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

# SAT: a jabber client
# Copyright (C) 2009-2016 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.memory import cache
from twisted.internet import task, defer
from twisted.words.protocols.jabber.xmlstream import XMPPHandler
from twisted.words.protocols.jabber import xmlstream
from twisted.words.protocols.jabber import error
from twisted.words.protocols.jabber import jid
from twisted.words.xish import domish
from twisted.python import failure
from wokkel import client as wokkel_client, disco, xmppim, generic, iwokkel
from wokkel import delay
from sat.core.log import getLogger
log = getLogger(__name__)
from sat.core import exceptions
from zope.interface import implements
import time
import calendar
import uuid
import sys


class SatXMPPClient(wokkel_client.XMPPClient):
    implements(iwokkel.IDisco)

    def __init__(self, host_app, profile, user_jid, password, host=None, port=C.XMPP_C2S_PORT, max_retries=C.XMPP_MAX_RETRIES):
        # XXX: DNS SRV records are checked when the host is not specified.
        # If no SRV record is found, the host is directly extracted from the JID.
        self.started = time.time()
        if sys.platform == "android":
            # FIXME: temporary hack as SRV is not working on android
            # TODO: remove this hack and fix SRV
            log.info(u"FIXME: Android hack, ignoring SRV")
            host = user_jid.host
            hosts_map = host_app.memory.getConfig("android", "hosts_dict", {})
            if host in hosts_map:
                log.info(u"using {host_to_use} for host {host_ori} as requested in config".format(
                    host_ori = host,
                    host_to_use = hosts_map[host]))
                host = hosts_map[host]
        wokkel_client.XMPPClient.__init__(self, user_jid, password, host or None, port or C.XMPP_C2S_PORT)
        self.factory.clientConnectionLost = self.connectionLost
        self.factory.maxRetries = max_retries
        self.__connected = False
        self.profile = profile
        self.host_app = host_app
        self.cache = cache.Cache(host_app, profile)
        self._mess_id_uid = {} # map from message id to uid use in history. Key: (full_jid,message_id) Value: uid
        self.conn_deferred = defer.Deferred()
        self._progress_cb = {}  # callback called when a progress is requested (key = progress id)
        self.actions = {} # used to keep track of actions for retrieval (key = action_id)

    def getConnectionDeferred(self):
        """Return a deferred which fire when the client is connected"""
        return self.conn_deferred

    def IQ(self, type_=u'set', timeout=None):
        """shortcut to create an IQ element managing deferred

        @param type_(unicode): IQ type ('set' or 'get')
        @param timeout(None, int): timeout in seconds
        @return((D)domish.Element: result stanza
            errback is called if and error stanza is returned
        """
        iq_elt = xmlstream.IQ(self.xmlstream, type_)
        iq_elt.timeout = timeout
        return iq_elt

    def sendError(self, iq_elt, condition):
        """Send error stanza build from iq_elt

        @param iq_elt(domish.Element): initial IQ element
        @param condition(unicode): error condition
        """
        iq_error_elt = error.StanzaError(condition).toResponse(iq_elt)
        self.xmlstream.send(iq_error_elt)

    def send(self, obj):
        # original send method accept string
        # but we restrict to domish.Element to make trigger treatments easier
        assert isinstance(obj, domish.Element)
        # XXX: this trigger is the last one before sending stanza on wire
        #      is it is intended for things like end 2 end encryption.
        #      *DO NOT* cancel (i.e. return False) without very good reason
        #      (out of band transmission for instance).
        #      e2e should have a priority of 0 here, and out of band transmission
        #      a lower priority
        if not self.host_app.trigger.point("send", self, obj):
            return
        return super(SatXMPPClient, self).send(obj)


    def _authd(self, xmlstream):
        if not self.host_app.trigger.point("XML Initialized", xmlstream, self.profile):
            return
        wokkel_client.XMPPClient._authd(self, xmlstream)
        self.__connected = True
        log.info(_("********** [%s] CONNECTED **********") % self.profile)
        self.streamInitialized()
        self.host_app.bridge.connected(self.profile, unicode(self.jid))  # we send the signal to the clients

    def streamInitialized(self):
        """Called after _authd"""
        log.debug(_("XML stream is initialized"))
        self.keep_alife = task.LoopingCall(self.xmlstream.send, " ")  # Needed to avoid disconnection (specially with openfire)
        self.keep_alife.start(C.XMPP_KEEP_ALIFE)

        self.disco = SatDiscoProtocol(self)
        self.disco.setHandlerParent(self)
        self.discoHandler = disco.DiscoHandler()
        self.discoHandler.setHandlerParent(self)
        disco_d = defer.succeed(None)

