#!/usr/bin/python
# -*- coding: utf-8 -*-

# SAT plugin for NAT port mapping
# Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014, 2015 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero 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 Affero General Public License for more details.

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

from sat.core.i18n import _
from sat.core.constants import Const as C
from sat.core.log import getLogger
log = getLogger(__name__)
from sat.core import exceptions
from twisted.internet import threads
from twisted.internet import defer

try:
    import miniupnpc
except ImportError:
    raise exceptions.MissingModule(u"Missing module MiniUPnPc, please download/install it (and its Python binding) at http://miniupnp.free.fr/")


PLUGIN_INFO = {
    "name": "NAT port mapping",
    "import_name": "NAT-PORT",
    "type": C.PLUG_TYPE_MISC,
    "main": "NatPort",
    "handler": "no",
    "description": _("""Automatic NAT port mapping using UPnP"""),
}


class NatPort(object):
    # TODO: refresh data if a new connection is detected (see plugin_misc_ip)

    def __init__(self, host):
        log.info(_("plugin NAT Port initialization"))
        self.host = host
        self._external_ip = None
        self._initialised = defer.Deferred()
        self._upnp = miniupnpc.UPnP() # will be None if no device is available
        self._upnp.discoverdelay=200
        discover_d = threads.deferToThread(self._discover)
        discover_d.chainDeferred(self._initialised)
        self._initialised.addErrback(self._init_failed)

    def _init_failed(self, failure):
        log.info(u"UPnP-GID not available")
        self._upnp = None

    def _discover(self):
        devices = self._upnp.discover()
        if devices:
            log.info(u"{nb} UPnP-IGD device(s) found".format(nb=devices))
        else:
            log.info(u"Can't find UPnP-IGD device on the local network")
            raise exceptions.NotFound
        self._upnp.selectigd()
        self._external_ip = self._upnp.externalipaddress()

    def getIP(self, local=False):
        """Return IP address found with UPnP-IGD

        @param local(bool): True to get external IP address, False to get local network one
        @return (None, str): found IP address, or None of something got wrong
        """
        def getIP(dummy):
            if self._upnp is None:
                return None
            # lanaddr can be the empty string if not found,
            # we need to return None in this case
            return (self._upnp.lanaddr or None) if local else self._external_ip
        return self._initialised.addCallback(getIP)