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

# Copyright 2012 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.

import uuid

import routes

from keystone import catalog
from keystone import exception
from keystone import identity
from keystone import policy
from keystone import token
from keystone.common import logging
from keystone.common import utils
from keystone.common import wsgi


LOG = logging.getLogger(__name__)


class AdminRouter(wsgi.ComposingRouter):
    def __init__(self):
        mapper = routes.Mapper()

        version_controller = VersionController('admin')
        mapper.connect('/',
                       controller=version_controller,
                       action='get_version')

        # Token Operations
        auth_controller = TokenController()
        mapper.connect('/tokens',
                       controller=auth_controller,
                       action='authenticate',
                       conditions=dict(method=['POST']))
        mapper.connect('/tokens/{token_id}',
                       controller=auth_controller,
                       action='validate_token',
                       conditions=dict(method=['GET']))
        mapper.connect('/tokens/{token_id}',
                       controller=auth_controller,
                       action='validate_token_head',
                       conditions=dict(method=['HEAD']))
        mapper.connect('/tokens/{token_id}',
                       controller=auth_controller,
                       action='delete_token',
                       conditions=dict(method=['DELETE']))
        mapper.connect('/tokens/{token_id}/endpoints',
                       controller=auth_controller,
                       action='endpoints',
                       conditions=dict(method=['GET']))

        # Miscellaneous Operations
        extensions_controller = AdminExtensionsController()
        mapper.connect('/extensions',
                       controller=extensions_controller,
                       action='get_extensions_info',
                       conditions=dict(method=['GET']))
        mapper.connect('/extensions/{extension_alias}',
                       controller=extensions_controller,
                       action='get_extension_info',
                       conditions=dict(method=['GET']))
        identity_router = identity.AdminRouter()
        routers = [identity_router]
        super(AdminRouter, self).__init__(mapper, routers)


class PublicRouter(wsgi.ComposingRouter):
    def __init__(self):
        mapper = routes.Mapper()

        version_controller = VersionController('public')
        mapper.connect('/',
                       controller=version_controller,
                       action='get_version')

        # Token Operations
        auth_controller = TokenController()
        mapper.connect('/tokens',
                       controller=auth_controller,
                       action='authenticate',
                       conditions=dict(method=['POST']))

        # Miscellaneous
        extensions_controller = PublicExtensionsController()
        mapper.connect('/extensions',
                       controller=extensions_controller,
                       action='get_extensions_info',
                       conditions=dict(method=['GET']))
        mapper.connect('/extensions/{extension_alias}',
                       controller=extensions_controller,
                       action='get_extension_info',
                       conditions=dict(method=['GET']))

        identity_router = identity.PublicRouter()
        routers = [identity_router]

        super(PublicRouter, self).__init__(mapper, routers)


class PublicVersionRouter(wsgi.ComposingRouter):
    def __init__(self):
        mapper = routes.Mapper()
        version_controller = VersionController('public')
        mapper.connect('/',
                       controller=version_controller,
                       action='get_versions')
        routers = []
        super(PublicVersionRouter, self).__init__(mapper, routers)


class AdminVersionRouter(wsgi.ComposingRouter):
    def __init__(self):
        mapper = routes.Mapper()
        version_controller = VersionController('admin')
        mapper.connect('/',
                       controller=version_controller,
                       action='get_versions')
        routers = []
        super(AdminVersionRouter, self).__init__(mapper, routers)


class VersionController(wsgi.Application):
    def __init__(self, version_type):
        self.catalog_api = catalog.Manager()
        self.url_key = "%sURL" % version_type

        super(VersionController, self).__init__()

    def _get_identity_url(self, context):
        catalog_ref = self.catalog_api.get_catalog(
                context=context,
                user_id=None,
                tenant_id=None)
        for region, region_ref in catalog_ref.iteritems():
            for service, service_ref in region_ref.iteritems():
                if service == 'identity':
                    return service_ref[self.url_key]

        raise exception.NotImplemented()

    def _get_versions_list(self, context):
        """The list of versions is dependent on the context."""
        identity_url = self._get_identity_url(context)
        if not identity_url.endswith('/'):
            identity_url = identity_url + '/'

