#
#    NEPI, a framework to manage network experiments
#    Copyright (C) 2014 INRIA
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License version 2 as
#    published by the Free Software Foundation;
#
#    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/>.
#
# Author: Alina Quereilhac <alina.quereilhac@inria.fr>

import base64
import pickle
import errno
import os
import socket
import time
import weakref
import threading

from optparse import OptionParser, SUPPRESS_HELP

from nepi.resources.ns3.ns3client import NS3Client
from nepi.resources.ns3.ns3server import NS3WrapperMessage

class LinuxNS3Client(NS3Client):
    def __init__(self, simulation):
        super(LinuxNS3Client, self).__init__()
        self._simulation = weakref.ref(simulation)
        self._socket_lock = threading.Lock()

    @property
    def simulation(self):
        return self._simulation()

    def send_msg(self, msg_type, *args, **kwargs):
        msg = [msg_type, args, kwargs]

        def encode(item):
            item = pickle.dumps(item)
            return base64.b64encode(item)

        encoded = "|".join(map(encode, msg))

        with self._socket_lock:
            if self.simulation.node.get("hostname") in ['localhost', '127.0.0.1']:
                sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
                sock.connect(self.simulation.remote_socket)
                sock.send("%s\n" % encoded)
                reply = sock.recv(1024)
                sock.close()
            else:
                command = ( "python -c 'import socket;"
                    "sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM);"
                    "sock.connect(\"%(socket_addr)s\");"
                    "msg = \"%(encoded_message)s\\n\";"
                    "sock.send(msg);"
                    "reply = sock.recv(1024);"
                    "sock.close();"
                    "print reply'") % {
                        "encoded_message": encoded,
                        "socket_addr": self.simulation.remote_socket,
                        }

                (reply, err), proc = self.simulation.node.execute(command, 
                        with_lock = True) 

                if (err and proc.poll()) or reply.strip() == "":
                    msg = (" Couldn't connect to remote socket %s - REPLY: %s "
                          "- ERROR: %s ") % (
                            self.simulation.remote_socket, reply, err)
                    self.simulation.error(msg, reply, err)
                    raise RuntimeError(msg)
                       
        reply = pickle.loads(base64.b64decode(reply))

        return reply

    def create(self, *args, **kwargs):
        return self.send_msg(NS3WrapperMessage.CREATE, *args, **kwargs)

    def factory(self, *args, **kwargs):
        return self.send_msg(NS3WrapperMessage.FACTORY, *args, **kwargs)

    def invoke(self, *args, **kwargs):
        return self.send_msg(NS3WrapperMessage.INVOKE, *args, **kwargs)

    def set(self, *args, **kwargs):
        return self.send_msg(NS3WrapperMessage.SET, *args, **kwargs)

    def get(self, *args, **kwargs):
        return self.send_msg(NS3WrapperMessage.GET, *args, **kwargs)

    def flush(self, *args, **kwargs):
        return self.send_msg(NS3WrapperMessage.FLUSH, *args, **kwargs)

    def start(self, *args, **kwargs):
        return self.send_msg(NS3WrapperMessage.START, *args, **kwargs)

    def stop(self, *args, **kwargs):
        return self.send_msg(NS3WrapperMessage.STOP, *args, **kwargs)

    def shutdown(self, *args, **kwargs):
        try:
            return self.send_msg(NS3WrapperMessage.SHUTDOWN, *args, **kwargs)
        except:
            pass

        return None