imap

# Copyright (C) 2012 Johnny Vestergaard <jkv@unixcluster.dk>
#
# This program 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, either version 3 of the License, or
# (at your option) any later version.

# This program 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 should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import logging
import socket

from heralding.capabilities.handlerbase import HandlerBase

logger = logging.getLogger(__name__)


class Imap(HandlerBase):
    max_tries = 10

    def __init__(self, options, ):
        super(Imap, self).__init__(options)
        Imap.max_tries = int(self.options['protocol_specific_data']['max_attempts'])

    def execute_capability(self, address, socket, session):
        self._handle_session(session, socket)

    def _handle_session(self, session, gsocket):
        fileobj = gsocket.makefile()

        self.send_message(session, gsocket, "* OK IMAP Server Ready")

        state = "Not Authenticated"
        while state != '' and session.connected:
            try:
                raw_msg = fileobj.readline()
            except socket.error:
                session.end_session()
                break

            session.activity()
            cmd_msg = raw_msg.rstrip().split(' ', 2)
            if len(cmd_msg) == 0:
                continue
            elif len(cmd_msg) == 1:
                tag = cmd_msg[0]
                self.send_message(session, gsocket, "* BAD invalid command")
                continue
            elif len(cmd_msg) == 2:
                tag = cmd_msg[0]
                cmd = cmd_msg[1]
                msg = ''
            else:
                tag = cmd_msg[0]
                cmd = cmd_msg[1]
                msg = cmd_msg[2]

            cmd = cmd.lower()
            if cmd not in ['login', 'logout', 'noop', 'capability']:
                self.send_message(session, gsocket, "* BAD invalid command")
            else:
                func_to_call = getattr(self, 'cmd_{0}'.format(cmd), None)
                return_value = func_to_call(session, gsocket, tag, msg)
                if state == 'Not Authenticated' or cmd == 'logout':
                    state = return_value

        session.end_session()

    def cmd_login(self, session, gsocket, tag, msg):
        user_cred= msg.split(' ', 1)
        if len(user_cred) == 1:
            user = user_cred[0].strip('\"')
            password = ''
        else:
            user = user_cred[0].strip('\"')
            password = user_cred[1].strip('\"')
        session.add_auth_attempt('plaintext', username=user, password=password)
        self.send_message(session, gsocket, tag + ' NO Authentication failed')
        return 'Not Authenticated'

    def cmd_noop(self, session, gsocket, tag, msg):
        self.send_message(session, gsocket, tag + ' OK NOOP COMPLETED')

    def cmd_logout(self, session, gsocket, tag, msg):
        self.send_message(session, gsocket, "* BYE IMAP Server logging out")
        self.send_message(session, gsocket, tag + ' OK LOGOUT COMPLETED')
        return ''

    def cmd_capability(self, session, gsocket, tag, msg):
        self.send_message(session, gsocket, '* CAPABILITY IMAP AUTH=LOGIN')
        self.send_message(session, gsocket, tag + ' OK CAPABILITY COMPLETED')
        return 'Not Authenticated'

    def send_message(self, session, gsocket, msg):
        try:
            gsocket.sendall(msg + "\n")
        except socket.error, (value, exceptionMessage):
            session.end_session()