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

"""Base45 Codec - base45 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 ._base import _get_charset, digits, lower, main, upper

from ..__common__ import *

__examples__ = {

'enc(base45|base-45|base_45)': {'this is a test!': "AWE+EDH44.OEOCC7WE QEX0"},

'enc(base45-inv|base_45_inv)': {'this is a test!': "K6O+ONREE.YOYMMH6O 0O7A"},

'dec(base45)': {'BAD STRING\00': None, 'AWE+EDH44.OEOCC7WE QEX000': None},

}

__guess__ = ["base45", "base45-inv"]

B45 = {

'': digits + upper + " $%*+-./:",

'[-_]inv(?:erted)?$': upper + digits + " $%*+-./:",

}

__chr = lambda c: chr(c >> 8) + chr(c & 0xff) if isinstance(c, int) and 256 <= c <= 65535 else \

chr(c) if isinstance(c, int) else c

__ord = lambda c: ord(c) if not isinstance(c, int) else c

def base45_encode(mode):

b45 = _get_charset(B45, mode)

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

t, s = b(text), ""

for i in range(0, len(text), 2):

n = 256 * __ord(t[i])

try:

n += __ord(t[i+1])

except IndexError:

n = __ord(t[i])

s += b45[n % 45] + b45[n // 45]

break

m = n // 45**2

n -= m * 45**2

s += b45[n % 45] + b45[n // 45] + b45[m]

return s, len(text)

return encode

def base45_decode(mode):

b45 = {c: i for i, c in enumerate(_get_charset(B45, mode))}

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

t, s = b(text), ""

ehandler = handle_error("base45", errors, decode=True)

for i in range(0, len(text), 3):

try:

n = b45[__chr(t[i])]

except KeyError:

ehandler(__chr(t[i]), i, s)

try:

j = i + 1

n += 45 * b45[__chr(t[j])]

except KeyError:

ehandler(__chr(t[j]), j, s)

except IndexError:

ehandler(__chr(t[i]), i, s)

try:

k = i + 2

n += 45 ** 2 * b45[__chr(t[k])]

except KeyError:

ehandler(__chr(t[k]), k, s)

except IndexError:

s += __chr(n)

continue

s += __chr(n // 256) + __chr(n % 256)

return s, len(text)

return decode

add("base45", base45_encode, base45_decode, r"^base[-_]?45(|[-_]inv(?:erted)?)$", expansion_factor=1.5)

main = main(45, "<https://datatracker.ietf.org/doc/html/draft-faltstrom-base45-04.txt>")