/* Copyright 2008-2010, Technische Universitaet Muenchen,
   Authors: Christian Hoeppner & Sebastian Neubert & Johannes Rauch

   This file is part of GENFIT.

   GENFIT is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as published
   by the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   GENFIT is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with GENFIT.  If not, see <http://www.gnu.org/licenses/>.
*/
/** @addtogroup genfit
 * @{
 */

#ifndef genfit_WireMeasurement_h
#define genfit_WireMeasurement_h

#include "AbsMeasurement.h"
#include "AbsHMatrix.h"
#include "MeasurementOnPlane.h"


namespace genfit {

/** @brief Class for measurements in wire detectors (Straw tubes and drift chambers)
 *  which do not measure the coordinate along the wire.
 *
 *  @author Christian H&ouml;ppner (Technische Universit&auml;t M&uuml;nchen, original author)
 *  @author Lia Lavezzi (INFN Pavia, original author)
 *  @author Sebastian Neubert  (Technische Universit&auml;t M&uuml;nchen, original author)
 *  @author Johannes Rauch  (Technische Universit&auml;t M&uuml;nchen, original author)
 *
 * This hit class is not valid for any kind of plane orientation
 * choice: to use it you MUST choose a plane described by u
 * and v axes with v coincident with the wire (and u orthogonal
 * to it, obviously).
 * The hit will be described by 7 coordinates:
 * w_x1, w_y1, w_z1, w_x2, w_y2, w_z2, rdrift
 * where w_ji (with j = x, y, z and i = 1, 2) are the wire
 * extremities coordinates; rdrift = distance from the wire (u
 * coordinate in the plane)
 *
 */
class WireMeasurement : public AbsMeasurement {

 public:
  WireMeasurement(int nDim = 7);
  WireMeasurement(const TVectorD& rawHitCoords, const TMatrixDSym& rawHitCov, int detId, int hitId, TrackPoint* trackPoint);

  virtual ~WireMeasurement() {;}

  virtual AbsMeasurement* clone() const {return new WireMeasurement(*this);}

  virtual SharedPlanePtr constructPlane(const StateOnPlane& state) const;

  /**  Hits with a small drift distance get a higher weight, whereas hits with
    * big drift distances become weighted down.
    * When these initial weights are used by the DAF, the smoothed track will be closer to the real
    * trajectory than if both sides are weighted with 0.5 regardless of the drift distance.
    * This helps a lot when resolving l/r ambiguities with the DAF.
    * The idea is that for the first iteration of the DAF, the wire positions are taken.
    * For small drift radii, the wire position does not bend the fit away from the
    * trajectory, whereas the wire position for hits with large drift radii is further away
    * from the trajectory and will therefore bias the fit if not weighted down.
    */
  virtual std::vector<MeasurementOnPlane*> constructMeasurementsOnPlane(const StateOnPlane& state) const;

  virtual const AbsHMatrix* constructHMatrix(const AbsTrackRep*) const;

  /** Set maximum drift distance. This is used to calculate the start weights of the two
   * measurementsOnPlane.
   */
  void setMaxDistance(double d){maxDistance_ = d;}
  /**
   * select how to resolve the left/right ambiguity:
   * -1: negative (left) side on vector (track direction) x (wire direction)
   * 0: auto select (take side with smallest distance to track)
   * 1: positive (right) side on vector (track direction) x (wire direction)
   */
  void setLeftRightResolution(int lr);

  virtual bool isLeftRightMeasurement() const {return true;}
  virtual int getLeftRightResolution() const {return leftRight_;}

  double getMaxDistance(){return maxDistance_;}

 protected:

  double maxDistance_;
  signed char leftRight_;

 public:

  ClassDef(WireMeasurement, 2)

};

} /* End of namespace genfit */
/** @} */

#endif // genfit_WireMeasurement_h