/////////////////////////////////////////////////////////////
//                                                         //
// Copyright (c) 2003-2014 by The University of Queensland //
// Centre for Geoscience Computing                         //
// http://earth.uq.edu.au/centre-geoscience-computing      //
//                                                         //
// Primary Business: Brisbane, Queensland, Australia       //
// Licensed under the Open Software License version 3.0    //
// http://www.opensource.org/licenses/osl-3.0.php          //
//                                                         //
/////////////////////////////////////////////////////////////

#ifndef __HERTZIANVISCOELASTICFRICTIONINTERACTION_H
#define __HERTZIANVISCOELASTICFRICTIONINTERACTION_H

#include "Model/IGParam.h"
#include "Model/Interaction.h"
#include "Model/Particle.h"
#include "Foundation/vec3.h"

#include <iostream>
#include <utility>

/*!
  \brief Interaction group parameters for Hertzian viscoelastic interactions with friction
*/
class CHertzianViscoElasticFrictionIGP : public AIGParam
{
public:
  CHertzianViscoElasticFrictionIGP();

  CHertzianViscoElasticFrictionIGP(
    const std::string &name,
    double A,
    double E,
    double nu,
    double fricCoef,
    double shearK,
    double dT
  );

  virtual std::string getTypeString() const
  {
    return "HertzianViscoElasticFriction";
  }

  void setTimeStepSize(double dt);
  
  double m_A;  // Dissipative constant
  double m_E;  // Young's modulus
  double m_nu; // Poisson ratio
  double mu;   // Friction coefficient
  double k_s;  // Shear coefficient
  double dt;
};

/*!
   \class CHertzianViscoElasticFrictionInteraction
   \brief Frictional+ViscoElastic interaction between particles
   \author Laura Heredia & Pablo Richeri
   $Date: 2009-12-26 20:00:00 (sat, 26 dec 2009) $
*/
class CHertzianViscoElasticFrictionInteraction : public APairInteraction
{
 public: // types
  typedef CHertzianViscoElasticFrictionIGP ParameterType;

  typedef
    double (CHertzianViscoElasticFrictionInteraction::* ScalarFieldFunction)(
    ) const;
  typedef
    std::pair<bool,double>
    (CHertzianViscoElasticFrictionInteraction::* CheckedScalarFieldFunction)(
    ) const;
  typedef
    Vec3 (CHertzianViscoElasticFrictionInteraction::* VectorFieldFunction)(
    ) const;

  static ScalarFieldFunction getScalarFieldFunction(const string&);
  static CheckedScalarFieldFunction getCheckedScalarFieldFunction(
    const string&
  );
  static VectorFieldFunction getVectorFieldFunction(const string&);

 protected:
  double m_A;     //!< Dissipative constant
  double m_E;     //!< Young's modulus
  double m_nu;    //!< Poisson ratio
  double m_r0;    //!< equilibrium distance
  double m_mu;    //!< coefficient of friction
  double m_ks;    //!< shear stiffness (Cundall)
  double m_dt;    //!< time step
  Vec3 m_Ffric;   //!< current frictional force
  Vec3 m_force_deficit; //!< difference between fric. force & force necessary for slip
  Vec3 m_cpos; //!< contact position
  Vec3 m_normal_force; //!< current normal force
  double m_dn; //!< caching displacement for E_pot
  bool m_is_slipping; //!< static/dynamic status of the interaction
  bool m_is_touching; //!< contact status of the interaction
  double m_E_diss; //!< dissipated energy

 public:
  CHertzianViscoElasticFrictionInteraction();
  CHertzianViscoElasticFrictionInteraction(CParticle*,CParticle*);
  CHertzianViscoElasticFrictionInteraction(
    CParticle*,
    CParticle*,
    const CHertzianViscoElasticFrictionIGP&
  );
  virtual ~CHertzianViscoElasticFrictionInteraction();

  static string getType() {return "HertzianViscoElasticFriction";};
  
  virtual void calcForces();
  virtual bool isPersistent();

  void setTimeStepSize(double dt);

  std::pair<bool,double> getAbsFrictionalForce() const;
  std::pair<bool,double> getAbsFN() const;
  std::pair<bool,double> getAbsMuFN() const;
  std::pair<bool,double> getSlipVelocity() const;
  std::pair<bool,double> getNormalStress() const;
  std::pair<bool,double> getMaxFricStress() const;
  std::pair<bool,double> getAbsFrictionalStress() const;

  double getAbsForceDeficit() const;
  double getPotentialEnergy() const;
  double getSlipping()const;
  double getSticking()const;
  double getDissipatedEnergy() const;
  double Count() const;
  Vec3 getForce() const;
  Vec3 getNormalForce() const;
  virtual Vec3 getPos() const {return m_cpos;};

  std::pair<bool,double> getMuEff(const Vec3&,const Vec3&) const;
  std::pair<bool,double> getMuEffXY() const
  {
    return getMuEff(Vec3(1.0,0.0,0.0),Vec3(0.0,1.0,0.0));
  };
  std::pair<bool,double> getMuEffXZ() const
  {
    return getMuEff(Vec3(1.0,0.0,0.0),Vec3(0.0,0.0,1.0));
  };

  friend std::ostream& operator<<(
    std::ostream&,
    const CHertzianViscoElasticFrictionInteraction&
  );
  friend class TML_PackedMessageInterface;
};

#endif //__HERTZIANVISCOELASTICFRICTIONINTERACTION_H