        versions = {}
        versions['v2.0'] = {
            "id": "v2.0",
            "status": "beta",
            "updated": "2011-11-19T00:00:00Z",
            "links": [
                {
                    "rel": "self",
                    "href": identity_url,
                }, {
                    "rel": "describedby",
                    "type": "text/html",
                    "href": "http://docs.openstack.org/api/openstack-"
                                "identity-service/2.0/content/"
                }, {
                    "rel": "describedby",
                    "type": "application/pdf",
                    "href": "http://docs.openstack.org/api/openstack-"
                                "identity-service/2.0/identity-dev-guide-"
                                "2.0.pdf"
                }
            ],
            "media-types": [
                {
                    "base": "application/json",
                    "type": "application/vnd.openstack.identity-v2.0"
                                "+json"
                }, {
                    "base": "application/xml",
                    "type": "application/vnd.openstack.identity-v2.0"
                                "+xml"
                }
            ]
        }

        return versions

    def get_versions(self, context):
        versions = self._get_versions_list(context)
        return wsgi.render_response(status=(300, 'Multiple Choices'), body={
            "versions": {
                "values": versions.values()
            }
        })

    def get_version(self, context):
        versions = self._get_versions_list(context)
        return wsgi.render_response(body={
            "version": versions['v2.0']
        })


class NoopController(wsgi.Application):
    def __init__(self):
        super(NoopController, self).__init__()

    def noop(self, context):
        return {}


class TokenController(wsgi.Application):
    def __init__(self):
        self.catalog_api = catalog.Manager()
        self.identity_api = identity.Manager()
        self.token_api = token.Manager()
        self.policy_api = policy.Manager()
        super(TokenController, self).__init__()

    def authenticate(self, context, auth=None):
        """Authenticate credentials and return a token.

        Accept auth as a dict that looks like::

            {
                "auth":{
                    "passwordCredentials":{
                        "username":"test_user",
                        "password":"mypass"
                    },
                    "tenantName":"customer-x"
                }
            }

        In this case, tenant is optional, if not provided the token will be
        considered "unscoped" and can later be used to get a scoped token.

        Alternatively, this call accepts auth with only a token and tenant
        that will return a token that is scoped to that tenant.
        """

        token_id = uuid.uuid4().hex
        if 'passwordCredentials' in auth:
            username = auth['passwordCredentials'].get('username', '')
            password = auth['passwordCredentials'].get('password', '')
            tenant_name = auth.get('tenantName', None)

            user_id = auth['passwordCredentials'].get('userId', None)
            if username:
                user_ref = self.identity_api.get_user_by_name(
                        context=context, user_name=username)
                if user_ref:
                    user_id = user_ref['id']

            # more compat
            tenant_id = auth.get('tenantId', None)
            if tenant_name:
                tenant_ref = self.identity_api.get_tenant_by_name(
                        context=context, tenant_name=tenant_name)
                if tenant_ref:
                    tenant_id = tenant_ref['id']

            try:
                auth_info = self.identity_api.authenticate(context=context,
                                                           user_id=user_id,
                                                           password=password,
                                                           tenant_id=tenant_id)
                (user_ref, tenant_ref, metadata_ref) = auth_info

                # If the user is disabled don't allow them to authenticate
                if not user_ref.get('enabled', True):
                    LOG.warning('User %s is disabled' % user_id)
                    raise exception.Unauthorized()
            except AssertionError as e:
                raise exception.Unauthorized(e.message)

            token_ref = self.token_api.create_token(
                    context, token_id, dict(id=token_id,
                                            user=user_ref,
                                            tenant=tenant_ref,
                                            metadata=metadata_ref))
            if tenant_ref:
                catalog_ref = self.catalog_api.get_catalog(
                        context=context,
                        user_id=user_ref['id'],
                        tenant_id=tenant_ref['id'],
                        metadata=metadata_ref)
            else:
                catalog_ref = {}

        elif 'token' in auth:
            token = auth['token'].get('id', None)

            tenant_name = auth.get('tenantName')

            # more compat
            if tenant_name:
                tenant_ref = self.identity_api.get_tenant_by_name(
                        context=context, tenant_name=tenant_name)
                tenant_id = tenant_ref['id']
            else:
                tenant_id = auth.get('tenantId', None)

            try:
                old_token_ref = self.token_api.get_token(context=context,
                                                         token_id=token)
            except exception.NotFound:
                raise exception.Unauthorized()

            user_ref = old_token_ref['user']

