# Copyright (c) 2014, Oracle and/or its affiliates. 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.
"""
ZFS Storage Appliance Cinder Volume Driver
"""
import base64

from cinder import exception
from cinder.openstack.common import log
from cinder.volume import driver
from oslo.config import cfg

from cinder.volume.drivers.zfssa import zfssarest


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

ZFSSA_OPTS = [
    cfg.StrOpt('zfssa_host', required=True,
               help='ZFSSA management IP address'),
    cfg.StrOpt('zfssa_auth_user', required=True, secret=True,
               help='ZFSSA management authorized user\'s name'),
    cfg.StrOpt('zfssa_auth_password', required=True, secret=True,
               help='ZFSSA management authorized user\'s password'),
    cfg.StrOpt('zfssa_pool', required=True,
               help='ZFSSA storage pool name'),
    cfg.StrOpt('zfssa_project', required=True,
               help='ZFSSA project name'),
    cfg.StrOpt('zfssa_lun_volblocksize', default='8k',
               help='Block size: 512, 1k, 2k, 4k, 8k, 16k, 32k, 64k, 128k'),
    cfg.BoolOpt('zfssa_lun_sparse', default=False,
                help='Flag to enable sparse (thin-provisioned): True, False'),
    cfg.StrOpt('zfssa_lun_compression', default='',
               help='Data compression-off, lzjb, gzip-2, gzip, gzip-9'),
    cfg.StrOpt('zfssa_lun_logbias', default='',
               help='Synchronous write bias-latency, throughput'),
    cfg.StrOpt('zfssa_initiator_group', default='',
               help='iSCSI initiator group'),
    cfg.StrOpt('zfssa_initiator', default='',
               help='iSCSI initiator IQNs (comma separated)'),
    cfg.StrOpt('zfssa_initiator_user', default='',
               help='iSCSI initiator CHAP user'),
    cfg.StrOpt('zfssa_initiator_password', default='',
               help='iSCSI initiator CHAP password'),
    cfg.StrOpt('zfssa_target_group', default='tgt-grp',
               help='iSCSI target group name'),
    cfg.StrOpt('zfssa_target_user', default='',
               help='iSCSI target CHAP user'),
    cfg.StrOpt('zfssa_target_password', default='',
               help='iSCSI target CHAP password'),
    cfg.StrOpt('zfssa_target_portal', required=True,
               help='iSCSI target portal (Data-IP:Port, w.x.y.z:3260)'),
    cfg.StrOpt('zfssa_target_interfaces', required=True,
               help='Network interfaces of iSCSI targets (comma separated)')
]

CONF.register_opts(ZFSSA_OPTS)

SIZE_GB = 1073741824


#pylint: disable=R0904
class ZFSSAISCSIDriver(driver.ISCSIDriver):
    """ZFSSA Cinder volume driver"""

    VERSION = '1.0.0'
    protocol = 'iSCSI'

    def __init__(self, *args, **kwargs):
        super(ZFSSAISCSIDriver, self).__init__(*args, **kwargs)
        self.configuration.append_config_values(ZFSSA_OPTS)
        self.zfssa = None
        self._stats = None

    def _get_target_alias(self):
        """return target alias"""
        return self.configuration.zfssa_target_group

    def do_setup(self, context):
        """Setup - create project, initiators, initiatorgroup, target,
                   targetgroup
        """
        self.configuration._check_required_opts()
        lcfg = self.configuration

        LOG.info('Connecting to host: %s' % lcfg.zfssa_host)
        self.zfssa = zfssarest.ZFSSAApi(lcfg.zfssa_host)
        auth_str = base64.encodestring('%s:%s' %
                                       (lcfg.zfssa_auth_user,
                                        lcfg.zfssa_auth_password))[:-1]
        self.zfssa.login(auth_str)
        self.zfssa.create_project(lcfg.zfssa_pool, lcfg.zfssa_project,
                                  compression=lcfg.zfssa_lun_compression,
                                  logbias=lcfg.zfssa_lun_logbias)

        if (lcfg.zfssa_initiator != '' and
            (lcfg.zfssa_initiator_group == '' or
             lcfg.zfssa_initiator_group == 'default')):
            LOG.warning('zfssa_initiator= %s wont be used on \
                        zfssa_initiator_group= %s' %
                        (lcfg.zfssa_initiator,
                         lcfg.zfssa_initiator_group))

        # Setup initiator and initiator group
        if lcfg.zfssa_initiator != '' and \
           lcfg.zfssa_initiator_group != '' and \
           lcfg.zfssa_initiator_group != 'default':
            for initiator in lcfg.zfssa_initiator.split(','):
                self.zfssa.create_initiator(initiator,
                                            lcfg.zfssa_initiator_group + '-' +
                                            initiator,
                                            chapuser=
                                            lcfg.zfssa_initiator_user,
                                            chapsecret=
                                            lcfg.zfssa_initiator_password)
                self.zfssa.add_to_initiatorgroup(initiator,
                                                 lcfg.zfssa_initiator_group)
        # Parse interfaces
        interfaces = []
        for interface in lcfg.zfssa_target_interfaces.split(','):
            if interface == '':
                continue
            interfaces.append(interface)

