#   Copyright 2013 Nebula 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.
#

"""OpenStackClient Plugin interface"""

import json
import logging
import uuid
import websocket

from osc_lib import utils
from swiftclient import client as swift_client

LOG = logging.getLogger(__name__)

DEFAULT_TRIPLEOCLIENT_API_VERSION = '1'

# Required by the OSC plugin interface
API_NAME = 'tripleoclient'
API_VERSION_OPTION = 'os_tripleoclient_api_version'
API_VERSIONS = {
    '1': 'tripleoclient.plugin'
}


def make_client(instance):
    return ClientWrapper(instance)


# Required by the OSC plugin interface
def build_option_parser(parser):
    """Hook to add global options

    Called from openstackclient.shell.OpenStackShell.__init__()
    after the builtin parser has been initialized.  This is
    where a plugin can add global options such as an API version setting.

    :param argparse.ArgumentParser parser: The parser object that has been
        initialized by OpenStackShell.
    """
    parser.add_argument(
        '--os-tripleoclient-api-version',
        metavar='<tripleoclient-api-version>',
        default=utils.env(
            'OS_TRIPLEOCLIENT_API_VERSION',
            default=DEFAULT_TRIPLEOCLIENT_API_VERSION),
        help='TripleO Client API version, default=' +
             DEFAULT_TRIPLEOCLIENT_API_VERSION +
             ' (Env: OS_TRIPLEOCLIENT_API_VERSION)')
    return parser


class WebsocketClient(object):

    def __init__(self, instance, queue_name):
        self._project_id = None
        self._ws = None
        self._websocket_client_id = None
        self._queue_name = queue_name

        endpoint = instance.get_endpoint_for_service_type(
            'messaging-websocket')
        token = instance.auth.get_token(instance.session)

        self._project_id = instance.auth_ref.project_id

        self._websocket_client_id = str(uuid.uuid4())

        LOG.debug('Instantiating messaging websocket client: %s', endpoint)
        self._ws = websocket.create_connection(endpoint)

        self.send('authenticate', extra_headers={'X-Auth-Token': token})

        # create and subscribe to a queue
        # NOTE: if the queue exists it will 204
        self.send('queue_create', {'queue_name': queue_name})
        self.send('subscription_create', {
            'queue_name': queue_name,
            'ttl': 10000
        })

    def cleanup(self):
        self.send('queue_delete', {'queue_name': self._queue_name})
        self._ws.close()

    def send(self, action, body=None, extra_headers=None):

        headers = {
            'Client-ID': self._websocket_client_id,
            'X-Project-ID': self._project_id
        }

        if extra_headers is not None:
            headers.update(extra_headers)

        msg = {'action': action, 'headers': headers}
        if body:
            msg['body'] = body
        self._ws.send(json.dumps(msg))
        data = self.recv()
        if data['headers']['status'] not in (200, 201, 204):
            raise RuntimeError(data)
        return data

    def recv(self):
        return json.loads(self._ws.recv())

    def wait_for_message(self, execution_id):
        """Wait for a message for a mistral execution ID

        This blocks until a message is received on the provided queue name
        with the execution ID.

        TODO(d0ugal): Add a timeout/break for the case when a message is
                      never arrives.
        """
        while True:
            body = self.recv()['body']
            if body['payload']['execution']['id'] == execution_id:
                return body['payload']

    def __enter__(self):
        """Return self to allow usage as a context manager"""
        return self

    def __exit__(self, *exc):
        """Call cleanup when exiting the context manager"""
        self.cleanup()


class ClientWrapper(object):

    def __init__(self, instance):
        self._instance = instance
        self._object_store = None

    def messaging_websocket(self, queue_name='tripleo'):
        """Returns a websocket for the messaging service"""
        return WebsocketClient(self._instance, queue_name)

    @property
    def object_store(self):
        """Returns an object_store service client

        The Swift/Object client returned by python-openstack client isn't an
        instance of python-swiftclient, and had far less functionality.
        """

        if self._object_store is not None:
            return self._object_store

        endpoint = self._instance.get_endpoint_for_service_type(
            "object-store",
            region_name=self._instance._region_name,
        )

        token = self._instance.auth.get_token(self._instance.session)

        kwargs = {
            'preauthurl': endpoint,
            'preauthtoken': token
        }

        self._object_store = swift_client.Connection(**kwargs)
        return self._object_store