# Copyright (c) 2017 Hitachi, Ltd.
#
#    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 datetime
from http import client as http_client

from ironic_lib import metrics_utils
from oslo_utils import uuidutils
from pecan import rest
import wsme

from ironic import api
from ironic.api.controllers import base
from ironic.api.controllers import link
from ironic.api.controllers.v1 import collection
from ironic.api.controllers.v1 import notification_utils as notify
from ironic.api.controllers.v1 import types
from ironic.api.controllers.v1 import utils as api_utils
from ironic.api import expose
from ironic.api import types as atypes
from ironic.common import exception
from ironic.common.i18n import _
from ironic.common import policy
from ironic import objects

METRICS = metrics_utils.get_metrics_logger(__name__)

_DEFAULT_RETURN_FIELDS = ('uuid', 'node_uuid', 'volume_type',
                          'boot_index', 'volume_id')


class VolumeTarget(base.APIBase):
    """API representation of a volume target.

    This class enforces type checking and value constraints, and converts
    between the internal object model and the API representation of a volume
    target.
    """

    _node_uuid = None

    def _get_node_uuid(self):
        return self._node_uuid

    def _set_node_identifiers(self, value):
        """Set both UUID and ID of a node for VolumeTarget object

        :param value: UUID, ID of a node, or atypes.Unset
        """
        if value == atypes.Unset:
            self._node_uuid = atypes.Unset
        elif value and self._node_uuid != value:
            try:
                node = objects.Node.get(api.request.context, value)
                self._node_uuid = node.uuid
                # NOTE(smoriya): Create the node_id attribute on-the-fly
                #                to satisfy the api -> rpc object conversion.
                self.node_id = node.id
            except exception.NodeNotFound as e:
                # Change error code because 404 (NotFound) is inappropriate
                # response for a POST request to create a VolumeTarget
                e.code = http_client.BAD_REQUEST  # BadRequest
                raise

    uuid = types.uuid
    """Unique UUID for this volume target"""

    volume_type = atypes.wsattr(str, mandatory=True)
    """The volume_type of volume target"""

    properties = {str: types.jsontype}
    """The properties for this volume target"""

    boot_index = atypes.wsattr(int, mandatory=True)
    """The boot_index of volume target"""

    volume_id = atypes.wsattr(str, mandatory=True)
    """The volume_id for this volume target"""

    extra = {str: types.jsontype}
    """The metadata for this volume target"""

    node_uuid = atypes.wsproperty(types.uuid, _get_node_uuid,
                                  _set_node_identifiers, mandatory=True)
    """The UUID of the node this volume target belongs to"""

    links = atypes.wsattr([link.Link], readonly=True)
    """A list containing a self link and associated volume target links"""

    def __init__(self, **kwargs):
        self.fields = []
        fields = list(objects.VolumeTarget.fields)
        for field in fields:
            # Skip fields we do not expose.
            if not hasattr(self, field):
                continue
            self.fields.append(field)
            setattr(self, field, kwargs.get(field, atypes.Unset))

        # NOTE(smoriya): node_id is an attribute created on-the-fly
        # by _set_node_uuid(), it needs to be present in the fields so
        # that as_dict() will contain node_id field when converting it
        # before saving it in the database.
        self.fields.append('node_id')
        # NOTE(smoriya): node_uuid is not part of objects.VolumeTarget.-
        #                fields because it's an API-only attribute
        self.fields.append('node_uuid')
        # NOTE(jtaryma): Additionally to node_uuid, node_id is handled as a
        # secondary identifier in case RPC volume target object dictionary
        # was passed to the constructor.
        self.node_uuid = kwargs.get('node_uuid') or kwargs.get('node_id',
                                                               atypes.Unset)

    @staticmethod
    def _convert_with_links(target, url):

        target.links = [link.Link.make_link('self', url,
                                            'volume/targets',
                                            target.uuid),
                        link.Link.make_link('bookmark', url,
                                            'volume/targets',
                                            target.uuid,
                                            bookmark=True)
                        ]
        return target

    @classmethod
    def convert_with_links(cls, rpc_target, fields=None, sanitize=True):
        target = VolumeTarget(**rpc_target.as_dict())

        if fields is not None:
            api_utils.check_for_invalid_fields(fields, target.as_dict())

        target = cls._convert_with_links(target, api.request.public_url)

        if not sanitize:
            return target

        target.sanitize(fields)

        return target

    def sanitize(self, fields=None):
        """Removes sensitive and unrequested data.

