#   Copyright 2012-2013 OpenStack Foundation
#
#   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.
#

"""Common identity code"""

from keystoneclient import exceptions as identity_exc
from keystoneclient.v3 import domains
from keystoneclient.v3 import groups
from keystoneclient.v3 import projects
from keystoneclient.v3 import users

from openstackclient.common import exceptions
from openstackclient.common import utils


def find_service(identity_client, name_type_or_id):
    """Find a service by id, name or type."""

    try:
        # search for the usual ID or name
        return utils.find_resource(identity_client.services, name_type_or_id)
    except exceptions.CommandError:
        try:
            # search for service type
            return identity_client.services.find(type=name_type_or_id)
        # FIXME(dtroyer): This exception should eventually come from
        #                 common client exceptions
        except identity_exc.NotFound:
            msg = ("No service with a type, name or ID of '%s' exists."
                   % name_type_or_id)
            raise exceptions.CommandError(msg)


def find_domain(identity_client, name_or_id):
    return _find_identity_resource(identity_client.domains, name_or_id,
                                   domains.Domain)


def find_group(identity_client, name_or_id, domain_id=None):
    return _find_identity_resource(identity_client.groups, name_or_id,
                                   groups.Group, domain_id=domain_id)


def find_project(identity_client, name_or_id, domain_id=None):
    return _find_identity_resource(identity_client.projects, name_or_id,
                                   projects.Project, domain_id=domain_id)


def find_user(identity_client, name_or_id, domain_id=None):
    return _find_identity_resource(identity_client.users, name_or_id,
                                   users.User, domain_id=domain_id)


def _find_identity_resource(identity_client_manager, name_or_id,
                            resource_type, **kwargs):
    """Find a specific identity resource.

    Using keystoneclient's manager, attempt to find a specific resource by its
    name or ID. If Forbidden to find the resource (a common case if the user
    does not have permission), then return the resource by creating a local
    instance of keystoneclient's Resource.

    The parameter identity_client_manager is a keystoneclient manager,
    for example: keystoneclient.v3.users or keystoneclient.v3.projects.

    The parameter resource_type is a keystoneclient resource, for example:
    keystoneclient.v3.users.User or keystoneclient.v3.projects.Project.

    :param identity_client_manager: the manager that contains the resource
    :type identity_client_manager: `keystoneclient.base.CrudManager`
    :param name_or_id: the resources's name or ID
    :type name_or_id: string
    :param resource_type: class that represents the resource type
    :type resource_type: `keystoneclient.base.Resource`

    :returns: the resource in question
    :rtype: `keystoneclient.base.Resource`

    """

    try:
        identity_resource = utils.find_resource(identity_client_manager,
                                                name_or_id, **kwargs)
        if identity_resource is not None:
            return identity_resource
    except identity_exc.Forbidden:
        pass

    return resource_type(None, {'id': name_or_id, 'name': name_or_id})