# Copyright (c) 2014 Huawei Technologies Co., Ltd.
# All Rights Reserved.
#
#    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.

"""Huawei Nas Driver for Huawei storage arrays."""
from xml.etree import ElementTree as ET

from oslo_config import cfg
from oslo_log import log
from oslo_utils import importutils

from manila import exception
from manila.i18n import _
from manila.share import driver


HUAWEI_UNIFIED_DRIVER_REGISTRY = {
    'V3': 'manila.share.drivers.huawei.v3.connection.V3StorageConnection', }


huawei_opts = [
    cfg.StrOpt('manila_huawei_conf_file',
               default='/etc/manila/manila_huawei_conf.xml',
               help='The configuration file for the Manila Huawei driver.')]

CONF = cfg.CONF
CONF.register_opts(huawei_opts)
LOG = log.getLogger(__name__)


class HuaweiNasDriver(driver.ShareDriver):
    """Huawei Share Driver.

    Executes commands relating to Shares.
    Driver version history:

        1.0 - Initial version.
        1.1 - Add shrink share.
              Add extend share.
              Add manage share.
              Add share level(ro).
              Add smartx capabilities.
              Support multi pools in one backend.
        1.2 - Add share server support.
              Add ensure share.
              Add QoS support.
              Add create share from snapshot.
        1.3 - Add manage snapshot.
              Support reporting disk type of pool.
              Add replication support.
    """

    def __init__(self, *args, **kwargs):
        """Do initialization."""
        LOG.debug("Enter into init function of Huawei Driver.")
        super(HuaweiNasDriver, self).__init__((True, False), *args, **kwargs)

        if not self.configuration:
            raise exception.InvalidInput(reason=_(
                "Huawei driver configuration missing."))

        self.configuration.append_config_values(huawei_opts)
        kwargs.pop('configuration')
        self.plugin = importutils.import_object(self.get_backend_driver(),
                                                self.configuration,
                                                **kwargs)

    def check_for_setup_error(self):
        """Returns an error if prerequisites aren't met."""
        self.plugin.check_conf_file()
        self.plugin.check_service()

    def get_backend_driver(self):
        filename = self.configuration.manila_huawei_conf_file

        try:
            tree = ET.parse(filename)
            root = tree.getroot()
        except Exception as err:
            message = (_('Read Huawei config file(%(filename)s)'
                         ' for Manila error: %(err)s')
                       % {'filename': filename,
                          'err': err})
            LOG.error(message)
            raise exception.InvalidInput(reason=message)
        product = root.findtext('Storage/Product')
        backend_driver = HUAWEI_UNIFIED_DRIVER_REGISTRY.get(product)
        if backend_driver is None:
            raise exception.InvalidInput(
                reason=_('Product %s is not supported. Product '
                         'must be set to V3.') % product)

        return backend_driver

    def do_setup(self, context):
        """Any initialization the huawei nas driver does while starting."""
        LOG.debug("Do setup the plugin.")
        self.plugin.connect()

    def create_share(self, context, share, share_server=None):
        """Create a share."""
        LOG.debug("Create a share.")
        location = self.plugin.create_share(share, share_server)
        return location

    def extend_share(self, share, new_size, share_server=None):
        LOG.debug("Extend a share.")
        self.plugin.extend_share(share, new_size, share_server)

    def create_share_from_snapshot(self, context, share, snapshot,
                                   share_server=None):
        """Create a share from snapshot."""
        LOG.debug("Create a share from snapshot %s.", snapshot['snapshot_id'])
        location = self.plugin.create_share_from_snapshot(share, snapshot)
        return location

    def shrink_share(self, share, new_size, share_server=None):
        """Shrinks size of existing share."""
        LOG.debug("Shrink a share.")
        self.plugin.shrink_share(share, new_size, share_server)

    def delete_share(self, context, share, share_server=None):
        """Delete a share."""
        LOG.debug("Delete a share.")
        self.plugin.delete_share(share, share_server)

    def create_snapshot(self, context, snapshot, share_server=None):
        """Create a snapshot."""
        LOG.debug("Create a snapshot.")
        snapshot_name = self.plugin.create_snapshot(snapshot, share_server)
        return {'provider_location': snapshot_name}

