# Copyright 2015, Hitachi Data Systems.
#
#    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.

"""
Data Service
"""

import os

from oslo_config import cfg
from oslo_log import log

from manila.common import constants
from manila import context
from manila.data import helper
from manila.data import utils as data_utils
from manila import exception
from manila import manager
from manila.share import rpcapi as share_rpc

from manila.i18n import _

LOG = log.getLogger(__name__)

data_opts = [
    cfg.StrOpt(
        'mount_tmp_location',
        default='/tmp/',
        help="Temporary path to create and mount shares during migration."),
    cfg.BoolOpt(
        'check_hash',
        default=False,
        help="Chooses whether hash of each file should be checked on data "
             "copying."),

]

CONF = cfg.CONF
CONF.register_opts(data_opts)


class DataManager(manager.Manager):
    """Receives requests to handle data and sends responses."""

    RPC_API_VERSION = '1.0'

    def __init__(self, service_name=None, *args, **kwargs):
        super(DataManager, self).__init__(*args, **kwargs)
        self.busy_tasks_shares = {}
        self.service_id = None

    def init_host(self, service_id=None):
        self.service_id = service_id
        ctxt = context.get_admin_context()
        shares = self.db.share_get_all(ctxt)
        for share in shares:
            if share['task_state'] in constants.BUSY_COPYING_STATES:
                self.db.share_update(
                    ctxt, share['id'],
                    {'task_state': constants.TASK_STATE_DATA_COPYING_ERROR})

    def migration_start(self, context, ignore_list, share_id,
                        share_instance_id, dest_share_instance_id,
                        connection_info_src, connection_info_dest):

        LOG.debug(
            "Received request to migrate share content from share instance "
            "%(instance_id)s to instance %(dest_instance_id)s.",
            {'instance_id': share_instance_id,
             'dest_instance_id': dest_share_instance_id})

        share_ref = self.db.share_get(context, share_id)
        share_instance_ref = self.db.share_instance_get(
            context, share_instance_id, with_share_data=True)

        share_rpcapi = share_rpc.ShareAPI()

        mount_path = CONF.mount_tmp_location

        try:
            copy = data_utils.Copy(
                os.path.join(mount_path, share_instance_id),
                os.path.join(mount_path, dest_share_instance_id),
                ignore_list, CONF.check_hash)

            self._copy_share_data(
                context, copy, share_ref, share_instance_id,
                dest_share_instance_id, connection_info_src,
                connection_info_dest)
        except exception.ShareDataCopyCancelled:
            share_rpcapi.migration_complete(
                context, share_instance_ref, dest_share_instance_id)
            return
        except Exception:
            self.db.share_update(
                context, share_id,
                {'task_state': constants.TASK_STATE_DATA_COPYING_ERROR})
            msg = _("Failed to copy contents from instance %(src)s to "
                    "instance %(dest)s.") % {'src': share_instance_id,
                                             'dest': dest_share_instance_id}
            LOG.exception(msg)
            share_rpcapi.migration_complete(
                context, share_instance_ref, dest_share_instance_id)
            raise exception.ShareDataCopyFailed(reason=msg)
        finally:
            self.busy_tasks_shares.pop(share_id, None)

        LOG.info(
            "Completed copy operation of migrating share content from share "
            "instance %(instance_id)s to instance %(dest_instance_id)s.",
            {'instance_id': share_instance_id,
             'dest_instance_id': dest_share_instance_id})

    def data_copy_cancel(self, context, share_id):
        LOG.debug("Received request to cancel data copy "
                  "of share %s.", share_id)
        copy = self.busy_tasks_shares.get(share_id)
        if copy:
            copy.cancel()
        else:
            msg = _("Data copy for migration of share %s cannot be cancelled"
                    " at this moment.") % share_id
            LOG.error(msg)
            raise exception.InvalidShare(reason=msg)

    def data_copy_get_progress(self, context, share_id):
        LOG.debug("Received request to get data copy information "
                  "of share %s.", share_id)
        copy = self.busy_tasks_shares.get(share_id)
        if copy:
            result = copy.get_progress()
            LOG.info("Obtained following data copy information "
                     "of share %(share)s: %(info)s.",
                     {'share': share_id,
                      'info': result})
            return result
        else:
            msg = _("Migration of share %s data copy progress cannot be "
                    "obtained at this moment.") % share_id
            LOG.error(msg)
            raise exception.InvalidShare(reason=msg)

    def _copy_share_data(
            self, context, copy, src_share, share_instance_id,
            dest_share_instance_id, connection_info_src, connection_info_dest):

        copied = False
        mount_path = CONF.mount_tmp_location

        share_instance = self.db.share_instance_get(
            context, share_instance_id, with_share_data=True)
        dest_share_instance = self.db.share_instance_get(
            context, dest_share_instance_id, with_share_data=True)

