/*
 * Copyright 2005-2017 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 jet 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;
}
