# -*- coding: utf-8 -*-

from syncano.exceptions import SyncanoValueError

class RelationValidatorMixin(object):

def validate(self, value, model_instance):

super(RelationValidatorMixin, self).validate(value, model_instance)

self._check_relation_value(value)

@classmethod

def _check_relation_value(cls, value):

if value is None:

return False

if '_add' in value or '_remove' in value:

check_value = value.get('_add') or value.get('_remove')

else:

check_value = value

check_value = cls._make_list(check_value)

all_ints = all([isinstance(x, int) for x in check_value])

from .archetypes import Model

all_objects = all([isinstance(obj, Model) for obj in check_value])

object_types = [type(obj) for obj in check_value]

if len(set(object_types)) != 1:

raise SyncanoValueError("All objects should be the same type.")

if (all_ints and all_objects) or (not all_ints and not all_objects):

raise SyncanoValueError("List elements should be objects or integers.")

if all_objects:

return True

return False

@classmethod

def _make_list(cls, value):

if not isinstance(value, (list, tuple)):

value = [value]

return value

class RelationManager(RelationValidatorMixin):

def __init__(self, instance, field_name):

super(RelationManager, self).__init__()

self.instance = instance

self.model = instance._meta

self.field_name = field_name

def add(self, *args):

self._add_or_remove(args)

def remove(self, *args):

self._add_or_remove(args, operation='_remove')

def _add_or_remove(self, id_list, operation='_add'):

if self._check_relation_value(id_list):

value_ids = [obj.id for obj in id_list]

else:

value_ids = id_list

meta = self.instance._meta

connection = meta.connection

data = {self.field_name: {operation: value_ids}}

update_path = meta.get_endpoint(name='detail')['path']

update_path = update_path.format(**self.instance.get_endpoint_data())

response = connection.request('PATCH', update_path, data=data)

self.instance.to_python(response)