from __future__ import unicode_literals

import pytest
from rlp import SerializationError, utils
from rlp.sedes import big_endian_int, BigEndianInt
from rlp.utils import int_to_big_endian

valid_data = (
    (256, b'\x01\x00'),
    (1024, b'\x04\x00'),
    (65535, b'\xff\xff'),
)

single_bytes = ((n, utils.ascii_chr(n)) for n in range(1, 256))

random_integers = (256, 257, 4839, 849302, 483290432, 483290483290482039482039,
                   48930248348219540325894323584235894327865439258743754893066)
assert random_integers[-1] < 2**256

negative_ints = (-1, -100, -255, -256, -2342423)


def test_neg():
    for n in negative_ints:
        with pytest.raises(SerializationError):
            big_endian_int.serialize(n)


def test_serialization():
    for n in random_integers:
        serial = big_endian_int.serialize(n)
        deserialized = big_endian_int.deserialize(serial)
        assert deserialized == n
        if n != 0:
            assert serial[0] != b'\x00'  # is not checked


def test_single_byte():
    for n, s in single_bytes:
        serial = big_endian_int.serialize(n)
        assert serial == s
        deserialized = big_endian_int.deserialize(serial)
        assert deserialized == n


def test_valid_data():
    for n, serial in valid_data:
        serialized = big_endian_int.serialize(n)
        deserialized = big_endian_int.deserialize(serial)
        assert serialized == serial
        assert deserialized == n


def test_fixedlength():
    s = BigEndianInt(4)
    for i in (0, 1, 255, 256, 256**3, 256**4 - 1):
        assert len(s.serialize(i)) == 4
        assert s.deserialize(s.serialize(i)) == i
    for i in (256**4, 256**4 + 1, 256**5, -1, -256, 'asdf'):
        with pytest.raises(SerializationError):
            s.serialize(i)


import binascii


def packl(lnum):
    """Packs the lnum (which must be convertable to a long) into a
       byte string 0 padded to a multiple of padmultiple bytes in size. 0
       means no padding whatsoever, so that packing 0 result in an empty
       string.  The resulting byte string is the big-endian two's
       complement representation of the passed in long."""

    if lnum == 0:
        return b'\0'
    s = hex(lnum)[2:]
    s = s.rstrip('L')
    if len(s) & 1:
        s = '0' + s
    s = binascii.unhexlify(s)
    return s


try:
    import ctypes
    PyLong_AsByteArray = ctypes.pythonapi._PyLong_AsByteArray
    PyLong_AsByteArray.argtypes = [ctypes.py_object,
                                   ctypes.c_char_p,
                                   ctypes.c_size_t,
                                   ctypes.c_int,
                                   ctypes.c_int]
    import sys
    long_start = sys.maxint + 1

    def packl_ctypes(lnum):
        if lnum < long_start:
            return int_to_big_endian(lnum)
        a = ctypes.create_string_buffer(lnum.bit_length() // 8 + 1)
        PyLong_AsByteArray(lnum, a, len(a), 0, 1)
        return a.raw.lstrip(b'\0')
except AttributeError:
    packl_ctypes = packl


def test_packl():
    for i in range(256):
        v = 2**i - 1
        rc = packl_ctypes(v)
        assert rc == int_to_big_endian(v)
        r = packl(v)
        assert r == int_to_big_endian(v)


def perf():
    import time

    st = time.time()
    for j in range(100000):
        for i in random_integers:
            packl(i)
    print('packl elapsed {}'.format(time.time() - st))

    st = time.time()
    for j in range(100000):
        for i in random_integers:
            packl_ctypes(i)
    print('ctypes elapsed {}'.format(time.time() - st))

    st = time.time()
    for j in range(100000):
        for i in random_integers:
            int_to_big_endian(i)
    print('py elapsed {}'.format(time.time() - st))


if __name__ == '__main__':
    # test_packl()
    perf()
