# Copyright (C) 2019 Philipp Hörist <philipp AT hoerist.com>
# Copyright (C) 2019 Pavel R. <pd at narayana dot im>

# This file is part of Gajim OTR Plugin.
#
# Gajim OTR Plugin is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published
# by the Free Software Foundation; version 3 only.
#
# This software is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You can always obtain full license text at <http://www.gnu.org/licenses/>.

# TODO: OTR state notifications
# TODO: Fingerprints authentication GUI
# TODO: SMP authentication GUI

ERROR = None

import logging
from gajim.common  import app
from gajim.plugins import GajimPlugin
try: from otrplugin.otr import OTR
except: ERROR = 'Error importing python3-potr module. Make sure it is installed.'

log = logging.getLogger('gajim.p.otr')

class OTRPlugin(GajimPlugin): 
    def init(self):
        self.encryption_name = OTR.ENCRYPTION_NAME
        self.description = 'Provides Off-the-Record encryption'
        self.activatable = not ERROR
        self.available_text = ERROR
        self.sessions = {}
        self.session = lambda account: self.sessions.setdefault(account, OTR(account, logger = log))
        self.gui_extension_points = {
            'encrypt' + self.encryption_name: (self._encrypt_message, None),
            'decrypt': (self._decrypt_message, None),
        }
        
    @staticmethod
    def activate_encryption(ctl): 
        return True

    @staticmethod 
    def encrypt_file(file, account, callback): 
        callback(file)

    def _encrypt_message(self, con, event, callback):
        if not event.message or event.type_ != 'chat': return # drop empty or non-chat messages 
        log.debug('encrypting message: %s' % event)
        otr = self.session(event.account)
        otr._encrypt(event, callback)

    def _decrypt_message(self, con, event, callback):
        if event.name == 'mam-message-received': event.msgtxt = ''   # drop mam messages because we cannot decrypt it post-factum 
        if not event.msgtxt or not event.msgtxt.startswith("?OTR"): return  # drop messages without OTR tag
        log.debug('received otr message: %s' % event)
        otr = self.session(event.account)
        otr._decrypt(event, callback)