#!/usr/bin/env python3


# SAT plugin for managing gateways (xep-0100)
# Copyright (C) 2009-2021 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 typing import cast
from pydantic import BaseModel, Field
from twisted.internet import defer, reactor
from twisted.words.protocols.jabber import jid
from wokkel import disco

from libervia.backend.core import exceptions
from libervia.backend.core.constants import Const as C
from libervia.backend.core.core_types import SatXMPPEntity
from libervia.backend.core.i18n import D_, _
from libervia.backend.core.log import getLogger
from libervia.backend.models.core import DiscoIdentity
from libervia.backend.models.types import StrictJIDType
from libervia.backend.tools import xml_tools

log = getLogger(__name__)


PLUGIN_INFO = {
    C.PI_NAME: "Gateways Plugin",
    C.PI_IMPORT_NAME: "XEP-0100",
    C.PI_TYPE: "XEP",
    C.PI_PROTOCOLS: ["XEP-0100"],
    C.PI_DEPENDENCIES: ["XEP-0077"],
    C.PI_MAIN: "XEP_0100",
    C.PI_DESCRIPTION: _("""Implementation of Gateways protocol"""),
}

WARNING_MSG = D_(
    "Please exercise caution. Gateways facilitate the use of external instant messaging "
    "platforms (legacy IM), enabling you to view your contacts as XMPP contacts. "
    "However, this process routes all messages through the external legacy IM server, "
    "raising significant privacy concerns. Specifically, it is possible for the external "
    "server, often operated by a private company, to monitor, record, and analyze all "
    "messages that traverse the gateway."
)

GATEWAY_TIMEOUT = 10  # time to wait before cancelling a gateway disco info, in seconds

TYPE_DESCRIPTIONS = {
    "irc": D_("Internet Relay Chat"),
    "xmpp": D_("XMPP"),
    "qq": D_("Tencent QQ"),
    "simple": D_("SIP/SIMPLE"),
    "icq": D_("ICQ"),
    "yahoo": D_("Yahoo! Messenger"),
    "gadu-gadu": D_("Gadu-Gadu"),
    "aim": D_("AOL Instant Messenger"),
    "msn": D_("Windows Live Messenger"),
    "smtp": D_("Email"),
}


class GatewayData(BaseModel):
    entity: StrictJIDType
    identities: list[DiscoIdentity]


class FoundGateways(BaseModel):
    available: list[GatewayData]
    unavailable: list[StrictJIDType] = Field(
        description="Gateways registered but not answering."
    )


class XEP_0100(object):
    def __init__(self, host):
        log.info(_("Gateways plugin initialization"))
        self.host = host
        self.__gateways = (
            {}
        )  # dict used to construct the answer to gateways_find. Key = target jid
        host.bridge.add_method(
            "gateways_find",
            ".plugin",
            in_sign="ss",
            out_sign="s",
            method=self._gateways_find,
        )
        host.bridge.add_method(
            "gateways_find_xmlui",
            ".plugin",
            in_sign="ss",
            out_sign="s",
            method=self._gateways_find_xmlui,
        )
        host.bridge.add_method(
            "gateway_register",
            ".plugin",
            in_sign="ss",
            out_sign="s",
            method=self._gateway_register,
            async_=True,
        )
        self.__menu_id = host.register_callback(self._gateways_menu, with_data=True)
        self.__selected_id = host.register_callback(
            self._gateway_selected_cb, with_data=True
        )
        host.import_menu(
            (D_("Service"), D_("Gateways")),
            self._gateways_menu,
            security_limit=1,
            help_string=D_("Find gateways"),
        )

    def _gateways_menu(self, data, profile):
        """XMLUI activated by menu: return Gateways UI

        @param profile: %(doc_profile)s
        """
        client = self.host.get_client(profile)
        try:
            jid_ = jid.JID(
                data.get(xml_tools.form_escape("external_jid"), client.jid.host)
            )
        except RuntimeError:
            raise exceptions.DataError(_("Invalid JID"))
        d = self.gateways_find_raw(jid_, profile)
        d.addCallback(self._gateways_result_2_xmlui, jid_)
        d.addCallback(lambda xmlui: {"xmlui": xmlui.toXml()})
        return d

    def _gateways_result_2_xmlui(self, result, entity):
        xmlui = xml_tools.XMLUI(title=_("Gateways manager (%s)") % entity.full())
        xmlui.addText(_(WARNING_MSG))
        xmlui.addDivider("dash")
        adv_list = xmlui.change_container(
            "advanced_list",
            columns=3,
            selectable="single",
            callback_id=self.__selected_id,
        )
        for success, gateway_data in result:
            if not success:
                fail_cond, disco_item = gateway_data
                xmlui.addJid(disco_item.entity)
                xmlui.addText(_("Failed (%s)") % fail_cond)
                xmlui.addEmpty()
            else:
                jid_, data = gateway_data
                for datum in data:
                    identity, name = datum
                    adv_list.set_row_index(jid_.full())
                    xmlui.addJid(jid_)
                    xmlui.addText(name)
                    xmlui.addText(self._get_identity_desc(identity))
        adv_list.end()
        xmlui.addDivider("blank")
        xmlui.change_container("advanced_list", columns=3)
        xmlui.addLabel(_("Use external XMPP server"))
        xmlui.addString("external_jid")
        xmlui.addButton(self.__menu_id, _("Go !"), fields_back=("external_jid",))
        return xmlui

    def _gateway_selected_cb(self, data, profile):
        try:
            target_jid = jid.JID(data["index"])
        except (KeyError, RuntimeError):
            log.warning(_("No gateway index selected"))
            return {}

        d = self.gateway_register(target_jid, profile)
        d.addCallback(lambda xmlui: {"xmlui": xmlui.toXml()})
        return d

    def _get_identity_desc(self, identity):
        """Return a human readable description of identity
        @param identity: tuple as returned by Disco identities (category, type)

