# -*- coding: utf-8 -*-
# vpnlaunchers.py
# Copyright (C) 2013 LEAP
#
# 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/>.

"""
Platform dependant VPN launchers
"""
import commands
import logging
import getpass
import os
import platform
import stat
import subprocess
try:
    import grp
except ImportError:
    pass  # ignore, probably windows

from abc import ABCMeta, abstractmethod
from functools import partial
from time import sleep

from leap.bitmask.config.leapsettings import LeapSettings

from leap.bitmask.config.providerconfig import ProviderConfig
from leap.bitmask.services.eip.eipconfig import EIPConfig, VPNGatewaySelector
from leap.bitmask.util import first
from leap.bitmask.util.privilege_policies import LinuxPolicyChecker
from leap.bitmask.util import privilege_policies
from leap.common.check import leap_assert, leap_assert_type
from leap.common.files import which

logger = logging.getLogger(__name__)


class VPNLauncherException(Exception):
    pass


class OpenVPNNotFoundException(VPNLauncherException):
    pass


class EIPNoPolkitAuthAgentAvailable(VPNLauncherException):
    pass


class EIPNoPkexecAvailable(VPNLauncherException):
    pass


class EIPNoTunKextLoaded(VPNLauncherException):
    pass


class VPNLauncher(object):
    """
    Abstract launcher class
    """
    __metaclass__ = ABCMeta

    UPDOWN_FILES = None
    OTHER_FILES = None

    @abstractmethod
    def get_vpn_command(self, eipconfig=None, providerconfig=None,
                        socket_host=None, socket_port=None):
        """
        Returns the platform dependant vpn launching command

        :param eipconfig: eip configuration object
        :type eipconfig: EIPConfig
        :param providerconfig: provider specific configuration
        :type providerconfig: ProviderConfig
        :param socket_host: either socket path (unix) or socket IP
        :type socket_host: str
        :param socket_port: either string "unix" if it's a unix
        socket, or port otherwise
        :type socket_port: str

        :return: A VPN command ready to be launched
        :rtype: list
        """
        return []

    @abstractmethod
    def get_vpn_env(self, providerconfig):
        """
        Returns a dictionary with the custom env for the platform.
        This is mainly used for setting LD_LIBRARY_PATH to the correct
        path when distributing a standalone client

        :param providerconfig: provider specific configuration
        :type providerconfig: ProviderConfig

        :rtype: dict
        """
        return {}

    @classmethod
    def missing_updown_scripts(kls):
        """
        Returns what updown scripts are missing.
        :rtype: list
        """
        leap_assert(kls.UPDOWN_FILES is not None,
                    "Need to define UPDOWN_FILES for this particular "
                    "auncher before calling this method")
        file_exist = partial(_has_updown_scripts, warn=False)
        zipped = zip(kls.UPDOWN_FILES, map(file_exist, kls.UPDOWN_FILES))
        missing = filter(lambda (path, exists): exists is False, zipped)
        return [path for path, exists in missing]

    @classmethod
    def missing_other_files(kls):
        """
        Returns what other important files are missing during startup.
        Same as missing_updown_scripts but does not check for exec bit.
        :rtype: list
        """
        leap_assert(kls.UPDOWN_FILES is not None,
                    "Need to define OTHER_FILES for this particular "
                    "auncher before calling this method")
        file_exist = partial(_has_other_files, warn=False)
        zipped = zip(kls.OTHER_FILES, map(file_exist, kls.OTHER_FILES))
        missing = filter(lambda (path, exists): exists is False, zipped)
        return [path for path, exists in missing]


def get_platform_launcher():
    launcher = globals()[platform.system() + "VPNLauncher"]
    leap_assert(launcher, "Unimplemented platform launcher: %s" %
                (platform.system(),))
    return launcher()


def _is_pkexec_in_system():
    """
    Checks the existence of the pkexec binary in system.
    """
    pkexec_path = which('pkexec')
    if len(pkexec_path) == 0:
        return False
    return True


def _has_updown_scripts(path, warn=True):
    """
    Checks the existence of the up/down scripts and its
    exec bit if applicable.