        # Setup target and target group
        iqn = self.zfssa.create_target(
            self._get_target_alias(),
            interfaces,
            tchapuser=lcfg.zfssa_target_user,
            tchapsecret=lcfg.zfssa_target_password)

        self.zfssa.add_to_targetgroup(iqn, lcfg.zfssa_target_group)

    def check_for_setup_error(self):
        """Check that driver can login and pool, project, initiators,
           initiatorgroup, target, targetgroup exist
        """
        lcfg = self.configuration

        self.zfssa.verify_pool(lcfg.zfssa_pool)
        self.zfssa.verify_project(lcfg.zfssa_pool, lcfg.zfssa_project)

        if lcfg.zfssa_initiator != '' and \
           lcfg.zfssa_initiator_group != '' and \
           lcfg.zfssa_initiator_group != 'default':
            for initiator in lcfg.zfssa_initiator.split(','):
                self.zfssa.verify_initiator(initiator)

            self.zfssa.verify_target(self._get_target_alias())

    def _get_provider_info(self, volume):
        """return provider information"""
        lcfg = self.configuration
        lun = self.zfssa.get_lun(lcfg.zfssa_pool,
                                 lcfg.zfssa_project, volume['name'])
        iqn = self.zfssa.get_target(self._get_target_alias())
        loc = "%s %s %s" % (lcfg.zfssa_target_portal, iqn, lun['number'])
        LOG.debug('_export_volume: provider_location: %s' % loc)
        provider = {'provider_location': loc}
        if lcfg.zfssa_target_user != '' and lcfg.zfssa_target_password != '':
            provider['provider_auth'] = 'CHAP %s %s' % \
                                        (lcfg.zfssa_target_user,
                                         lcfg.zfssa_target_password)
        return provider

    def create_volume(self, volume):
        """Create a volume on ZFSSA"""
        LOG.debug('zfssa.create_volume: volume=' + volume['name'])
        lcfg = self.configuration
        volsize = str(volume['size']) + 'g'
        self.zfssa.create_lun(lcfg.zfssa_pool,
                              lcfg.zfssa_project,
                              volume['name'],
                              volsize,
                              targetgroup=lcfg.zfssa_target_group,
                              volblocksize=lcfg.zfssa_lun_volblocksize,
                              sparse=lcfg.zfssa_lun_sparse,
                              compression=lcfg.zfssa_lun_compression,
                              logbias=lcfg.zfssa_lun_logbias)

        return self._get_provider_info(volume)

    def delete_volume(self, volume):
        """Deletes a volume with the given volume['name']."""
        LOG.debug('zfssa.delete_volume: name=' + volume['name'])
        lcfg = self.configuration
        lun2del = self.zfssa.get_lun(lcfg.zfssa_pool,
                                     lcfg.zfssa_project,
                                     volume['name'])
        """Delete clone's temp snapshot. see create_cloned_volume()"""
        """clone is deleted as part of the snapshot delete."""
        tmpsnap = 'tmp-snapshot-%s' % volume['id']
        if 'origin' in lun2del and lun2del['origin']['snapshot'] == tmpsnap:
            self.zfssa.delete_snapshot(lcfg.zfssa_pool,
                                       lcfg.zfssa_project,
                                       lun2del['origin']['share'],
                                       lun2del['origin']['snapshot'])
            return

        self.zfssa.delete_lun(pool=lcfg.zfssa_pool,
                              project=lcfg.zfssa_project,
                              lun=volume['name'])

    def create_snapshot(self, snapshot):
        """Creates a snapshot with the given snapshot['name'] of the
           snapshot['volume_name']
        """
        LOG.debug('zfssa.create_snapshot: snapshot=' + snapshot['name'])
        lcfg = self.configuration
        self.zfssa.create_snapshot(lcfg.zfssa_pool,
                                   lcfg.zfssa_project,
                                   snapshot['volume_name'],
                                   snapshot['name'])

    def delete_snapshot(self, snapshot):
        """Deletes a snapshot."""
        LOG.debug('zfssa.delete_snapshot: snapshot=' + snapshot['name'])
        lcfg = self.configuration
        has_clones = self.zfssa.has_clones(lcfg.zfssa_pool,
                                           lcfg.zfssa_project,
                                           snapshot['volume_name'],
                                           snapshot['name'])
        if has_clones:
            LOG.error('snapshot %s: has clones' % snapshot['name'])
            raise exception.SnapshotIsBusy(snapshot_name=snapshot['name'])

        self.zfssa.delete_snapshot(lcfg.zfssa_pool,
                                   lcfg.zfssa_project,
                                   snapshot['volume_name'],
                                   snapshot['name'])

    def create_volume_from_snapshot(self, volume, snapshot):
        """Creates a volume from a snapshot - clone a snapshot"""
        LOG.debug('zfssa.create_volume_from_snapshot: volume=' +
                  volume['name'])
        LOG.debug('zfssa.create_volume_from_snapshot: snapshot=' +
                  snapshot['name'])
        if not self._verify_clone_size(snapshot, volume['size'] * SIZE_GB):
            exception_msg = (_('Error verifying clone size on '
                               'Volume clone: %(clone)s '
                               'Size: %(size)d on'
                               'Snapshot: %(snapshot)s')
                             % {'clone': volume['name'],
                                'size': volume['size'],
                                'snapshot': snapshot['name']})
            LOG.error(exception_msg)
            raise exception.InvalidInput(reason=exception_msg)

