/* VModis_latlon_resolve.cpp */

/*
remap
Copyright (C) 2006 Fabrice Ducos, fabrice.ducos@icare.univ-lille1.fr

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/

#include "common.h"
#include <glob.h>
#include <libgen.h>
#include "VModis_latlon_resolve.h"

char *VModis_latlon_resolve(char *modis_data_file, char *modis_latlon_path) {

  char modis_data_file_dirbak[STRING_MAXLEN + 1]; /* calls to dirname and basename may modify their arguments, so we work on copies */
  char modis_data_file_basbak[STRING_MAXLEN + 1];
  char modis_latlon_pattern[STRING_MAXLEN + 1];
  char modis_latlon_dir_pattern[STRING_MAXLEN + 1];
  char modis_slot_time[STRING_MAXLEN + 1];
  static char modis_latlon_file[STRING_MAXLEN + 1];
  char *modis_data_dirname;
  char *modis_latlon_dirname;
  char *modis_data_basename;
  int globerr;
  glob_t paths;

  strncpy(modis_data_file_dirbak, modis_data_file, STRING_MAXLEN);
  strncpy(modis_data_file_basbak, modis_data_file, STRING_MAXLEN);

  modis_data_dirname = dirname(modis_data_file_dirbak);
  modis_data_basename = basename(modis_data_file_basbak);

  if (modis_latlon_path) {
    modis_latlon_dirname = modis_latlon_path;
  }
  else {
    modis_latlon_dirname = modis_data_dirname;
  }

  assert(modis_data_basename[1] == 'O' || modis_data_basename[1] == 'Y');
  strncpy(modis_slot_time, &modis_data_basename[10], 12); // extracts YYYYDDD.HHMM in the filename
  modis_slot_time[12] = '\0';

  snprintf(modis_latlon_pattern, STRING_MAXLEN, "M%cD03.A%s.???.?????????????.hdf", 
	   modis_data_basename[1] /* O (Terra) or Y (Aqua) */,
	   modis_slot_time /* format YYYYDDD.HHMM */);

  snprintf(modis_latlon_dir_pattern, STRING_MAXLEN, "%s/%s", modis_latlon_dirname, modis_latlon_pattern);

  /* only the first occurence is kept (we don't expect to have several lat-lon files for the same MODIS granule) */
  globerr = glob(modis_latlon_dir_pattern, 0, NULL, &paths);
  if ((globerr != 0) && (globerr != GLOB_NOMATCH)) {
    perror(modis_data_file); // FIXME: should print APPNAME before error message
    return NULL;
  }

  if (paths.gl_pathc < 1) {
    std::cerr << APPNAME << ": no lat-lon file found for " << modis_data_file << std::endl;
    return NULL;
  }

  strncpy(modis_latlon_file, paths.gl_pathv[0], STRING_MAXLEN);
  globfree(&paths);

  return modis_latlon_file;

}