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

"""Shift Codec - Shift-ordinal-with-N 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 *

__examples__ = {

'enc(shift0|shift--10|shift256)': None,

'enc(shift1|shift_1|shift-1)': {'this is a test': "uijt!jt!b!uftu"},

'enc(shift9|shift_9|shift-9)': {'this is a test': "}qr|)r|)j)}n|}"},

}

__guess__ = ["shift-%d" % i for i in range(1, 256)]

def ord_shift_decode(i):

return ord_shift_encode(-int(i))

def ord_shift_encode(i):

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

r = "".join(chr((ord(c) + int(i)) % 256) for c in text)

return r, len(r)

return encode

add("shift", ord_shift_encode, ord_shift_decode, r"shift[-_]?([1-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])$",

transitive=True)