"""
# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright 2011 Cisco Systems, Inc.  All rights reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.
#
# @author: Sumit Naiksatam, Cisco Systems, Inc.
#
"""

import inspect
from abc import ABCMeta, abstractmethod


class L2NetworkSegmentationMgrBase(object):
    """
    Base class for L2 Network Segmentation Manager
    """

    __metaclass__ = ABCMeta

    @abstractmethod
    def reserve_segmentation_id(self, tenant_id, net_name, **kwargs):
        """
        :returns:
        :raises:
        """
        pass

    @abstractmethod
    def release_segmentation_id(self, tenant_id, net_id, **kwargs):
        """
        :returns:
        :raises:
        """
        pass

    @classmethod
    def __subclasshook__(cls, klass):
        """
        The __subclasshook__ method is a class method
        that will be called everytime a class is tested
        using issubclass(klass, Plugin).
        In that case, it will check that every method
        marked with the abstractmethod decorator is
        provided by the plugin class.
        """
        if cls is L2NetworkSegmentationMgrBase:
            for method in cls.__abstractmethods__:
                method_ok = False
                for base in klass.__mro__:
                    if method in base.__dict__:
                        fn_obj = base.__dict__[method]
                        if inspect.isfunction(fn_obj):
                            abstract_fn_obj = cls.__dict__[method]
                            arg_count = fn_obj.func_code.co_argcount
                            expected_arg_count = \
                                abstract_fn_obj.func_code.co_argcount
                            method_ok = arg_count == expected_arg_count
                if method_ok:
                    continue
                return NotImplemented
            return True
        return NotImplemented
