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

    Unlike most of the other codecs which target Unicode, this codec

    will return Python string objects for both encode and decode.

    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, binascii

### Codec APIs

def uu_encode(input,errors='strict',filename='<data>',mode=0666):

    """ Encodes the object input and returns a tuple (output

        object, length consumed).

        errors defines the error handling to apply. It defaults to

        'strict' handling which is the only currently supported

        error handling for this codec.

    """

    assert errors == 'strict'

    from cStringIO import StringIO

    from binascii import b2a_uu

    infile = StringIO(input)

    outfile = StringIO()

    read = infile.read

    write = outfile.write

    # Encode

    write('begin %o %s\n' % (mode & 0777, filename))

    chunk = read(45)

    while chunk:

        write(b2a_uu(chunk))

        chunk = read(45)

    write(' \nend\n')

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

def uu_decode(input,errors='strict'):

    """ Decodes the object input and returns a tuple (output

        object, length consumed).

        input must be an object which provides the bf_getreadbuf

        buffer slot. Python strings, buffer objects and memory

        mapped files are examples of objects providing this slot.

        errors defines the error handling to apply. It defaults to

        'strict' handling which is the only currently supported

        error handling for this codec.

        Note: filename and file mode information in the input data is

        ignored.

    """

    assert errors == 'strict'

    from cStringIO import StringIO

    from binascii import a2b_uu

    infile = StringIO(input)

    outfile = StringIO()

    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] == 'begin':

            break

    # Decode

    while 1:

        s = readline()

        if not s or \

           s == 'end\n':

            break

        try:

            data = a2b_uu(s)

        except binascii.Error, v:

            # Workaround for broken uuencoders by /Fredrik Lundh

            nbytes = (((ord(s[0])-32) & 63) * 4 + 5) / 3

            data = 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):

    pass

class StreamReader(Codec,codecs.StreamReader):

    pass

### encodings module API

def getregentry():

    return codecs.CodecInfo(

        name='uu',

        encode=uu_encode,

        decode=uu_decode,

        incrementalencoder=IncrementalEncoder,

        incrementaldecoder=IncrementalDecoder,

        streamreader=StreamReader,

        streamwriter=StreamWriter,

    )