# -*- coding: utf-8 -*-

# 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.

import netaddr
import os_net_config
from os_net_config import utils

from os_net_config.openstack.common import processutils


# TODO(?): should move to interfaces.d
def _network_config_path():
    return "/etc/network/interfaces"


class ENINetConfig(os_net_config.NetConfig):
    """Ubuntu/Debian implementation for network config

       Configure iface/bridge/routes using debian/ubuntu
       /etc/network/interfaces format.
    """

    def __init__(self):
        self.interfaces = {}
        self.routes = {}
        self.bridges = {}

    def _addCommon(self, interface):

        def _static_addresses(_v4, _v6):
            addr = _v4 + _v6
            address_data = ""
            if addr:
                address_data += "address %s\n" % addr[0].ip
                address_data += "netmask %s\n" % addr[0].netmask
            return address_data

        _v6 = interface.v6_addresses()
        _v4 = interface.v4_addresses()
        _iface = "iface %s " % interface.name
        if _v6:
            _iface += "inet6 "
        else:
            _iface += "inet "
        if interface.use_dhcp:
            _iface += "dhcp\n"
        elif interface.addresses:
            _iface += "static\n"
        else:
            _iface += "manual\n"
        data = ""
        if interface.type == 'ovs_bridge':
            data += "allow-ovs %s\n" % interface.name
            data += _iface
            data += _static_addresses(_v4, _v6)
            data += "ovs_type OVSBridge\n"
            if interface.members:
                data += "ovs_ports"
                for i in interface.members:
                    data += " %s" % i.name
                data += "\n"
        elif interface.type == 'ovs_port':
            data += "allow-%s %s\n" % (interface.bridge_name, interface.name)
            data += _iface
            data += _static_addresses(_v4, _v6)
            data += "ovs_bridge %s\n" % interface.bridge_name
            data += "ovs_type OVSPort\n"
        else:
            data += "auto %s\n" % interface.name
            data += _iface
            data += _static_addresses(_v4, _v6)
        return data

    def addInterface(self, interface):
        data = self._addCommon(interface)

        self.interfaces[interface.name] = data
        if interface.routes:
            self._addRoutes(interface.name, interface.routes)

    def addBridge(self, bridge):
        data = self._addCommon(bridge)

        self.bridges[bridge.name] = data
        if bridge.routes:
            self._addRoutes(bridge.name, bridge.routes)
        if bridge.routes:
            self._addRoutes(bridge.name, bridge.routes)

    def _addRoutes(self, interface_name, routes=[]):
        data = ""
        for route in routes:
            rt = netaddr.IPNetwork(route.ip_netmask)
            data += "up route add -net %s netmask %s gw %s\n" % (
                    str(rt.ip), str(rt.netmask), route.next_hop)
            data += "down route del -net %s netmask %s gw %s\n" % (
                    str(rt.ip), str(rt.netmask), route.next_hop)
        self.routes[interface_name] = data

    def apply(self):
        new_config = ""
        for interface_name, iface_data in self.interfaces.iteritems():
            route_data = self.routes.get(interface_name)
            iface_data += (route_data or '')
            new_config += iface_data

        for bridge_name, bridge_data in self.bridges.iteritems():
            route_data = self.routes.get(bridge_name)
            bridge_data += (route_data or '')
            new_config += bridge_data
        if (utils.diff(_network_config_path(), new_config)):
            for interface in self.interfaces.keys():
                processutils.execute('/sbin/ifdown', interface,
                                     check_exit_code=False)

            for bridge in self.bridges.keys():
                processutils.execute('/sbin/ifdown', bridge,
                                     check_exit_code=False)

            utils.write_config(_network_config_path(), new_config)