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

#    Copyright (C) 2014 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.

import futurist
import testtools

from taskflow.engines.action_engine import engine
from taskflow.engines.action_engine import executor
from taskflow.engines.action_engine import process_executor
from taskflow.patterns import linear_flow as lf
from taskflow.persistence import backends
from taskflow import test
from taskflow.tests import utils
from taskflow.utils import eventlet_utils as eu
from taskflow.utils import persistence_utils as pu


class ParallelCreationTest(test.TestCase):
    @staticmethod
    def _create_engine(**kwargs):
        flow = lf.Flow('test-flow').add(utils.DummyTask())
        backend = backends.fetch({'connection': 'memory'})
        flow_detail = pu.create_flow_detail(flow, backend=backend)
        options = kwargs.copy()
        return engine.ParallelActionEngine(flow, flow_detail,
                                           backend, options)

    def test_thread_string_creation(self):
        for s in ['threads', 'threaded', 'thread']:
            eng = self._create_engine(executor=s)
            self.assertIsInstance(eng._task_executor,
                                  executor.ParallelThreadTaskExecutor)

    def test_process_string_creation(self):
        for s in ['process', 'processes']:
            eng = self._create_engine(executor=s)
            self.assertIsInstance(eng._task_executor,
                                  process_executor.ParallelProcessTaskExecutor)

    def test_thread_executor_creation(self):
        with futurist.ThreadPoolExecutor(1) as e:
            eng = self._create_engine(executor=e)
            self.assertIsInstance(eng._task_executor,
                                  executor.ParallelThreadTaskExecutor)

    def test_process_executor_creation(self):
        with futurist.ProcessPoolExecutor(1) as e:
            eng = self._create_engine(executor=e)
            self.assertIsInstance(eng._task_executor,
                                  process_executor.ParallelProcessTaskExecutor)

    @testtools.skipIf(not eu.EVENTLET_AVAILABLE, 'eventlet is not available')
    def test_green_executor_creation(self):
        with futurist.GreenThreadPoolExecutor(1) as e:
            eng = self._create_engine(executor=e)
            self.assertIsInstance(eng._task_executor,
                                  executor.ParallelThreadTaskExecutor)

    def test_sync_executor_creation(self):
        with futurist.SynchronousExecutor() as e:
            eng = self._create_engine(executor=e)
            self.assertIsInstance(eng._task_executor,
                                  executor.ParallelThreadTaskExecutor)

    def test_invalid_creation(self):
        self.assertRaises(ValueError, self._create_engine, executor='crap')
        self.assertRaises(TypeError, self._create_engine, executor=2)
        self.assertRaises(TypeError, self._create_engine, executor=object())