/*
 * (C) Copyright 2005- ECMWF.
 *
 * This software is licensed under the terms of the Apache Licence Version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
 *
 * In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
 * virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
 */

/*
 * C Implementation: fieldset
 *
 * Description: how to use a fieldset.
 *
 */

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

#include "eccodes.h"

void usage(char* prog)
{
    printf("Usage: %s order_by grib_file grib_file ...\n", prog);
    exit(1);
}

int main(int argc, char** argv)
{
    int err = 0;
    long step, levelType;
    char** filenames;
    size_t nkeys, nfiles;
    int i        = 0;
    char* keys[] = { "step", "date", "param", "levelType" };
    codes_fieldset* set;
    codes_handle* h;
    char param[20] = {0,};
    char date[10] = {0,};
    size_t datelen = 10;
    size_t len     = 20;
    char* order_by = 0;

    if (argc != 3) usage(argv[0]);

    nkeys    = sizeof(keys) / sizeof(*keys);
    order_by = strdup(argv[1]);

    nfiles    = argc - 2;
    filenames = (char**)malloc(sizeof(char*) * nfiles);
    for (i = 0; i < nfiles; i++)
        filenames[i] = (char*)strdup(argv[i + 2]);

    set = codes_fieldset_new_from_files(0, filenames, nfiles, keys, nkeys, 0, 0, &err);
    CODES_CHECK(err, 0);

    /* not yet implemented */
    /* err=codes_fieldset_apply_where(set,"(centre=='ecmf') && number==1 || step==6 "); */
    /* CODES_CHECK(err,0); */

    codes_fieldset_apply_order_by(set, order_by);
    CODES_CHECK(err, 0);

    printf("\nordering by %s\n", order_by);
    printf("\n%d fields in the fieldset\n", codes_fieldset_count(set));
    printf("step,date,levelType,levelType\n");
    while ((h = codes_fieldset_next_handle(set, &err)) != NULL) {
        CODES_CHECK(codes_get_long(h, "step", &step), 0);
        CODES_CHECK(codes_get_string(h, "date", date, &datelen), 0);
        CODES_CHECK(codes_get_string(h, "param", param, &len), 0);
        CODES_CHECK(codes_get_long(h, "levelType", &levelType), 0);

        printf("%ld %s %ld %s\n", step, date, levelType, param);
        codes_handle_delete(h);
    }

    codes_fieldset_delete(set);
    codes_handle_delete(h);

    return 0;
}
