#
#    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>

from nepi.execution.attribute import Attribute, Flags, Types
from nepi.execution.resource import clsinit_copy, ResourceState, \
        reschedule_delay
from nepi.resources.linux.application import LinuxApplication
from nepi.resources.planetlab.node import PlanetlabNode
from nepi.util.timefuncs import tnow, tdiffsec

import os
import time

# TODO: - routes!!!
#       - CREATE GRE - PlanetlabGRE - it only needs to set the gre and remote
#               properties when configuring the vif_up

PYTHON_VSYS_VERSION = "1.0"

@clsinit_copy
class PlanetlabTap(LinuxApplication):
    _rtype = "PlanetlabTap"
    _help = "Creates a TAP device on a PlanetLab host"
    _backend = "planetlab"

    @classmethod
    def _register_attributes(cls):
        ip4 = Attribute("ip4", "IPv4 Address",
              flags = Flags.ExecReadOnly)

        mac = Attribute("mac", "MAC Address",
                flags = Flags.ExecReadOnly)

        prefix4 = Attribute("prefix4", "IPv4 network prefix",
                type = Types.Integer,
                flags = Flags.ExecReadOnly)

        mtu = Attribute("mtu", "Maximum transmition unit for device",
                type = Types.Integer)

        devname = Attribute("deviceName", 
                "Name of the network interface (e.g. eth0, wlan0, etc)",
                flags = Flags.ReadOnly)

        up = Attribute("up", "Link up", 
                type = Types.Bool)
        
        snat = Attribute("snat", "Set SNAT=1", 
                type = Types.Bool,
                flags = Flags.ExecReadOnly)
        
        pointopoint = Attribute("pointopoint", "Peer IP address", 
                flags = Flags.ExecReadOnly)

        tear_down = Attribute("tearDown", "Bash script to be executed before " + \
                "releasing the resource",
                flags = Flags.ExecReadOnly)

        cls._register_attribute(ip4)
        cls._register_attribute(mac)
        cls._register_attribute(prefix4)
        cls._register_attribute(mtu)
        cls._register_attribute(devname)
        cls._register_attribute(up)
        cls._register_attribute(snat)
        cls._register_attribute(pointopoint)
        cls._register_attribute(tear_down)

    def __init__(self, ec, guid):
        super(PlanetlabTap, self).__init__(ec, guid)
        self._home = "tap-%s" % self.guid

    @property
    def node(self):
        node = self.get_connected(PlanetlabNode.get_rtype())
        if node: return node[0]
        return None

    def upload_sources(self):
        # upload vif-creation python script
        pl_vif_create = os.path.join(os.path.dirname(__file__), "scripts",
                "pl-vif-create.py")

        self.node.upload(pl_vif_create,
                os.path.join(self.node.src_dir, "pl-vif-create.py"),
                overwrite = False)

        # upload vif-stop python script
        pl_vif_stop = os.path.join(os.path.dirname(__file__), "scripts",
                "pl-vif-stop.py")

        self.node.upload(pl_vif_stop,
                os.path.join(self.node.src_dir, "pl-vif-stop.py"),
                overwrite = False)

        # upload vif-connect python script
        pl_vif_connect = os.path.join(os.path.dirname(__file__), "scripts",
                "pl-vif-udp-connect.py")

        self.node.upload(pl_vif_connect,
                os.path.join(self.node.src_dir, "pl-vif-udp-connect.py"),
                overwrite = False)

        # upload tun-connect python script
        tunchannel = os.path.join(os.path.dirname(__file__), "..", "linux",
                "scripts", "tunchannel.py")

        self.node.upload(tunchannel,
                os.path.join(self.node.src_dir, "tunchannel.py"),
                overwrite = False)

        # upload stop.sh script
        stop_command = self.replace_paths(self._stop_command)
        self.node.upload(stop_command,
                os.path.join(self.app_home, "stop.sh"),
                text = True,
                # Overwrite file every time. 
                # The stop.sh has the path to the socket, wich should change
                # on every experiment run.
                overwrite = True)

    def upload_start_command(self):
        # Overwrite file every time. 
        # The stop.sh has the path to the socket, wich should change
        # on every experiment run.
        super(PlanetlabTap, self).upload_start_command(overwrite = True)

        # We want to make sure the device is up and running
        # before the deploy finishes (so things will be ready
        # before other stuff starts running).
        # Run the command as a bash script in background,
        # in the host ( but wait until the command has
        # finished to continue )
        self._run_in_background()
        
