/***************************************************************************
                                 sph_lj.h
                             -------------------
                            Trung Nguyen (U Chicago)

  Class for acceleration of the sph lj pair style.

 __________________________________________________________________________
    This file is part of the LAMMPS Accelerator Library (LAMMPS_AL)
 __________________________________________________________________________

    begin                : December 2023
    email                : ndactrung@gmail.com
 ***************************************************************************/

#ifndef LAL_SPH_LJ_H
#define LAL_SPH_LJ_H

#include "lal_base_sph.h"

namespace LAMMPS_AL {

template <class numtyp, class acctyp>
class SPHLJ : public BaseSPH<numtyp, acctyp> {
 public:
  SPHLJ();
  ~SPHLJ();

  /// Clear any previous data and set up for a new LAMMPS run
  /** \param max_nbors initial number of rows in the neighbor matrix
    * \param cell_size cutoff + skin
    * \param gpu_split fraction of particles handled by device
    *
    * Returns:
    * -  0 if successful
    * - -1 if fix gpu not found
    * - -3 if there is an out of memory error
    * - -4 if the GPU library was not compiled for GPU
    * - -5 Double precision is not supported on card **/
  int init(const int ntypes, double **host_cutsq,
           double** host_cut, double **host_viscosity, double *host_mass,
           const int dimension,
           double *host_special_lj, const int nlocal, const int nall, const int max_nbors,
           const int maxspecial, const double cell_size, const double gpu_split,
           FILE *screen);

  /// Clear all host and device data
  /** \note This is called at the beginning of the init() routine **/
  void clear();

  /// Returns memory usage on device per atom
  int bytes_per_atom(const int max_nbors) const;

  /// Total host memory used by library for pair style
  double host_memory_usage() const;

  void get_extra_data(double *host_rho, double *host_esph,
                      double *host_cv);

  /// copy drho and desph from device to host
  void update_drhoE(void **drhoE_ptr);

  // --------------------------- TYPE DATA --------------------------

  /// coeff.x = viscosity, coeff.y = cut, coeff.z = cutsq
  UCL_D_Vec<numtyp4> coeff;

  /// per-type coeffs
  UCL_D_Vec<numtyp> mass;

  /// Special LJ values
  UCL_D_Vec<numtyp> sp_lj;

  /// If atom type constants fit in shared memory, use fast kernels
  bool shared_types;

  /// Number of atom types
  int _lj_types;

  /// Per-atom arrays
  UCL_Vector<acctyp,acctyp> drhoE;
  int _max_drhoE_size;

  int _dimension;

  /// pointer to host data
  double *rho, *esph, *cv;

 private:
  bool _allocated;
  int loop(const int eflag, const int vflag);
};

}

#endif
