/***************************************************************************
                                vashishta.cpp
                             -------------------
                            Anders Hafreager (UiO)

  Class for acceleration of the vashishta pair style.

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

    begin                : Mon June 12, 2017
    email                : andershaf@gmail.com
 ***************************************************************************/

#if defined(USE_OPENCL)
#include "vashishta_cl.h"
#elif defined(USE_CUDART)
const char *vashishta=0;
#else
#include "vashishta_cubin.h"
#endif

#include "lal_vashishta.h"
#include <cassert>
namespace LAMMPS_AL {
#define VashishtaT Vashishta<numtyp, acctyp>

extern Device<PRECISION,ACC_PRECISION> device;

template <class numtyp, class acctyp>
VashishtaT::Vashishta() : BaseThree<numtyp,acctyp>(), _allocated(false) {
}

template <class numtyp, class acctyp>
VashishtaT::~Vashishta() {
  clear();
}

template <class numtyp, class acctyp>
int VashishtaT::bytes_per_atom(const int max_nbors) const {
  return this->bytes_per_atom_atomic(max_nbors);
}

template <class numtyp, class acctyp>
int VashishtaT::init(const int ntypes, const int nlocal, const int nall, const int max_nbors,
           const double cell_size, const double gpu_split, FILE *_screen,
           int* host_map, const int nelements, int*** host_elem2param, const int nparams,
           const double* cutsq, const double* r0,
           const double* gamma, const double* eta,
           const double* lam1inv, const double* lam4inv,
           const double* zizj, const double* mbigd,
           const double* dvrc, const double* big6w, 
           const double* heta, const double* bigh,
           const double* bigw, const double* c0,
           const double* costheta, const double* bigb,
           const double* big2b, const double* bigc)
{
  int success;
  success=this->init_three(nlocal,nall,max_nbors,0,cell_size,gpu_split,
                           _screen,vashishta,"k_vashishta","k_vashishta_three_center",
                           "k_vashishta_three_end","k_vashishta_short_nbor");
  if (success!=0)
    return success;

  // If atom type constants fit in shared memory use fast kernel
  int lj_types=ntypes;
  shared_types=false;
  int max_shared_types=this->device->max_shared_types();
  if (lj_types<=max_shared_types && this->_block_size>=max_shared_types) {
    lj_types=max_shared_types;
    shared_types=true;
  }
  _lj_types=lj_types;

  _nparams = nparams;
  _nelements = nelements;

  UCL_H_Vec<numtyp4> dview(nparams,*(this->ucl_device),
                             UCL_WRITE_ONLY);

  for (int i=0; i<nparams; i++) {
    dview[i].x=(numtyp)0;
    dview[i].y=(numtyp)0;
    dview[i].z=(numtyp)0;
    dview[i].w=(numtyp)0;
  }

  // pack coefficients into arrays
  param1.alloc(nparams,*(this->ucl_device),UCL_READ_ONLY);

  for (int i=0; i<nparams; i++) {
    dview[i].x=static_cast<numtyp>(eta[i]);
    dview[i].y=static_cast<numtyp>(lam1inv[i]);
    dview[i].z=static_cast<numtyp>(lam4inv[i]);
    dview[i].w=static_cast<numtyp>(zizj[i]);
  }

  ucl_copy(param1,dview,false);
  param1_tex.get_texture(*(this->pair_program),"param1_tex");
  param1_tex.bind_float(param1,4);

  param2.alloc(nparams,*(this->ucl_device),UCL_READ_ONLY);

  for (int i=0; i<nparams; i++) {
    dview[i].x=static_cast<numtyp>(mbigd[i]);
    dview[i].y=static_cast<numtyp>(dvrc[i]);
    dview[i].z=static_cast<numtyp>(big6w[i]);
    dview[i].w=static_cast<numtyp>(heta[i]);
  }

  ucl_copy(param2,dview,false);
  param2_tex.get_texture(*(this->pair_program),"param2_tex");
  param2_tex.bind_float(param2,4);

