# -*- coding: UTF-8 -*-

"""Manchester Codec - Manchester content encoding.

This codec:

- en/decodes strings from str to str

- en/decodes strings from bytes to bytes

- decodes file content to str (read)

- encodes file content from str to bytes (write)

"""

from ..__common__ import *

__examples1__ = {'enc(manchester)': {'This is a test!': "fei\x95i\x96jZYUi\x96jZYUiVYUjeifjZjeYV"}}

__examples2__ = {

'enc(manchester-inverted|ethernet|ieee802.4)': {

'This is a test!': "\x99\x9a\x96j\x96i\x95\xa5\xa6\xaa\x96i\x95\xa5\xa6\xaa\x96\xa9\xa6\xaa\x95\x9a\x96\x99"

"\x95\xa5\x95\x9a\xa6\xa9",

},

}

def manchester_encode(clock):

def encode(text, errors="strict"):

r = ""

for c in text:

bin_c = bin(ord(c))[2:].zfill(8)

for i in range(0, 8, 4):

r += chr(int("".join(2*bit for bit in bin_c[i:i+4]), 2) ^ clock)

return r, len(b(text))

return encode

def manchester_decode(clock):

def decode(text, errors="strict"):

r, bits = "", ""

for c in text:

bin_c = bin(ord(c) ^ clock)[2:].zfill(8)

bits += "".join(bin_c[i] for i in range(0, len(bin_c), 2))

if len(bits) == 8:

r += chr(int(bits, 2))

bits = ""

return r, len(b(text))

return decode

add("manchester", manchester_encode(0x55), manchester_decode(0x55), examples=__examples1__, printables_rate=.25,

entropy=lambda e: .17616*e+2.56229)

add("manchester-inverted", manchester_encode(0xaa), manchester_decode(0xaa), examples=__examples2__,

pattern=r"^(?:manchester-inverted|ethernet|ieee802\.4)$", entropy=lambda e: .17616*e+2.56229)