/*
   This procedure opens and reads ACE MAG snapshot data from a level 1
   HDF file.  Data records are read into a structure.

   This procedure was modified from its original source to be called
   from a Fortran main routine and pass back the data set contents
   as a structure array.

   Original source:  ACE Science Center
   Modifications:    Sandy Kramer, NASA/GSFC, code 692 - 09/08/97
*/

#include <stdio.h>
#include <string.h>

#include "mag_snapshot.h"
#include "df.h"

int rd_snap(name, snapdat, snapcnt)

  char *name;
  struct MagSnapSet *snapdat;
  int *snapcnt;

{
  int32 hdf_fp,SD_id;
  struct MagSnapSet testdata;
  int ii,retval;

  printf("ACE MAG snapshot read routine\n");
  printf("File name is <%s>\n", name);

  if (name[0] == ' ')
    {
      printf("Usage: rd_hdf hdf_file\n");
      return(1);
    }

  /* open hdf input file */

  if ((hdf_fp=Hopen(name, DFACC_ALL, 0))==FAIL)
    {
      fprintf(stderr, "Hopen: could not open hdf file\n");
      return(-1);
    }
  printf("File successfully opened.\n");
  Vstart(hdf_fp);

  if ((SD_id=SDstart(name, DFACC_WRITE))==FAIL)
      {
	fprintf(stderr, "SDstart: could not open hdf file\n");
	return(-1);
      }

  init_rd_mag_snap(hdf_fp, SD_id);

  ii=0;
  while((retval= read_mag_snap(&testdata,ii))!=-1) {
     snapdat[ii] = testdata;
/*
     printf("%4d sc clock = %8d\n", ii,testdata.sctime_readout);
*/
     ii++;
  }
  *snapcnt = ii; 

  /* all done, close HDF file */

  close_rd_mag_snap();
  Vend(hdf_fp);
  if (Hclose(hdf_fp)==FAIL)
    {
      fprintf(stderr, "Hclose: could not close hdf file\n");
      return(-1);
    }
  return(0);
}