# Copyright 2017 The Armada Authors.
#
# 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 re

from uuid import UUID

from oslo_config import cfg
from oslo_log import log as logging

CONF = cfg.CONF


class AuthMiddleware(object):

    def __init__(self):
        self.logger = logging.getLogger(__name__)

    # Authentication
    def process_request(self, req, resp):
        ctx = req.context

        auth_status = req.get_header('X-SERVICE-IDENTITY-STATUS')
        service = True

        if auth_status is None:
            auth_status = req.get_header('X-IDENTITY-STATUS')
            service = False

        if auth_status == 'Confirmed':
            # Process account and roles
            ctx.authenticated = True
            ctx.user = req.get_header(
                'X-SERVICE-USER-NAME') if service else req.get_header(
                    'X-USER-NAME')
            ctx.user_id = req.get_header(
                'X-SERVICE-USER-ID') if service else req.get_header(
                    'X-USER-ID')
            ctx.user_domain_id = req.get_header(
                'X-SERVICE-USER-DOMAIN-ID') if service else req.get_header(
                    'X-USER-DOMAIN-ID')
            ctx.project_id = req.get_header(
                'X-SERVICE-PROJECT-ID') if service else req.get_header(
                    'X-PROJECT-ID')
            ctx.project_domain_id = req.get_header(
                'X-SERVICE-PROJECT-DOMAIN-ID') if service else req.get_header(
                    'X-PROJECT-DOMAIN-NAME')
            if service:
                ctx.add_roles(req.get_header('X-SERVICE-ROLES').split(','))
            else:
                ctx.add_roles(req.get_header('X-ROLES').split(','))

            if req.get_header('X-IS-ADMIN-PROJECT') == 'True':
                ctx.is_admin_project = True
            else:
                ctx.is_admin_project = False

            self.logger.debug(
                'Request from authenticated user %s with roles %s' %
                (ctx.user, ','.join(ctx.roles)))
        else:
            ctx.authenticated = False


class ContextMiddleware(object):

    def process_request(self, req, resp):
        ctx = req.context

        ext_marker = req.get_header('X-Context-Marker')

        if ext_marker is not None and self.is_valid_uuid(ext_marker):
            ctx.set_external_marker(ext_marker)

    def is_valid_uuid(self, id, version=4):
        try:
            uuid_obj = UUID(id, version=version)
        except (TypeError, ValueError):
            return False

        return str(uuid_obj) == id


class LoggingMiddleware(object):
    def __init__(self):
        self.logger = logging.getLogger(__name__)

    # don't log any headers beginning with X-*
    hdr_exclude = re.compile('x-.*', re.IGNORECASE)

    def process_request(self, req, resp):
        """ Set up values to be logged across the request
        """
        ctx = req.context
        extra = {
            'user': ctx.user,
            'req_id': ctx.request_id,
            'external_ctx': ctx.external_marker,
        }
        self.logger.info("Request %s %s" % (req.method, req.url), extra=extra)
        self._log_headers(req.headers)

    def process_response(self, req, resp, resource, req_succeeded):
        """ Log the response information
        """
        ctx = req.context
        extra = {
            'user': ctx.user,
            'req_id': ctx.request_id,
            'external_ctx': ctx.external_marker,
        }
        resp.append_header('X-Armada-Req', ctx.request_id)
        self.logger.info("%s %s - %s" % (req.method, req.uri, resp.status),
                         extra=extra)
        self.logger.debug("Response body:%s", resp.body)

    def _log_headers(self, headers):
        """ Log request headers, while scrubbing sensitive values
        """
        for header, header_value in headers.items():
            if not LoggingMiddleware.hdr_exclude.match(header):
                self.logger.debug("Header %s: %s", header, header_value)