#
# Copyright (c) 2022 Pim van Pelt
#
# 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 logging
import config.lcp as lcp
import config.address as address
import config.mac as mac

def get_loopbacks(yaml):
    """ Return a list of all loopbacks. """
    ret = []
    if 'loopbacks' in yaml:
        for ifname, iface in yaml['loopbacks'].items():
            ret.append(ifname)
    return ret


def get_by_lcp_name(yaml, lcpname):
    """ Returns the loopback by a given lcp name, or None,None if it does not exist """
    if not 'loopbacks' in yaml:
        return None,None
    for ifname, iface in yaml['loopbacks'].items():
        if 'lcp' in iface and iface['lcp'] == lcpname:
            return ifname, iface
    return None,None


def get_by_name(yaml, ifname):
    """ Return the loopback by name, if it exists. Return None otherwise. """
    try:
        if ifname in yaml['loopbacks']:
            return ifname, yaml['loopbacks'][ifname]
    except:
        pass
    return None, None


def is_loopback(yaml, ifname):
    """ Returns True if the interface name is an existing loopback. """
    ifname, iface = get_by_name(yaml, ifname)
    return not iface == None


def validate_loopbacks(yaml):
    result = True
    msgs = []
    logger = logging.getLogger('vppcfg.config')
    logger.addHandler(logging.NullHandler())

    if not 'loopbacks' in yaml:
        return result, msgs

    for ifname, iface in yaml['loopbacks'].items():
        logger.debug("loopback %s" % iface)
        instance = int(ifname[4:])
        if instance > 4095:
            msgs.append("loopback %s has instance %d which is too large" % (ifname, instance))
            result = False
        if 'lcp' in iface and not lcp.is_unique(yaml, iface['lcp']):
            msgs.append("loopback %s does not have a unique LCP name %s" % (ifname, iface['lcp']))
            result = False
        if 'addresses' in iface:
            for a in iface['addresses']:
                if not address.is_allowed(yaml, ifname, iface['addresses'], a):
                    msgs.append("loopback %s IP address %s conflicts with another" % (ifname, a))
                    result = False
        if 'mac' in iface and mac.is_multicast(iface['mac']):
            msgs.append("loopback %s MAC address %s cannot be multicast" % (ifname, iface['mac']))
            result = False

    return result, msgs