# Copyright 2018 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.
"""Helper utilities for unit tests."""
import itertools

import pytest

from dynamodb_encryption_sdk.delegated_keys.jce import JceNameLocalDelegatedKey
from dynamodb_encryption_sdk.material_providers.wrapped import WrappedCryptographicMaterialsProvider


@pytest.fixture
def wrapped_cmp():
    wrapping_key = JceNameLocalDelegatedKey.generate("AES", 256)
    signing_key = JceNameLocalDelegatedKey.generate("HmacSHA512", 256)
    cmp = WrappedCryptographicMaterialsProvider(
        signing_key=signing_key, wrapping_key=wrapping_key, unwrapping_key=wrapping_key
    )
    return cmp


def all_possible_combinations(*base_values):
    combinations = [itertools.combinations(base_values, i) for i in range(1, len(base_values) + 1)]
    return itertools.chain(*combinations)


def all_possible_combinations_kwargs(*base_values):
    for combo in all_possible_combinations(*base_values):
        kwargs = {}
        for values in combo:
            kwargs.update(values)
        yield kwargs