# Copyright 2017 AT&T Intellectual Property.  All other 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.

import falcon
import logging
import uuid

import drydock_provisioner.config as config

class AuthMiddleware(object):

    # Authentication
    def process_request(self, req, resp):
        ctx = req.context
        token = req.get_header('X-Auth-Token')

        user = self.validate_token(token)

        if user is not None:
            ctx.set_user(user)
            user_roles = self.role_list(user)
            ctx.add_roles(user_roles)
        else:
            ctx.add_role('anyone')

    # Authorization
    def process_resource(self, req, resp, resource, params):
        ctx = req.context

        if not resource.authorize_roles(ctx.roles):
            raise falcon.HTTPUnauthorized('Authentication required',
                                          ('This resource requires an authorized role.'))

    # Return the username associated with an authenticated token or None
    def validate_token(self, token):
        if token == '42':
            return 'scott'
        elif token == 'bigboss':
            return 'admin'
        else:
            return None

    # Return the list of roles assigned to the username
    # Roles need to be an enum
    def role_list(self, username):
        if username == 'scott':
            return ['user']
        elif username == 'admin':
            return ['user', 'admin']

class ContextMiddleware(object):

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

        requested_logging = req.get_header('X-Log-Level')

        if (config.DrydockConfig.global_config.get('log_level', '') == 'DEBUG' or
           (requested_logging == 'DEBUG' and 'admin' in ctx.roles)):
            ctx.set_log_level('DEBUG')
        elif requested_logging == 'INFO':
            ctx.set_log_level('INFO')

        ctx.req_id = str(uuid.uuid4())

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

        ctx.external_ctx = ext_marker if ext_marker is not None else ''

class LoggingMiddleware(object):

    def __init__(self):
        self.logger = logging.getLogger('drydock.control')

    def process_response(self, req, resp, resource, req_succeeded):
        ctx = req.context
        extra = {
            'user': ctx.user,
            'req_id': ctx.req_id,
            'external_ctx': ctx.external_ctx,
        }
        resp.append_header('X-Drydock-Req', ctx.req_id)
        self.logger.info("%s - %s" % (req.uri, resp.status), extra=extra)