""" Network objects """

from . import settings
from . import util
from .xml_template import XMLTemplate

import uuid
import libvirt


class Network(util.NumberedClass):
    class AlreadyExists(Exception):
        def __str__(self):
            return "This network is already instanciated"

    class TooMany(Exception):
        def __init__(self, count):
            self.count = count

        def __str__(self):
            return (
                "Limit number reached. The current instance #{} does not fit in IPv4"
            ).format(self.count)

    def __init__(self, conn, name=None):
        super().__init__()

        if self.id > 250:
            raise self.TooMany(self.id)

        if not name:
            name = str(self.id)

        self.conn = conn
        self.uuid = uuid.uuid4()
        self.name = settings.PREFIX + "_" + name
        self.bridge_id = settings.NETWORK_ID * 0xFF + self.id
        self.bridge_mac = util.MACAddress(self.id, None)
        self.ipv4 = util.Addrv4(self.id, None)
        self.ipv6 = util.Addrv6(self.id, None)
        self.lxc_network = None

        try:
            if self.conn.networkLookupByName(self.name):
                raise self.AlreadyExists()
        except libvirt.libvirtError:
            pass

    def create(self):
        if self.lxc_network:
            raise self.AlreadyExists()

        xml = XMLTemplate("templates/network.xml").inst(
            name=self.name,
            uuid=self.uuid,
            bridge_id=self.bridge_id,
            mac=self.bridge_mac,
            addrv4=self.ipv4,
            netmaskv4=self.ipv4.netmask,
            addrv6=self.ipv6,
            prefixv6=self.ipv6.prefix,
        )

        self.lxc_network = self.conn.networkCreateXML(xml)

    def cleanup(self):
        if self.lxc_network:
            self.lxc_network.destroy()

    def __enter__(self):
        self.create()
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.cleanup()

    def __del__(self):
        self.cleanup()