/* ----------------------------------------------------------------------
   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
   http://lammps.sandia.gov, Sandia National Laboratories
   Steve Plimpton, sjplimp@sandia.gov

   Copyright (2003) Sandia Corporation.  Under the terms of Contract
   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
   certain rights in this software.  This software is distributed under 
   the GNU General Public License.

   See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */

#include "dump_vac.h"
#include "stdlib.h"
#include "string.h"
#include "atom.h"
#include "force.h"
#include "domain.h"
#include "region.h"
#include "group.h"
#include "update.h"
#include "modify.h"
#include "compute.h"
#include "memory.h"
#include "error.h"
#include "output.h"
#include "thermo.h"
#include "comm.h"
#include "integrate.h"

using namespace LAMMPS_NS;

/* ---------------------------------------------------------------------- */

DumpVAC::DumpVAC(LAMMPS *lmp, int narg, char **arg) : Dump(lmp, narg, arg)
{
  if (narg != 5) error->all("Illegal dump atom command");

  // one-time file open

  if (multifile == 0) openfile();
}

/* ---------------------------------------------------------------------- */

void DumpVAC::init()
{
  size_one = 4;
}

/* ---------------------------------------------------------------------- */

int DumpVAC::count()
{
  if (igroup == 0) return atom->nlocal;

  int *mask = atom->mask;
  int nlocal = atom->nlocal;

  int m = 0;
  for (int i = 0; i < nlocal; i++)
    if (mask[i] & groupbit) m++;
  return m;
}

/* ---------------------------------------------------------------------- */

void DumpVAC::write_header(int ndump)
{
  double epot,ekin,temp,vol,press;
  output->thermo->compute_pe();
  epot = output->thermo->potential_energy;
  temp = output->thermo->temperature->compute_scalar();
  press = output->thermo->pressure->compute_scalar();
  ekin = temp * 0.5 * output->thermo->temperature->dof * force->boltz;
  vol = (boxxhi-boxxlo)*(boxyhi-boxylo)*(boxzhi-boxzlo);

  fprintf(fp,"ITEM: TIMESTEP\n");
  fprintf(fp,"%d\n",update->ntimestep);
  fprintf(fp,"ITEM: NUMBER OF ATOMS\n");
  fprintf(fp,"%d\n",ndump);
  fprintf(fp,"ITEM: THERMODYNAMICS\n");
  fprintf(fp,"%.2f %.2f %.2f %.2f %.2f %.2f\n",(epot+ekin),epot,ekin,temp,vol,press);
  fprintf(fp,"ITEM: ATOMS\n");
}

/* ---------------------------------------------------------------------- */

int DumpVAC::pack()
{
  int *tag = atom->tag;
  int *type = atom->type;
  int *mask = atom->mask;
  double **v = atom->v;
  int nlocal = atom->nlocal;

  int m = 0;
  for (int i = 0; i < nlocal; i++)
    if (mask[i] & groupbit) {
      buf[m++] = tag[i];
      buf[m++] = v[i][0];
      buf[m++] = v[i][1];
      buf[m++] = v[i][2];
    }

  return m;
}

/* ---------------------------------------------------------------------- */

void DumpVAC::write_data(int n, double *buf)
{
  int m = 0;
  for (int i = 0; i < n; i++) {
    fprintf(fp,"%d %g %g %g\n",
	    static_cast<int> (buf[m]), buf[m+1],
	    buf[m+2],buf[m+3]);
    m += size_one;
  }
}