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

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

#    Copyright (C) 2012 Yahoo! Inc. All Rights Reserved.
#
#    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 taskflow import task

ARGS_KEY = '__args__'
KWARGS_KEY = '__kwargs__'
ORDER_KEY = '__order__'


def close_all(*args):
    for a in args:
        if not a:
            continue
        a.close()


def null_functor(*args, **kwargs):  # pylint: disable=W0613
    return None


class ProvidesRequiresTask(task.Task):
    def __init__(self, name, provides, requires):
        super(ProvidesRequiresTask, self).__init__(name)
        self.provides = provides
        self.requires = requires

    def apply(self, context, *args, **kwargs):
        outs = {
            KWARGS_KEY: dict(kwargs),
            ARGS_KEY: list(args),
        }
        if not ORDER_KEY in context:
            context[ORDER_KEY] = []
        context[ORDER_KEY].append(self.name)
        for v in self.provides:
            outs[v] = True
        return outs