"""Python 'uu_codec' Codec - UU content transfer encoding.

This codec de/encodes from bytes to bytes.

Written by Marc-Andre Lemburg (mal@lemburg.com). Some details were
adapted from uu.py which was written by Lance Ellinghouse and
modified by Jack Jansen and Fredrik Lundh.
"""

import codecs
import binascii
from io import BytesIO

### Codec APIs

def uu_encode(input, errors='strict', filename='<data>', mode=0o666):
 assert errors == 'strict'
 infile = BytesIO(input)
 outfile = BytesIO()
 read = infile.read
 write = outfile.write

 # Remove newline chars from filename
 filename = filename.replace('\n','\\n')
 filename = filename.replace('\r','\\r')

 # Encode
 write(('begin %o %s\n' % (mode & 0o777, filename)).encode('ascii'))
 chunk = read(45)
 while chunk:
 write(binascii.b2a_uu(chunk))
 chunk = read(45)
 write(b' \nend\n')

 return (outfile.getvalue(), len(input))

def uu_decode(input, errors='strict'):
 assert errors == 'strict'
 infile = BytesIO(input)
 outfile = BytesIO()
 readline = infile.readline
 write = outfile.write

 # Find start of encoded data
 while 1:
 s = readline()
 if not s:
 raise ValueError('Missing "begin" line in input data')
 if s[:5] == b'begin':
 break

 # Decode
 while True:
 s = readline()
 if not s or s == b'end\n':
 break
 try:
 data = binascii.a2b_uu(s)
 except binascii.Error as v:
 # Workaround for broken uuencoders by /Fredrik Lundh
 nbytes = (((s[0]-32) & 63) * 4 + 5) // 3
 data = binascii.a2b_uu(s[:nbytes])
 #sys.stderr.write("Warning: %s\n" % str(v))
 write(data)
 if not s:
 raise ValueError('Truncated input data')

 return (outfile.getvalue(), len(input))

class Codec(codecs.Codec):
 def encode(self, input, errors='strict'):
 return uu_encode(input, errors)

 def decode(self, input, errors='strict'):
 return uu_decode(input, errors)

class IncrementalEncoder(codecs.IncrementalEncoder):
 def encode(self, input, final=False):
 return uu_encode(input, self.errors)[0]

class IncrementalDecoder(codecs.IncrementalDecoder):
 def decode(self, input, final=False):
 return uu_decode(input, self.errors)[0]

class StreamWriter(Codec, codecs.StreamWriter):
 charbuffertype = bytes

class StreamReader(Codec, codecs.StreamReader):
 charbuffertype = bytes

### encodings module API

def getregentry():
 return codecs.CodecInfo(
 name='uu',
 encode=uu_encode,
 decode=uu_decode,
 incrementalencoder=IncrementalEncoder,
 incrementaldecoder=IncrementalDecoder,
 streamreader=StreamReader,
 streamwriter=StreamWriter,
 _is_text_encoding=False,
 )