from django.conf import settings

from django.core.exceptions import ImproperlyConfigured

from django.utils.importlib import import_module

def get_storage(import_path):

    """

    Imports the message storage class described by import_path, where

    import_path is the full Python path to the class.

    """

    try:

        dot = import_path.rindex('.')

    except ValueError:

        raise ImproperlyConfigured("%s isn't a Python path." % import_path)

    module, classname = import_path[:dot], import_path[dot + 1:]

    try:

        mod = import_module(module)

    except ImportError, e:

        raise ImproperlyConfigured('Error importing module %s: "%s"' %

                                   (module, e))

    try:

        return getattr(mod, classname)

    except AttributeError:

        raise ImproperlyConfigured('Module "%s" does not define a "%s" '

                                   'class.' % (module, classname))

# Callable with the same interface as the storage classes i.e.  accepts a

# 'request' object.  It is wrapped in a lambda to stop 'settings' being used at

# the module level

default_storage = lambda request: get_storage(settings.MESSAGE_STORAGE)(request)