# Copyright 2010-present Basho Technologies, Inc.
#
# 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.


def default_resolver(riak_object):
    """
    The default conflict-resolution function, which does nothing. To
    implement a resolver, define a function that sets the
    :attr:`siblings <aioriak.riak_object.RiakObject.siblings>` property
    on the passed :class:`RiakObject <aioriak.riak_object.RiakObject>`
    instance to a list containing a single :class:`RiakContent
    <aioriak.content.RiakContent>` object.

    :param riak_object: an object-in-conflict that will be resolved
    :type riak_object: :class:`RiakObject <aioriak.riak_object.RiakObject>`
    """
    pass


def last_written_resolver(riak_object):
    """
    A conflict-resolution function that resolves by selecting the most
    recently-modified sibling by timestamp.

    :param riak_object: an object-in-conflict that will be resolved
    :type riak_object: :class:`RiakObject <aioriak.riak_object.RiakObject>`
    """
    riak_object.siblings = [max(riak_object.siblings,
                                key=lambda x: x.last_modified), ]
