# SPDX-License-Identifier: MIT
#
# Copyright (c) 2017 PySecretHandshake contributors (see AUTHORS for more details)
#
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# of this software and associated documentation files (the "Software"), to deal
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# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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"""Tests for utility functions"""

import math

import pytest

from secret_handshake.util import bytes_to_long, long_to_bytes


@pytest.mark.parametrize(
    "in_,out",
    (
        (0, b"\x00"),
        (1, b"\x01"),
        (4278255360, b"\xff\x00\xff\x00"),
        (65536, b"\x01\x00\x00"),
        (4546694913, b"\x01\x0f\x01\x0f\x01"),
    ),
)
@pytest.mark.parametrize("blocksize", (0, 4, 6))
def test_long_to_bytes(in_: int, out: bytes, blocksize: int) -> None:
    """Test long_to_bytes"""

    result = long_to_bytes(in_, blocksize=blocksize)

    if blocksize:
        block_count = math.ceil(len(out) / blocksize)
    else:
        block_count = 1

    padding = b"\x00" * blocksize * block_count
    expected = (padding + out)[-(blocksize * block_count) :]

    if blocksize:
        assert not len(result) % blocksize

    assert result == expected


@pytest.mark.parametrize(
    "in_,out",
    (
        (b"\x00\x00\x00\x00", 0),
        (b"\x00\x00\x00\x01", 1),
        (b"\xff\x00\xff\x00", 4278255360),
        (b"\x01\x00\x00", 65536),
        (b"\x01\x0f\x01\x0f\x01", 4546694913),
    ),
)
def test_bytes_to_long(in_: bytes, out: int) -> None:
    """Test bytes_to_long"""

    assert bytes_to_long(in_) == out