    :param path: the path to be checked
    :type path: str

    :param warn: whether we should log the absence
    :type warn: bool

    :rtype: bool
    """
    is_file = os.path.isfile(path)
    if warn and not is_file:
        logger.error("Could not find up/down script %s. "
                     "Might produce DNS leaks." % (path,))

    # XXX check if applies in win
    is_exe = False
    try:
        is_exe = (stat.S_IXUSR & os.stat(path)[stat.ST_MODE] != 0)
    except OSError as e:
        logger.warn("%s" % (e,))
    if warn and not is_exe:
        logger.error("Up/down script %s is not executable. "
                     "Might produce DNS leaks." % (path,))
    return is_file and is_exe


def _has_other_files(path, warn=True):
    """
    Checks the existence of other important files.

    :param path: the path to be checked
    :type path: str

    :param warn: whether we should log the absence
    :type warn: bool

    :rtype: bool
    """
    is_file = os.path.isfile(path)
    if warn and not is_file:
        logger.warning("Could not find file during checks: %s. " % (
            path,))
    return is_file


def _is_auth_agent_running():
    """
    Checks if a polkit daemon is running.

    :return: True if it's running, False if it's not.
    :rtype: boolean
    """
    ps = 'ps aux | grep polkit-%s-authentication-agent-1'
    opts = (ps % case for case in ['[g]nome', '[k]de'])
    is_running = map(lambda l: commands.getoutput(l), opts)
    return any(is_running)


def _try_to_launch_agent(standalone=False):
    """
    Tries to launch a polkit daemon.
    """
    env = None
    if standalone is True:
        env = {
            "PYTHONPATH": os.path.abspath('../../../../lib/')}
    try:
        # We need to quote the command because subprocess call
        # will do "sh -c 'foo'", so if we do not quoute it we'll end
        # up with a invocation to the python interpreter. And that
        # is bad.
        subprocess.call(["python -m leap.bitmask.util.polkit_agent"],
                        shell=True, env=env)
    except Exception as exc:
        logger.exception(exc)


class LinuxVPNLauncher(VPNLauncher):
    """
    VPN launcher for the Linux platform
    """

    PKEXEC_BIN = 'pkexec'
    OPENVPN_BIN = 'openvpn'
    OPENVPN_BIN_PATH = os.path.join(
        ProviderConfig().get_path_prefix(),
        "..", "apps", "eip", OPENVPN_BIN)

    SYSTEM_CONFIG = "/etc/leap"
    UP_DOWN_FILE = "resolv-update"
    UP_DOWN_PATH = "%s/%s" % (SYSTEM_CONFIG, UP_DOWN_FILE)

    # We assume this is there by our openvpn dependency, and
    # we will put it there on the bundle too.
    # TODO adapt to the bundle path.
    OPENVPN_DOWN_ROOT_BASE = "/usr/lib/openvpn/"
    OPENVPN_DOWN_ROOT_FILE = "openvpn-plugin-down-root.so"
    OPENVPN_DOWN_ROOT_PATH = "%s/%s" % (
        OPENVPN_DOWN_ROOT_BASE,
        OPENVPN_DOWN_ROOT_FILE)

    UPDOWN_FILES = (UP_DOWN_PATH,)
    POLKIT_PATH = LinuxPolicyChecker.get_polkit_path()
    OTHER_FILES = (POLKIT_PATH, )

    def missing_other_files(self):
        """
        'Extend' the VPNLauncher's missing_other_files to check if the polkit
        files is outdated. If the polkit file that is in OTHER_FILES exists but
        is not up to date, it is added to the missing list.

        :returns: a list of missing files
        :rtype: list of str
        """
        missing = VPNLauncher.missing_other_files.im_func(self)
        polkit_file = LinuxPolicyChecker.get_polkit_path()
        if polkit_file not in missing:
            if privilege_policies.is_policy_outdated(self.OPENVPN_BIN_PATH):
                missing.append(polkit_file)

        return missing

    @classmethod
    def cmd_for_missing_scripts(kls, frompath, pol_file):
        """
        Returns a sh script that can copy the missing files.

        :param frompath: The path where the up/down scripts live
        :type frompath: str
        :param pol_file: The path where the dynamically generated
                         policy file lives
        :type pol_file: str

        :rtype: str
        """
        to = kls.SYSTEM_CONFIG

        cmd = '#!/bin/sh\n'
        cmd += 'mkdir -p "%s"\n' % (to, )
        cmd += 'cp "%s/%s" "%s"\n' % (frompath, kls.UP_DOWN_FILE, to)
        cmd += 'cp "%s" "%s"\n' % (pol_file, kls.POLKIT_PATH)
        cmd += 'chmod 644 "%s"\n' % (kls.POLKIT_PATH, )

        return cmd

    @classmethod
    def maybe_pkexec(kls):
        """
        Checks whether pkexec is available in the system, and
        returns the path if found.

