Wammu/IMAP.py

   1 # -*- coding: UTF-8 -*-
   2 # vim: expandtab sw=4 ts=4 sts=4:
   3 '''
   4 Wammu - Phone manager
   5 IMAP UTF-7 codec
   6 '''
   7 __author__ = 'Michal Čihař'
   8 __email__ = 'michal@cihar.com'
   9 __license__ = '''
  10 Copyright (c) 2003 - 2007 Michal Čihař
  11
  12 This program is free software; you can redistribute it and/or modify it
  13 under the terms of the GNU General Public License version 2 as published by
  14 the Free Software Foundation.
  15
  16 This program is distributed in the hope that it will be useful, but WITHOUT
  17 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  19 more details.
  20
  21 You should have received a copy of the GNU General Public License along with
  22 this program; if not, write to the Free Software Foundation, Inc.,
  23 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  24 '''
  25
  26 import codecs
  27 def modified_base64(s):
  28     s_utf7 = s.encode('utf-7')
  29     return s_utf7[1:-1].replace('/', ',')
  30
  31 def modified_unbase64(s):
  32     s_utf7 = '+' + s.replace(',', '/') + '-'
  33     return unicode(s_utf7, 'utf-7')
  34
  35 def encoder(s):
  36     r = []
  37     _in = []
  38     for c in s:
  39         if ord(c) in (range(0x20, 0x26) + range(0x27, 0x7f)):
  40             if _in:
  41                 r.extend(['&', modified_base64(''.join(_in)), '-'])
  42                 del _in[:]
  43             r.append(str(c))
  44         elif c == '&':
  45             if _in:
  46                 r.extend(['&', modified_base64(''.join(_in)), '-'])
  47                 del _in[:]
  48             r.append('&-')
  49         else:
  50             _in.append(c)
  51     if _in:
  52         r.extend(['&', modified_base64(''.join(_in)), '-'])
  53     return (''.join(r), len(s))
  54
  55 def decoder(s):
  56     r = []
  57     decode = []
  58     for c in s:
  59         if c == '&' and not decode:
  60             decode.append('&')
  61         elif c == '-' and decode:
  62             if len(decode) == 1:
  63                 r.append('&')
  64             else:
  65                 r.append(modified_unbase64(''.join(decode[1:])))
  66             decode = []
  67         elif decode:
  68             decode.append(c)
  69         else:
  70             r.append(c)
  71     if decode:
  72         r.append(modified_unbase64(''.join(decode[1:])))
  73     return (u''.join(r), len(s))
  74
  75 class StreamReader(codecs.StreamReader):
  76     def decode(self, s, errors='strict'):
  77         return decoder(s)
  78
  79 class StreamWriter(codecs.StreamWriter):
  80     def decode(self, s, errors='strict'):
  81         return encoder(s)
  82
  83 def imap4_utf_7(name):
  84     if name == 'imap4-utf-7':
  85         return (encoder, decoder, StreamReader, StreamWriter)
  86
  87 codecs.register(imap4_utf_7)