        lcfg = self.configuration
        self.zfssa.clone_snapshot(lcfg.zfssa_pool,
                                  lcfg.zfssa_project,
                                  snapshot['volume_name'],
                                  snapshot['name'],
                                  volume['name'])

    def _update_volume_status(self):
        """Retrieve status info from volume group."""
        LOG.debug("Updating volume status")
        self._stats = None
        data = {}
        data["volume_backend_name"] = self.__class__.__name__
        data["vendor_name"] = 'Oracle'
        data["driver_version"] = self.VERSION
        data["storage_protocol"] = self.protocol

        lcfg = self.configuration
        (avail, used) = self.zfssa.get_pool_stats(lcfg.zfssa_pool)
        if avail is None or used is None:
            return
        total = int(avail) + int(used)

        if lcfg.zfssa_lun_sparse:
            data['total_capacity_gb'] = 'infinite'
        else:
            data['total_capacity_gb'] = total / SIZE_GB
        data['free_capacity_gb'] = int(avail) / SIZE_GB
        data['reserved_percentage'] = 0
        data['QoS_support'] = False
        self._stats = data

    def get_volume_stats(self, refresh=False):
        """Get volume status.
           If 'refresh' is True, run update the stats first.
        """
        if refresh:
            self._update_volume_status()
        return self._stats

    def _export_volume(self, volume):
        """Export the volume - set the initiatorgroup property."""
        LOG.debug('_export_volume: volume name: %s' % volume['name'])
        lcfg = self.configuration

        self.zfssa.set_lun_initiatorgroup(lcfg.zfssa_pool,
                                          lcfg.zfssa_project,
                                          volume['name'],
                                          lcfg.zfssa_initiator_group)
        return self._get_provider_info(volume)

    def create_export(self, context, volume):
        """Driver entry point to get the  export info for a new volume."""
        LOG.debug('create_export: volume name: %s' % volume['name'])
        return self._export_volume(volume)

    def remove_export(self, context, volume):
        """Driver entry point to remove an export for a volume."""
        LOG.debug('remove_export: volume name: %s' % volume['name'])
        lcfg = self.configuration
        self.zfssa.set_lun_initiatorgroup(lcfg.zfssa_pool,
                                          lcfg.zfssa_project,
                                          volume['name'],
                                          '')

    def ensure_export(self, context, volume):
        """Driver entry point to get the export info for an existing volume."""
        LOG.debug('ensure_export: volume name: %s' % volume['name'])
        return self._export_volume(volume)

    def copy_image_to_volume(self, context, volume, image_service, image_id):
        self.ensure_export(context, volume)
        super(ZFSSAISCSIDriver, self).copy_image_to_volume(
            context, volume, image_service, image_id)

    def extend_volume(self, volume, new_size):
        """Driver entry point to extent volume size."""
        LOG.debug('extend_volume: volume name: %s' % volume['name'])
        lcfg = self.configuration
        self.zfssa.set_lun_size(lcfg.zfssa_pool,
                                lcfg.zfssa_project,
                                volume['name'],
                                new_size * SIZE_GB)

    def _get_iscsi_properties(self, volume):
        lcfg = self.configuration
        lun = self.zfssa.get_lun(lcfg.zfssa_pool,
                                 lcfg.zfssa_project,
                                 volume['name'])
        iqn = self.zfssa.get_target(self._get_target_alias())

        return {'target_discovered': True,
                'target_iqn': iqn,
                'target_portal': lcfg.zfssa_target_portal,
                'volume_id': lun['number'],
                'access_mode': 'rw'}

    def create_cloned_volume(self, volume, src_vref):
        """Create a clone of the specified volume."""
        zfssa_snapshot = {'volume_name': src_vref['name'],
                          'name': 'tmp-snapshot-%s' % volume['id']}
        self.create_snapshot(zfssa_snapshot)
        try:
            self.create_volume_from_snapshot(volume, zfssa_snapshot)
        except exception.VolumeBackendAPIException:
            LOG.error("Clone Volume '%s' failed from source volume '%s'"
                      % (volume['name'], src_vref['name']))
            # Cleanup snapshot
            self.delete_snapshot(zfssa_snapshot)

    def local_path(self, volume):
        """Not implemented"""
        pass

    def backup_volume(self, context, backup, backup_service):
        """Not implemented"""
        pass

    def restore_backup(self, context, backup, volume, backup_service):
        """Not implemented"""
        pass

    def _verify_clone_size(self, snapshot, size):
        """Check whether the clone size is the same as the parent volume"""
        lcfg = self.configuration
        lun = self.zfssa.get_lun(lcfg.zfssa_pool,
                                 lcfg.zfssa_project,
                                 snapshot['volume_name'])
        return (lun['size'] == size)