# Copyright 2015 Intel Corporation.
#
# 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.
"""VNF Controller for the PVP scenario
"""

import logging

from core.vnf_controller import IVnfController

class VnfControllerPVP(IVnfController):
    """VNF controller for the PVP scenario.

    Used to set-up and control a VNF provider for the PVP scenario.

    Attributes:
        _vnf_class: A class object representing the VNF to be used.
        _deployment_scenario: A string describing the scenario to set-up in the
            constructor.
        _vnfs: A list of vnfs controlled by the controller.
    """

    #TODO: Decide on contextmanager or __enter/exit__ strategy <MH 2015-05-01>
    def __init__(self, vnf_class):
        """Sets up the VNF infrastructure for the PVP deployment scenario.

        :param vnf_class: The VNF class to be used.
        """
        self._logger = logging.getLogger(__name__)
        self._vnf_class = vnf_class()
        self._deployment_scenario = "PVP"
        self._vnfs = [vnf_class(deployment=self._deployment_scenario)]
        self._logger.debug('__init__ with ' + str(self._vnfs[0]))
        #TODO call vnf.xxx to carry out the required setup

    def get_vnfs(self):
        """See IVnfController for description
        """
        self._logger.debug('get_vnfs with ' + str(self._vnfs[0]))
        return self._vnfs

    def start(self):
        """See IVnfController for description
        """
        self._logger.debug('start with ' + str(self._vnfs[0]))
        for vnf in self._vnfs:
            vnf.start()

    def stop(self):
        """See IVnfController for description
        """
        self._logger.debug('stop with ' + str(self._vnfs[0]))
        self._vnfs[0].stop()

    def __enter__(self):
        self.start()

    def __exit__(self, type_, value, traceback):
        self.stop()