        self.db.share_update(
            context, src_share['id'],
            {'task_state': constants.TASK_STATE_DATA_COPYING_STARTING})

        helper_src = helper.DataServiceHelper(context, self.db, src_share)
        helper_dest = helper_src

        access_ref_list_src = helper_src.allow_access_to_data_service(
            share_instance, connection_info_src, dest_share_instance,
            connection_info_dest)
        access_ref_list_dest = access_ref_list_src

        def _call_cleanups(items):
            for item in items:
                if 'unmount_src' == item:
                    helper_src.cleanup_unmount_temp_folder(
                        connection_info_src['unmount'], mount_path,
                        share_instance_id)
                elif 'temp_folder_src' == item:
                    helper_src.cleanup_temp_folder(share_instance_id,
                                                   mount_path)
                elif 'temp_folder_dest' == item:
                    helper_dest.cleanup_temp_folder(dest_share_instance_id,
                                                    mount_path)
                elif 'access_src' == item:
                    helper_src.cleanup_data_access(access_ref_list_src,
                                                   share_instance_id)
                elif 'access_dest' == item:
                    helper_dest.cleanup_data_access(access_ref_list_dest,
                                                    dest_share_instance_id)
        try:
            helper_src.mount_share_instance(
                connection_info_src['mount'], mount_path, share_instance)
        except Exception:
            msg = _("Data copy failed attempting to mount "
                    "share instance %s.") % share_instance_id
            LOG.exception(msg)
            _call_cleanups(['temp_folder_src', 'access_dest', 'access_src'])
            raise exception.ShareDataCopyFailed(reason=msg)

        try:
            helper_dest.mount_share_instance(
                connection_info_dest['mount'], mount_path,
                dest_share_instance)
        except Exception:
            msg = _("Data copy failed attempting to mount "
                    "share instance %s.") % dest_share_instance_id
            LOG.exception(msg)
            _call_cleanups(['temp_folder_dest', 'unmount_src',
                            'temp_folder_src', 'access_dest', 'access_src'])
            raise exception.ShareDataCopyFailed(reason=msg)

        self.busy_tasks_shares[src_share['id']] = copy
        self.db.share_update(
            context, src_share['id'],
            {'task_state': constants.TASK_STATE_DATA_COPYING_IN_PROGRESS})

        try:
            copy.run()

            self.db.share_update(
                context, src_share['id'],
                {'task_state': constants.TASK_STATE_DATA_COPYING_COMPLETING})

            if copy.get_progress()['total_progress'] == 100:
                copied = True

        except Exception:
            LOG.exception("Failed to copy data from share instance "
                          "%(share_instance_id)s to "
                          "%(dest_share_instance_id)s.",
                          {'share_instance_id': share_instance_id,
                           'dest_share_instance_id': dest_share_instance_id})

        try:
            helper_src.unmount_share_instance(connection_info_src['unmount'],
                                              mount_path, share_instance_id)
        except Exception:
            LOG.exception("Could not unmount folder of instance"
                          " %s after its data copy.", share_instance_id)

        try:
            helper_dest.unmount_share_instance(
                connection_info_dest['unmount'], mount_path,
                dest_share_instance_id)
        except Exception:
            LOG.exception("Could not unmount folder of instance"
                          " %s after its data copy.", dest_share_instance_id)

        try:
            helper_src.deny_access_to_data_service(
                access_ref_list_src, share_instance)
        except Exception:
            LOG.exception("Could not deny access to instance"
                          " %s after its data copy.", share_instance_id)

        try:
            helper_dest.deny_access_to_data_service(
                access_ref_list_dest, dest_share_instance)
        except Exception:
            LOG.exception("Could not deny access to instance"
                          " %s after its data copy.", dest_share_instance_id)

        if copy and copy.cancelled:
            self.db.share_update(
                context, src_share['id'],
                {'task_state': constants.TASK_STATE_DATA_COPYING_CANCELLED})
            LOG.warning("Copy of data from share instance "
                        "%(src_instance)s to share instance "
                        "%(dest_instance)s was cancelled.",
                        {'src_instance': share_instance_id,
                         'dest_instance': dest_share_instance_id})
            raise exception.ShareDataCopyCancelled(
                src_instance=share_instance_id,
                dest_instance=dest_share_instance_id)

        elif not copied:
            msg = _("Copying data from share instance %(instance_id)s "
                    "to %(dest_instance_id)s did not succeed.") % (
                {'instance_id': share_instance_id,
                 'dest_instance_id': dest_share_instance_id})
            raise exception.ShareDataCopyFailed(reason=msg)

        self.db.share_update(
            context, src_share['id'],
            {'task_state': constants.TASK_STATE_DATA_COPYING_COMPLETED})

        LOG.debug("Copy of data from share instance %(src_instance)s to "
                  "share instance %(dest_instance)s was successful.",
                  {'src_instance': share_instance_id,
                   'dest_instance': dest_share_instance_id})
