#!/usr/bin/env python
# Copyright 2014, Rackspace US, Inc.
#
# 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.

DOCUMENTATION='''
---
module: neutron
short_description:
    - Basic module for interacting with openstack neutron
description:
    - Basic module for interacting with openstack neutron
options:
    command:
        description:
            - Operation for the module to perform. Currently available
        choices:
            - create_network_with_subnet
    openrc_path:
        decription:
            - Path to openrc file from which credentials and keystone endpoint will be extracted
    network_name:
        description:
            - Name of the image to create
    cidr:
        description:
            - cidr to use for the subnet
author: Hugh Saunders
'''

EXAMPLES = '''
# Create a subnet with parent network
- name: Ensure tempest network exists
  neutron:
    command: create_network_with_subnet
    openrc_path: /root/openrc
    network_name: tempest
    cidr: "192.168.74.0/24"
'''

import re
import keystoneclient.v2_0.client as ksclient
from neutronclient.neutron import client as nclient

COMMAND_MAP = {'create_network_with_subnet': 'create_subnet'}

class ManageNeutron(object):
    def __init__(self, module):
        self.state_change = False
        self.neutron = None
        self.keystone = None
        self.module = module
        try:
            self._keystone_authenticate()
            self._init_neutron()
        except Exception as e:
            self.module.fail_json(
                err="Initialisation Error: %s" % e,
                rc=2, msg=str(e))

    def _parse_openrc(self):
        """ Get credentials from an openrc file """
        openrc_path = self.module.params['openrc_path']
        line_re = re.compile('^export (?P<key>OS_\w*)=(?P<value>[^\n]*)')
        with open(openrc_path) as openrc:
            matches = [line_re.match(l) for l in openrc]
            return dict(
                (g.groupdict()['key'], g.groupdict()['value'])
                    for g in matches if g)

    def _keystone_authenticate(self):
        """ Authenticate with Keystone """
        openrc = self._parse_openrc()
        self.keystone = ksclient.Client(username=openrc['OS_USERNAME'],
                                        password=openrc['OS_PASSWORD'],
                                        tenant_name=openrc['OS_TENANT_NAME'],
                                        auth_url=openrc['OS_AUTH_URL'])

    def _init_neutron(self):
        """ Create neutron client object using token and url from keystone """
        self.neutron = nclient.Client(
            '2.0',
            endpoint_url=self.keystone.service_catalog.url_for(
                service_type='network'),
            token=self.keystone.get_token(self.keystone.session))

    def route(self):
        """ Run the command specified by the command parameter """
        getattr(self, COMMAND_MAP[self.module.params['command']])()

    def create_network(self):
        name = self.module.params['name']
        if not self.neutron.list_networks(name=name)['networks']:
            # network doesn't exist, create it
            self.state_change = True
            self.neutron.create_network(
                    {"network": {"name": name, "admin_state_up": True}})

    def _get_network_by_name(self, name):
        return self.neutron.list_networks(name=name)['networks'][0]

    def create_subnet(self, network_id=None):
        name = self.module.params['name']
        cidr = self.module.params['cidr']
        if network_id is None:
            self.create_network()
            network_id = self._get_network_by_name(name)['id']
        if not self.neutron.list_subnets(
                cidr=cidr, network_id=network_id)['subnets']:
            # subnet doesn't exist, create it
            self.state_change = True
            self.neutron.create_subnet(
                    {"subnet": {"cidr": cidr,
                                "ip_version": 4,
                                "network_id": network_id}})
        self.module.exit_json(
            changed=self.state_change,
            ansible_facts=dict(neutron=self._get_network_facts()))

    def _get_network_facts(self):
        facts={}
        facts['networks']=self.neutron.list_networks()['networks']
        facts['subnets']=self.neutron.list_subnets()['subnets']
        return facts


def main():
    module = AnsibleModule(
        argument_spec=dict(
            command=dict(required=True, choices=COMMAND_MAP.keys()),
            openrc_path=dict(required=True),
            name=dict(required=True),
            cidr=dict(required=True),
        ),
        supports_check_mode=False
    )
    mg = ManageNeutron(module)
    mg.route()

from ansible.module_utils.basic import *
if __name__ == '__main__':
    main()