# Copyright (c) 2015 Mirantis, 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.

from oslo_log import log as logging
from oslo_serialization import jsonutils

from pecan import hooks
import webob.exc

from neutron._i18n import _
from neutron.api.v2 import base as v2_base
from neutron.pecan_wsgi.hooks import utils

LOG = logging.getLogger(__name__)


class BodyValidationHook(hooks.PecanHook):

    priority = 120

    def before(self, state):
        if state.request.method not in ('POST', 'PUT'):
            return
        resource = state.request.context.get('resource')
        collection = state.request.context.get('collection')
        neutron_context = state.request.context['neutron_context']
        is_create = state.request.method == 'POST'
        if not resource:
            return

        if not state.request.body:
            return
        try:
            json_data = jsonutils.loads(state.request.body)
            if not isinstance(json_data, dict):
                raise ValueError()
        except ValueError:
            msg = _("Body contains invalid data")
            raise webob.exc.HTTPBadRequest(msg)
        # Raw data are consumed by member actions such as add_router_interface
        state.request.context['request_data'] = json_data
        if not (resource in json_data or collection in json_data):
            # there is no resource in the request. This can happen when a
            # member action is being processed or on agent scheduler operations
            return
        # Prepare data to be passed to the plugin from request body
        controller = utils.get_controller(state)
        try:
            data = v2_base.Controller.prepare_request_body(
                neutron_context,
                json_data,
                is_create,
                resource,
                controller.resource_info,
                allow_bulk=is_create)
        except Exception as e:
            LOG.warning("An exception happened while processing the request "
                        "body. The exception message is [%s].", e)
            raise e

        if collection in data:
            state.request.context['resources'] = [item[resource] for item in
                                                  data[collection]]
            state.request.context['is_bulk'] = True
        else:
            state.request.context['resources'] = [data[resource]]
            state.request.context['is_bulk'] = False