  param3.alloc(nparams,*(this->ucl_device),UCL_READ_ONLY);

  for (int i=0; i<nparams; i++) {
    dview[i].x=static_cast<numtyp>(bigh[i]);
    dview[i].y=static_cast<numtyp>(bigw[i]);
    dview[i].z=static_cast<numtyp>(dvrc[i]);
    dview[i].w=static_cast<numtyp>(c0[i]);
  }

  ucl_copy(param3,dview,false);
  param3_tex.get_texture(*(this->pair_program),"param3_tex");
  param3_tex.bind_float(param3,4);

  param4.alloc(nparams,*(this->ucl_device),UCL_READ_ONLY);

  double r0sqmax = 0;
  for (int i=0; i<nparams; i++) {
    double r0sq = r0[i]*r0[i]; // TODO: should we have the 1e-4?
    if (r0sqmax < r0sq) r0sqmax = r0sq;
    dview[i].x=static_cast<numtyp>(r0sq);
    dview[i].y=static_cast<numtyp>(gamma[i]);
    dview[i].z=static_cast<numtyp>(cutsq[i]);
    dview[i].w=static_cast<numtyp>(r0[i]);
  }

  _cutshortsq = static_cast<numtyp>(r0sqmax);

  ucl_copy(param4,dview,false);
  param4_tex.get_texture(*(this->pair_program),"param4_tex");
  param4_tex.bind_float(param4,4);

  param5.alloc(nparams,*(this->ucl_device),UCL_READ_ONLY);

  for (int i=0; i<nparams; i++) {
    dview[i].x=static_cast<numtyp>(bigc[i]);
    dview[i].y=static_cast<numtyp>(costheta[i]);
    dview[i].z=static_cast<numtyp>(bigb[i]);
    dview[i].w=static_cast<numtyp>(big2b[i]);
  }

  ucl_copy(param5,dview,false);
  param5_tex.get_texture(*(this->pair_program),"param5_tex");
  param5_tex.bind_float(param5,4);

  UCL_H_Vec<int> dview_elem2param(nelements*nelements*nelements,
                           *(this->ucl_device), UCL_WRITE_ONLY);

  elem2param.alloc(nelements*nelements*nelements,*(this->ucl_device),
                   UCL_READ_ONLY);

  for (int i = 0; i < nelements; i++)
    for (int j = 0; j < nelements; j++)
      for (int k = 0; k < nelements; k++) {
         int idx = i*nelements*nelements+j*nelements+k;
         dview_elem2param[idx] = host_elem2param[i][j][k];
      }

  ucl_copy(elem2param,dview_elem2param,false);

  UCL_H_Vec<int> dview_map(lj_types, *(this->ucl_device), UCL_WRITE_ONLY);
  for (int i = 0; i < ntypes; i++)
    dview_map[i] = host_map[i];

  map.alloc(lj_types,*(this->ucl_device), UCL_READ_ONLY);
  ucl_copy(map,dview_map,false);

  _allocated=true;
  this->_max_bytes=param1.row_bytes()+param2.row_bytes()+param3.row_bytes()+param4.row_bytes()+param5.row_bytes()+
    map.row_bytes()+elem2param.row_bytes();
  return 0;
}

template <class numtyp, class acctyp>
void VashishtaT::clear() {
  if (!_allocated)
    return;
  _allocated=false;

  param1.clear();
  param2.clear();
  param3.clear();
  param4.clear();
  param5.clear();
  map.clear();
  elem2param.clear();
  this->clear_atomic();
}

template <class numtyp, class acctyp>
double VashishtaT::host_memory_usage() const {
  return this->host_memory_usage_atomic()+sizeof(Vashishta<numtyp,acctyp>);
}

