#
#    NEPI, a framework to manage network experiments
#    Copyright (C) 2013 INRIA
#
#    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/>.
#
# Author: Alina Quereilhac <alina.quereilhac@inria.fr>
#         Julien Tribino <julien.tribino@inria.fr>


from nepi.execution.resource import ResourceManager, clsinit_copy, ResourceState, \
        reschedule_delay
from nepi.execution.attribute import Attribute, Flags 
from nepi.resources.omf.omf_resource import ResourceGateway, OMFResource
from nepi.resources.omf.omf_api import OMFAPIFactory

import time


@clsinit_copy
class OMFNode(OMFResource):
    """
    .. class:: Class Args :
      
        :param ec: The Experiment controller
        :type ec: ExperimentController
        :param guid: guid of the RM
        :type guid: int
        :param creds: Credentials to communicate with the rm (XmppClient for OMF)
        :type creds: dict

    .. note::

       This class is used only by the Experiment Controller through the Resource Factory

    """
    _rtype = "OMFNode"
    _authorized_connections = ["OMFApplication" , "OMFWifiInterface"]

    @classmethod
    def _register_attributes(cls):
        """Register the attributes of an OMF Node

        """
        hostname = Attribute("hostname", "Hostname of the machine")

        cls._register_attribute(hostname)

    # XXX: We don't necessary need to have the credentials at the 
    # moment we create the RM
    def __init__(self, ec, guid):
        """
        :param ec: The Experiment controller
        :type ec: ExperimentController
        :param guid: guid of the RM
        :type guid: int

        """
        super(OMFNode, self).__init__(ec, guid)

        self._omf_api = None 

    @property
    def exp_id(self):
        return self.ec.exp_id

    def valid_connection(self, guid):
        """ Check if the connection with the guid in parameter is possible. 
        Only meaningful connections are allowed.

        :param guid: Guid of the current RM
        :type guid: int
        :rtype:  Boolean

        """
        rm = self.ec.get_resource(guid)
        if rm.rtype() in self._authorized_connections:
            msg = "Connection between %s %s and %s %s accepted" % (
                    self.rtype(), self._guid, rm.rtype(), guid)
            self.debug(msg)

            return True

        msg = "Connection between %s %s and %s %s refused" % (
                self.rtype(), self._guid, rm.rtype(), guid)
        self.debug(msg)

        return False

    def deploy(self):
        """ Deploy the RM. It means : Send Xmpp Message Using OMF protocol 
            to enroll the node into the experiment.
            It becomes DEPLOYED after sending messages to enroll the node

        """ 
        if not self._omf_api :
            self._omf_api = OMFAPIFactory.get_api(self.get('xmppSlice'), 
                self.get('xmppHost'), self.get('xmppPort'), 
                self.get('xmppPassword'), exp_id = self.exp_id)

        if not self._omf_api :
            msg = "Credentials are not initialzed. XMPP Connections impossible"
            self.error(msg)
            self.fail()
            return

        if not self.get('hostname') :
            msg = "Hostname's value is not initialized"
            self.error(msg)
            self.fail()
            return False

        try:
            self._omf_api.enroll_host(self.get('hostname'))
        except AttributeError:
            msg = "Credentials are not initialzed. XMPP Connections impossible"
            self.error(msg)
            self.fail()
            #raise AttributeError, msg

        super(OMFNode, self).deploy()

    def discover(self):
        """ Discover the availables nodes

        """
        pass
     
    def provision(self):
        """ Provision some availables nodes

        """
        pass

    def start(self):
        """Start the RM. It means nothing special for an interface for now
           It becomes STARTED as soon as this method starts.

        """

        super(OMFNode, self).start()

    def stop(self):
        """Stop the RM. It means nothing special for an interface for now
           It becomes STOPPED as soon as this method stops

        """
        super(OMFNode, self).stop()
        self.set_finished()

    def release(self):
        """Clean the RM at the end of the experiment

        """
        if self._omf_api :
            self._omf_api.release(self.get('hostname'))

            OMFAPIFactory.release_api(self.get('xmppSlice'), 
                self.get('xmppHost'), self.get('xmppPort'), 
                self.get('xmppPassword'), exp_id = self.exp_id)

        super(OMFNode, self).release()