# Copyright (C) 2013-2014 Canonical Ltd.

#

# Author: Scott Moser <scott.moser@canonical.com>

# Author: Blake Rouse <blake.rouse@canonical.com>

#

# This file is part of cloud-init. See LICENSE file for license information.

import abc

import io

from .network_state import parse_net_config_data

from .udev import generate_udev_rule

def filter_by_type(match_type):

    return lambda iface: match_type == iface['type']

def filter_by_name(match_name):

    return lambda iface: match_name == iface['name']

def filter_by_attr(match_name):

    return lambda iface: (match_name in iface and iface[match_name])

filter_by_physical = filter_by_type('physical')

class Renderer(object):

    @staticmethod

    def _render_persistent_net(network_state):

        """Given state, emit udev rules to map mac to ifname."""

        # TODO(harlowja): this seems shared between eni renderer and

        # this, so move it to a shared location.

        content = io.StringIO()

        for iface in network_state.iter_interfaces(filter_by_physical):

            # for physical interfaces write out a persist net udev rule

            if 'name' in iface and iface.get('mac_address'):

                driver = iface.get('driver', None)

                content.write(generate_udev_rule(iface['name'],

                                                 iface['mac_address'],

                                                 driver=driver))

        return content.getvalue()

    @abc.abstractmethod

    def render_network_state(self, network_state, templates=None,

                             target=None):

        """Render network state."""

    def render_network_config(self, network_config, templates=None,

                              target=None):

        return self.render_network_state(

            network_state=parse_net_config_data(network_config),

            templates=templates, target=target)

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