# Copyright 2017 Amazon.com, Inc. or its affiliates. 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. A copy of
# the License is located at
#
# http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file 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 contextlib
from tests import BaseSessionTest, mock, ClientHTTPStubber

from botocore.exceptions import ClientError
from botocore.config import Config


class TestRetry(BaseSessionTest):
    def setUp(self):
        super(TestRetry, self).setUp()
        self.region = 'us-west-2'
        self.sleep_patch = mock.patch('time.sleep')
        self.sleep_patch.start()

    def tearDown(self):
        self.sleep_patch.stop()

    @contextlib.contextmanager
    def assert_will_retry_n_times(self, client, num_retries):
        num_responses = num_retries + 1
        with ClientHTTPStubber(client) as http_stubber:
            for _ in range(num_responses):
                http_stubber.add_response(status=500, body=b'{}')
            with self.assertRaisesRegexp(
                    ClientError, 'reached max retries: %s' % num_retries):
                yield
            self.assertEqual(len(http_stubber.requests), num_responses)

    def test_can_override_max_attempts(self):
        client = self.session.create_client(
            'dynamodb', self.region, config=Config(
                retries={'max_attempts': 1}))
        with self.assert_will_retry_n_times(client, 1):
            client.list_tables()

    def test_do_not_attempt_retries(self):
        client = self.session.create_client(
            'dynamodb', self.region, config=Config(
                retries={'max_attempts': 0}))
        with self.assert_will_retry_n_times(client, 0):
            client.list_tables()

    def test_setting_max_attempts_does_not_set_for_other_clients(self):
        # Make one client with max attempts configured.
        self.session.create_client(
            'codecommit', self.region, config=Config(
                retries={'max_attempts': 1}))

        # Make another client that has no custom retry configured.
        client = self.session.create_client('codecommit', self.region)
        # It should use the default max retries, which should be four retries
        # for this service.
        with self.assert_will_retry_n_times(client, 4):
            client.list_repositories()

    def test_service_specific_defaults_do_not_mutate_general_defaults(self):
        # This tests for a bug where if you created a client for a service
        # with specific retry configurations and then created a client for
        # a service whose retry configurations fallback to the general
        # defaults, the second client would actually use the defaults of
        # the first client.

        # Make a dynamodb client. It's a special case client that is
        # configured to a make a maximum of 10 requests (9 retries).
        client = self.session.create_client('dynamodb', self.region)
        with self.assert_will_retry_n_times(client, 9):
            client.list_tables()

        # A codecommit client is not a special case for retries. It will at
        # most make 5 requests (4 retries) for its default.
        client = self.session.create_client('codecommit', self.region)
        with self.assert_will_retry_n_times(client, 4):
            client.list_repositories()

    def test_set_max_attempts_on_session(self):
        self.session.set_default_client_config(
            Config(retries={'max_attempts': 1}))
        # Max attempts should be inherited from the session.
        client = self.session.create_client('codecommit', self.region)
        with self.assert_will_retry_n_times(client, 1):
            client.list_repositories()

    def test_can_clobber_max_attempts_on_session(self):
        self.session.set_default_client_config(
            Config(retries={'max_attempts': 1}))
        # Max attempts should override the session's configured max attempts.
        client = self.session.create_client(
            'codecommit', self.region, config=Config(
                retries={'max_attempts': 0}))
        with self.assert_will_retry_n_times(client, 0):
            client.list_repositories()