"""Tests for Kindle PID generation helpers (kgenpids)."""

import dedrm_test_utils as U

kg = U.load("kgenpids")


def test_encode_known_vector():
    assert kg.encode(b"\x00\x01\x42\xff\x80", kg.charMap1) == b"6n65tPrMnn"


def test_encode_doubles_length():
    data = b"\x10\x20\x30"
    assert len(kg.encode(data, kg.charMap1)) == 2 * len(data)


def test_two_bits_from_bit_field():
    assert [kg.getTwoBitsFromBitField(b"\x1b\x2c\x3d\x4e", i) for i in range(4)] == [0, 1, 2, 3]


def test_six_bits_from_bit_field():
    assert kg.getSixBitsFromBitField(b"\xff\xff\xff\xff", 0) == 63


def test_pid_encryption_table_is_crc32_table():
    table = kg.generatePidEncryptionTable()
    assert len(table) == 256
    assert table[0] == 0
    # Standard reflected CRC-32 table entry.
    assert table[1] == 0x77073096


def test_generate_device_pid_known_vector():
    table = kg.generatePidEncryptionTable()
    assert kg.generateDevicePID(table, b"\x12\x34\x56\x78", 4) == b"22I8IQVF"