        Might raise EIPNoPkexecAvailable or EIPNoPolkitAuthAgentAvailable

        :returns: a list of the paths where pkexec is to be found
        :rtype: list
        """
        if _is_pkexec_in_system():
            if not _is_auth_agent_running():
                _try_to_launch_agent(ProviderConfig.standalone)
                sleep(0.5)
            if _is_auth_agent_running():
                pkexec_possibilities = which(kls.PKEXEC_BIN)
                leap_assert(len(pkexec_possibilities) > 0,
                            "We couldn't find pkexec")
                return pkexec_possibilities
            else:
                logger.warning("No polkit auth agent found. pkexec " +
                               "will use its own auth agent.")
                raise EIPNoPolkitAuthAgentAvailable()
        else:
            logger.warning("System has no pkexec")
            raise EIPNoPkexecAvailable()

    @classmethod
    def maybe_down_plugin(kls):
        """
        Returns the path of the openvpn down-root-plugin, searching first
        in the relative path for the standalone bundle, and then in the system
        path where the debian package puts it.

        :returns: the path where the plugin was found, or None
        :rtype: str or None
        """
        cwd = os.getcwd()
        rel_path_in_bundle = os.path.join(
            'apps', 'eip', 'files', kls.OPENVPN_DOWN_ROOT_FILE)
        abs_path_in_bundle = os.path.join(cwd, rel_path_in_bundle)
        if os.path.isfile(abs_path_in_bundle):
            return abs_path_in_bundle
        abs_path_in_system = kls.OPENVPN_DOWN_ROOT_PATH
        if os.path.isfile(abs_path_in_system):
            return abs_path_in_system

        logger.warning("We could not find the down-root-plugin, so no updown "
                       "scripts will be run. DNS leaks are likely!")
        return None

    def get_vpn_command(self, eipconfig=None, providerconfig=None,
                        socket_host=None, socket_port="unix", openvpn_verb=1):
        """
        Returns the platform dependant vpn launching command. It will
        look for openvpn in the regular paths and algo in
        path_prefix/apps/eip/ (in case standalone is set)

        Might raise:
            VPNLauncherException,
            OpenVPNNotFoundException.

        :param eipconfig: eip configuration object
        :type eipconfig: EIPConfig

        :param providerconfig: provider specific configuration
        :type providerconfig: ProviderConfig

        :param socket_host: either socket path (unix) or socket IP
        :type socket_host: str

        :param socket_port: either string "unix" if it's a unix
                            socket, or port otherwise
        :type socket_port: str

        :param openvpn_verb: openvpn verbosity wanted
        :type openvpn_verb: int

        :return: A VPN command ready to be launched
        :rtype: list
        """
        leap_assert(eipconfig, "We need an eip config")
        leap_assert_type(eipconfig, EIPConfig)
        leap_assert(providerconfig, "We need a provider config")
        leap_assert_type(providerconfig, ProviderConfig)
        leap_assert(socket_host, "We need a socket host!")
        leap_assert(socket_port, "We need a socket port!")

        kwargs = {}
        if ProviderConfig.standalone:
            kwargs['path_extension'] = os.path.join(
                providerconfig.get_path_prefix(),
                "..", "apps", "eip")

        openvpn_possibilities = which(self.OPENVPN_BIN, **kwargs)

        if len(openvpn_possibilities) == 0:
            raise OpenVPNNotFoundException()

        openvpn = first(openvpn_possibilities)
        args = []

        pkexec = self.maybe_pkexec()
        if pkexec:
            args.append(openvpn)
            openvpn = first(pkexec)

        args += [
            '--setenv', "LEAPOPENVPN", "1"
        ]

        if openvpn_verb is not None:
            args += ['--verb', '%d' % (openvpn_verb,)]

        gateways = []
        leap_settings = LeapSettings(ProviderConfig.standalone)
        domain = providerconfig.get_domain()
        gateway_conf = leap_settings.get_selected_gateway(domain)

        if gateway_conf == leap_settings.GATEWAY_AUTOMATIC:
            gateway_selector = VPNGatewaySelector(eipconfig)
            gateways = gateway_selector.get_gateways()
        else:
            gateways = [gateway_conf]

        if not gateways:
            logger.error('No gateway was found!')
            raise VPNLauncherException(self.tr('No gateway was found!'))

