/*
 * (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: bufr_subset
 *
 * Description: how to read data values from a given subset of a BUFR message.
 *
 */

#include "eccodes.h"
#include <assert.h>

int main(int argc, char* argv[])
{
    char key[200] = {0,};
    FILE* in = NULL;

    /* message handle. Required in all the eccodes calls acting on a message.*/
    codes_handle* h = NULL;

    long numberOfSubsets = 0;
    long longVal;
    double doubleVal;
    size_t stringLen;
    char stringVal[100] = {0,};
    int i, err = 0;
    int cnt            = 0;
    const char* infile = "../../data/bufr/synop_multi_subset.bufr";

    in = fopen(infile, "rb");
    if (!in) {
        fprintf(stderr, "Error: unable to open file %s\n", infile);
        return 1;
    }

    /* loop over the messages in the BUFR file */
    while ((h = codes_handle_new_from_file(NULL, in, PRODUCT_BUFR, &err)) != NULL || err != CODES_SUCCESS) {
        if (h == NULL) {
            fprintf(stderr, "Error: unable to create handle for message %d\n", cnt);
            cnt++;
            continue;
        }

        printf("message: %d\n", cnt);

        /* we need to instruct ecCodes to expand all the descriptors i.e. unpack the data values */
        CODES_CHECK(codes_set_long(h, "unpack", 1), 0);

        /* find out the number of subsets */
        CODES_CHECK(codes_get_long(h, "numberOfSubsets", &numberOfSubsets), 0);
        printf("  numberOfSubsets: %ld\n", numberOfSubsets);

        /* loop over the subsets */
        for (i = 1; i <= numberOfSubsets; i++) {
            snprintf(key, sizeof(key), "/subsetNumber=%d/blockNumber", i);

            printf("  subsetNumber=%d", i);
            /* read and print some data values */
            CODES_CHECK(codes_get_long(h, key, &longVal), 0);
            printf("  blockNumber=%ld", longVal);

            snprintf(key, sizeof(key), "/subsetNumber=%d/stationNumber", i);
            CODES_CHECK(codes_get_long(h, key, &longVal), 0);
            printf("  stationNumber=%ld", longVal);

            snprintf(key, sizeof(key), "/subsetNumber=%d/stationOrSiteName->units", i);
            CODES_CHECK(codes_get_length(h, key, &stringLen), 0);
            assert(stringLen == 10); /* should be "CCITT IA5" */

            snprintf(key, sizeof(key), "/subsetNumber=%d/stationOrSiteName", i);
            CODES_CHECK(codes_get_length(h, key, &stringLen), 0);
            CODES_CHECK(codes_get_string(h, key, stringVal, &stringLen), 0);
            assert(stringLen > 0 && stringLen < 17);
            printf("  stationOrSiteName=\"%s\"", stringVal);

            snprintf(key, sizeof(key), "/subsetNumber=%d/airTemperature", i);
            CODES_CHECK(codes_get_double(h, key, &doubleVal), 0);
            printf("  airTemperature=%g\n", doubleVal);
            assert(doubleVal > 265 && doubleVal < 278);
        }

        /* delete handle */
        codes_handle_delete(h);

        cnt++;
    }

    fclose(in);
    return 0;
}
