#!/usr/bin/env python2
# -*- coding: utf-8 -*-

# SAT plugin for adding D-Bus to Ad-Hoc Commands
# Copyright (C) 2009-2018 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero 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 Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from sat.core.i18n import _
from sat.core.constants import Const as C
from sat.core.log import getLogger

log = getLogger(__name__)
from sat.core import exceptions
from twisted.internet import defer
from wokkel import data_form

try:
    from lxml import etree
except ImportError:
    raise exceptions.MissingModule(
        u"Missing module lxml, please download/install it from http://lxml.de/"
    )
import os.path
import uuid
import dbus
from dbus.mainloop.glib import DBusGMainLoop

DBusGMainLoop(set_as_default=True)

FD_NAME = "org.freedesktop.DBus"
FD_PATH = "/org/freedekstop/DBus"
INTROSPECT_IFACE = "org.freedesktop.DBus.Introspectable"

INTROSPECT_METHOD = "Introspect"
IGNORED_IFACES_START = (
    "org.freedesktop",
    "org.qtproject",
    "org.kde.KMainWindow",
)  # commands in interface starting with these values will be ignored
FLAG_LOOP = "LOOP"

PLUGIN_INFO = {
    C.PI_NAME: "Ad-Hoc Commands - D-Bus",
    C.PI_IMPORT_NAME: "AD_HOC_DBUS",
    C.PI_TYPE: "Misc",
    C.PI_PROTOCOLS: [],
    C.PI_DEPENDENCIES: ["XEP-0050"],
    C.PI_MAIN: "AdHocDBus",
    C.PI_HANDLER: "no",
    C.PI_DESCRIPTION: _("""Add D-Bus management to Ad-Hoc commands"""),
}


class AdHocDBus(object):
    def __init__(self, host):
        log.info(_("plugin Ad-Hoc D-Bus initialization"))
        self.host = host
        host.bridge.addMethod(
            "adHocDBusAddAuto",
            ".plugin",
            in_sign="sasasasasasass",
            out_sign="(sa(sss))",
            method=self._adHocDBusAddAuto,
            async=True,
        )
        self.session_bus = dbus.SessionBus()
        self.fd_object = self.session_bus.get_object(FD_NAME, FD_PATH, introspect=False)
        self.XEP_0050 = host.plugins["XEP-0050"]

    def _DBusAsyncCall(self, proxy, method, *args, **kwargs):
        """ Call a DBus method asynchronously and return a deferred
        @param proxy: DBus object proxy, as returner by get_object
        @param method: name of the method to call
        @param args: will be transmitted to the method
        @param kwargs: will be transmetted to the method, except for the following poped values:
                       - interface: name of the interface to use
        @return: a deferred

        """
        d = defer.Deferred()
        interface = kwargs.pop("interface", None)
        kwargs["reply_handler"] = lambda ret=None: d.callback(ret)
        kwargs["error_handler"] = d.errback
        proxy.get_dbus_method(method, dbus_interface=interface)(*args, **kwargs)
        return d

    def _DBusListNames(self):
        return self._DBusAsyncCall(self.fd_object, "ListNames")

    def _DBusIntrospect(self, proxy):
        return self._DBusAsyncCall(proxy, INTROSPECT_METHOD, interface=INTROSPECT_IFACE)

    def _acceptMethod(self, method):
        """ Return True if we accept the method for a command
        @param method: etree.Element
        @return: True if the method is acceptable

        """
        if method.xpath(
            "arg[@direction='in']"
        ):  # we don't accept method with argument for the moment
            return False
        return True

    @defer.inlineCallbacks
    def _introspect(self, methods, bus_name, proxy):
        log.debug("introspecting path [%s]" % proxy.object_path)
        introspect_xml = yield self._DBusIntrospect(proxy)
        el = etree.fromstring(introspect_xml)
        for node in el.iterchildren("node", "interface"):
            if node.tag == "node":
                new_path = os.path.join(proxy.object_path, node.get("name"))
                new_proxy = self.session_bus.get_object(
                    bus_name, new_path, introspect=False
                )
                yield self._introspect(methods, bus_name, new_proxy)
            elif node.tag == "interface":
                name = node.get("name")
                if any(name.startswith(ignored) for ignored in IGNORED_IFACES_START):
                    log.debug("interface [%s] is ignored" % name)
                    continue
                log.debug("introspecting interface [%s]" % name)
                for method in node.iterchildren("method"):
                    if self._acceptMethod(method):
                        method_name = method.get("name")
                        log.debug("method accepted: [%s]" % method_name)
                        methods.add((proxy.object_path, name, method_name))

    def _adHocDBusAddAuto(
        self,
        prog_name,
        allowed_jids,
        allowed_groups,
        allowed_magics,
        forbidden_jids,
        forbidden_groups,
        flags,
        profile_key,
    ):
        return self.adHocDBusAddAuto(
            prog_name,
            allowed_jids,
            allowed_groups,
            allowed_magics,
            forbidden_jids,
            forbidden_groups,
            flags,
            profile_key,
        )

