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 © 2003 - 2010 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
  28 def modified_base64(s):
  29     s_utf7 = s.encode('utf-7')
  30     return s_utf7[1:-1].replace('/', ',')
  31
  32 def modified_unbase64(s):
  33     s_utf7 = '+' + s.replace(',', '/') + '-'
  34     return s_utf7.decode('utf-7')
  35
  36 def encoder(s):
  37     r = []
  38     _in = []
  39     for c in s:
  40         if ord(c) in (range(0x20, 0x26) + range(0x27, 0x7f)):
  41             if _in:
  42                 r.extend(['&', modified_base64(''.join(_in)), '-'])
  43                 del _in[:]
  44             r.append(str(c))
  45         elif c == '&':
  46             if _in:
  47                 r.extend(['&', modified_base64(''.join(_in)), '-'])
  48                 del _in[:]
  49             r.append('&-')
  50         else:
  51             _in.append(c)
  52     if _in:
  53         r.extend(['&', modified_base64(''.join(_in)), '-'])
  54     return (''.join(r), len(s))
  55
  56 def decoder(s):
  57     r = []
  58     decode = []
  59     for c in s:
  60         if c == '&' and not decode:
  61             decode.append('&')
  62         elif c == '-' and decode:
  63             if len(decode) == 1:
  64                 r.append('&')
  65             else:
  66                 r.append(modified_unbase64(''.join(decode[1:])))
  67             decode = []
  68         elif decode:
  69             decode.append(c)
  70         else:
  71             r.append(c)
  72     if decode:
  73         r.append(modified_unbase64(''.join(decode[1:])))
  74     return (u''.join(r), len(s))
  75
  76 class StreamReader(codecs.StreamReader):
  77     def decode(self, s, errors='strict'):
  78         return decoder(s)
  79
  80 class StreamWriter(codecs.StreamWriter):
  81     def decode(self, s, errors='strict'):
  82         return encoder(s)
  83
  84 def imap4_utf_7(name):
  85     if name == 'imap4-utf-7':
  86         return (encoder, decoder, StreamReader, StreamWriter)
  87
  88 codecs.register(imap4_utf_7)