        logger.debug("Using gateways ips: {0}".format(', '.join(gateways)))

        for gw in gateways:
            args += ['--remote', gw, '1194', 'udp']

        args += [
            '--client',
            '--dev', 'tun',
            ##############################################################
            # persist-tun makes ping-restart fail because it leaves a
            # broken routing table
            ##############################################################
            # '--persist-tun',
            '--persist-key',
            '--tls-client',
            '--remote-cert-tls',
            'server'
        ]

        openvpn_configuration = eipconfig.get_openvpn_configuration()

        for key, value in openvpn_configuration.items():
            args += ['--%s' % (key,), value]

        ##############################################################
        # The down-root plugin fails in some situations, so we don't
        # drop privs for the time being
        ##############################################################
        # args += [
        #     '--user', getpass.getuser(),
        #     '--group', grp.getgrgid(os.getgroups()[-1]).gr_name
        # ]

        if socket_port == "unix":  # that's always the case for linux
            args += [
                '--management-client-user', getpass.getuser()
            ]

        args += [
            '--management-signal',
            '--management', socket_host, socket_port,
            '--script-security', '2'
        ]

        plugin_path = self.maybe_down_plugin()
        # If we do not have the down plugin neither in the bundle
        # nor in the system, we do not do updown scripts. The alternative
        # is leaving the user without the ability to restore dns and routes
        # to its original state.

        if plugin_path and _has_updown_scripts(self.UP_DOWN_PATH):
            args += [
                '--up', self.UP_DOWN_PATH,
                '--down', self.UP_DOWN_PATH,
                ##############################################################
                # For the time being we are disabling the usage of the
                # down-root plugin, because it doesn't quite work as
                # expected (i.e. it doesn't run route -del as root
                # when finishing, so it fails to properly
                # restart/quit)
                ##############################################################
                # '--plugin', plugin_path,
                # '\'script_type=down %s\'' % self.UP_DOWN_PATH
            ]

        args += [
            '--cert', eipconfig.get_client_cert_path(providerconfig),
            '--key', eipconfig.get_client_cert_path(providerconfig),
            '--ca', providerconfig.get_ca_cert_path()
        ]

        logger.debug("Running VPN with command:")
        logger.debug("%s %s" % (openvpn, " ".join(args)))

        return [openvpn] + args

    def get_vpn_env(self, providerconfig):
        """
        Returns a dictionary with the custom env for the platform.
        This is mainly used for setting LD_LIBRARY_PATH to the correct
        path when distributing a standalone client

        :param providerconfig: provider specific configuration
        :type providerconfig: ProviderConfig

        :rtype: dict
        """
        leap_assert(providerconfig, "We need a provider config")
        leap_assert_type(providerconfig, ProviderConfig)

        return {"LD_LIBRARY_PATH": os.path.join(
                providerconfig.get_path_prefix(),
                "..", "lib")}


class DarwinVPNLauncher(VPNLauncher):
    """
    VPN launcher for the Darwin Platform
    """

    COCOASUDO = "cocoasudo"
    # XXX need the good old magic translate for these strings
    # (look for magic in 0.2.0 release)
    SUDO_MSG = ("Bitmask needs administrative privileges to run "
                "Encrypted Internet.")
    INSTALL_MSG = ("\"Bitmask needs administrative privileges to install "
                   "missing scripts and fix permissions.\"")

    INSTALL_PATH = os.path.realpath(os.getcwd() + "/../../")
    INSTALL_PATH_ESCAPED = os.path.realpath(os.getcwd() + "/../../")
    OPENVPN_BIN = 'openvpn.leap'
    OPENVPN_PATH = "%s/Contents/Resources/openvpn" % (INSTALL_PATH,)
    OPENVPN_PATH_ESCAPED = "%s/Contents/Resources/openvpn" % (
        INSTALL_PATH_ESCAPED,)

    UP_SCRIPT = "%s/client.up.sh" % (OPENVPN_PATH,)
    DOWN_SCRIPT = "%s/client.down.sh" % (OPENVPN_PATH,)
    OPENVPN_DOWN_PLUGIN = '%s/openvpn-down-root.so' % (OPENVPN_PATH,)