        # Retrive if_name
        if_name = self.wait_if_name()
        self.set("deviceName", if_name) 

    def do_deploy(self):
        if not self.node or self.node.state < ResourceState.PROVISIONED:
            self.ec.schedule(reschedule_delay, self.deploy)
        else:
            if not self.get("command"):
                self.set("command", self._start_command)

            if not self.get("depends"):
                self.set("depends", self._dependencies)

            if not self.get("install"):
                self.set("install", self._install)

            self.do_discover()
            self.do_provision()

            self.debug("----- READY ---- ")
            self.set_ready()

    def do_start(self):
        if self.state == ResourceState.READY:
            command = self.get("command")
            self.info("Starting command '%s'" % command)

            self.set_started()
        else:
            msg = " Failed to execute command '%s'" % command
            self.error(msg, out, err)
            raise RuntimeError, msg

    def do_stop(self):
        command = self.get('command') or ''
        
        if self.state == ResourceState.STARTED:
            self.info("Stopping command '%s'" % command)

            command = "bash %s" % os.path.join(self.app_home, "stop.sh")
            (out, err), proc = self.execute_command(command,
                    blocking = True)

            self.set_stopped()

    @property
    def state(self):
        # First check if the ccnd has failed
        state_check_delay = 0.5
        if self._state == ResourceState.STARTED and \
                tdiffsec(tnow(), self._last_state_check) > state_check_delay:

            if self.get("deviceName"):
                (out, err), proc = self.node.execute("ifconfig")

                if out.strip().find(self.get("deviceName")) == -1: 
                    # tap is not running is not running (socket not found)
                    self.set_stopped()

            self._last_state_check = tnow()

        return self._state

    def do_release(self):
        # Node needs to wait until all associated RMs are released
        # to be released
        from nepi.resources.linux.udptunnel import UdpTunnel
        rms = self.get_connected(UdpTunnel.get_rtype())
        for rm in rms:
            if rm.state < ResourceState.STOPPED:
                self.ec.schedule(reschedule_delay, self.release)
                return 

        super(PlanetlabTap, self).do_release()

    def wait_if_name(self):
        """ Waits until the if_name file for the command is generated, 
            and returns the if_name for the device """
        if_name = None
        delay = 1.0

        for i in xrange(4):
            (out, err), proc = self.node.check_output(self.run_home, "if_name")

            if out:
                if_name = out.strip()
                break
            else:
                time.sleep(delay)
                delay = delay * 1.5
        else:
            msg = "Couldn't retrieve if_name"
            self.error(msg, out, err)
            raise RuntimeError, msg

        return if_name

    def udp_connect_command(self, remote_ip, local_port_file, 
            remote_port_file, ret_file, cipher, cipher_key,
            bwlimit, txqueuelen):
        command = ["sudo -S "]
        command.append("PYTHONPATH=$PYTHONPATH:${SRC}")
        command.append("python ${SRC}/pl-vif-udp-connect.py")
        command.append("-t %s" % self.vif_type)
        command.append("-S %s " % self.sock_name)
        command.append("-l %s " % local_port_file)
        command.append("-r %s " % remote_port_file)
        command.append("-H %s " % remote_ip)
        command.append("-R %s " % ret_file)
        if cipher:
            command.append("-c %s " % cipher)
        if cipher_key:
            command.append("-k %s " % cipher_key)
        if txqueuelen:
            command.append("-q %s " % txqueuelen)
        if bwlimit:
            command.append("-b %s " % bwlimit)

        command = " ".join(command)
        command = self.replace_paths(command)
        return command

    @property
    def _start_command(self):
        command = ["sudo -S python ${SRC}/pl-vif-create.py"]
        
        command.append("-t %s" % self.vif_type)
        command.append("-a %s" % self.get("ip4"))
        command.append("-n %d" % self.get("prefix4"))
        command.append("-f %s " % self.if_name_file)
        command.append("-S %s " % self.sock_name)
        if self.get("snat") == True:
            command.append("-s")
        if self.get("pointopoint"):
            command.append("-p %s" % self.get("pointopoint"))

        return " ".join(command)

    @property
    def _stop_command(self):
        command = ["sudo -S python ${SRC}/pl-vif-stop.py"]
        
        command.append("-S %s " % self.sock_name)
        return " ".join(command)

    @property
    def vif_type(self):
        return "IFF_TAP"

    @property
    def if_name_file(self):
        return os.path.join(self.run_home, "if_name")

    @property
    def sock_name(self):
        return os.path.join(self.run_home, "tap.sock")

    @property
    def _dependencies(self):
        return "mercurial make gcc"

    @property
    def _install(self):
        # Install python-vsys and python-passfd
        install_vsys = ( " ( "
                    "   python -c 'import vsys, os;  vsys.__version__ == \"%(version)s\" or os._exit(1)' "
                    " ) "
                    " || "
                    " ( "
                    "   cd ${SRC} ; "
                    "   hg clone http://nepi.inria.fr/code/python-vsys ; "
                    "   cd python-vsys ; "
                    "   make all ; "
                    "   sudo -S make install "
                    " )" ) % ({
                        "version": PYTHON_VSYS_VERSION
                        })

        install_passfd = ( " ( python -c 'import passfd' ) "
                    " || "
                    " ( "
                    "   cd ${SRC} ; "
                    "   hg clone http://nepi.inria.fr/code/python-passfd ; "
                    "   cd python-passfd ; "
                    "   make all ; "
                    "   sudo -S make install "
                    " )" )

        return "%s ; %s" % ( install_vsys, install_passfd )

    def valid_connection(self, guid):
        # TODO: Validate!
        return True