#
#    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.node import OMFNode
from nepi.resources.omf.omf_resource import ResourceGateway, OMFResource
from nepi.resources.omf.channel import OMFChannel
from nepi.resources.omf.omf_api import OMFAPIFactory

@clsinit_copy
class OMFWifiInterface(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 = "OMFWifiInterface"
    _authorized_connections = ["OMFNode" , "OMFChannel"]

    #alias2name = dict({'w0':'wlan0', 'w1':'wlan1'})

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

        """
        alias = Attribute("alias","Alias of the interface", default = "w0")
        mode = Attribute("mode","Mode of the interface")
        type = Attribute("type","Type of the interface")
        essid = Attribute("essid","Essid of the interface")
        ip = Attribute("ip","IP of the interface")
        cls._register_attribute(alias)
        cls._register_attribute(mode)
        cls._register_attribute(type)
        cls._register_attribute(essid)
        cls._register_attribute(ip)

    def __init__(self, ec, guid):
        """
        :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

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

        self._omf_api = None
        self._alias = self.get('alias')

    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

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

    @property
    def node(self):
        rm_list = self.get_connected(OMFNode.rtype())
        if rm_list: return rm_list[0]
        return None

    @property
    def channel(self):
        rm_list = self.get_connected(OMFChannel.rtype())
        if rm_list: return rm_list[0]
        return None


    def configure_iface(self):
        """ Configure the interface without the ip

        """
        if self.node.state < ResourceState.READY:
            self.ec.schedule(reschedule_delay, self.deploy)
            return False

        try :
            for attrname in ["mode", "type", "essid"]:
                attrval = self.get(attrname)
                attrname = "net/%s/%s" % (self._alias, attrname)
                self._omf_api.configure(self.node.get('hostname'), attrname, 
                        attrval)
        except AttributeError:
            self._state = ResourceState.FAILED
            msg = "Credentials are not initialzed. XMPP Connections impossible"
            self.debug(msg)
            #raise
        
        super(OMFWifiInterface, self).provision()
        return True

    def configure_ip(self):
        """ Configure the ip of the interface

        """
        if self.channel.state < ResourceState.READY:
            self.ec.schedule(reschedule_delay, self.deploy)
            return False

        try :
            attrval = self.get("ip")
            attrname = "net/%s/%s" % (self._alias, "ip")
            self._omf_api.configure(self.node.get('hostname'), attrname, 
                    attrval)
        except AttributeError:
            msg = "Credentials are not initialzed. XMPP Connections impossible"
            self.debug(msg)
            self.fail()
            #raise

        return True

    def deploy(self):
        """ Deploy the RM. It means : Get the xmpp client and send messages 
        using OMF 5.4 protocol to configure the interface.
        It becomes DEPLOYED after sending messages to configure the interface
        """
        self.set('xmppSlice', self.node.get('xmppSlice'))
        self.set('xmppHost', self.node.get('xmppHost'))
        self.set('xmppPort', self.node.get('xmppPort'))
        self.set('xmppPassword', self.node.get('xmppPassword'))

        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('mode') and self.get('type') and self.get('essid') \
                and self.get('ip')):
            msg = "Interface's variable are not initialized"
            self.error(msg)
            self.fail()
            return False

        if not self.node.get('hostname') :
            msg = "The channel is connected with an undefined node"
            self.error(msg)
            self.fail()
            return False

        # Just for information
        self.debug(" " + self.rtype() + " ( Guid : " + str(self._guid) +") : " + \
            self.get('mode') + " : " + self.get('type') + " : " + \
            self.get('essid') + " : " + self.get('ip'))
    
        # Check if the node is already deployed
        chk1 = True
        if self.state < ResourceState.PROVISIONED:
            chk1 = self.configure_iface()
        if chk1:
            chk2 = self.configure_ip()

        if not (chk1 and chk2) :
            return False
            
        super(OMFWifiInterface, self).deploy()
        return True


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

        """

        super(OMFWifiInterface, self).start()

    def stop(self):
        """ Stop the RM. It means nothing special for a channel for now
        It becomes STOPPED as soon as this method is called

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

    def 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(OMFWifiInterface, self).release()