    @defer.inlineCallbacks
    def adHocDBusAddAuto(
        self,
        prog_name,
        allowed_jids=None,
        allowed_groups=None,
        allowed_magics=None,
        forbidden_jids=None,
        forbidden_groups=None,
        flags=None,
        profile_key=C.PROF_KEY_NONE,
    ):
        bus_names = yield self._DBusListNames()
        bus_names = [bus_name for bus_name in bus_names if "." + prog_name in bus_name]
        if not bus_names:
            log.info("Can't find any bus for [%s]" % prog_name)
            defer.returnValue(("", []))
        bus_names.sort()
        for bus_name in bus_names:
            if bus_name.endswith(prog_name):
                break
        log.info("bus name found: [%s]" % bus_name)
        proxy = self.session_bus.get_object(bus_name, "/", introspect=False)
        methods = set()

        yield self._introspect(methods, bus_name, proxy)

        if methods:
            self._addCommand(
                prog_name,
                bus_name,
                methods,
                allowed_jids=allowed_jids,
                allowed_groups=allowed_groups,
                allowed_magics=allowed_magics,
                forbidden_jids=forbidden_jids,
                forbidden_groups=forbidden_groups,
                flags=flags,
                profile_key=profile_key,
            )

        defer.returnValue((bus_name, methods))

    def _addCommand(
        self,
        adhoc_name,
        bus_name,
        methods,
        allowed_jids=None,
        allowed_groups=None,
        allowed_magics=None,
        forbidden_jids=None,
        forbidden_groups=None,
        flags=None,
        profile_key=C.PROF_KEY_NONE,
    ):
        if flags is None:
            flags = set()

        def DBusCallback(command_elt, session_data, action, node, profile):
            actions = session_data.setdefault("actions", [])
            names_map = session_data.setdefault("names_map", {})
            actions.append(action)

            if len(actions) == 1:
                # it's our first request, we ask the desired new status
                status = self.XEP_0050.STATUS.EXECUTING
                form = data_form.Form("form", title=_("Command selection"))
                options = []
                for path, iface, command in methods:
                    label = command.rsplit(".", 1)[-1]
                    name = str(uuid.uuid4())
                    names_map[name] = (path, iface, command)
                    options.append(data_form.Option(name, label))

                field = data_form.Field(
                    "list-single", "command", options=options, required=True
                )
                form.addField(field)

                payload = form.toElement()
                note = None

            elif len(actions) == 2:
                # we should have the answer here
                try:
                    x_elt = command_elt.elements(data_form.NS_X_DATA, "x").next()
                    answer_form = data_form.Form.fromElement(x_elt)
                    command = answer_form["command"]
                except (KeyError, StopIteration):
                    raise self.XEP_0050.AdHocError(self.XEP_0050.ERROR.BAD_PAYLOAD)

                if command not in names_map:
                    raise self.XEP_0050.AdHocError(self.XEP_0050.ERROR.BAD_PAYLOAD)

                path, iface, command = names_map[command]
                proxy = self.session_bus.get_object(bus_name, path)

                self._DBusAsyncCall(proxy, command, interface=iface)

                # job done, we can end the session, except if we have FLAG_LOOP
                if FLAG_LOOP in flags:
                    # We have a loop, so we clear everything and we execute again the command as we had a first call (command_elt is not used, so None is OK)
                    del actions[:]
                    names_map.clear()
                    return DBusCallback(
                        None, session_data, self.XEP_0050.ACTION.EXECUTE, node, profile
                    )
                form = data_form.Form("form", title=_(u"Updated"))
                form.addField(data_form.Field("fixed", u"Command sent"))
                status = self.XEP_0050.STATUS.COMPLETED
                payload = None
                note = (self.XEP_0050.NOTE.INFO, _(u"Command sent"))
            else:
                raise self.XEP_0050.AdHocError(self.XEP_0050.ERROR.INTERNAL)

            return (payload, status, None, note)

        self.XEP_0050.addAdHocCommand(
            DBusCallback,
            adhoc_name,
            allowed_jids=allowed_jids,
            allowed_groups=allowed_groups,
            allowed_magics=allowed_magics,
            forbidden_jids=forbidden_jids,
            forbidden_groups=forbidden_groups,
            profile_key=profile_key,
        )