        """
        category, type_ = identity
        if category != "gateway":
            log.error(
                _(
                    'INTERNAL ERROR: identity category should always be "gateway" in '
                    '_getTypeString, got "%s"'
                )
                % category
            )
        try:
            return _(TYPE_DESCRIPTIONS[type_])
        except KeyError:
            return _("Unknown IM")

    def _registration_successful(self, jid_, profile):
        """Called when in_band registration is ok, we must now follow the rest of procedure"""
        log.debug(_("Registration successful, doing the rest"))
        self.host.contact_add(jid_, profile_key=profile)
        self.host.presence_set(jid_, profile_key=profile)

    def _gateway_register(self, target_jid_s, profile_key=C.PROF_KEY_NONE):
        client = self.host.get_client(profile_key)
        d = self.gateway_register(client, jid.JID(target_jid_s))
        d.addCallback(lambda xmlui: xmlui.toXml())
        return d

    def gateway_register(
        self, client: SatXMPPEntity, target_jid: jid.JID
    ) -> defer.Deferred:
        """Register gateway using in-band registration, then log-in to gateway"""
        return defer.ensureDeferred(
            self.host.plugins["XEP-0077"].in_band_register(
                client, target_jid, self._registration_successful
            )
        )

    def _gateways_find(self, target_jid_s: str, profile_key: str) -> defer.Deferred[str]:
        client = self.host.get_client(profile_key)
        target_jid = jid.JID(target_jid_s) if target_jid_s else client.server_jid
        d = defer.ensureDeferred(self.gateways_find(client, target_jid))
        d.addCallback(lambda found_gateways: found_gateways.model_dump_json())
        # The Deferred will actually return a str due to `model_dump_json`, but type
        # checker doesn't get that.
        d = cast(defer.Deferred[str], d)
        return d

    async def gateways_find(
        self, client: SatXMPPEntity, target: jid.JID
    ) -> FoundGateways:
        """Find gateways and convert FoundGateways instance."""
        gateways_data = await self.gateways_find_raw(client, target)
        available = []
        unavailable = []
        for gw_available, data in gateways_data:
            if gw_available:
                data = cast(tuple[jid.JID, list[tuple[tuple[str, str], str]]], data)
                identities = []
                for (category, type_), name in data[1]:
                    identities.append(
                        DiscoIdentity(name=name, category=category, type=type_)
                    )
                available.append(GatewayData(entity=data[0], identities=identities))
            else:
                disco_item = cast(disco.DiscoItem, data[1])
                unavailable.append(disco_item.entity)
        return FoundGateways(available=available, unavailable=unavailable)

    def _gateways_find_xmlui(
        self, target_jid_s: str, profile_key: str
    ) -> defer.Deferred[str]:
        target_jid = jid.JID(target_jid_s)
        client = self.host.get_client(profile_key)
        d = defer.ensureDeferred(self.gateways_find_raw(client, target_jid))
        d.addCallback(self._gateways_result_2_xmlui, target_jid)
        d.addCallback(lambda xmlui: xmlui.toXml())
        d = cast(defer.Deferred[str], d)
        return d

    async def gateways_find_raw(self, client: SatXMPPEntity, target: jid.JID) -> list:
        """Find gateways in the target JID, using discovery protocol"""
        log.debug(
            _("find gateways (target = {target}, profile = {profile})").format(
                target=target.full(), profile=client.profile
            )
        )
        disco = await client.disco.requestItems(target)
        if len(disco._items) == 0:
            log.debug(_("No gateway found"))
            return []

        defers_ = []
        for item in disco._items:
            log.debug(_("item found: {}").format(item.entity))
            defers_.append(client.disco.requestInfo(item.entity))
        deferred_list = defer.DeferredList(defers_)
        dl_result = await deferred_list
        reactor.callLater(GATEWAY_TIMEOUT, deferred_list.cancel)
        items = disco._items
        ret = []
        for idx, (success, result) in enumerate(dl_result):
            if not success:
                if isinstance(result.value, defer.CancelledError):
                    msg = _("Timeout")
                else:
                    try:
                        msg = result.value.condition
                    except AttributeError:
                        msg = str(result)
                ret.append((success, (msg, items[idx])))
            else:
                entity = items[idx].entity
                gateways = [
                    (identity, result.identities[identity])
                    for identity in result.identities
                    if identity[0] == "gateway"
                ]
                if gateways:
                    log.debug(
                        _("Found gateway [{jid}]: {identity_name}").format(
                            jid=entity.full(),
                            identity_name=" - ".join(
                                [gateway[1] for gateway in gateways]
                            ),
                        )
                    )
                    ret.append((success, (entity, gateways)))
                else:
                    log.debug(
                        _("Skipping [{jid}] which is not a gateway").format(
                            jid=entity.full()
                        )
                    )

        return ret