import os
import sys
from multiprocessing.pool import ThreadPool
from functools import partial
from contextlib import contextmanager
from keystoneauth1.session import Session as KeystoneSession
from keystoneclient.auth.identity.v3 import Password as PasswordClient
from neutronclient.neutron.client import Client as NeutronClient


def get_session_keystone_session():
    return KeystoneSession(
        auth=PasswordClient(
            auth_url=os.environ['OS_AUTH_URL'],
            username=os.environ['OS_USERNAME'],
            password=os.environ['OS_PASSWORD'],
            project_name=os.environ.get('OS_PROJECT_NAME', 'admin'),
            user_domain_id=os.environ.get('OS_USER_DOMAIN_ID', 'default'),
            project_domain_id=os.environ.get('OS_PROJECT_DOMAIN_ID',
                                             'default')
        )
    )


def get_neutron_client():
    return NeutronClient(
        '2.0',
        session=get_session_keystone_session(),
        region_name=os.environ['OS_REGION_NAME'],
        endpoint_type=os.environ.get('OS_ENDPOINT_TYPE', 'adminURL'),
    )


def add_tag(network_id, client, tag):
    client.add_tag('networks', network_id, tag)
    return network_id, neutron.show_network(network_id)['network']['tags']


def remove_tag(network_id, client, tag):
    client.remove_tag('networks', network_id, tag)
    return network_id, neutron.show_network(network_id)['network']['tags']


@contextmanager
def poolcontext(*args, **kwargs):
    pool = ThreadPool(*args, **kwargs)
    yield pool
    pool.terminate()


ACTION = {
    'add': add_tag,
    'remove': remove_tag,
}


if __name__ == '__main__':
    if len(sys.argv) < 4:
        print('Usage: %s <file> <action> <tag>' % sys.argv[0])
        sys.exit(1)
    if sys.argv[2] not in ACTION.keys():
        print('Action may be only: %s' % ACTION.keys())
        sys.exit(1)
    neutron = get_neutron_client()
    with open(sys.argv[1]) as f:
        networks = f.read().splitlines()
    with poolcontext(processes=10) as pool:
        results = pool.map(partial(ACTION[sys.argv[2]], client=neutron,
                                   tag=sys.argv[3]),
                           networks)
    print(results)