/** FOPIField.h
 ** @author P Buehler <paul.buehler@oeaw.ac.at>
 ** @since 20.12.2011
 ** @version1.0
 ** The FOPI magnetic field
 **/


#ifndef FOPIFIELD_H
#define FOPIFIELD_H 1

#include "FairField.h"
#include "TGeoMatrix.h"
#include "TVector3.h"
#include "TLorentzVector.h"
#include "TMatrixD.h"

#include <string>
#include <map>
#include <iostream>
#include <vector>

class PndConstPar;

class FOPIField : public FairField
{

 public:    

  /** Default constructor **/
  FOPIField();
  FOPIField(Double_t mfvalnorm);


  /** Standard constructor 
   ** @param name   Object name
   ** @param xMin,xMax   x region of field (global coordinates)
   ** @param yMin,yMax   y region of field (global coordinates)
   ** @param zMin,zMax   z region of field (global coordinates)
   ** @param bX,bY,bZ    Field values [kG]
   **/
  FOPIField(const char* name, Double_t xMin, Double_t xMax,
		Double_t yMin, Double_t yMax, Double_t zMin,
		Double_t zMax);


  /** Constructor from PndFieldPar **/
  FOPIField(PndConstPar* fieldPar);


  /** Destructor **/
  virtual ~FOPIField();


  void FillParContainer();		
	
	
  /** Set the field region
   ** @param xMin,xMax   x region of field (global coordinates)
   ** @param yMin,yMax   y region of field (global coordinates)
   ** @param zMin,zMax   z region of field (global coordinates)
   **/
  void SetFieldRegion(Double_t xMin, Double_t xMax, Double_t yMin, 
		      Double_t yMax, Double_t zMin, Double_t zMax);

  void SetAlignment(Double_t x, Double_t y, Double_t z, 
		    Double_t phi, Double_t theta, Double_t psi);
          
  /** Set the target offset, taroff **/
  void SetTargetOffset(Double_t value) { taroff = value; }

  /** Set central field value **/
  void SetFieldNorm(Double_t mfvalnorm) { fldval = mfvalnorm; }

  /** Get components of field at a given point 
   ** @param x,y,z   Point coordinates [cm]
   **/

  void Alignment(Double_t x, Double_t y, Double_t z);
  virtual Double_t GetNewPointX(Double_t x, Double_t y, Double_t z);
  virtual Double_t GetNewPointY(Double_t x, Double_t y, Double_t z);
  virtual Double_t GetNewPointZ(Double_t x, Double_t y, Double_t z);

  void CompField(Double_t x, Double_t y, Double_t z);
  virtual Double_t GetBx(Double_t x, Double_t y, Double_t z);
  virtual Double_t GetBy(Double_t x, Double_t y, Double_t z);
  virtual Double_t GetBz(Double_t x, Double_t y, Double_t z);


  /** Accessors to field region **/
  Double_t GetXmin() const { return fXmin; }
  Double_t GetXmax() const { return fXmax; }
  Double_t GetYmin() const { return fYmin; }
  Double_t GetYmax() const { return fYmax; }
  Double_t GetZmin() const { return fZmin; }
  Double_t GetZmax() const { return fZmax; }


  /** Accessors to field values **/
  TVector3 GetBxyz() const { return TVector3(fBx,fBy,fBz); }
  void GetFieldValue(const Double_t point[3], Double_t* bField);

  /** Screen output **/
  virtual void Print();
  
  ClassDef(FOPIField, 1);

 private:

  /** Limits of the field region **/
  Double_t fXmin;   
  Double_t fXmax;
  Double_t fYmin;
  Double_t fYmax;
  Double_t fZmin;
  Double_t fZmax;

  /** Transformed point**/
  Bool_t falign;
  Double_t fnpx;
  Double_t fnpy;
  Double_t fnpz;
  
  /** Field components inside the field region **/
  Double_t fBx;
  Double_t fBy;
  Double_t fBz;
  
  /** Target offset: distance between center of magnet and target **/
  Double_t taroff;
  
  /** Value of the magnetic field normalization **/
  Double_t fldval;

  TGeoTranslation* trans;
  TGeoRotation* rot;
  TGeoCombiTrans fTransformation;

};


#endif