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

# Copyright (c) 2011 OpenStack, LLC
#
#    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.
"""
Nova Auth Middleware.

"""

import webob.dec
import webob.exc

from nova import context
from nova import flags
from nova import wsgi


FLAGS = flags.FLAGS
flags.DECLARE('use_forwarded_for', 'nova.api.auth')


class NovaKeystoneContext(wsgi.Middleware):
    """Make a request context from keystone headers"""

    @webob.dec.wsgify(RequestClass=wsgi.Request)
    def __call__(self, req):
        try:
            user_id = req.headers['X_USER']
        except KeyError:
            return webob.exc.HTTPUnauthorized()
        # get the roles
        roles = [r.strip() for r in req.headers.get('X_ROLE', '').split(',')]
        project_id = req.headers['X_TENANT']
        # Get the auth token
        auth_token = req.headers.get('X_AUTH_TOKEN',
                                     req.headers.get('X_STORAGE_TOKEN'))

        # Build a context, including the auth_token...
        remote_address = getattr(req, 'remote_address', '127.0.0.1')
        remote_address = req.remote_addr
        if FLAGS.use_forwarded_for:
            remote_address = req.headers.get('X-Forwarded-For', remote_address)
        ctx = context.RequestContext(user_id,
                                     project_id,
                                     roles=roles,
                                     auth_token=auth_token,
                                     strategy='keystone',
                                     remote_address=remote_address)

        req.environ['nova.context'] = ctx
        return self.application