            # If the user is disabled don't allow them to authenticate
            current_user_ref = self.identity_api.get_user(
                                                    context=context,
                                                    user_id=user_ref['id'])
            if not current_user_ref.get('enabled', True):
                LOG.warning('User %s is disabled' % user_ref['id'])
                raise exception.Unauthorized()

            tenants = self.identity_api.get_tenants_for_user(context,
                                                             user_ref['id'])
            if tenant_id:
                assert tenant_id in tenants

            tenant_ref = self.identity_api.get_tenant(context=context,
                                                      tenant_id=tenant_id)
            if tenant_ref:
                metadata_ref = self.identity_api.get_metadata(
                        context=context,
                        user_id=user_ref['id'],
                        tenant_id=tenant_ref['id'])
                catalog_ref = self.catalog_api.get_catalog(
                        context=context,
                        user_id=user_ref['id'],
                        tenant_id=tenant_ref['id'],
                        metadata=metadata_ref)
            else:
                metadata_ref = {}
                catalog_ref = {}

            token_ref = self.token_api.create_token(
                    context, token_id, dict(id=token_id,
                                            user=user_ref,
                                            tenant=tenant_ref,
                                            metadata=metadata_ref,
                                            expires=old_token_ref['expires']))

        # TODO(termie): optimize this call at some point and put it into the
        #               the return for metadata
        # fill out the roles in the metadata
        roles_ref = []
        for role_id in metadata_ref.get('roles', []):
            roles_ref.append(self.identity_api.get_role(context, role_id))
        logging.debug('TOKEN_REF %s', token_ref)
        return self._format_authenticate(token_ref, roles_ref, catalog_ref)

    def _get_token_ref(self, context, token_id, belongs_to=None):
        """Returns a token if a valid one exists.

        Optionally, limited to a token owned by a specific tenant.

        """
        # TODO(termie): this stuff should probably be moved to middleware
        self.assert_admin(context)

        token_ref = self.token_api.get_token(context=context,
                                             token_id=token_id)

        if belongs_to:
            assert token_ref['tenant']['id'] == belongs_to

        return token_ref

    # admin only
    def validate_token_head(self, context, token_id):
        """Check that a token is valid.

        Optionally, also ensure that it is owned by a specific tenant.

        Identical to ``validate_token``, except does not return a response.

        """
        belongs_to = context['query_string'].get("belongsTo")
        assert self._get_token_ref(context, token_id, belongs_to)

    # admin only
    def validate_token(self, context, token_id):
        """Check that a token is valid.

        Optionally, also ensure that it is owned by a specific tenant.

        Returns metadata about the token along any associated roles.

        """
        belongs_to = context['query_string'].get("belongsTo")
        token_ref = self._get_token_ref(context, token_id, belongs_to)

        # TODO(termie): optimize this call at some point and put it into the
        #               the return for metadata
        # fill out the roles in the metadata
        metadata_ref = token_ref['metadata']
        roles_ref = []
        for role_id in metadata_ref.get('roles', []):
            roles_ref.append(self.identity_api.get_role(context, role_id))

        # Get a service catalog if belongs_to is not none
        # This is needed for on-behalf-of requests
        catalog_ref = None
        if belongs_to is not None:
            catalog_ref = self.catalog_api.get_catalog(
                context=context,
                user_id=token_ref['user']['id'],
                tenant_id=token_ref['tenant']['id'],
                metadata=metadata_ref)
        return self._format_token(token_ref, roles_ref, catalog_ref)

    def delete_token(self, context, token_id):
        """Delete a token, effectively invalidating it for authz."""
        # TODO(termie): this stuff should probably be moved to middleware
        self.assert_admin(context)

        self.token_api.delete_token(context=context, token_id=token_id)

    def endpoints(self, context, token_id):
        """Return a list of endpoints available to the token."""
        raise exception.NotImplemented()

    def _format_authenticate(self, token_ref, roles_ref, catalog_ref):
        o = self._format_token(token_ref, roles_ref)
        o['access']['serviceCatalog'] = self._format_catalog(catalog_ref)
        return o

