# Copyright (c) 2014 Hewlett-Packard Development Company, L.P.
#
# 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.

from oslo.serialization import jsonutils
import six
import webob.exc
from wsme.rest import json

from glance.api import policy
from glance.api.v2 import metadef_namespaces as namespaces
from glance.api.v2.model.metadef_namespace import Namespace
from glance.api.v2.model.metadef_property_type import PropertyType
from glance.api.v2.model.metadef_property_type import PropertyTypes
from glance.common import exception
from glance.common import utils
from glance.common import wsgi
import glance.db
import glance.gateway
from glance import i18n
import glance.notifier
import glance.openstack.common.log as logging
import glance.schema

LOG = logging.getLogger(__name__)
_LE = i18n._LE
_LI = i18n._LI


class NamespacePropertiesController(object):
    def __init__(self, db_api=None, policy_enforcer=None):
        self.db_api = db_api or glance.db.get_api()
        self.policy = policy_enforcer or policy.Enforcer()
        self.gateway = glance.gateway.Gateway(db_api=self.db_api,
                                              policy_enforcer=self.policy)

    def _to_dict(self, model_property_type):
        # Convert the model PropertyTypes dict to a JSON encoding
        db_property_type_dict = dict()
        db_property_type_dict['schema'] = json.tojson(
            PropertyType, model_property_type)
        db_property_type_dict['name'] = model_property_type.name
        return db_property_type_dict

    def _to_model(self, db_property_type):
        # Convert the persisted json schema to a dict of PropertyTypes
        property_type = json.fromjson(
            PropertyType, db_property_type.schema)
        property_type.name = db_property_type.name
        return property_type

    def index(self, req, namespace):
        try:
            filters = dict()
            filters['namespace'] = namespace
            prop_repo = self.gateway.get_metadef_property_repo(req.context)
            db_properties = prop_repo.list(filters=filters)
            property_list = Namespace.to_model_properties(db_properties)
            namespace_properties = PropertyTypes()
            namespace_properties.properties = property_list
        except exception.Forbidden as e:
            raise webob.exc.HTTPForbidden(explanation=e.msg)
        except exception.NotFound as e:
            raise webob.exc.HTTPNotFound(explanation=e.msg)
        except Exception as e:
            LOG.error(utils.exception_to_str(e))
            raise webob.exc.HTTPInternalServerError()
        return namespace_properties

    def show(self, req, namespace, property_name, filters=None):
        try:
            if filters and filters['resource_type']:
                rs_repo = self.gateway.get_metadef_resource_type_repo(
                    req.context)
                db_resource_type = rs_repo.get(filters['resource_type'],
                                               namespace)
                prefix = db_resource_type.prefix
                if prefix and property_name.startswith(prefix):
                    property_name = property_name[len(prefix):]
                else:
                    msg = (_("Property %(property_name)s does not start "
                             "with the expected resource type association "
                             "prefix of '%(prefix)s'.")
                           % {'property_name': property_name,
                              'prefix': prefix})
                    raise exception.NotFound(msg)

            prop_repo = self.gateway.get_metadef_property_repo(req.context)
            db_property = prop_repo.get(namespace, property_name)
            property = self._to_model(db_property)
        except exception.Forbidden as e:
            raise webob.exc.HTTPForbidden(explanation=e.msg)
        except exception.NotFound as e:
            raise webob.exc.HTTPNotFound(explanation=e.msg)
        except Exception as e:
            LOG.error(utils.exception_to_str(e))
            raise webob.exc.HTTPInternalServerError()
        return property

    def create(self, req, namespace, property_type):
        prop_factory = self.gateway.get_metadef_property_factory(req.context)
        prop_repo = self.gateway.get_metadef_property_repo(req.context)
        try:
            new_property_type = prop_factory.new_namespace_property(
                namespace=namespace, **self._to_dict(property_type))
            prop_repo.add(new_property_type)
        except exception.Forbidden as e:
            raise webob.exc.HTTPForbidden(explanation=e.msg)
        except exception.NotFound as e:
            raise webob.exc.HTTPNotFound(explanation=e.msg)
        except exception.Duplicate as e:
            raise webob.exc.HTTPConflict(explanation=e.msg)
        except Exception as e:
            LOG.error(utils.exception_to_str(e))
            raise webob.exc.HTTPInternalServerError()
        return self._to_model(new_property_type)

    def update(self, req, namespace, property_name, property_type):
        prop_repo = self.gateway.get_metadef_property_repo(req.context)
        try:
            db_property_type = prop_repo.get(namespace, property_name)
            db_property_type.name = property_type.name
            db_property_type.schema = (self._to_dict(property_type))['schema']
            updated_property_type = prop_repo.save(db_property_type)
        except exception.Forbidden as e:
            raise webob.exc.HTTPForbidden(explanation=e.msg)
        except exception.NotFound as e:
            raise webob.exc.HTTPNotFound(explanation=e.msg)
        except exception.Duplicate as e:
            raise webob.exc.HTTPConflict(explanation=e.msg)
        except Exception as e:
            LOG.error(utils.exception_to_str(e))
            raise webob.exc.HTTPInternalServerError()
        return self._to_model(updated_property_type)