#define KTHREADS this->_threads_per_atom
#define JTHREADS this->_threads_per_atom
// ---------------------------------------------------------------------------
// Calculate energies, forces, and torques
// ---------------------------------------------------------------------------
template <class numtyp, class acctyp>
void VashishtaT::loop(const bool _eflag, const bool _vflag, const int evatom) {
  // Compute the block size and grid size to keep all cores busy
  int BX=this->block_pair();
  int eflag, vflag;
  if (_eflag)
    eflag=1;
  else
    eflag=0;

  if (_vflag)
    vflag=1;
  else
    vflag=0;

  // build the short neighbor list
  int ainum=this->_ainum;
  int nbor_pitch=this->nbor->nbor_pitch();
  int GX=static_cast<int>(ceil(static_cast<double>(ainum)/
                               (BX/this->_threads_per_atom)));

  this->k_short_nbor.set_size(GX,BX);
  this->k_short_nbor.run(&this->atom->x, &param4, &map,
                 &elem2param, &_nelements, &_nparams,
                 &this->nbor->dev_nbor, &this->_nbor_data->begin(),
                 &this->dev_short_nbor, &ainum,
                 &nbor_pitch, &this->_threads_per_atom);

  // this->_nbor_data == nbor->dev_packed for gpu_nbor == 0 and tpa > 1
  // this->_nbor_data == nbor->dev_nbor for gpu_nbor == 1 or tpa == 1
  ainum=this->ans->inum();
  nbor_pitch=this->nbor->nbor_pitch();
  GX=static_cast<int>(ceil(static_cast<double>(this->ans->inum())/
                               (BX/this->_threads_per_atom)));
  this->time_pair.start();

  // note that k_pair does not run with the short neighbor list
  this->k_pair.set_size(GX,BX);
  this->k_pair.run(&this->atom->x, &param1, &param2, &param3, &param4, &param5,
                   &map, &elem2param, &_nelements,
                   &this->nbor->dev_nbor, &this->_nbor_data->begin(),
                   &this->ans->force, &this->ans->engv,
                   &eflag, &vflag, &ainum, &nbor_pitch,
                   &this->_threads_per_atom);

  BX=this->block_size();
  GX=static_cast<int>(ceil(static_cast<double>(this->ans->inum())/
                           (BX/(KTHREADS*JTHREADS))));
  
  this->k_three_center.set_size(GX,BX);
  this->k_three_center.run(&this->atom->x, &param1, &param2, &param3, &param4, &param5,
                           &map, &elem2param, &_nelements,
                           &this->nbor->dev_nbor, &this->_nbor_data->begin(),
                           &this->dev_short_nbor,
                           &this->ans->force, &this->ans->engv, &eflag, &vflag, &ainum,
                           &nbor_pitch, &this->_threads_per_atom, &evatom);
  Answer<numtyp,acctyp> *end_ans;
  #ifdef THREE_CONCURRENT
  end_ans=this->ans2;
  #else
  end_ans=this->ans;
  #endif
  if (evatom!=0) {
    this->k_three_end_vatom.set_size(GX,BX);
    this->k_three_end_vatom.run(&this->atom->x, &param1, &param2, &param3, &param4, &param5,
                          &map, &elem2param, &_nelements,
                          &this->nbor->dev_nbor, &this->_nbor_data->begin(),
                          &this->nbor->dev_ilist, &this->dev_short_nbor,
                          &end_ans->force, &end_ans->engv, &eflag, &vflag, &ainum,
                          &nbor_pitch, &this->_threads_per_atom, &this->_gpu_nbor);
  } else {
    this->k_three_end.set_size(GX,BX);
    this->k_three_end.run(&this->atom->x, &param1, &param2, &param3, &param4, &param5,
                          &map, &elem2param, &_nelements,
                          &this->nbor->dev_nbor, &this->_nbor_data->begin(),
                          &this->nbor->dev_ilist, &this->dev_short_nbor,
                          &end_ans->force, &end_ans->engv, &eflag, &vflag, &ainum,
                          &nbor_pitch, &this->_threads_per_atom, &this->_gpu_nbor);
  }

  this->time_pair.stop();
}

template class Vashishta<PRECISION,ACC_PRECISION>;
}