    UPDOWN_FILES = (UP_SCRIPT, DOWN_SCRIPT, OPENVPN_DOWN_PLUGIN)
    OTHER_FILES = []

    @classmethod
    def cmd_for_missing_scripts(kls, frompath):
        """
        Returns a command that can copy the missing scripts.
        :rtype: str
        """
        to = kls.OPENVPN_PATH_ESCAPED
        cmd = "#!/bin/sh\nmkdir -p %s\ncp \"%s/\"* %s\nchmod 744 %s/*" % (
            to, frompath, to, to)
        return cmd

    @classmethod
    def maybe_kextloaded(kls):
        """
        Checks if the needed kext is loaded before launching openvpn.
        """
        return bool(commands.getoutput('kextstat | grep "leap.tun"'))

    def _get_resource_path(self):
        """
        Returns the absolute path to the app resources directory

        :rtype: str
        """
        return os.path.abspath(
            os.path.join(
                os.getcwd(),
                "../../Contents/Resources"))

    def _get_icon_path(self):
        """
        Returns the absolute path to the app icon

        :rtype: str
        """
        return os.path.join(self._get_resource_path(),
                            "leap-client.tiff")

    def get_cocoasudo_ovpn_cmd(self):
        """
        Returns a string with the cocoasudo command needed to run openvpn
        as admin with a nice password prompt. The actual command needs to be
        appended.

        :rtype: (str, list)
        """
        iconpath = self._get_icon_path()
        has_icon = os.path.isfile(iconpath)
        args = ["--icon=%s" % iconpath] if has_icon else []
        args.append("--prompt=%s" % (self.SUDO_MSG,))

        return self.COCOASUDO, args

    def get_cocoasudo_installmissing_cmd(self):
        """
        Returns a string with the cocoasudo command needed to install missing
        files as admin with a nice password prompt. The actual command needs to
        be appended.

        :rtype: (str, list)
        """
        iconpath = self._get_icon_path()
        has_icon = os.path.isfile(iconpath)
        args = ["--icon=%s" % iconpath] if has_icon else []
        args.append("--prompt=%s" % (self.INSTALL_MSG,))

        return self.COCOASUDO, args

    def get_vpn_command(self, eipconfig=None, providerconfig=None,
                        socket_host=None, socket_port="unix", openvpn_verb=1):
        """
        Returns the platform dependant vpn launching command

        Might raise VPNException.

        :param eipconfig: eip configuration object
        :type eipconfig: EIPConfig

        :param providerconfig: provider specific configuration
        :type providerconfig: ProviderConfig

        :param socket_host: either socket path (unix) or socket IP
        :type socket_host: str

        :param socket_port: either string "unix" if it's a unix
                            socket, or port otherwise
        :type socket_port: str

        :param openvpn_verb: openvpn verbosity wanted
        :type openvpn_verb: int

        :return: A VPN command ready to be launched
        :rtype: list
        """
        leap_assert(eipconfig, "We need an eip config")
        leap_assert_type(eipconfig, EIPConfig)
        leap_assert(providerconfig, "We need a provider config")
        leap_assert_type(providerconfig, ProviderConfig)
        leap_assert(socket_host, "We need a socket host!")
        leap_assert(socket_port, "We need a socket port!")

        if not self.maybe_kextloaded():
            raise EIPNoTunKextLoaded

        kwargs = {}
        if ProviderConfig.standalone:
            kwargs['path_extension'] = os.path.join(
                providerconfig.get_path_prefix(),
                "..", "apps", "eip")

        openvpn_possibilities = which(
            self.OPENVPN_BIN,
            **kwargs)
        if len(openvpn_possibilities) == 0:
            raise OpenVPNNotFoundException()

        openvpn = first(openvpn_possibilities)
        args = [openvpn]

        args += [
            '--setenv', "LEAPOPENVPN", "1"
        ]

        if openvpn_verb is not None:
            args += ['--verb', '%d' % (openvpn_verb,)]

        gateways = []
        leap_settings = LeapSettings(ProviderConfig.standalone)
        domain = providerconfig.get_domain()
        gateway_conf = leap_settings.get_selected_gateway(domain)

        if gateway_conf == leap_settings.GATEWAY_AUTOMATIC:
            gateway_selector = VPNGatewaySelector(eipconfig)
            gateways = gateway_selector.get_gateways()
        else:
            gateways = [gateway_conf]

        if not gateways:
            logger.error('No gateway was found!')
            raise VPNLauncherException(self.tr('No gateway was found!'))

