#include "simfront.h"


/*
 * read and set topology
 */

int setup_topology(SimFront *sf)
{
  Topo *topo = &(sf->topo);
  Tbuf *tbuf = &(sf->tbuf);
  MD_Sim *sim = sf->sim;
  int index_atom = 0, index_bond = 0, index_angle = 0,
      index_dihed = 0, index_impr = 0, index_excl = 0;
  int k;


  /* open topology file */
  if (topo_open(topo, sf->topofile, TOPO_XPLOR)) {
    ERRMSG(sf, "call to topo_open failed");
    return -1;
  }

  /* read in topology file */
  /*
   * Here is the strangeness in the MDIO Topo interface:
   *
   *   Must have some amount of initial buffer space
   *   (this was set up in init()).  Return value from
   *   topo_read() indicates by nonzero which buffer is
   *   full so that we can set this much of the corresponding
   *   engine array.  Unlike Param interface, writing always
   *   starts at beginning of buffer, so need to "empty" that
   *   buffer (make call to MD_setdata) after each return from
   *   topo_read().
   */
  while ((k = topo_read(topo)) != 0) {
    switch (k) {
    case MD_ATOM:
      if (MD_getlen(sim, sf->id_atom) != tbuf->atom_max
          && (MD_setlen(sim, sf->id_atom, tbuf->atom_max) || MD_wait(sim))) {
        ERRMSG(sf, MD_errmsg(sim));
        return -1;
      }
      if (MD_setdata(sim,sf->id_atom,tbuf->atom,tbuf->atom_num,index_atom)
          || MD_wait(sim)) {
        ERRMSG(sf, MD_errmsg(sim));
        return -1;
      }
      index_atom += tbuf->atom_num;
      break;

    case MD_BOND:
      if (MD_getlen(sim, sf->id_bond) != tbuf->bond_max
          && (MD_setlen(sim, sf->id_bond, tbuf->bond_max) || MD_wait(sim))) {
        ERRMSG(sf, MD_errmsg(sim));
        return -1;
      }
      if (MD_setdata(sim,sf->id_bond,tbuf->bond,tbuf->bond_num,index_bond)
          || MD_wait(sim)) {
        ERRMSG(sf, MD_errmsg(sim));
        return -1;
      }
      index_bond += tbuf->bond_num;
      break;

    case MD_ANGLE:
      if (MD_getlen(sim, sf->id_angle) != tbuf->angle_max
          && (MD_setlen(sim, sf->id_angle, tbuf->angle_max) || MD_wait(sim))) {
        ERRMSG(sf, MD_errmsg(sim));
        return -1;
      }
      if (MD_setdata(sim,sf->id_angle,tbuf->angle,tbuf->angle_num,index_angle)
          || MD_wait(sim)) {
        ERRMSG(sf, MD_errmsg(sim));
        return -1;
      }
      index_angle += tbuf->angle_num;
      break;

    case MD_DIHED:
      if (MD_getlen(sim, sf->id_dihed) != tbuf->dihed_max
          && (MD_setlen(sim, sf->id_dihed, tbuf->dihed_max) || MD_wait(sim))) {
        ERRMSG(sf, MD_errmsg(sim));
        return -1;
      }
      if (MD_setdata(sim,sf->id_dihed,tbuf->dihed,tbuf->dihed_num,index_dihed)
          || MD_wait(sim)) {
        ERRMSG(sf, MD_errmsg(sim));
        return -1;
      }
      index_dihed += tbuf->dihed_num;
      break;

    case MD_IMPR:
      if (MD_getlen(sim, sf->id_impr) != tbuf->impr_max
          && (MD_setlen(sim, sf->id_impr, tbuf->impr_max) || MD_wait(sim))) {
        ERRMSG(sf, MD_errmsg(sim));
        return -1;
      }
      if (MD_setdata(sim,sf->id_impr,tbuf->impr,tbuf->impr_num,index_impr)
          || MD_wait(sim)) {
        ERRMSG(sf, MD_errmsg(sim));
        return -1;
      }
      index_impr += tbuf->impr_num;
      break;

    case MD_EXCL:
      if (MD_getlen(sim, sf->id_excl) != tbuf->excl_max
          && (MD_setlen(sim, sf->id_excl, tbuf->excl_max) || MD_wait(sim))) {
        ERRMSG(sf, MD_errmsg(sim));
        return -1;
      }
      if (MD_setdata(sim,sf->id_excl,tbuf->excl,tbuf->excl_num,index_excl)
          || MD_wait(sim)) {
        ERRMSG(sf, MD_errmsg(sim));
        return -1;
      }
      index_excl += tbuf->excl_num;
      break;

    default:
      ERRMSG(sf, "unknown return value from topo_read");
      return -1;
    }
  }

  /* close topology file */
  if (topo_close(topo)) {
    ERRMSG(sf, "call to topo_close failed");
    return -1;
  }

  /* verify that we read and set everything */
  if (index_atom != tbuf->atom_max) {
    ERRMSG(sf, "do not have expected number of atoms");
    return -1;
  }
  if (index_bond != tbuf->bond_max) {
    ERRMSG(sf, "do not have expected number of bonds");
    return -1;
  }
  if (index_angle != tbuf->angle_max) {
    ERRMSG(sf, "do not have expected number of angles");
    return -1;
  }
  if (index_dihed != tbuf->dihed_max) {
    ERRMSG(sf, "do not have expected number of dihedrals");
    return -1;
  }
  if (index_impr != tbuf->impr_max) {
    ERRMSG(sf, "do not have expected number of impropers");
    return -1;
  }
  if (index_excl != tbuf->excl_max) {
    ERRMSG(sf, "do not have expected number of exclusions");
    return -1;
  }

  return 0;
}