/***************************************************************************
                               coul_dsf_ext.cpp
                             -------------------
                            Trung Dac Nguyen (ORNL)

  Functions for LAMMPS access to coul/dsf acceleration routines.

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

    begin                : 8/15/2012
    email                : nguyentd@ornl.gov
 ***************************************************************************/

#include <iostream>
#include <cassert>
#include <cmath>

#include "lal_coul_dsf.h"

using namespace std;
using namespace LAMMPS_AL;

static CoulDSF<PRECISION,ACC_PRECISION> CDMF;

// ---------------------------------------------------------------------------
// Allocate memory on host and device and copy constants to device
// ---------------------------------------------------------------------------
int cdsf_gpu_init(const int ntypes, const int inum, const int nall,
                  const int max_nbors, const int maxspecial,
                  const double cell_size, int &gpu_mode, FILE *screen,
                  const double host_cut_coulsq, double *host_special_coul,
                  const double qqrd2e, const double e_shift, const double f_shift,
                  const double alpha) {
  CDMF.clear();
  gpu_mode=CDMF.device->gpu_mode();
  double gpu_split=CDMF.device->particle_split();
  int first_gpu=CDMF.device->first_device();
  int last_gpu=CDMF.device->last_device();
  int world_me=CDMF.device->world_me();
  int gpu_rank=CDMF.device->gpu_rank();
  int procs_per_gpu=CDMF.device->procs_per_gpu();

  CDMF.device->init_message(screen,"coul/dsf",first_gpu,last_gpu);

  bool message=false;
  if (CDMF.device->replica_me()==0 && screen)
    message=true;

  if (message) {
    fprintf(screen,"Initializing Device and compiling on process 0...");
    fflush(screen);
  }

  int init_ok=0;
  if (world_me==0)
    init_ok=CDMF.init(ntypes, inum, nall, 300, maxspecial, cell_size,
                      gpu_split, screen, host_cut_coulsq, host_special_coul,
                      qqrd2e, e_shift, f_shift, alpha);

  CDMF.device->world_barrier();
  if (message)
    fprintf(screen,"Done.\n");

  for (int i=0; i<procs_per_gpu; i++) {
    if (message) {
      if (last_gpu-first_gpu==0)
        fprintf(screen,"Initializing Device %d on core %d...",first_gpu,i);
      else
        fprintf(screen,"Initializing Devices %d-%d on core %d...",first_gpu,
                last_gpu,i);
      fflush(screen);
    }
    if (gpu_rank==i && world_me!=0)
      init_ok=CDMF.init(ntypes, inum, nall, 300, maxspecial, cell_size,
                        gpu_split, screen, host_cut_coulsq, host_special_coul,
                        qqrd2e, e_shift, f_shift, alpha);

    CDMF.device->gpu_barrier();
    if (message)
      fprintf(screen,"Done.\n");
  }
  if (message)
    fprintf(screen,"\n");

  if (init_ok==0)
    CDMF.estimate_gpu_overhead();
  return init_ok;
}

void cdsf_gpu_clear() {
  CDMF.clear();
}

int** cdsf_gpu_compute_n(const int ago, const int inum_full,
                         const int nall, double **host_x, int *host_type,
                         double *sublo, double *subhi, tagint *tag, int **nspecial,
                         tagint **special, const bool eflag, const bool vflag,
                         const bool eatom, const bool vatom, int &host_start,
                         int **ilist, int **jnum, const double cpu_time,
                         bool &success, double *host_q, double *boxlo,
                         double *prd) {
  return CDMF.compute(ago, inum_full, nall, host_x, host_type, sublo,
                      subhi, tag, nspecial, special, eflag, vflag, eatom,
                      vatom, host_start, ilist, jnum, cpu_time, success,
                      host_q, boxlo, prd);
}

void cdsf_gpu_compute(const int ago, const int inum_full, const int nall,
                      double **host_x, int *host_type, int *ilist, int *numj,
                      int **firstneigh, const bool eflag, const bool vflag,
                      const bool eatom, const bool vatom, int &host_start,
                      const double cpu_time, bool &success, double *host_q,
                      const int nlocal, double *boxlo, double *prd) {
  CDMF.compute(ago,inum_full,nall,host_x,host_type,ilist,numj,firstneigh,eflag,
               vflag,eatom,vatom,host_start,cpu_time,success,host_q,
               nlocal,boxlo,prd);
}

double cdsf_gpu_bytes() {
  return CDMF.host_memory_usage();
}