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

# SAT plugin for managing xep-0077
# 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 import exceptions
from sat.core.log import getLogger
log = getLogger(__name__)
from twisted.words.protocols.jabber import jid
from twisted.words.protocols.jabber import xmlstream
from twisted.internet import defer, reactor
from sat.tools import xml_tools

from wokkel import data_form

NS_REG = 'jabber:iq:register'

PLUGIN_INFO = {
    C.PI_NAME: "XEP 0077 Plugin",
    C.PI_IMPORT_NAME: "XEP-0077",
    C.PI_TYPE: "XEP",
    C.PI_PROTOCOLS: ["XEP-0077"],
    C.PI_DEPENDENCIES: [],
    C.PI_MAIN: "XEP_0077",
    C.PI_DESCRIPTION: _("""Implementation of in-band registration""")
}

# FIXME: this implementation is incomplete

class RegisteringAuthenticator(xmlstream.ConnectAuthenticator):
    # FIXME: request IQ is not send to check available fields, while XEP recommand to use it
    # FIXME: doesn't handle data form or oob

    def __init__(self, jid_, password, email=None):
        xmlstream.ConnectAuthenticator.__init__(self, jid_.host)
        self.jid = jid_
        self.password = password
        self.email = email
        self.registered = defer.Deferred()
        log.debug(_(u"Registration asked for {jid}").format(
            jid = jid_))

    def connectionMade(self):
        log.debug(_(u"Connection made with {server}".format(server=self.jid.host)))
        self.xmlstream.otherEntity = jid.JID(self.jid.host)
        self.xmlstream.namespace = C.NS_CLIENT
        self.xmlstream.sendHeader()

        iq = XEP_0077.buildRegisterIQ(self.xmlstream, self.jid, self.password, self.email)
        d = iq.send(self.jid.host).addCallbacks(self.registrationCb, self.registrationEb)
        d.chainDeferred(self.registered)

    def registrationCb(self, answer):
        log.debug(_(u"Registration answer: {}").format(answer.toXml()))
        self.xmlstream.sendFooter()

    def registrationEb(self, failure_):
        log.info(_("Registration failure: {}").format(unicode(failure_.value)))
        self.xmlstream.sendFooter()
        raise failure_


class XEP_0077(object):

    def __init__(self, host):
        log.info(_("Plugin XEP_0077 initialization"))
        self.host = host
        host.bridge.addMethod("inBandRegister", ".plugin", in_sign='ss', out_sign='',
                              method=self._inBandRegister,
                              async=True)
        host.bridge.addMethod("inBandAccountNew", ".plugin", in_sign='ssssi', out_sign='',
                              method=self._registerNewAccount,
                              async=True)
        host.bridge.addMethod("inBandUnregister", ".plugin", in_sign='ss', out_sign='',
                              method=self._unregister,
                              async=True)
        host.bridge.addMethod("inBandPasswordChange", ".plugin", in_sign='ss', out_sign='',
                              method=self._changePassword,
                              async=True)

    @staticmethod
    def buildRegisterIQ(xmlstream_, jid_, password, email=None):
        iq_elt = xmlstream.IQ(xmlstream_, 'set')
        iq_elt["to"] = jid_.host
        query_elt = iq_elt.addElement(('jabber:iq:register', 'query'))
        username_elt = query_elt.addElement('username')
        username_elt.addContent(jid_.user)
        password_elt = query_elt.addElement('password')
        password_elt.addContent(password)
        if email is not None:
            email_elt = query_elt.addElement('email')
            email_elt.addContent(email)
        return iq_elt

    def _regCb(self, answer, client, post_treat_cb):
        """Called after the first get IQ"""
        try:
            query_elt = answer.elements(NS_REG, 'query').next()
        except StopIteration:
            raise exceptions.DataError("Can't find expected query element")

        try:
            x_elem = query_elt.elements(data_form.NS_X_DATA, 'x').next()
        except StopIteration:
            # XXX: it seems we have an old service which doesn't manage data forms
            log.warning(_("Can't find data form"))
            raise exceptions.DataError(_("This gateway can't be managed by SàT, sorry :("))

        def submitForm(data, profile):
            form_elt = xml_tools.XMLUIResultToElt(data)

