#! /usr/bin/env python3

# Copyright 1994 by Lance Ellinghouse
# Cathedral City, California Republic, United States of America.
# All Rights Reserved
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose and without fee is hereby granted,
# provided that the above copyright notice appear in all copies and that
# both that copyright notice and this permission notice appear in
# supporting documentation, and that the name of Lance Ellinghouse
# not be used in advertising or publicity pertaining to distribution
# of the software without specific, written prior permission.
# LANCE ELLINGHOUSE DISCLAIMS ALL WARRANTIES WITH REGARD TO
# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
# FITNESS, IN NO EVENT SHALL LANCE ELLINGHOUSE CENTRUM BE LIABLE
# FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#
# Modified by Jack Jansen, CWI, July 1995:
# - Use binascii module to do the actual line-by-line conversion
# between ascii and binary. This results in a 1000-fold speedup. The C
# version is still 5 times faster, though.
# - Arguments more compliant with python standard

"""Implementation of the UUencode and UUdecode functions.

encode(in_file, out_file [,name, mode], *, backtick=False)
decode(in_file [, out_file, mode, quiet])
"""

import binascii
import os
import sys

__all__ = ["Error", "encode", "decode"]

class Error(Exception):
 pass

def encode(in_file, out_file, name=None, mode=None, *, backtick=False):
 """Uuencode file"""
 #
 # If in_file is a pathname open it and change defaults
 #
 opened_files = []
 try:
 if in_file == '-':
 in_file = sys.stdin.buffer
 elif isinstance(in_file, str):
 if name is None:
 name = os.path.basename(in_file)
 if mode is None:
 try:
 mode = os.stat(in_file).st_mode
 except AttributeError:
 pass
 in_file = open(in_file, 'rb')
 opened_files.append(in_file)
 #
 # Open out_file if it is a pathname
 #
 if out_file == '-':
 out_file = sys.stdout.buffer
 elif isinstance(out_file, str):
 out_file = open(out_file, 'wb')
 opened_files.append(out_file)
 #
 # Set defaults for name and mode
 #
 if name is None:
 name = '-'
 if mode is None:
 mode = 0o666

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

 #
 # Write the data
 #
 out_file.write(('begin %o %s\n' % ((mode & 0o777), name)).encode("ascii"))
 data = in_file.read(45)
 while len(data) > 0:
 out_file.write(binascii.b2a_uu(data, backtick=backtick))
 data = in_file.read(45)
 if backtick:
 out_file.write(b'`\nend\n')
 else:
 out_file.write(b' \nend\n')
 finally:
 for f in opened_files:
 f.close()


def decode(in_file, out_file=None, mode=None, quiet=False):
 """Decode uuencoded file"""
 #
 # Open the input file, if needed.
 #
 opened_files = []
 if in_file == '-':
 in_file = sys.stdin.buffer
 elif isinstance(in_file, str):
 in_file = open(in_file, 'rb')
 opened_files.append(in_file)

 try:
 #
 # Read until a begin is encountered or we've exhausted the file
 #
 while True:
 hdr = in_file.readline()
 if not hdr:
 raise Error('No valid begin line found in input file')
 if not hdr.startswith(b'begin'):
 continue
 hdrfields = hdr.split(b' ', 2)
 if len(hdrfields) == 3 and hdrfields[0] == b'begin':
 try:
 int(hdrfields[1], 8)
 break
 except ValueError:
 pass
 if out_file is None:
 # If the filename isn't ASCII, what's up with that?!?
 out_file = hdrfields[2].rstrip(b' \t\r\n\f').decode("ascii")
 if os.path.exists(out_file):
 raise Error('Cannot overwrite existing file: %s' % out_file)
 if mode is None:
 mode = int(hdrfields[1], 8)
 #
 # Open the output file
 #
 if out_file == '-':
 out_file = sys.stdout.buffer
 elif isinstance(out_file, str):
 fp = open(out_file, 'wb')
 os.chmod(out_file, mode)
 out_file = fp
 opened_files.append(out_file)
 #
 # Main decoding loop
 #
 s = in_file.readline()
 while s and s.strip(b' \t\r\n\f') != b'end':
 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])
 if not quiet:
 sys.stderr.write("Warning: %s\n" % v)
 out_file.write(data)
 s = in_file.readline()
 if not s:
 raise Error('Truncated input file')
 finally:
 for f in opened_files:
 f.close()

def test():
 """uuencode/uudecode main program"""

 import optparse
 parser = optparse.OptionParser(usage='usage: %prog [-d] [-t] [input [output]]')
 parser.add_option('-d', '--decode', dest='decode', help='Decode (instead of encode)?', default=False, action='store_true')
 parser.add_option('-t', '--text', dest='text', help='data is text, encoded format unix-compatible text?', default=False, action='store_true')

 (options, args) = parser.parse_args()
 if len(args) > 2:
 parser.error('incorrect number of arguments')
 sys.exit(1)

 # Use the binary streams underlying stdin/stdout
 input = sys.stdin.buffer
 output = sys.stdout.buffer
 if len(args) > 0:
 input = args[0]
 if len(args) > 1:
 output = args[1]

 if options.decode:
 if options.text:
 if isinstance(output, str):
 output = open(output, 'wb')
 else:
 print(sys.argv[0], ': cannot do -t to stdout')
 sys.exit(1)
 decode(input, output)
 else:
 if options.text:
 if isinstance(input, str):
 input = open(input, 'rb')
 else:
 print(sys.argv[0], ': cannot do -t from stdin')
 sys.exit(1)
 encode(input, output)

if __name__ == '__main__':
 test()