/** LitTrackFitter.h
 * @author Andrey Lebedev <andrey.lebedev@gsi.de>
 * @since 2009
 * @version 1.0
 *
 * Functions to fit a track
 * for fast parallel version of the Littrack tracking.
 **/

#ifndef LITTRACKFITTER_H_
#define LITTRACKFITTER_H_

#include "parallel/LitTypes.h"
#include "parallel/LitTrackParam.h"
#include "parallel/LitDetectorGeometry.h"
#include "parallel/LitExtrapolation.h"
#include "parallel/LitFiltration.h"
#include "parallel/LitAddMaterial.h"

/* Performs SIMDized/scalar fast track fit.
 * Number of hits must be equal to the number of stations.
 *
 */
template<class T>
inline void LitTrackFitter(
		LitTrack<T>& track,
		const LitDetectorLayout<T>& layout)
{
     //   track.paramLast = track.paramFirst;
	LitTrackParam<T>& par = track.paramLast;
	unsigned char ihit = 0;

	for (unsigned char isg = 0; isg < layout.GetNofStationGroups(); isg++) {
		const LitStationGroup<T>& stationGroup = layout.stationGroups[isg];
	    //Propagation through the absorber
	    LitFieldRegion<T> field;
	    LitFieldValue<T> v1, v2;
	    const LitAbsorber<T>& absorber = stationGroup.absorber;
	    absorber.fieldSliceFront.GetFieldValue(par.X, par.Y, v1);
	    absorber.fieldSliceBack.GetFieldValue(par.X, par.Y, v2);
	    field.Set(v1, absorber.fieldSliceFront.Z, v2, absorber.fieldSliceBack.Z);
	    LitRK4Extrapolation(par, absorber.Z, field);
	    LitAddMaterial(par, absorber.material);

	    //Approximate the field between the absorbers
	    const LitSubstation<T>& ss1 = stationGroup.stations[0].substations[0];
	    const LitSubstation<T>& ss2 = stationGroup.stations[1].substations[0];
	    ss1.fieldSlice.GetFieldValue(par.X, par.Y, v1);
	    ss2.fieldSlice.GetFieldValue(par.X, par.Y, v2);
	    field.Set(v1, ss1.fieldSlice.Z, v2, ss2.fieldSlice.Z);
	    for (unsigned char ist = 0; ist < stationGroup.GetNofStations(); ist++) {
	       const LitStation<T>& station = stationGroup.stations[ist];
//           const LitSubstation<T>& substation0 = station.substations[0];
//           LitRK4Extrapolation(par, substation0.Z, field);
//		   LitAddMaterial(par, substation0.material);
		   for (unsigned char iss = 0; iss < station.GetNofSubstations(); iss++) {
	    	  const LitSubstation<T>& substation = station.substations[iss];
			  // Propagation through station
		      LitRK4Extrapolation(par, substation.Z, field);
//               LitLineExtrapolation(par, substation.Z);
			  LitAddMaterial(par, substation.material);
	       }
           LitPixelHit<T>* hit = track.hits[ihit];
           LitFiltration(par, *hit);
           ihit++;
	    }
	}
}

#endif /* LITTRACKFITTER_H_ */