#    Copyright (c) 2013 Mirantis, 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.

import uuid

from oslo import messaging
from oslo.messaging import localcontext
from oslo.messaging import serializer as msg_serializer
from oslo.messaging import target

from sqlalchemy import desc

from muranoapi.common import config
from muranoapi.db import models
from muranoapi.db import session
from muranoapi.openstack.common.gettextutils import _  # noqa
from muranoapi.openstack.common import log as logging
from muranoapi.openstack.common import timeutils
from muranocommon.helpers import token_sanitizer

RPC_SERVICE = None
NOTIFICATION_SERVICE = None

log = logging.getLogger(__name__)


class ResultEndpoint(object):
    @staticmethod
    def process_result(context, result):
        secure_result = token_sanitizer.TokenSanitizer().sanitize(result)
        log.debug(_('Got result from orchestration '
                    'engine:\n{0}'.format(secure_result)))

        if 'deleted' in result:
            log.debug(_('Result for environment {0} is dropped. Environment '
                        'is deleted'.format(result['id'])))
            return

        unit = session.get_session()
        environment = unit.query(models.Environment).get(result['id'])

        if not environment:
            log.warning(_('Environment result could not be handled, specified '
                          'environment was not found in database'))
            return

        environment.description = result
        environment.networking = result.get('networking', {})
        environment.version += 1
        environment.save(unit)

        #close session
        conf_session = unit.query(models.Session).filter_by(
            **{'environment_id': environment.id, 'state': 'deploying'}).first()
        conf_session.state = 'deployed'
        conf_session.save(unit)

        #close deployment
        deployment = get_last_deployment(unit, environment.id)
        deployment.finished = timeutils.utcnow()

        num_errors = unit.query(models.Status)\
            .filter_by(level='error', deployment_id=deployment.id).count()
        num_warnings = unit.query(models.Status)\
            .filter_by(level='warning', deployment_id=deployment.id).count()

        final_status_text = "Deployment finished"
        if num_errors:
            final_status_text += " with errors"

        elif num_warnings:
            final_status_text += " with warnings"

        status = models.Status()
        status.deployment_id = deployment.id
        status.text = final_status_text
        status.level = 'info'
        deployment.statuses.append(status)
        deployment.save(unit)


class ReportNotificationEndpoint(object):
    @staticmethod
    def report_notification(context, report):
        log.debug(_('Got report from orchestration '
                    'engine:\n{0}'.format(report)))

        report['entity_id'] = report['id']
        del report['id']

        status = models.Status()
        status.update(report)

        unit = session.get_session()
        #connect with deployment
        with unit.begin():
            running_deployment = get_last_deployment(unit,
                                                     status.environment_id)
            status.deployment_id = running_deployment.id
            unit.add(status)


class NotificationDispatcher(object):
    def __init__(self, srv_target, endpoints, serializer):
        self.endpoints = endpoints
        self.serializer = serializer or msg_serializer.NoOpSerializer()
        self._default_target = target.Target()
        self._target = srv_target

    def _listen(self, transport):
        return transport._listen(self._target)

    def _dispatch(self, endpoint, method, ctxt, payload):
        ctxt = self.serializer.deserialize_context(ctxt)
        result = getattr(endpoint, method)(ctxt, payload)
        return self.serializer.serialize_entity(ctxt, result)

    def __call__(self, ctxt, message):
        event_type = message.get('event_type')
        if not event_type.startswith('murano.'):
            return

        method = '{0}_notification'.format(event_type[7:])
        for endpoint in self.endpoints:
            if hasattr(endpoint, method):
                localcontext.set_local_context(ctxt)
                try:
                    payload = message.get('payload')
                    return self._dispatch(endpoint, method, ctxt, payload)
                finally:
                    localcontext.clear_local_context()

            msg = 'Could not find notification handler for event \'{0}\''
            raise Exception(msg.format(method))


def get_last_deployment(unit, env_id):
    query = unit.query(models.Deployment)\
        .filter_by(environment_id=env_id)\
        .order_by(desc(models.Deployment.started))
    return query.first()


def _prepare_rpc_service(server_id):
    endpoints = [ResultEndpoint()]

    transport = messaging.get_transport(config.CONF)
    s_target = target.Target('murano', 'results', server=server_id)
    return messaging.get_rpc_server(transport, s_target, endpoints, 'eventlet')


def _prepare_notification_service(server_id):
    endpoints = [ReportNotificationEndpoint()]

    transport = messaging.get_transport(config.CONF)
    s_target = target.Target(topic='notifications.info', server=server_id)
    dispatcher = NotificationDispatcher(s_target, endpoints, None)
    return messaging.MessageHandlingServer(transport, dispatcher, 'eventlet')


def get_rpc_service():
    global RPC_SERVICE

    if RPC_SERVICE is None:
        RPC_SERVICE = _prepare_rpc_service(str(uuid.uuid4()))
    return RPC_SERVICE


def get_notification_service():
    global NOTIFICATION_SERVICE

    if NOTIFICATION_SERVICE is None:
        NOTIFICATION_SERVICE = _prepare_notification_service(str(uuid.uuid4()))
    return NOTIFICATION_SERVICE