# Copyright (C) 2001-2006 Python Software Foundation
# Author: Barry Warsaw
# Contact: [email protected]

"""Encodings and related functions."""

__all__ = [
'encode_7or8bit',
'encode_base64',
'encode_noop',
'encode_quopri',
]


from base64 import encodebytes as _bencode
from quopri import encodestring as _encodestring



def _qencode(s):
enc = _encodestring(s, quotetabs=True)
# Must encode spaces, which quopri.encodestring() doesn't do
return enc.replace(b' ', b'=20')


def encode_base64(msg):
"""Encode the message's payload in Base64.

Also, add an appropriate Content-Transfer-Encoding header.
"""
orig = msg.get_payload(decode=True)
encdata = str(_bencode(orig), 'ascii')
msg.set_payload(encdata)
msg['Content-Transfer-Encoding'] = 'base64'



def encode_quopri(msg):
"""Encode the message's payload in quoted-printable.

Also, add an appropriate Content-Transfer-Encoding header.
"""
orig = msg.get_payload(decode=True)
encdata = _qencode(orig)
msg.set_payload(encdata)
msg['Content-Transfer-Encoding'] = 'quoted-printable'



def encode_7or8bit(msg):
"""Set the Content-Transfer-Encoding header to 7bit or 8bit."""
orig = msg.get_payload(decode=True)
if orig is None:
# There's no payload. For backwards compatibility we use 7bit
msg['Content-Transfer-Encoding'] = '7bit'
return
# We play a trick to make this go fast. If decoding from ASCII succeeds,
# we know the data must be 7bit, otherwise treat it as 8bit.
try:
orig.decode('ascii')
except UnicodeError:
msg['Content-Transfer-Encoding'] = '8bit'
else:
msg['Content-Transfer-Encoding'] = '7bit'



def encode_noop(msg):
"""Do nothing."""