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

# This file is part of Beremiz runtime.
#
# Copyright (C) 2007: Edouard TISSERANT and Laurent BESSARD
#
# See COPYING.Runtime file for copyrights details.
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.

# This library 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
# Lesser General Public License for more details.

# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA


from __future__ import absolute_import
from __future__ import print_function
import socket
import threading
import zeroconf


service_type = '_Beremiz._tcp.local.'


class ServicePublisher(object):
    def __init__(self, protocol):
        # type: fully qualified service type name
        self.serviceproperties = {
            'description': 'Beremiz remote PLC',
            'protocol': protocol
        }

        self.name = None
        self.ip_32b = None
        self.port = None
        self.server = None
        self.service_name = None
        self.retrytimer = None

    def RegisterService(self, name, ip, port):
        try:
            self._RegisterService(name, ip, port)
        except Exception:
            self.retrytimer = threading.Timer(2, self.RegisterService, [name, ip, port])
            self.retrytimer.start()

    def _RegisterService(self, name, ip, port):
        # name: fully qualified service name
        self.service_name = '%s.%s' % (name, service_type)
        self.name = name
        self.port = port

        if ip == "0.0.0.0":
            print("MDNS brodcasted on all interfaces")
            interfaces = zeroconf.InterfaceChoice.All
            ip = self.gethostaddr()
        else:
            interfaces = [ip]

        self.server = zeroconf.Zeroconf(interfaces=interfaces)

        print("MDNS brodcasted service address :" + ip)
        self.ip_32b = socket.inet_aton(ip)

        self.server.register_service(
            zeroconf.ServiceInfo(service_type,
                                 self.service_name,
                                 self.ip_32b,
                                 self.port,
                                 properties=self.serviceproperties))
        self.retrytimer = None

    def UnRegisterService(self):
        if self.retrytimer is not None:
            self.retrytimer.cancel()

        if self.server is not None:
            self.server.unregister_service(
                zeroconf.ServiceInfo(service_type,
                                     self.service_name,
                                     self.ip_32b,
                                     self.port,
                                     properties=self.serviceproperties))
            self.server.close()
            self.server = None

    def gethostaddr(self, dst='224.0.1.41'):
        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        try:
            s.connect((dst, 7))
            (host, _port) = s.getsockname()
            s.close()
            if host != '0.0.0.0':
                return host
        except Exception:
            pass
        return socket.gethostbyname(socket.gethostname())