        logger.debug("Using gateways ips: {0}".format(', '.join(gateways)))

        for gw in gateways:
            args += ['--remote', gw, '1194', 'udp']

        args += [
            '--client',
            '--dev', 'tun',
            ##############################################################
            # persist-tun makes ping-restart fail because it leaves a
            # broken routing table
            ##############################################################
            # '--persist-tun',
            '--persist-key',
            '--tls-client',
            '--remote-cert-tls',
            'server'
        ]

        openvpn_configuration = eipconfig.get_openvpn_configuration()
        for key, value in openvpn_configuration.items():
            args += ['--%s' % (key,), value]

        user = getpass.getuser()

        ##############################################################
        # The down-root plugin fails in some situations, so we don't
        # drop privs for the time being
        ##############################################################
        # args += [
        #     '--user', user,
        #     '--group', grp.getgrgid(os.getgroups()[-1]).gr_name
        # ]

        if socket_port == "unix":
            args += [
                '--management-client-user', user
            ]

        args += [
            '--management-signal',
            '--management', socket_host, socket_port,
            '--script-security', '2'
        ]

        if _has_updown_scripts(self.UP_SCRIPT):
            args += [
                '--up', '\"%s\"' % (self.UP_SCRIPT,),
            ]

        if _has_updown_scripts(self.DOWN_SCRIPT):
            args += [
                '--down', '\"%s\"' % (self.DOWN_SCRIPT,)
            ]

            # should have the down script too
            if _has_updown_scripts(self.OPENVPN_DOWN_PLUGIN):
                args += [
                    ###########################################################
                    # For the time being we are disabling the usage of the
                    # down-root plugin, because it doesn't quite work as
                    # expected (i.e. it doesn't run route -del as root
                    # when finishing, so it fails to properly
                    # restart/quit)
                    ###########################################################
                    # '--plugin', self.OPENVPN_DOWN_PLUGIN,
                    # '\'%s\'' % self.DOWN_SCRIPT
                ]

        # we set user to be passed to the up/down scripts
        args += [
            '--setenv', "LEAPUSER", "%s" % (user,)]

        args += [
            '--cert', eipconfig.get_client_cert_path(providerconfig),
            '--key', eipconfig.get_client_cert_path(providerconfig),
            '--ca', providerconfig.get_ca_cert_path()
        ]

        command, cargs = self.get_cocoasudo_ovpn_cmd()
        cmd_args = cargs + args

        logger.debug("Running VPN with command:")
        logger.debug("%s %s" % (command, " ".join(cmd_args)))

        return [command] + cmd_args

    def get_vpn_env(self, providerconfig):
        """
        Returns a dictionary with the custom env for the platform.
        This is mainly used for setting LD_LIBRARY_PATH to the correct
        path when distributing a standalone client

        :param providerconfig: provider specific configuration
        :type providerconfig: ProviderConfig

        :rtype: dict
        """
        return {"DYLD_LIBRARY_PATH": os.path.join(
                providerconfig.get_path_prefix(),
                "..", "lib")}


class WindowsVPNLauncher(VPNLauncher):
    """
    VPN launcher for the Windows platform
    """

    OPENVPN_BIN = 'openvpn_leap.exe'

    # XXX UPDOWN_FILES ... we do not have updown files defined yet!
    # (and maybe we won't)

    def get_vpn_command(self, eipconfig=None, providerconfig=None,
                        socket_host=None, socket_port="9876", openvpn_verb=1):
        """
        Returns the platform dependant vpn launching command. It will
        look for openvpn in the regular paths and algo in
        path_prefix/apps/eip/ (in case standalone is set)

        Might raise VPNException.

