"""
Module for querying information about users.  This mostly asks plugins for
the extra information, and falls back to using a default that should work
on most systems (but by no means all systems.)
"""

import pkg_resources
import os

def quota(dir=None):
    """
    Returns a tuple (quota usage, quota limit).  Returns ``(0, None)`` if
    the quota usage is unknown.  If ``dir`` is omitted, the current
    working directory is assumed.  Value returned is in bytes.

    This function implements a plugin interface named
    :ref:`wizard.user.quota`.
    """
    if dir is None:
        dir = os.getcwd()
    unknown = (0, None)
    for entry in pkg_resources.iter_entry_points("wizard.user.quota"):
        func = entry.load()
        r = func(dir)
        if r != unknown:
            return r
    return unknown