Float_t y, Int_t &iPadX, Int_t &iPadY)
//__________________________________________________________________________________________________
Float_t AliRICHParam::Gain(Float_t y)
{//Calculates the gain
  if(fWireSag){
    Float_t gainK=9e-6*TMath::Power(y,4)+2e-7*TMath::Power(y,3)-0.0316*TMath::Power(y,2)-3e-4*y+25.367;
    Float_t gain = (ChargeSlope()+ChargeSlope()*gainK/100)*0.9;
    return -gain*TMath::Log(gRandom->Rndm());
  }else     
    return -ChargeSlope()*TMath::Log(gRandom->Rndm());
}//Float_t AliRICHParam::IntPH(Float_t yhit)
//__________________________________________________________________________________________________
Float_t AliRICHParam::TotalCharge(Int_t iPID,Float_t eloss,Float_t y)
{//Get number of electrons and return charge
    
  if(iPID==kCerenkov||iPID==kFeedback)
    return Gain(y);
  else{  
    Int_t iNelectrons=Int_t(eloss/fEIonisation);if(iNelectrons==0) iNelectrons=1;
    Float_t charge=0;
    for(Int_t i=1;i<=iNelectrons;i++)
      charge-=Gain(y);
    return charge;
  }
}//Float_t AliRICHParam::TotalCharge(Int_t iPID,Float_t eloss, Float_t y)
//__________________________________________________________________________________________________