# Copyright 2013 Red Hat, Inc.
# 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.

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 node
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', 'description')


class Chassis(base.APIBase):
    """API representation of a chassis.

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

    uuid = types.uuid
    """The UUID of the chassis"""

    description = atypes.StringType(max_length=255)
    """The description of the chassis"""

    extra = {str: types.jsontype}
    """The metadata of the chassis"""

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

    nodes = atypes.wsattr([link.Link], readonly=True)
    """Links to the collection of nodes contained in this chassis"""

    def __init__(self, **kwargs):
        self.fields = []
        for field in objects.Chassis.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))

    @staticmethod
    def _convert_with_links(chassis, url, fields=None):
        if fields is None:
            chassis.nodes = [link.Link.make_link('self',
                                                 url,
                                                 'chassis',
                                                 chassis.uuid + "/nodes"),
                             link.Link.make_link('bookmark',
                                                 url,
                                                 'chassis',
                                                 chassis.uuid + "/nodes",
                                                 bookmark=True)
                             ]
        chassis.links = [link.Link.make_link('self',
                                             url,
                                             'chassis', chassis.uuid),
                         link.Link.make_link('bookmark',
                                             url,
                                             'chassis', chassis.uuid,
                                             bookmark=True)
                         ]
        return chassis

    @classmethod
    def convert_with_links(cls, rpc_chassis, fields=None, sanitize=True):
        chassis = Chassis(**rpc_chassis.as_dict())

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

        chassis = cls._convert_with_links(chassis, api.request.public_url,
                                          fields)

        if not sanitize:
            return chassis

        chassis.sanitize(fields)
        return chassis

    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)

    @classmethod
    def sample(cls, expand=True):
        time = datetime.datetime(2000, 1, 1, 12, 0, 0)
        sample = cls(uuid='eaaca217-e7d8-47b4-bb41-3f99f20eed89', extra={},
                     description='Sample chassis', created_at=time,
                     updated_at=time)
        fields = None if expand else _DEFAULT_RETURN_FIELDS
        return cls._convert_with_links(sample, 'http://localhost:6385',
                                       fields=fields)


class ChassisPatchType(types.JsonPatchType):

    _api_base = Chassis


class ChassisCollection(collection.Collection):
    """API representation of a collection of chassis."""

    chassis = [Chassis]
    """A list containing chassis objects"""

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

    @staticmethod
    def convert_with_links(chassis, limit, url=None, fields=None, **kwargs):
        collection = ChassisCollection()
        collection.chassis = [Chassis.convert_with_links(ch, fields=fields,
                                                         sanitize=False)
                              for ch in chassis]
        url = url or None
        collection.next = collection.get_next(limit, url=url, fields=fields,
                                              **kwargs)
        for item in collection.chassis:
            item.sanitize(fields)
        return collection

    @classmethod
    def sample(cls):
        # FIXME(jroll) hack for docs build, bug #1560508
        if not hasattr(objects, 'Chassis'):
            objects.register_all()
        sample = cls()
        sample.chassis = [Chassis.sample(expand=False)]
        return sample


class ChassisController(rest.RestController):
    """REST controller for Chassis."""

    nodes = node.NodesController()
    """Expose nodes as a sub-element of chassis"""

    # Set the flag to indicate that the requests to this resource are
    # coming from a top-level resource
    nodes.from_chassis = True

    _custom_actions = {
        'detail': ['GET'],
    }

    invalid_sort_key_list = ['extra']

    def _get_chassis_collection(self, 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.Chassis.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})

        chassis = objects.Chassis.list(api.request.context, limit,
                                       marker_obj, sort_key=sort_key,
                                       sort_dir=sort_dir)
        parameters = {}
        if detail is not None:
            parameters['detail'] = detail

        return ChassisCollection.convert_with_links(chassis, limit,
                                                    url=resource_url,
                                                    fields=fields,
                                                    sort_key=sort_key,
                                                    sort_dir=sort_dir,
                                                    **parameters)

    @METRICS.timer('ChassisController.get_all')
    @expose.expose(ChassisCollection, types.uuid, int,
                   str, str, types.listtype, types.boolean)
    def get_all(self, marker=None, limit=None, sort_key='id', sort_dir='asc',
                fields=None, detail=None):
        """Retrieve a list of chassis.