        Will only keep the fields specified in the ``fields`` parameter.

        :param fields:
            list of fields to preserve, or ``None`` to preserve them all
        :type fields: list of str
        """

        if fields is not None:
            self.unset_fields_except(fields)

        # never expose the node_id attribute
        self.node_id = atypes.Unset

    @classmethod
    def sample(cls, expand=True):
        time = datetime.datetime(2000, 1, 1, 12, 0, 0)
        properties = {"auth_method": "CHAP",
                      "auth_username": "XXX",
                      "auth_password": "XXX",
                      "target_iqn": "iqn.2010-10.com.example:vol-X",
                      "target_portal": "192.168.0.123:3260",
                      "volume_id": "a2f3ff15-b3ea-4656-ab90-acbaa1a07607",
                      "target_lun": 0,
                      "access_mode": "rw"}

        sample = cls(uuid='667808d4-622f-4629-b629-07753a19e633',
                     volume_type='iscsi',
                     boot_index=0,
                     volume_id='a2f3ff15-b3ea-4656-ab90-acbaa1a07607',
                     properties=properties,
                     extra={'foo': 'bar'},
                     created_at=time,
                     updated_at=time)
        sample._node_uuid = '7ae81bb3-dec3-4289-8d6c-da80bd8001ae'
        fields = None if expand else _DEFAULT_RETURN_FIELDS
        return cls._convert_with_links(sample, 'http://localhost:6385',
                                       fields=fields)


class VolumeTargetPatchType(types.JsonPatchType):

    _api_base = VolumeTarget


class VolumeTargetCollection(collection.Collection):
    """API representation of a collection of volume targets."""

    targets = [VolumeTarget]
    """A list containing volume target objects"""

    def __init__(self, **kwargs):
        self._type = 'targets'

    @staticmethod
    def convert_with_links(rpc_targets, limit, url=None, fields=None,
                           detail=None, **kwargs):
        collection = VolumeTargetCollection()
        collection.targets = [
            VolumeTarget.convert_with_links(p, fields=fields, sanitize=False)
            for p in rpc_targets]
        if detail:
            kwargs['detail'] = detail
        collection.next = collection.get_next(limit, url=url, fields=fields,
                                              **kwargs)
        for target in collection.targets:
            target.sanitize(fields)
        return collection

    @classmethod
    def sample(cls):
        sample = cls()
        sample.targets = [VolumeTarget.sample(expand=False)]
        return sample


class VolumeTargetsController(rest.RestController):
    """REST controller for VolumeTargets."""

    invalid_sort_key_list = ['extra', 'properties']

    def __init__(self, node_ident=None):
        super(VolumeTargetsController, self).__init__()
        self.parent_node_ident = node_ident

    def _get_volume_targets_collection(self, node_ident, marker, limit,
                                       sort_key, sort_dir, resource_url=None,
                                       fields=None, detail=None):
        limit = api_utils.validate_limit(limit)
        sort_dir = api_utils.validate_sort_dir(sort_dir)

        marker_obj = None
        if marker:
            marker_obj = objects.VolumeTarget.get_by_uuid(
                api.request.context, marker)

        if sort_key in self.invalid_sort_key_list:
            raise exception.InvalidParameterValue(
                _("The sort_key value %(key)s is an invalid field for "
                  "sorting") % {'key': sort_key})

        node_ident = self.parent_node_ident or node_ident

        if node_ident:
            # FIXME(comstud): Since all we need is the node ID, we can
            #                 make this more efficient by only querying
            #                 for that column. This will get cleaned up
            #                 as we move to the object interface.
            node = api_utils.get_rpc_node(node_ident)
            targets = objects.VolumeTarget.list_by_node_id(
                api.request.context, node.id, limit, marker_obj,
                sort_key=sort_key, sort_dir=sort_dir)
        else:
            targets = objects.VolumeTarget.list(api.request.context,
                                                limit, marker_obj,
                                                sort_key=sort_key,
                                                sort_dir=sort_dir)
        return VolumeTargetCollection.convert_with_links(targets, limit,
                                                         url=resource_url,
                                                         fields=fields,
                                                         sort_key=sort_key,
                                                         sort_dir=sort_dir,
                                                         detail=detail)

    @METRICS.timer('VolumeTargetsController.get_all')
    @expose.expose(VolumeTargetCollection, types.uuid_or_name, types.uuid,
                   int, str, str, types.listtype,
                   types.boolean)
    def get_all(self, node=None, marker=None, limit=None, sort_key='id',
                sort_dir='asc', fields=None, detail=None):
        """Retrieve a list of volume targets.

