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

# Copyright 2011 OpenStack LLC.
# 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.config import cfg
import webob

from quantum.api import extensions
from quantum.api.v2 import base
from quantum.common import exceptions
from quantum.manager import QuantumManager
from quantum.openstack.common import importutils
from quantum import quota
from quantum import wsgi


RESOURCE_NAME = 'quota'
RESOURCE_COLLECTION = RESOURCE_NAME + "s"
QUOTAS = quota.QUOTAS
DB_QUOTA_DRIVER = 'quantum.db.quota_db.DbQuotaDriver'
EXTENDED_ATTRIBUTES_2_0 = {
    RESOURCE_COLLECTION: {}
}

for quota_resource in QUOTAS.resources.iterkeys():
    attr_dict = EXTENDED_ATTRIBUTES_2_0[RESOURCE_COLLECTION]
    attr_dict[quota_resource] = {'allow_post': False,
                                 'allow_put': True,
                                 'convert_to': int,
                                 'is_visible': True}


class QuotaSetsController(wsgi.Controller):

    def __init__(self, plugin):
        self._resource_name = RESOURCE_NAME
        self._plugin = plugin
        self._driver = importutils.import_class(DB_QUOTA_DRIVER)

    def _get_body(self, request):
        body = self._deserialize(request.body,
                                 request.best_match_content_type())
        attr_info = EXTENDED_ATTRIBUTES_2_0[RESOURCE_COLLECTION]
        req_body = base.Controller.prepare_request_body(
            request.context, body, False, self._resource_name, attr_info)
        return req_body

    def _get_quotas(self, request, tenant_id):
        return self._driver.get_tenant_quotas(
            request.context, QUOTAS.resources, tenant_id)

    def create(self, request, body=None):
        raise NotImplementedError()

    def index(self, request):
        context = request.context
        if not context.is_admin:
            raise webob.exc.HTTPForbidden()
        return {self._resource_name + "s":
                self._driver.get_all_quotas(context, QUOTAS.resources)}

    def tenant(self, request):
        """Retrieve the tenant info in context."""
        context = request.context
        if not context.tenant_id:
            raise webob.exc.HTTPBadRequest('invalid tenant')
        return {'tenant': {'tenant_id': context.tenant_id}}

    def show(self, request, id):
        context = request.context
        tenant_id = id
        if not tenant_id:
            raise webob.exc.HTTPBadRequest('invalid tenant')
        if (tenant_id != context.tenant_id and
            not context.is_admin):
            raise webob.exc.HTTPForbidden()
        return {self._resource_name:
                self._get_quotas(request, tenant_id)}

    def _check_modification_delete_privilege(self, context, tenant_id):
        if not tenant_id:
            raise webob.exc.HTTPBadRequest('invalid tenant')
        if not context.is_admin:
            raise webob.exc.HTTPForbidden()
        return tenant_id

    def delete(self, request, id):
        tenant_id = self._check_modification_delete_privilege(request.context,
                                                              id)
        self._driver.delete_tenant_quota(request.context, tenant_id)

    def update(self, request, id):
        tenant_id = self._check_modification_delete_privilege(request.context,
                                                              id)
        req_body = self._get_body(request)
        for key in req_body[self._resource_name].keys():
            if key in QUOTAS.resources:
                value = int(req_body[self._resource_name][key])
                self._driver.update_quota_limit(request.context,
                                                tenant_id,
                                                key,
                                                value)
        return {self._resource_name: self._get_quotas(request, tenant_id)}


class Quotasv2(extensions.ExtensionDescriptor):
    """Quotas management support"""

    @classmethod
    def get_name(cls):
        return "Quotas for each tenant"

    @classmethod
    def get_alias(cls):
        return RESOURCE_COLLECTION

    @classmethod
    def get_description(cls):
        return ("Expose functions for cloud admin to update quotas"
                "for each tenant")

    @classmethod
    def get_namespace(cls):
        return "http://docs.openstack.org/network/ext/quotas-sets/api/v2.0"

    @classmethod
    def get_updated(cls):
        return "2012-07-29T10:00:00-00:00"

    @classmethod
    def get_resources(cls):
        """ Returns Ext Resources """
        controller = QuotaSetsController(QuantumManager.get_plugin())
        return [extensions.ResourceExtension(
            Quotasv2.get_alias(),
            controller,
            collection_actions={'tenant': 'GET'})]

    def get_extended_resources(self, version):
        if version == "2.0":
            return EXTENDED_ATTRIBUTES_2_0
        else:
            return {}

    def check_env(self):
        if cfg.CONF.QUOTAS.quota_driver != DB_QUOTA_DRIVER:
            msg = _('Quota driver %s is needed.') % DB_QUOTA_DRIVER
            raise exceptions.InvalidExtenstionEnv(reason=msg)