    def delete_snapshot(self, context, snapshot, share_server=None):
        """Delete a snapshot."""
        LOG.debug("Delete a snapshot.")
        self.plugin.delete_snapshot(snapshot, share_server)

    def ensure_share(self, context, share, share_server=None):
        """Ensure that share is exported."""
        LOG.debug("Ensure share.")
        location = self.plugin.ensure_share(share, share_server)
        return location

    def allow_access(self, context, share, access, share_server=None):
        """Allow access to the share."""
        LOG.debug("Allow access.")
        self.plugin.allow_access(share, access, share_server)

    def deny_access(self, context, share, access, share_server=None):
        """Deny access to the share."""
        LOG.debug("Deny access.")
        self.plugin.deny_access(share, access, share_server)

    def update_access(self, context, share, access_rules, add_rules,
                      delete_rules, share_server=None):
        """Update access rules list."""
        LOG.debug("Update access.")
        self.plugin.update_access(share, access_rules,
                                  add_rules, delete_rules, share_server)

    def get_pool(self, share):
        """Return pool name where the share resides on."""
        LOG.debug("Get pool.")
        return self.plugin.get_pool(share)

    def get_network_allocations_number(self):
        """Get number of network interfaces to be created."""
        LOG.debug("Get network allocations number.")
        return self.plugin.get_network_allocations_number()

    def manage_existing(self, share, driver_options):
        """Manage existing share."""
        LOG.debug("Manage existing share to manila.")
        share_size, location = self.plugin.manage_existing(share,
                                                           driver_options)
        return {'size': share_size, 'export_locations': location}

    def manage_existing_snapshot(self, snapshot, driver_options):
        """Manage existing snapshot."""
        LOG.debug("Manage existing snapshot to manila.")
        snapshot_name = self.plugin.manage_existing_snapshot(snapshot,
                                                             driver_options)
        return {'provider_location': snapshot_name}

    def _update_share_stats(self):
        """Retrieve status info from share group."""

        backend_name = self.configuration.safe_get('share_backend_name')
        data = dict(
            share_backend_name=backend_name or 'HUAWEI_NAS_Driver',
            vendor_name='Huawei',
            driver_version='1.3',
            storage_protocol='NFS_CIFS',
            qos=True,
            total_capacity_gb=0.0,
            free_capacity_gb=0.0,
            snapshot_support=self.plugin.snapshot_support,
        )

        # huawei array doesn't support snapshot replication, so driver can't
        # create replicated snapshot, this's not fit the requirement of
        # replication feature.
        # to avoid this problem, we specify huawei driver can't support
        # snapshot and replication both, as a workaround.
        if not data['snapshot_support'] and self.plugin.replication_support:
            data['replication_type'] = 'dr'

        self.plugin.update_share_stats(data)
        super(HuaweiNasDriver, self)._update_share_stats(data)

    def _setup_server(self, network_info, metadata=None):
        """Set up share server with given network parameters."""
        return self.plugin.setup_server(network_info, metadata)

    def _teardown_server(self, server_details, security_services=None):
        """Teardown share server."""
        return self.plugin.teardown_server(server_details, security_services)

    def create_replica(self, context, replica_list, new_replica,
                       access_rules, replica_snapshots, share_server=None):
        """Replicate the active replica to a new replica on this backend."""
        return self.plugin.create_replica(context,
                                          replica_list,
                                          new_replica,
                                          access_rules,
                                          replica_snapshots,
                                          share_server)

    def update_replica_state(self, context, replica_list, replica,
                             access_rules, replica_snapshots,
                             share_server=None):
        """Update the replica_state of a replica."""
        return self.plugin.update_replica_state(context,
                                                replica_list,
                                                replica,
                                                access_rules,
                                                replica_snapshots,
                                                share_server)

    def promote_replica(self, context, replica_list, replica, access_rules,
                        share_server=None):
        """Promote a replica to 'active' replica state.."""
        return self.plugin.promote_replica(context,
                                           replica_list,
                                           replica,
                                           access_rules,
                                           share_server)

    def delete_replica(self, context, replica_list, replica_snapshots,
                       replica, share_server=None):
        """Delete a replica."""
        self.plugin.delete_replica(context,
                                   replica_list,
                                   replica_snapshots,
                                   replica,
                                   share_server)