        :param node: UUID or name of a node, to get only volume targets
                     for that node.
        :param marker: pagination marker for large data sets.
        :param limit: maximum number of resources to return in a single result.
                      This value cannot be larger than the value of max_limit
                      in the [api] section of the ironic configuration, or only
                      max_limit resources will be returned.
        :param sort_key: column to sort results by. Default: id.
        :param sort_dir: direction to sort. "asc" or "desc". Default: "asc".
        :param fields: Optional, a list with a specified set of fields
                       of the resource to be returned.
        :param detail: Optional, whether to retrieve with detail.

        :returns: a list of volume targets, or an empty list if no volume
                  target is found.

        :raises: InvalidParameterValue if sort_key does not exist
        :raises: InvalidParameterValue if sort key is invalid for sorting.
        :raises: InvalidParameterValue if both fields and detail are specified.
        """
        cdict = api.request.context.to_policy_values()
        policy.authorize('baremetal:volume:get', cdict, cdict)

        if fields is None and not detail:
            fields = _DEFAULT_RETURN_FIELDS

        if fields and detail:
            raise exception.InvalidParameterValue(
                _("Can't fetch a subset of fields with 'detail' set"))

        resource_url = 'volume/targets'
        return self._get_volume_targets_collection(node, marker, limit,
                                                   sort_key, sort_dir,
                                                   resource_url=resource_url,
                                                   fields=fields,
                                                   detail=detail)

    @METRICS.timer('VolumeTargetsController.get_one')
    @expose.expose(VolumeTarget, types.uuid, types.listtype)
    def get_one(self, target_uuid, fields=None):
        """Retrieve information about the given volume target.

        :param target_uuid: UUID of a volume target.
        :param fields: Optional, a list with a specified set of fields
               of the resource to be returned.

        :returns: API-serializable volume target object.

        :raises: OperationNotPermitted if accessed with specifying a parent
                 node.
        :raises: VolumeTargetNotFound if no volume target with this UUID exists
        """
        cdict = api.request.context.to_policy_values()
        policy.authorize('baremetal:volume:get', cdict, cdict)

        if self.parent_node_ident:
            raise exception.OperationNotPermitted()

        rpc_target = objects.VolumeTarget.get_by_uuid(
            api.request.context, target_uuid)
        return VolumeTarget.convert_with_links(rpc_target, fields=fields)

    @METRICS.timer('VolumeTargetsController.post')
    @expose.expose(VolumeTarget, body=VolumeTarget,
                   status_code=http_client.CREATED)
    def post(self, target):
        """Create a new volume target.

        :param target: a volume target within the request body.

        :returns: API-serializable volume target object.

        :raises: OperationNotPermitted if accessed with specifying a parent
                 node.
        :raises: VolumeTargetBootIndexAlreadyExists if a volume target already
                 exists with the same node ID and boot index
        :raises: VolumeTargetAlreadyExists if a volume target with the same
                 UUID exists
        """
        context = api.request.context
        cdict = context.to_policy_values()
        policy.authorize('baremetal:volume:create', cdict, cdict)

        if self.parent_node_ident:
            raise exception.OperationNotPermitted()

        target_dict = target.as_dict()
        # NOTE(hshiina): UUID is mandatory for notification payload
        if not target_dict.get('uuid'):
            target_dict['uuid'] = uuidutils.generate_uuid()

        new_target = objects.VolumeTarget(context, **target_dict)

        notify.emit_start_notification(context, new_target, 'create',
                                       node_uuid=target.node_uuid)
        with notify.handle_error_notification(context, new_target, 'create',
                                              node_uuid=target.node_uuid):
            new_target.create()
        notify.emit_end_notification(context, new_target, 'create',
                                     node_uuid=target.node_uuid)
        # Set the HTTP Location Header
        api.response.location = link.build_url('volume/targets',
                                               new_target.uuid)
        return VolumeTarget.convert_with_links(new_target)

    @METRICS.timer('VolumeTargetsController.patch')
    @wsme.validate(types.uuid, [VolumeTargetPatchType])
    @expose.expose(VolumeTarget, types.uuid,
                   body=[VolumeTargetPatchType])
    def patch(self, target_uuid, patch):
        """Update an existing volume target.

