# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2011 University of Southern California
# 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.

""" The instance type extra specs extension"""

from webob import exc

from nova import db
from nova import quota
from nova.api.openstack import extensions
from nova.api.openstack import wsgi


class FlavorExtraSpecsController(object):
    """ The flavor extra specs API controller for the Openstack API """

    def _get_extra_specs(self, context, flavor_id):
        extra_specs = db.instance_type_extra_specs_get(context, flavor_id)
        specs_dict = {}
        for key, value in extra_specs.iteritems():
            specs_dict[key] = value
        return dict(extra_specs=specs_dict)

    def _check_body(self, body):
        if body == None or body == "":
            expl = _('No Request Body')
            raise exc.HTTPBadRequest(explanation=expl)

    def index(self, req, flavor_id):
        """ Returns the list of extra specs for a givenflavor """
        context = req.environ['nova.context']
        return self._get_extra_specs(context, flavor_id)

    def create(self, req, flavor_id, body):
        self._check_body(body)
        context = req.environ['nova.context']
        specs = body.get('extra_specs')
        try:
            db.instance_type_extra_specs_update_or_create(context,
                                                              flavor_id,
                                                              specs)
        except quota.QuotaError as error:
            self._handle_quota_error(error)
        return body

    def update(self, req, flavor_id, id, body):
        self._check_body(body)
        context = req.environ['nova.context']
        if not id in body:
            expl = _('Request body and URI mismatch')
            raise exc.HTTPBadRequest(explanation=expl)
        if len(body) > 1:
            expl = _('Request body contains too many items')
            raise exc.HTTPBadRequest(explanation=expl)
        try:
            db.instance_type_extra_specs_update_or_create(context,
                                                               flavor_id,
                                                               body)
        except quota.QuotaError as error:
            self._handle_quota_error(error)

        return body

    def show(self, req, flavor_id, id):
        """ Return a single extra spec item """
        context = req.environ['nova.context']
        specs = self._get_extra_specs(context, flavor_id)
        if id in specs['extra_specs']:
            return {id: specs['extra_specs'][id]}
        else:
            raise exc.HTTPNotFound()

    def delete(self, req, flavor_id, id):
        """ Deletes an existing extra spec """
        context = req.environ['nova.context']
        db.instance_type_extra_specs_delete(context, flavor_id, id)

    def _handle_quota_error(self, error):
        """Reraise quota errors as api-specific http exceptions."""
        if error.code == "MetadataLimitExceeded":
            raise exc.HTTPBadRequest(explanation=error.message)
        raise error


class Flavorextraspecs(extensions.ExtensionDescriptor):
    """Instance type (flavor) extra specs"""

    name = "FlavorExtraSpecs"
    alias = "os-flavor-extra-specs"
    namespace = "http://docs.openstack.org/ext/flavor_extra_specs/api/v1.1"
    updated = "2011-06-23T00:00:00+00:00"

    def get_resources(self):
        resources = []
        res = extensions.ResourceExtension(
                'os-extra_specs',
                FlavorExtraSpecsController(),
                parent=dict(member_name='flavor', collection_name='flavors'))

        resources.append(res)
        return resources
