#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "mdutil.h"
#include "simfront.h"

#undef   NELEMS
#define  NELEMS(x)  (sizeof(x)/sizeof((x)[0]))


#undef   MIN
#define  MIN(a,b)   ( ((a)<(b)) ? (a) : (b) )


/* static constant variable */
static const char *Title[] = {
  "bond",
  "angle",
  "dihedral",
  "improper",
  "elec",
  "vdw",
  "bound",
  "kin",
  "pot",
  "total",
  "temp",
};


/* prototypes for internal functions */
static MD_Int output_energy(void *info, MD_Callback_Data *cbdata, MD_Int len,
                            MD_Int stepnum, MD_Int numer, MD_Int denom);

#define  WIDTH     19
#define  STRWIDTH  "19"
#define  REDUCFMT  " %18.13g"

int setup_callbacks(SimFront *sf)
{
  MD_Sim *sim = sf->sim;
  MD_String *reduclabel;
  CallbackInfo *cbinfo = &(sf->cbinfo);
  MD_Callback_Data cbdata[1];
  MD_Int idreduc, idreduclabel, len;
  MD_String sbuf;  /* this is a length 64 array of char */
  int i, j, k, cnt;
  const char *cs;

  idreduc = MD_lookup(sim, "Reduction");
  idreduclabel = MD_lookup(sim, "ReductionLabel");
  len = MD_getlen(sim, idreduc);
  reduclabel = (MD_String *) calloc(len, sizeof(MD_String));
  MD_getdata(sim, idreduclabel, reduclabel, len, 0);
  MD_wait(sim);

  sprintf(cbinfo->reductitle, "%8s", "stepnum");
  cnt = 8;
  strcpy(cbinfo->reducfmt, "%8d");
  for (i = 0;  i < len && cnt+WIDTH < NELEMS(cbinfo->reductitle);  i++) {
    /* look through known titles */
    for (j = 0;  j < NELEMS(Title);  j++) {
      k = MIN(MIN(strlen(reduclabel[i]), strlen(Title[j])), 8);
      if (mdutil_strncasecmp(reduclabel[i], Title[j], k) == 0) {
        strncpy(sbuf, Title[j], 8);
        sbuf[8] = '\0';
        break;
      }
    }
    if (j == NELEMS(Title)) {
      /*
       * we didn't have a partial match with any of our titles --
       * so try to obtain an abbrev for ith label by taking first
       * letter of each word in label --
       * if result is length 1, then just use up to first 8 letters
       */
      cs = reduclabel[i];
      while (isspace(cs[0])) cs++;
      k = 0;
      sbuf[k++] = cs[0];
      while ((cs = strchr(cs, ' ')) != NULL && k < 8) {
        if (cs[1] != ' ') {
          sbuf[k++] = cs[1];
          cs++;
        }
      }
      sbuf[k] = '\0';
      if (k == 1) {
        strncpy(sbuf, reduclabel[i], 8);
        sbuf[8] = '\0';
      }
    }
    sprintf(cbinfo->reductitle + cnt, "%" STRWIDTH "s", sbuf);
    cnt += WIDTH;
    strcat(cbinfo->reducfmt, REDUCFMT);
  }
  strcat(cbinfo->reducfmt, "\n");
  cbinfo->numcols = i;
  cbinfo->titlefreq = 20;

  cbdata[0].nelems = cbinfo->numcols;
  cbdata[0].first = 0;
  cbdata[0].attr.idnum = idreduc;
  cbdata[0].attr.access = MD_DATA_CBREAD;
  if (MD_set_callback(sim, output_energy, cbdata, 1, sf->energyfreq)) {
    ERRMSG(sf, MD_errmsg(sim));
    return -1;
  }
  MD_setinfo(sim, cbinfo);
  return 0;
}


MD_Int output_energy(void *info, MD_Callback_Data *cbdata, MD_Int len,
                     MD_Int stepnum, MD_Int numer, MD_Int denom)
{
  /* trust MDAPI to pass us correct values */
  CallbackInfo *cbinfo = (CallbackInfo *) info;
  double *reduc = (double *) (cbdata[0].data);
  int k;
  char buf[STRING_SIZE];
  char *pbuf = buf;

  if (stepnum % cbinfo->titlefreq == 0) {
    printf("#%s\n", cbinfo->reductitle);
  }
  sprintf(pbuf, "%9d", stepnum);
  pbuf += 9;
  for (k = 0;  k < cbinfo->numcols;  k++) {
    sprintf(pbuf, REDUCFMT, reduc[k]);
    pbuf += WIDTH;
  }
  printf("%s\n", buf);

/*
  printf("step %d:\n", stepnum);
  for (k = 0;  k < cbdata[0].nelems;  k++) {
    printf("  %s = %g\n", reduclabel[k], reduc[k]);
  }
*/
  return 0;
}