# 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 os

from oslo_config import cfg
from oslo_log import log
from oslo_service import systemd
from oslo_service import wsgi as oslo_wsgi
import stevedore

from sahara.api import acl
from sahara import config
from sahara.i18n import _LI
from sahara.i18n import _LW
from sahara.plugins import base as plugins_base
from sahara.service import api as service_api
from sahara.service.edp import api as edp_api
from sahara.service import ops as service_ops
from sahara.service import periodic
from sahara.utils.openstack import cinder
from sahara.utils import remote
from sahara.utils import rpc as messaging
from sahara.utils import wsgi

LOG = log.getLogger(__name__)


opts = [
    cfg.StrOpt('os_region_name',
               help='Region name used to get services endpoints.'),
    cfg.StrOpt('infrastructure_engine',
               default='heat',
               help='An engine which will be used to provision '
                    'infrastructure for Hadoop cluster.'),
    cfg.StrOpt('remote',
               default='ssh',
               help='A method for Sahara to execute commands '
                    'on VMs.'),
    cfg.IntOpt('api_workers', default=0,
               help="Number of workers for Sahara API service (0 means "
                    "all-in-one-thread configuration).")
]

CONF = cfg.CONF
CONF.register_opts(opts)


def setup_common(possible_topdir, service_name):
    dev_conf = os.path.join(possible_topdir,
                            'etc',
                            'sahara',
                            'sahara.conf')
    config_files = None
    if os.path.exists(dev_conf):
        config_files = [dev_conf]

    config.parse_configs(config_files)
    log.setup(CONF, "sahara")

    # Validate other configurations (that may produce logs) here
    cinder.validate_config()

    if service_name != 'all-in-one' or cfg.CONF.enable_notifications:
        messaging.setup()

    plugins_base.setup_plugins()

    LOG.info(_LI('Sahara {service} started').format(service=service_name))


def setup_sahara_api(mode):
    ops = _get_ops_driver(mode)

    service_api.setup_service_api(ops)
    edp_api.setup_edp_api(ops)


def setup_sahara_engine():
    periodic.setup()

    engine = _get_infrastructure_engine()
    service_ops.setup_ops(engine)

    remote_driver = _get_remote_driver()
    remote.setup_remote(remote_driver, engine)


def setup_auth_policy():
    acl.setup_policy()


def make_app():
    app_loader = oslo_wsgi.Loader(CONF)
    return app_loader.load_app("sahara")


def _load_driver(namespace, name):
    extension_manager = stevedore.DriverManager(
        namespace=namespace,
        name=name,
        invoke_on_load=True
    )
    LOG.info(_LI("Driver {name} successfully loaded").format(name=name))

    return extension_manager.driver


def _get_infrastructure_engine():
    """Import and return one of sahara.service.*_engine.py modules."""

    LOG.debug("Infrastructure engine {engine} is loading".format(
        engine=CONF.infrastructure_engine))

    if CONF.infrastructure_engine == "direct":
        LOG.warning(_LW("Direct infrastructure engine is deprecated in Liberty"
                        " release and will be removed after that release."
                        " Use Heat infrastructure engine instead."))

    return _load_driver('sahara.infrastructure.engine',
                        CONF.infrastructure_engine)


def _get_remote_driver():
    LOG.debug("Remote {remote} is loading".format(remote=CONF.remote))

    return _load_driver('sahara.remote', CONF.remote)


def _get_ops_driver(driver_name):
    LOG.debug("Ops {driver} is loading".format(driver=driver_name))

    return _load_driver('sahara.run.mode', driver_name)


def start_server(app):
    server = wsgi.Server()
    server.start(app)
    systemd.notify_once()
    server.wait()