    def _format_token(self, token_ref, roles_ref, catalog_ref=None):
        user_ref = token_ref['user']
        metadata_ref = token_ref['metadata']
        expires = token_ref['expires']
        if expires is not None:
            expires = utils.isotime(expires)
        o = {'access': {'token': {'id': token_ref['id'],
                                  'expires': expires,
                                  },
                        'user': {'id': user_ref['id'],
                                 'name': user_ref['name'],
                                 'username': user_ref['name'],
                                 'roles': roles_ref,
                                 'roles_links': metadata_ref.get('roles_links',
                                                               [])
                                 }
                        }
             }
        if 'tenant' in token_ref and token_ref['tenant']:
            token_ref['tenant']['enabled'] = True
            o['access']['token']['tenant'] = token_ref['tenant']
        if catalog_ref is not None:
            o['access']['serviceCatalog'] = self._format_catalog(catalog_ref)
        return o

    def _format_catalog(self, catalog_ref):
        """Munge catalogs from internal to output format
        Internal catalogs look like:

        {$REGION: {
            {$SERVICE: {
                $key1: $value1,
                ...
                }
            }
        }

        The legacy api wants them to look like

        [{'name': $SERVICE[name],
          'type': $SERVICE,
          'endpoints': [{
              'tenantId': $tenant_id,
              ...
              'region': $REGION,
              }],
          'endpoints_links': [],
         }]

        """
        if not catalog_ref:
            return {}

        services = {}
        for region, region_ref in catalog_ref.iteritems():
            for service, service_ref in region_ref.iteritems():
                new_service_ref = services.get(service, {})
                new_service_ref['name'] = service_ref.pop('name')
                new_service_ref['type'] = service
                new_service_ref['endpoints_links'] = []
                service_ref['region'] = region

                endpoints_ref = new_service_ref.get('endpoints', [])
                endpoints_ref.append(service_ref)

                new_service_ref['endpoints'] = endpoints_ref
                services[service] = new_service_ref

        return services.values()


class ExtensionsController(wsgi.Application):
    """Base extensions controller to be extended by public and admin API's."""

    def __init__(self, extensions=None):
        super(ExtensionsController, self).__init__()

        self.extensions = extensions or {}

    def get_extensions_info(self, context):
        return {'extensions': {'values': self.extensions.values()}}

    def get_extension_info(self, context, extension_alias):
        try:
            return {'extension': self.extensions[extension_alias]}
        except KeyError:
            raise exception.NotFound(target=extension_alias)


class PublicExtensionsController(ExtensionsController):
    pass


class AdminExtensionsController(ExtensionsController):
    def __init__(self, *args, **kwargs):
        super(AdminExtensionsController, self).__init__(*args, **kwargs)

        # TODO(dolph): Extensions should obviously provide this information
        #               themselves, but hardcoding it here allows us to match
        #               the API spec in the short term with minimal complexity.
        self.extensions['OS-KSADM'] = {
            'name': 'Openstack Keystone Admin',
            'namespace': 'http://docs.openstack.org/identity/api/ext/'
                         'OS-KSADM/v1.0',
            'alias': 'OS-KSADM',
            'updated': '2011-08-19T13:25:27-06:00',
            'description': 'Openstack extensions to Keystone v2.0 API '
                           'enabling Admin Operations.',
            'links': [
                {
                    'rel': 'describedby',
                    # TODO(dolph): link needs to be revised after
                    #              bug 928059 merges
                    'type': 'text/html',
                    'href': ('https://github.com/openstack/'
                        'identity-api'),
                }
            ]
        }


@logging.fail_gracefully
def public_app_factory(global_conf, **local_conf):
    conf = global_conf.copy()
    conf.update(local_conf)
    return PublicRouter()


@logging.fail_gracefully
def admin_app_factory(global_conf, **local_conf):
    conf = global_conf.copy()
    conf.update(local_conf)
    return AdminRouter()


@logging.fail_gracefully
def public_version_app_factory(global_conf, **local_conf):
    conf = global_conf.copy()
    conf.update(local_conf)
    return PublicVersionRouter()


@logging.fail_gracefully
def admin_version_app_factory(global_conf, **local_conf):
    conf = global_conf.copy()
    conf.update(local_conf)
    return AdminVersionRouter()
