# 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.
#
# Copyright (c) 2019 Wind River Systems, Inc.
#
# SPDX-License-Identifier: Apache-2.0
#

import pecan
from pecan import hooks

from oslo_context import context as base_context
from oslo_utils import encodeutils

from dcdbsync.common import policy
from dcdbsync.db.identity import api as db_api

ALLOWED_WITHOUT_AUTH = '/'


class RequestContext(base_context.RequestContext):
    """Stores information about the security context.

    The context encapsulates information related to the user accessing the
    the system, as well as additional request information.
    """

    def __init__(self, auth_token=None, user=None, project=None,
                 domain=None, user_domain=None, project_domain=None,
                 is_admin=None, read_only=False, show_deleted=False,
                 request_id=None, auth_url=None, trusts=None,
                 user_name=None, project_name=None, domain_name=None,
                 user_domain_name=None, project_domain_name=None,
                 auth_token_info=None, region_name=None, roles=None,
                 password=None, **kwargs):

        # Initializer of request context.
        # We still have 'tenant' param because oslo_context still use it.
        super(RequestContext, self).__init__(
            auth_token=auth_token, user=user, tenant=project,
            domain=domain, user_domain=user_domain,
            project_domain=project_domain, roles=roles,
            read_only=read_only, show_deleted=show_deleted,
            request_id=request_id)

        # request_id might be a byte array
        self.request_id = encodeutils.safe_decode(self.request_id)

        # we save an additional 'project' internally for use
        self.project = project

        # Session for DB access
        self._session = None

        self.auth_url = auth_url
        self.trusts = trusts

        self.user_name = user_name
        self.project_name = project_name
        self.domain_name = domain_name
        self.user_domain_name = user_domain_name
        self.project_domain_name = project_domain_name

        self.auth_token_info = auth_token_info
        self.region_name = region_name
        self.roles = roles or []
        self.password = password

        # Check user is admin or not
        if is_admin is None:
            self.is_admin = policy.enforce(self, 'context_is_admin',
                                           target={'project': self.project},
                                           do_raise=False)
        else:
            self.is_admin = is_admin

    @property
    def session(self):
        if self._session is None:
            self._session = db_api.get_session()
        return self._session

    def to_dict(self):
        return {
            'auth_url': self.auth_url,
            'auth_token': self.auth_token,
            'auth_token_info': self.auth_token_info,
            'user': self.user,
            'user_name': self.user_name,
            'user_domain': self.user_domain,
            'user_domain_name': self.user_domain_name,
            'project': self.project,
            'project_name': self.project_name,
            'project_domain': self.project_domain,
            'project_domain_name': self.project_domain_name,
            'domain': self.domain,
            'domain_name': self.domain_name,
            'trusts': self.trusts,
            'region_name': self.region_name,
            'roles': self.roles,
            'show_deleted': self.show_deleted,
            'is_admin': self.is_admin,
            'request_id': self.request_id,
            'password': self.password,
        }

    @classmethod
    def from_dict(cls, values):
        return cls(**values)


def get_admin_context(show_deleted=False):
    return RequestContext(is_admin=True, show_deleted=show_deleted)


def get_service_context(**args):
    """An abstraction layer for getting service context."""

    pass


class AuthHook(hooks.PecanHook):
    def before(self, state):
        if state.request.path == ALLOWED_WITHOUT_AUTH:
            return
        req = state.request
        identity_status = req.headers.get('X-Identity-Status')
        service_identity_status = req.headers.get('X-Service-Identity-Status')
        if (identity_status == 'Confirmed' or
                service_identity_status == 'Confirmed'):
            return
        if req.headers.get('X-Auth-Token'):
            msg = 'Auth token is invalid: %s' % req.headers['X-Auth-Token']
        else:
            msg = 'Authentication required'
        msg = "Failed to validate access token: %s" % str(msg)
        pecan.abort(status_code=401, detail=msg)