        :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.
        """
        cdict = api.request.context.to_policy_values()
        policy.authorize('baremetal:chassis:get', cdict, cdict)

        api_utils.check_allow_specify_fields(fields)

        fields = api_utils.get_request_return_fields(fields, detail,
                                                     _DEFAULT_RETURN_FIELDS)

        return self._get_chassis_collection(marker, limit, sort_key, sort_dir,
                                            fields=fields, detail=detail)

    @METRICS.timer('ChassisController.detail')
    @expose.expose(ChassisCollection, types.uuid, int,
                   str, str)
    def detail(self, marker=None, limit=None, sort_key='id', sort_dir='asc'):
        """Retrieve a list of chassis with detail.

        :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.
        """
        cdict = api.request.context.to_policy_values()
        policy.authorize('baremetal:chassis:get', cdict, cdict)

        # /detail should only work against collections
        parent = api.request.path.split('/')[:-1][-1]
        if parent != "chassis":
            raise exception.HTTPNotFound()

        resource_url = '/'.join(['chassis', 'detail'])
        return self._get_chassis_collection(marker, limit, sort_key, sort_dir,
                                            resource_url)

    @METRICS.timer('ChassisController.get_one')
    @expose.expose(Chassis, types.uuid, types.listtype)
    def get_one(self, chassis_uuid, fields=None):
        """Retrieve information about the given chassis.

        :param chassis_uuid: UUID of a chassis.
        :param fields: Optional, a list with a specified set of fields
            of the resource to be returned.
        """
        cdict = api.request.context.to_policy_values()
        policy.authorize('baremetal:chassis:get', cdict, cdict)

        api_utils.check_allow_specify_fields(fields)
        rpc_chassis = objects.Chassis.get_by_uuid(api.request.context,
                                                  chassis_uuid)
        return Chassis.convert_with_links(rpc_chassis, fields=fields)

    @METRICS.timer('ChassisController.post')
    @expose.expose(Chassis, body=Chassis, status_code=http_client.CREATED)
    def post(self, chassis):
        """Create a new chassis.

        :param chassis: a chassis within the request body.
        """
        context = api.request.context
        cdict = context.to_policy_values()
        policy.authorize('baremetal:chassis:create', cdict, cdict)

        # NOTE(yuriyz): UUID is mandatory for notifications payload
        if not chassis.uuid:
            chassis.uuid = uuidutils.generate_uuid()

        new_chassis = objects.Chassis(context, **chassis.as_dict())
        notify.emit_start_notification(context, new_chassis, 'create')
        with notify.handle_error_notification(context, new_chassis, 'create'):
            new_chassis.create()
        notify.emit_end_notification(context, new_chassis, 'create')
        # Set the HTTP Location Header
        api.response.location = link.build_url('chassis', new_chassis.uuid)
        return Chassis.convert_with_links(new_chassis)

    @METRICS.timer('ChassisController.patch')
    @wsme.validate(types.uuid, [ChassisPatchType])
    @expose.expose(Chassis, types.uuid, body=[ChassisPatchType])
    def patch(self, chassis_uuid, patch):
        """Update an existing chassis.

        :param chassis_uuid: UUID of a chassis.
        :param patch: a json PATCH document to apply to this chassis.
        """
        context = api.request.context
        cdict = context.to_policy_values()
        policy.authorize('baremetal:chassis:update', cdict, cdict)

        rpc_chassis = objects.Chassis.get_by_uuid(context, chassis_uuid)
        chassis = Chassis(
            **api_utils.apply_jsonpatch(rpc_chassis.as_dict(), patch))

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

        notify.emit_start_notification(context, rpc_chassis, 'update')
        with notify.handle_error_notification(context, rpc_chassis, 'update'):
            rpc_chassis.save()
        notify.emit_end_notification(context, rpc_chassis, 'update')
        return Chassis.convert_with_links(rpc_chassis)

    @METRICS.timer('ChassisController.delete')
    @expose.expose(None, types.uuid, status_code=http_client.NO_CONTENT)
    def delete(self, chassis_uuid):
        """Delete a chassis.

        :param chassis_uuid: UUID of a chassis.
        """
        context = api.request.context
        cdict = context.to_policy_values()
        policy.authorize('baremetal:chassis:delete', cdict, cdict)

        rpc_chassis = objects.Chassis.get_by_uuid(context, chassis_uuid)
        notify.emit_start_notification(context, rpc_chassis, 'delete')
        with notify.handle_error_notification(context, rpc_chassis, 'delete'):
            rpc_chassis.destroy()
        notify.emit_end_notification(context, rpc_chassis, 'delete')
