# -*- coding: utf-8 -*-
"""
    MoinMoin - MoinCrypt Action

    PURPOSE:
        This action is used to display an encrypted page

    MODIFICATION HISTORY:
        @copyright: 2008 by Frank Maloschytzki (Frank.Maloschytzki@gansnett.de)
        @license: GNU GPL, see COPYING for details.
        Version: 0.1

    Part of code is copied from Whois.py  and test.py



"""

from MoinMoin.PageEditor import PageEditor
from MoinMoin.action import ActionBase
from base64 import b64decode
from Crypto.Cipher import AES


PAGENAME = u'ThisPageDoesNotExistsAndWillNeverBeReally'

CRYPTHEADER = 'Encrypted Page:'




class MoinCrypt(ActionBase):
    """ Show Decrypted page action

    """


    def __init__(self, pagename, request):
        ActionBase.__init__(self, pagename, request)
        self.use_ticket = False
        _ = self._
        self.form_trigger = 'passphrase'
        self.form_trigger_label = _('Crypt / Decrypt')
        self.thispage = PageEditor(request, pagename)


    def expandto16(self, text, fillchar=' '):
        """ Expand length of string to multiple of 16 by adding spaces
            """
        i = len(text) % 16
        if i != 0:
            return text + fillchar*(16-i)
        else:
            return text


    def do_action(self):
        
        _ = self._
        form = self.form
        passphrase = self.expandto16(form.get('pass', [u''])[0])
        text = self.thispage.get_body().encode('latin-1')
        if text.find(CRYPTHEADER) == -1:
            # Encrypt Page
            obj = AES.new(passphrase)
            ctext = obj.encrypt(self.expandto16(text))

            self.thispage.saveText(CRYPTHEADER+ctext.encode("base64"), 0, comment=u"Encrypt")
            self.render_msg(_('Successfully encrypted'))
            return
        else:
            # Page ist encrypted, so decrypt
            text = text[len(CRYPTHEADER):]
            text = b64decode(text)
            
            obj = AES.new(passphrase, AES.MODE_ECB)

            ctext = obj.decrypt(text)
            self.thispage.saveText(unicode(ctext,'latin-1'), 0, comment=u"Decrypt")
            self.render_msg(_('Successfully decrypted'))
            return


    def get_form_html(self, buttons_html):
        _ = self._
        d = {
            'pagename': self.pagename,
            'pass_label': _("Passphrase"),
            'buttons_html': buttons_html,
        }
        return '''
<table>
               <tr>
               <td class="label"><label>%(pass_label)s</label></td>
               <td class="content">
               <input type="text" name="pass" maxlength="128">
               </td>
               </tr>
               <tr>
               <td></td>
               <td class="buttons">
               %(buttons_html)s
               </td>
               </tr>
</table>
''' % d

    def work(self):
        """ Render action - this is the main function called by action's
            execute() function.

            We usually render a form here, check for posted forms, etc.
        """
        _ = self._
        form = self.form

        if form.has_key(self.form_cancel):
            self.render_cancel()
            return

        # Validate allowance, user rights and other conditions.
        error = None
        if self.is_excluded():
            error = _('Action %(actionname)s is excluded in this wiki!') % {'actionname': self.actionname }
        elif not self.is_allowed():
            error = _('You are not allowed to use action %(actionname)s on thispage!') % {'actionname': self.actionname }
        if error is None:
            self.check_condition()
        if error:
            self.render_msg(error)
        elif form.has_key(self.form_trigger) or form.has_key('pass'): # user hit the trigger button
            if self.ticket_ok():
                self.do_action()
                return
            else:
                self.render_msg(_('Please use the interactive user interface to use action %(actionname)s!') % {'actionname': self.actionname })
            return
        else:
            # Return a new form
            self.render_msg(self.make_form())

def execute(pagename, request):
    """ Do your work
    """
    _ = request.getText

# Don't check if personal wiki

#    if request.user.valid:
#        username = request.user.name
#    else:
#        username = ''
#
#    if not username:
#        return thispage.send_page(
#            msg = _('Please log in first.'))

    
    MoinCrypt(pagename, request).work()