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

"""Atbash Cipher Codec - atbash-based 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)

Reference: https://crypto.interactive-maths.com/atbash-cipher.html

"""

from ..__common__ import *

__guess__ = ["atbash"]

def encmap_factory(mask=None):

mask = mask or "?u?l"

# [...] enclosure causes the mask to be handled as a whole

if mask[0] == "[" and mask[-1] == "]":

alphabet = get_alphabet_from_mask(mask[1:-1])

return {k: v for k, v in zip(alphabet, alphabet[::-1])}

# not enclosing the whole mask means that each group is to be considered separately

else:

m = {}

for group in re.findall(r"(\?.|[^?]+)", mask):

alphabet = get_alphabet_from_mask(group)

m.update({k: v for k, v in zip(alphabet, alphabet[::-1])})

return m

add_map("atbash", encmap_factory, no_error=True, pattern=r"atbash(?:[-_]cipher)?(?:[-_](.+))?$")