        :param target_uuid: UUID of a volume target.
        :param patch: a json PATCH document to apply to this volume target.

        :returns: API-serializable volume target object.

        :raises: OperationNotPermitted if accessed with specifying a
                 parent node.
        :raises: PatchError if a given patch can not be applied.
        :raises: InvalidParameterValue if the volume target's UUID is being
                 changed
        :raises: NodeLocked if the node is already locked
        :raises: NodeNotFound if the node associated with the volume target
                 does not exist
        :raises: VolumeTargetNotFound if the volume target cannot be found
        :raises: VolumeTargetBootIndexAlreadyExists if a volume target already
                 exists with the same node ID and boot index values
        :raises: InvalidUUID if invalid node UUID is passed in the patch.
        :raises: InvalidStateRequested If a node associated with the
                 volume target is not powered off.
        """
        context = api.request.context
        cdict = context.to_policy_values()
        policy.authorize('baremetal:volume:update', cdict, cdict)

        if self.parent_node_ident:
            raise exception.OperationNotPermitted()

        values = api_utils.get_patch_values(patch, '/node_uuid')
        for value in values:
            if not uuidutils.is_uuid_like(value):
                message = _("Expected a UUID for node_uuid, but received "
                            "%(uuid)s.") % {'uuid': str(value)}
                raise exception.InvalidUUID(message=message)

        rpc_target = objects.VolumeTarget.get_by_uuid(context, target_uuid)
        target_dict = rpc_target.as_dict()
        # NOTE(smoriya):
        # 1) Remove node_id because it's an internal value and
        #    not present in the API object
        # 2) Add node_uuid
        target_dict['node_uuid'] = target_dict.pop('node_id', None)
        target = VolumeTarget(
            **api_utils.apply_jsonpatch(target_dict, patch))

        # Update only the fields that have changed.
        for field in objects.VolumeTarget.fields:
            try:
                patch_val = getattr(target, field)
            except AttributeError:
                # Ignore fields that aren't exposed in the API
                continue
            if patch_val == atypes.Unset:
                patch_val = None
            if rpc_target[field] != patch_val:
                rpc_target[field] = patch_val

        rpc_node = objects.Node.get_by_id(context, rpc_target.node_id)
        notify.emit_start_notification(context, rpc_target, 'update',
                                       node_uuid=rpc_node.uuid)
        with notify.handle_error_notification(context, rpc_target, 'update',
                                              node_uuid=rpc_node.uuid):
            topic = api.request.rpcapi.get_topic_for(rpc_node)
            new_target = api.request.rpcapi.update_volume_target(
                context, rpc_target, topic)

        api_target = VolumeTarget.convert_with_links(new_target)
        notify.emit_end_notification(context, new_target, 'update',
                                     node_uuid=rpc_node.uuid)
        return api_target

    @METRICS.timer('VolumeTargetsController.delete')
    @expose.expose(None, types.uuid, status_code=http_client.NO_CONTENT)
    def delete(self, target_uuid):
        """Delete a volume target.

        :param target_uuid: UUID of a volume target.

        :raises: OperationNotPermitted if accessed with specifying a
                 parent node.
        :raises: NodeLocked if node is locked by another conductor
        :raises: NodeNotFound if the node associated with the target does
                 not exist
        :raises: VolumeTargetNotFound if the volume target cannot be found
        :raises: InvalidStateRequested If a node associated with the
                 volume target is not powered off.
        """
        context = api.request.context
        cdict = context.to_policy_values()
        policy.authorize('baremetal:volume:delete', cdict, cdict)

        if self.parent_node_ident:
            raise exception.OperationNotPermitted()

        rpc_target = objects.VolumeTarget.get_by_uuid(context, target_uuid)
        rpc_node = objects.Node.get_by_id(context, rpc_target.node_id)
        notify.emit_start_notification(context, rpc_target, 'delete',
                                       node_uuid=rpc_node.uuid)
        with notify.handle_error_notification(context, rpc_target, 'delete',
                                              node_uuid=rpc_node.uuid):
            topic = api.request.rpcapi.get_topic_for(rpc_node)
            api.request.rpcapi.destroy_volume_target(context,
                                                     rpc_target, topic)
        notify.emit_end_notification(context, rpc_target, 'delete',
                                     node_uuid=rpc_node.uuid)
