//
//  Copyright (C) 2013 Paolo Tosco
//
//  Copyright (C) 2004-2006 Rational Discovery LLC
//
//   @@ All Rights Reserved @@
//  This file is part of the RDKit.
//  The contents are covered by the terms of the BSD license
//  which is included in the file license.txt, found at the root
//  of the RDKit source tree.
//
#include <RDGeneral/export.h>
#ifndef __RD_MMFFANGLECONSTRAINT_H__
#define __RD_MMFFANGLECONSTRAINT_H__
#include <iostream>
#include <ForceField/Contrib.h>

namespace ForceFields {
namespace MMFF {

//! An angle range constraint modelled after a AngleBendContrib
class RDKIT_FORCEFIELD_EXPORT RDKIT_FORCEFIELD_EXPORT AngleConstraintContrib : public ForceFieldContrib {
 public:
  AngleConstraintContrib() : d_at1Idx(-1), d_at2Idx(-1), d_at3Idx(-1){};
  //! Constructor
  /*!
  \param owner       pointer to the owning ForceField
  \param idx1        index of atom1 in the ForceField's positions
  \param idx2        index of atom2 in the ForceField's positions
  \param idx3        index of atom3 in the ForceField's positions
  \param minAngle    minimum angle
  \param maxAngle    maximum angle
  \param forceConst  force Constant

  */
  AngleConstraintContrib(ForceField *owner, unsigned int idx1,
                         unsigned int idx2, unsigned int idx3,
                         double minAngleDeg, double maxAngleDeg,
                         double forceConst);
  AngleConstraintContrib(ForceField *owner, unsigned int idx1,
                         unsigned int idx2, unsigned int idx3, bool relative,
                         double minAngleDeg, double maxAngleDeg,
                         double forceConst);

  ~AngleConstraintContrib() {}
  double getEnergy(double *pos) const;

  void getGrad(double *pos, double *grad) const;

  virtual AngleConstraintContrib *copy() const {
    return new AngleConstraintContrib(*this);
  };

 private:
  int d_at1Idx, d_at2Idx, d_at3Idx;     //!< indices of atoms forming the angle
  double d_minAngleDeg, d_maxAngleDeg;  //!< rest amplitudes of the angle
  double d_forceConstant;  //!< force constant of the angle constraint
};
}
}
#endif
