# Copyright 2018 VyOS maintainers and contributors <maintainers@vyos.io>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library.  If not, see <http://www.gnu.org/licenses/>.

import re
import json

import netifaces


intf_type_data_file = '/usr/share/vyos/interface-types.json'

def list_interfaces():
    interfaces = netifaces.interfaces()

    # Remove "fake" interfaces associated with drivers
    for i in ["dummy0", "ip6tnl0", "tunl0", "ip_vti0", "ip6_vti0"]:
        try:
            interfaces.remove(i)
        except ValueError:
            pass

    return interfaces

def list_interfaces_of_type(typ):
    with open(intf_type_data_file, 'r') as f:
        types_data = json.load(f)

    all_intfs = list_interfaces()
    if not (typ in types_data.keys()):
        raise ValueError("Unknown interface type: {0}".format(typ))
    else:
        r = re.compile('^{0}\d+'.format(types_data[typ]))
        return list(filter(lambda i: re.match(r, i), all_intfs))

def get_type_of_interface(intf):
    with open(intf_type_data_file, 'r') as f:
        types_data = json.load(f)

    for key,val in types_data.items():
        r = re.compile('^{0}\d+'.format(val))
        if re.match(r, intf):
            return key

    raise ValueError("No type found for interface name: {0}".format(intf))