# Copyright 2005-2018 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.

import traceback
import sys

from gribapi import *

INPUT = '../../data/reduced_latlon_surface.grib1'
VERBOSE = 1  # verbose error reporting


def example():
    f = open(INPUT)

    keys = [
        'Ni',
        'Nj',
        'latitudeOfFirstGridPointInDegrees',
        'longitudeOfFirstGridPointInDegrees',
        'latitudeOfLastGridPointInDegrees',
        'longitudeOfLastGridPointInDegrees',
    ]

    while 1:
        gid = grib_new_from_file(f)
        if gid is None:
            break

        for key in keys:
            if not grib_is_defined(gid, key):
                raise Exception("Key was not defined")
            print '%s=%s' % (key, grib_get(gid, key))

        if grib_is_defined(gid, "A_very_silly_girl"):
            raise Exception("Key was defined")

        print 'There are %d values, average is %f, min is %f, max is %f' % (
            grib_get_size(gid, 'values'),
            grib_get(gid, 'average'),
            grib_get(gid, 'min'),
            grib_get(gid, 'max')
        )

        grib_release(gid)

    f.close()


def main():
    try:
        example()
    except GribInternalError, err:
        if VERBOSE:
            traceback.print_exc(file=sys.stderr)
        else:
            print >>sys.stderr, err.msg

        return 1

if __name__ == "__main__":
    sys.exit(main())