    def delete(self, req, namespace, property_name):
        prop_repo = self.gateway.get_metadef_property_repo(req.context)
        try:
            property_type = prop_repo.get(namespace, property_name)
            property_type.delete()
            prop_repo.remove(property_type)
        except exception.Forbidden as e:
            raise webob.exc.HTTPForbidden(explanation=e.msg)
        except exception.NotFound as e:
            raise webob.exc.HTTPNotFound(explanation=e.msg)
        except Exception as e:
            LOG.error(utils.exception_to_str(e))
            raise webob.exc.HTTPInternalServerError()


class RequestDeserializer(wsgi.JSONRequestDeserializer):
    _disallowed_properties = ['created_at', 'updated_at']

    def __init__(self, schema=None):
        super(RequestDeserializer, self).__init__()
        self.schema = schema or get_schema()

    def _get_request_body(self, request):
        output = super(RequestDeserializer, self).default(request)
        if 'body' not in output:
            msg = _('Body expected in request.')
            raise webob.exc.HTTPBadRequest(explanation=msg)
        return output['body']

    @classmethod
    def _check_allowed(cls, image):
        for key in cls._disallowed_properties:
            if key in image:
                msg = _("Attribute '%s' is read-only.") % key
                raise webob.exc.HTTPForbidden(explanation=msg)

    def create(self, request):
        body = self._get_request_body(request)
        self._check_allowed(body)
        try:
            self.schema.validate(body)
        except exception.InvalidObject as e:
            raise webob.exc.HTTPBadRequest(explanation=e.msg)
        property_type = json.fromjson(PropertyType, body)
        return dict(property_type=property_type)

    def update(self, request):
        body = self._get_request_body(request)
        self._check_allowed(body)
        try:
            self.schema.validate(body)
        except exception.InvalidObject as e:
            raise webob.exc.HTTPBadRequest(explanation=e.msg)
        property_type = json.fromjson(PropertyType, body)
        return dict(property_type=property_type)

    def show(self, request):
        params = request.params.copy()
        query_params = {
            'filters': params
        }
        return query_params


class ResponseSerializer(wsgi.JSONResponseSerializer):
    def __init__(self, schema=None):
        super(ResponseSerializer, self).__init__()
        self.schema = schema

    def show(self, response, result):
        property_type_json = json.tojson(PropertyType, result)
        body = jsonutils.dumps(property_type_json, ensure_ascii=False)
        response.unicode_body = six.text_type(body)
        response.content_type = 'application/json'

    def index(self, response, result):
        property_type_json = json.tojson(PropertyTypes, result)
        body = jsonutils.dumps(property_type_json, ensure_ascii=False)
        response.unicode_body = six.text_type(body)
        response.content_type = 'application/json'

    def create(self, response, result):
        response.status_int = 201
        self.show(response, result)

    def update(self, response, result):
        response.status_int = 200
        self.show(response, result)

    def delete(self, response, result):
        response.status_int = 204


def _get_base_definitions():
    return {
        "positiveInteger": {
            "type": "integer",
            "minimum": 0
        },
        "positiveIntegerDefault0": {
            "allOf": [
                {"$ref": "#/definitions/positiveInteger"},
                {"default": 0}
            ]
        },
        "stringArray": {
            "type": "array",
            "items": {"type": "string"},
            "minItems": 1,
            "uniqueItems": True
        }
    }


def _get_base_properties():
    base_def = namespaces.get_schema_definitions()
    return base_def['property']['additionalProperties']['properties']


def get_schema():
    definitions = _get_base_definitions()
    properties = _get_base_properties()
    mandatory_attrs = PropertyType.get_mandatory_attrs()
    # name is required attribute when use as single property type
    mandatory_attrs.append('name')
    schema = glance.schema.Schema(
        'property',
        properties,
        required=mandatory_attrs,
        definitions=definitions
    )
    return schema


def get_collection_schema():
    namespace_properties_schema = get_schema()
    # Property name is a dict key and not a required attribute in
    # individual property schema inside property collections
    namespace_properties_schema.required.remove('name')
    return glance.schema.DictCollectionSchema('properties',
                                              namespace_properties_schema)


def create_resource():
    """NamespaceProperties resource factory method"""
    schema = get_schema()
    deserializer = RequestDeserializer(schema)
    serializer = ResponseSerializer(schema)
    controller = NamespacePropertiesController()
    return wsgi.Resource(controller, deserializer, serializer)
