"""
NETCONF for APK Distributions server:
    ietf-ip module

Copyright © 2020 Adélie Software in the Public Benefit, Inc.

Released under the terms of the NCSA license.  See the LICENSE file included
with this source distribution for more information.

SPDX-License-Identifier: NCSA
"""

import logging

from lxml.etree import QName  # pylint: disable=E0611
from netconf import util

from ncserver.base.modman import MODMAN
from ncserver.base.util import _


LOGGER = logging.getLogger(__name__)
"""The object used for logging informational messages."""


M_ABI_VERSION = 1
"""The ABI version of this NETCONF module."""


M_PREFIX = "ip"
"""The XML tag prefix for this module's tags."""


M_NS = "urn:ietf:params:xml:ns:yang:ietf-ip"
"""The XML namespace for this module."""


M_NAME = "ietf-ip"
"""The YANG model name for this module."""


M_REVISION = "2018-02-22"
"""The YANG revision date for this module."""


M_IMPORTS = {
    'ietf-inet-types@2013-07-15': {
        'ns': "urn:ietf:params:xml:ns:yang:ietf-inet-types", 'prefix': "inet"
    },
    'ietf-yang-types@2013-07-15': {
        'ns': "urn:ietf:params:xml:ns:yang:ietf-yang-types", 'prefix': "yang"
    }
}
"""The imported YANG modules for this module."""


M_FEATURES = ('ipv6-privacy-autoconf',)
"""The supported features declared in YANG for this module."""


IF_NS = "urn:ietf:params:xml:ns:yang:ietf-interfaces"
"""The namespace of the ietf-interfaces module."""


M_AUGMENTS = (IF_NS,)
"""The namespaces that this YANG module augments."""


def _get_ifaces(node):
    """Retrieve the /if:interfaces node."""
    ifaces = node.find('{'+IF_NS+'}interfaces')
    if ifaces is None:
        LOGGER.error(_("interfaces node not found: "
                       "This module requires ietf-interfaces to be loaded"))

    return ifaces


def _get_nmsa():
    """Retrieve our NMSA module handle."""
    nmsa_ns = "http://netconf.adelielinux.org/ns/netmgmt"
    nmsa = MODMAN._module_for_ns(nmsa_ns)  # pylint: disable=W0212

    return nmsa


def from_bool(value: bool) -> str:
    """Turn a Python bool into an XML bool."""
    return str(value).lower()


def _add_ipv4(iface, getter):
    """Add IPv4 configuration nodes."""
    name = iface.find('{'+IF_NS+'}name').text
    ipv4 = util.subelm(iface, 'ip:ipv4')
    #ipv4.append(util.leaf_elm('ip:enabled',
    #                          from_bool(getter(name, 'ipv4_enabled'))))
    ipv4.append(util.leaf_elm('ip:forwarding',
                              from_bool(getter(name, 'ipv4_forwarding'))))
    v4mtu = getter(name, 'ipv4_mtu')
    if v4mtu is not None:
        ipv4.append(util.leaf_elm('ip:mtu', v4mtu - 28))

    return ipv4


def _add_ipv6(iface, getter):
    """Add IPv6 configuration nodes."""
    name = iface.find('{'+IF_NS+'}name').text
    ipv6 = util.subelm(iface, 'ip:ipv6')
    ipv6.append(util.leaf_elm('ip:enabled',
                              from_bool(getter(name, 'ipv6_enabled'))))
    ipv6.append(util.leaf_elm('ip:forwarding',
                              from_bool(getter(name, 'ipv6_forwarding'))))
    v6mtu = getter(name, 'ipv6_mtu')
    if v6mtu is not None:
        ipv6.append(util.leaf_elm('ip:mtu', v6mtu))
    ipv6.append(
        util.leaf_elm('ip:dup-addr-detect-transmits',
                      getter(name, 'ipv6_dad_xmit'))
    )
    if any((getter(name, 'ipv6_slaac_globaladdr'),
            getter(name, 'ipv6_slaac_tempaddr'))):
        autoconf = util.subelm(ipv6, 'ip:autoconf')
        autoconf.append(util.leaf_elm('ip:create-global-addresses',
                                      from_bool(
                                          getter(name, 'ipv6_slaac_globaladdr')
                                      )))
        autoconf.append(util.leaf_elm('ip:create-temporary-addresses',
                                      from_bool(
                                          getter(name, 'ipv6_slaac_tempaddr')
                                      )))
        autoconf.append(util.leaf_elm('ip:temporary-valid-lifetime',
                                      getter(name, 'ipv6_slaac_validlft')))
        autoconf.append(util.leaf_elm('ip:temporary-preferred-lifetime',
                                      getter(name, 'ipv6_slaac_preflft')))

    return ipv6


def running(node):
    """Retrieve the IP configuration for this device."""
    ifaces = _get_ifaces(node)
    nmsa = _get_nmsa()

    if None in (ifaces, nmsa):
        # We can't retrieve configuration unless both the ietf-interfaces and
        # the NMSA module is loaded.
        return

    for iface in ifaces.iterchildren():
        name = iface.find('{'+IF_NS+'}name').text

        # IPv4
        ipv4 = _add_ipv4(iface, nmsa.get_param)
        for address in nmsa.list_addresses(name):
            # Only IPv4 addresses count.
            if '.' not in address:
                continue

            ipaddr, subnet = address.split('/')

            addr = util.subelm(ipv4, 'ip:address')
            addr.append(util.leaf_elm('ip:ip', ipaddr))
            addr.append(util.leaf_elm('ip:prefix-length', subnet))
        # No neighbor support.

        # IPv6
        ipv6 = _add_ipv6(iface, nmsa.get_param)
        for address in nmsa.list_addresses(name):
            # Only IPv6 addesses count.
            if ':' not in address:
                continue

            ipaddr, length = address.split('/')

            addr = util.subelm(ipv6, 'ip:address')
            addr.append(util.leaf_elm('ip:ip', ipaddr))
            addr.append(util.leaf_elm('ip:prefix-length', length))
        # No neighbor support.


def operational(node):
    """Retrieve the IP state for this device."""
    ifaces = _get_ifaces(node)
    nmsa = _get_nmsa()

    if None in (ifaces, nmsa):
        # We can't retrieve configuration unless both the ietf-interfaces and
        # the NMSA module is loaded.
        return

    for iface in ifaces.iterchildren():
        # IPv4
        _add_ipv4(iface, nmsa.curr_param)
        # IPv6
        _add_ipv6(iface, nmsa.curr_param)


def edit(session, rpc, node, def_op):
    """Edit the IP configuration for this device."""