from django.conf import settings

from django.core.exceptions import ImproperlyConfigured

from django.utils.importlib import import_module

geom_backend = getattr(settings, 'GEOMETRY_BACKEND', 'geos')

try:

    module = import_module('.%s' % geom_backend, 'django.contrib.gis.geometry.backend')

except ImportError, e:

    try:

        module = import_module(geom_backend)

    except ImportError, e_user:

        raise ImproperlyConfigured('Could not import user-defined GEOMETRY_BACKEND '

                                   '"%s".' % geom_backend)

try:

    Geometry = module.Geometry

    GeometryException = module.GeometryException

except AttributeError:

    raise ImproperlyConfigured('Cannot import Geometry from the "%s" '

                               'geometry backend.' % geom_backend)