# -*- coding: utf-8 -*-
#
# Copyright (C) 2013 GNS3 Technologies Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""
Interface for dummy NIOs (mostly for tests).
"""

import asyncio
from .nio import NIO

import logging
log = logging.getLogger(__name__)


class NIONull(NIO):

    """
    Dynamips NULL NIO.

    :param hypervisor: Dynamips hypervisor instance
    """

    _instance_count = 0

    def __init__(self, hypervisor):

        # create an unique ID and name
        nio_id = NIONull._instance_count
        NIONull._instance_count += 1
        name = 'nio_null' + str(nio_id)
        NIO.__init__(self, name, hypervisor)

    @classmethod
    def reset(cls):
        """
        Reset the instance count.
        """

        cls._instance_count = 0

    @asyncio.coroutine
    def create(self):

        yield from self._hypervisor.send("nio create_null {}".format(self._name))
        log.info("NIO NULL {name} created.".format(name=self._name))

    def __json__(self):

        return {"type": "nio_null"}
