#
#    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


@clsinit_copy
class OMFChannel(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

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

    @classmethod
    def _register_attributes(cls):
        """Register the attributes of an OMF channel
        
        """
        channel = Attribute("channel", "Name of the application")
        cls._register_attribute(channel)

    def __init__(self, ec, guid):
        """
        :param ec: The Experiment controller
        :type ec: ExperimentController
        :param guid: guid of the RM
        :type guid: int

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

        self._nodes_guid = list()

        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.get_rtype() in self._authorized_connections:
            msg = "Connection between %s %s and %s %s accepted" % (
                    self.get_rtype(), self._guid, rm.get_rtype(), guid)
            self.debug(msg)
            return True

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

    def _get_target(self, conn_set):
        """
        Get the couples (host, interface) that uses this channel

        :param conn_set: Connections of the current Guid
        :type conn_set: set
        :rtype: list
        :return: self._nodes_guid

        """
        res = []
        for elt in conn_set:
            rm_iface = self.ec.get_resource(elt)
            for conn in rm_iface.connections:
                rm_node = self.ec.get_resource(conn)
                if rm_node.get_rtype() == "OMFNode" and rm_node.get('hostname'):
                    if rm_iface.state < ResourceState.PROVISIONED or \
                            rm_node.state < ResourceState.READY:
                        return "reschedule"
                    couple = [rm_node.get('hostname'), rm_iface.get('alias')]
                    #print couple
                    res.append(couple)
        return res

    def do_deploy(self):
        """ Deploy the RM. It means : Get the xmpp client and send messages 
        using OMF 5.4 protocol to configure the channel.
        It becomes DEPLOYED after sending messages to configure the channel

        """
        if not (self.get('xmppSlice') and self.get('xmppHost')
              and self.get('xmppPort') and self.get('xmppPassword')):
            msg = "Credentials are not initialzed. XMPP Connections impossible"
            self.error(msg)
            raise RuntimeError, msg

        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.get('channel'):
            msg = "Channel's value is not initialized"
            self.error(msg)
            raise RuntimeError, msg

        self._nodes_guid = self._get_target(self._connections)

        if self._nodes_guid == "reschedule" :
            self.ec.schedule("2s", self.deploy)
        else:
            for couple in self._nodes_guid:
                attrval = self.get('channel')
                attrname = "net/%s/%s" % (couple[1], 'channel')
                self._omf_api.configure(couple[0], attrname, attrval)

            super(OMFChannel, self).do_deploy()

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

        """
        if self._omf_api :
            OMFAPIFactory.release_api(self.get('xmppSlice'), 
                self.get('xmppHost'), self.get('xmppPort'), 
                self.get('xmppPassword'), exp_id = self.exp_id)

        super(OMFChannel, self).do_release()