# Copyright (c) 2014 TrilioData, Inc.
# All Rights Reserved.

from workloadmgrclient import base
from workloadmgrclient import utils


class Extension(utils.HookableMixin):
    """Extension descriptor."""

    SUPPORTED_HOOKS = ("__pre_parse_args__", "__post_parse_args__")

    def __init__(self, name, module):
        self.name = name
        self.module = module
        self._parse_extension_module()

    def _parse_extension_module(self):
        self.manager_class = None
        for attr_name, attr_value in list(self.module.__dict__.items()):
            if attr_name in self.SUPPORTED_HOOKS:
                self.add_hook(attr_name, attr_value)
            elif utils.safe_issubclass(attr_value, base.Manager):
                self.manager_class = attr_value

    def __repr__(self):
        return "<Extension '%s'>" % self.name