            iq_elt = client.IQ()
            iq_elt['id'] = answer['id']
            iq_elt['to'] = answer['from']
            query_elt = iq_elt.addElement("query", NS_REG)
            query_elt.addChild(form_elt)
            d = iq_elt.send()
            d.addCallback(self._regSuccess, client, post_treat_cb)
            d.addErrback(self._regFailure, client)
            return d

        form = data_form.Form.fromElement(x_elem)
        submit_reg_id = self.host.registerCallback(submitForm, with_data=True, one_shot=True)
        return xml_tools.dataForm2XMLUI(form, submit_reg_id)

    def _regEb(self, failure, client):
        """Called when something is wrong with registration"""
        log.info(_("Registration failure: %s") % unicode(failure.value))
        raise failure

    def _regSuccess(self, answer, client, post_treat_cb):
        log.debug(_(u"registration answer: %s") % answer.toXml())
        if post_treat_cb is not None:
            post_treat_cb(jid.JID(answer['from']), client.profile)
        return {}

    def _regFailure(self, failure, client):
        log.info(_(u"Registration failure: %s") % unicode(failure.value))
        if failure.value.condition == 'conflict':
            raise exceptions.ConflictError( _("Username already exists, please choose an other one"))
        raise failure

    def _inBandRegister(self, to_jid_s, profile_key=C.PROF_KEY_NONE):
        return self.inBandRegister, jid.JID(to_jid_s, profile_key)

    def inBandRegister(self, to_jid, post_treat_cb=None, profile_key=C.PROF_KEY_NONE):
        """register to a service

        @param to_jid(jid.JID): jid of the service to register to
        """
        # FIXME: this post_treat_cb arguments seems wrong, check it
        client = self.host.getClient(profile_key)
        log.debug(_(u"Asking registration for {}").format(to_jid.full()))
        reg_request = client.IQ(u'get')
        reg_request["from"] = client.jid.full()
        reg_request["to"] = to_jid.full()
        reg_request.addElement('query', NS_REG)
        d = reg_request.send(to_jid.full()).addCallbacks(self._regCb, self._regEb, callbackArgs=[client, post_treat_cb], errbackArgs=[client])
        return d

    def _registerNewAccount(self, jid_, password, email, host, port):
        kwargs = {}
        if email:
            kwargs['email'] = email
        if host:
            kwargs['host'] = host
        if port:
            kwargs['port'] = port
        return self.registerNewAccount(jid.JID(jid_), password, **kwargs)

    def registerNewAccount(self, jid_, password, email=None, host=u"127.0.0.1", port=C.XMPP_C2S_PORT):
        """register a new account on a XMPP server

        @param jid_(jid.JID): request jid to register
        @param password(unicode): password of the account
        @param email(unicode): email of the account
        @param host(unicode): host of the server to register to
        @param port(int): port of the server to register to
        """
        authenticator = RegisteringAuthenticator(jid_, password, email)
        registered_d = authenticator.registered
        serverRegistrer = xmlstream.XmlStreamFactory(authenticator)
        connector = reactor.connectTCP(host, port, serverRegistrer)
        serverRegistrer.clientConnectionLost = lambda conn, reason: connector.disconnect()
        return registered_d

    def _changePassword(self, new_password, profile_key):
        client = self.host.getClient(profile_key)
        return self.changePassword(client, new_password)

    def changePassword(self, client, new_password):
        iq_elt = self.buildRegisterIQ(client.xmlstream, client.jid, new_password)
        d = iq_elt.send(client.jid.host)
        d.addCallback(lambda dummy: self.host.memory.setParam("Password", new_password, "Connection", profile_key=client.profile))
        return d

    def _unregister(self, to_jid_s, profile_key):
        client = self.host.getClient(profile_key)
        return self.unregister(client, jid.JID(to_jid_s))

    def unregister(self, client, to_jid):
        """remove registration from a server/service

        BEWARE! if you remove registration from profile own server, this will
        DELETE THE XMPP ACCOUNT WITHOUT WARNING
        @param to_jid(jid.JID): jid of the service or server
        """
        iq_elt = client.IQ()
        iq_elt['to'] = to_jid.full()
        query_elt = iq_elt.addElement((NS_REG, u'query'))
        query_elt.addElement(u'remove')
        return iq_elt.send()