        :param eipconfig: eip configuration object
        :type eipconfig: EIPConfig

        :param providerconfig: provider specific configuration
        :type providerconfig: ProviderConfig

        :param socket_host: either socket path (unix) or socket IP
        :type socket_host: str

        :param socket_port: either string "unix" if it's a unix
        socket, or port otherwise
        :type socket_port: str

        :param openvpn_verb: the openvpn verbosity wanted
        :type openvpn_verb: int

        :return: A VPN command ready to be launched
        :rtype: list
        """
        leap_assert(eipconfig, "We need an eip config")
        leap_assert_type(eipconfig, EIPConfig)
        leap_assert(providerconfig, "We need a provider config")
        leap_assert_type(providerconfig, ProviderConfig)
        leap_assert(socket_host, "We need a socket host!")
        leap_assert(socket_port, "We need a socket port!")
        leap_assert(socket_port != "unix",
                    "We cannot use unix sockets in windows!")

        openvpn_possibilities = which(
            self.OPENVPN_BIN,
            path_extension=os.path.join(providerconfig.get_path_prefix(),
                                        "..", "apps", "eip"))

        if len(openvpn_possibilities) == 0:
            raise OpenVPNNotFoundException()

        openvpn = first(openvpn_possibilities)
        args = []

        args += [
            '--setenv', "LEAPOPENVPN", "1"
        ]

        if openvpn_verb is not None:
            args += ['--verb', '%d' % (openvpn_verb,)]

        gateways = []
        leap_settings = LeapSettings(ProviderConfig.standalone)
        domain = providerconfig.get_domain()
        gateway_conf = leap_settings.get_selected_gateway(domain)

        if gateway_conf == leap_settings.GATEWAY_AUTOMATIC:
            gateway_selector = VPNGatewaySelector(eipconfig)
            gateways = gateway_selector.get_gateways()
        else:
            gateways = [gateway_conf]

        if not gateways:
            logger.error('No gateway was found!')
            raise VPNLauncherException(self.tr('No gateway was found!'))

        logger.debug("Using gateways ips: {0}".format(', '.join(gateways)))

        for gw in gateways:
            args += ['--remote', gw, '1194', 'udp']

        args += [
            '--client',
            '--dev', 'tun',
            ##############################################################
            # persist-tun makes ping-restart fail because it leaves a
            # broken routing table
            ##############################################################
            # '--persist-tun',
            '--persist-key',
            '--tls-client',
            # We make it log to a file because we cannot attach to the
            # openvpn process' stdout since it's a process with more
            # privileges than we are
            '--log-append', 'eip.log',
            '--remote-cert-tls',
            'server'
        ]

        openvpn_configuration = eipconfig.get_openvpn_configuration()
        for key, value in openvpn_configuration.items():
            args += ['--%s' % (key,), value]

        ##############################################################
        # The down-root plugin fails in some situations, so we don't
        # drop privs for the time being
        ##############################################################
        # args += [
        #     '--user', getpass.getuser(),
        #     #'--group', grp.getgrgid(os.getgroups()[-1]).gr_name
        # ]

        args += [
            '--management-signal',
            '--management', socket_host, socket_port,
            '--script-security', '2'
        ]

        args += [
            '--cert', eipconfig.get_client_cert_path(providerconfig),
            '--key', eipconfig.get_client_cert_path(providerconfig),
            '--ca', providerconfig.get_ca_cert_path()
        ]

        logger.debug("Running VPN with command:")
        logger.debug("%s %s" % (openvpn, " ".join(args)))

        return [openvpn] + args

    def get_vpn_env(self, providerconfig):
        """
        Returns a dictionary with the custom env for the platform.
        This is mainly used for setting LD_LIBRARY_PATH to the correct
        path when distributing a standalone client

        :param providerconfig: provider specific configuration
        :type providerconfig: ProviderConfig

        :rtype: dict
        """
        return {}


if __name__ == "__main__":
    logger = logging.getLogger(name='leap')
    logger.setLevel(logging.DEBUG)
    console = logging.StreamHandler()
    console.setLevel(logging.DEBUG)
    formatter = logging.Formatter(
        '%(asctime)s '
        '- %(name)s - %(levelname)s - %(message)s')
    console.setFormatter(formatter)
    logger.addHandler(console)

    try:
        abs_launcher = VPNLauncher()
    except Exception as e:
        assert isinstance(e, TypeError), "Something went wrong"
        print "Abstract Prefixer class is working as expected"

    vpnlauncher = get_platform_launcher()

    eipconfig = EIPConfig()
    eipconfig.set_api_version('1')
    if eipconfig.load("leap/providers/bitmask.net/eip-service.json"):
        provider = ProviderConfig()
        if provider.load("leap/providers/bitmask.net/provider.json"):
            vpnlauncher.get_vpn_command(eipconfig=eipconfig,
                                        providerconfig=provider,
                                        socket_host="/blah")