        if not self.host_app.trigger.point("Disco handled", disco_d, self.profile):
            return

        def finish_connection(dummy):
            self.roster.requestRoster()
            self.presence.available()
            self.conn_deferred.callback(None)

        disco_d.addCallback(finish_connection)

    def initializationFailed(self, reason):
        log.error(_(u"ERROR: XMPP connection failed for profile '%(profile)s': %(reason)s" % {'profile': self.profile, 'reason': reason}))
        self.conn_deferred.errback(reason.value)
        try:
            wokkel_client.XMPPClient.initializationFailed(self, reason)
        except:
            # we already chained an errback, no need to raise an exception
            pass

    def isConnected(self):
        return self.__connected

    def connectionLost(self, connector, unused_reason):
        try:
            self.keep_alife.stop()
        except AttributeError:
            log.debug(_("No keep_alife"))
        if self.__connected:
            log.info(_("********** [%s] DISCONNECTED **********") % self.profile)
            self.host_app.bridge.disconnected(self.profile)  # we send the signal to the clients
            self.host_app.purgeClient(self.profile)  # and we remove references to this client
        self.__connected = False


class SatMessageProtocol(xmppim.MessageProtocol):

    def __init__(self, host):
        xmppim.MessageProtocol.__init__(self)
        self.host = host

    @staticmethod
    def parseMessage(message_elt, client=None):
        """parse a message XML and return message_data

        @param message_elt(domish.Element): raw <message> xml
        @param client(SatXMPPClient, None): client to map message id to uid
            if None, mapping will not be done
        @return(dict): message data
        """
        message = {}
        subject = {}
        extra = {}
        data = {"from": jid.JID(message_elt['from']),
                "to": jid.JID(message_elt['to']),
                "uid": message_elt.getAttribute('uid', unicode(uuid.uuid4())), # XXX: uid is not a standard attribute but may be added by plugins
                "message": message,
                "subject": subject,
                "type": message_elt.getAttribute('type', 'normal'),
                "extra": extra}

        if client is not None:
            try:
                data['stanza_id'] = message_elt['id']
            except KeyError:
                pass
            else:
                client._mess_id_uid[(data['from'], data['stanza_id'])] = data['uid']

        # message
        for e in message_elt.elements(C.NS_CLIENT, 'body'):
            message[e.getAttribute((C.NS_XML,'lang'),'')] = unicode(e)

        # subject
        for e in message_elt.elements(C.NS_CLIENT, 'subject'):
            subject[e.getAttribute((C.NS_XML, 'lang'),'')] = unicode(e)

        # delay and timestamp
        try:
            delay_elt = message_elt.elements(delay.NS_DELAY, 'delay').next()
        except StopIteration:
            data['timestamp'] = time.time()
        else:
            parsed_delay = delay.Delay.fromElement(delay_elt)
            data['timestamp'] = calendar.timegm(parsed_delay.stamp.utctimetuple())
            data['received_timestamp'] = unicode(time.time())
            if parsed_delay.sender:
                data['delay_sender'] = parsed_delay.sender.full()
        return data

    def onMessage(self, message_elt):
        # TODO: handle threads
        client = self.parent
        if not 'from' in message_elt.attributes:
            message_elt['from'] = client.jid.host
        log.debug(_(u"got message from: {from_}").format(from_=message_elt['from']))
        post_treat = defer.Deferred() # XXX: plugin can add their treatments to this deferred

        if not self.host.trigger.point("MessageReceived", client, message_elt, post_treat):
            return

        data = self.parseMessage(message_elt, client)

        post_treat.addCallback(self.skipEmptyMessage)
        post_treat.addCallback(self.addToHistory, client)
        post_treat.addErrback(self.treatmentsEb)
        post_treat.addCallback(self.bridgeSignal, client, data)
        post_treat.addErrback(self.cancelErrorTrap)
        post_treat.callback(data)

    def skipEmptyMessage(self, data):
        if not data['message'] and not data['extra'] and not data['subject']:
            raise failure.Failure(exceptions.CancelError("Cancelled empty message"))
        return data

    def addToHistory(self, data, client):
        return self.host.memory.addToHistory(client, data)

    def treatmentsEb(self, failure_):
        failure_.trap(exceptions.SkipHistory)

    def bridgeSignal(self, dummy, client, data):
        try:
            data['extra']['received_timestamp'] = data['received_timestamp']
            data['extra']['delay_sender'] = data['delay_sender']
        except KeyError:
            pass
        if data is not None:
            self.host.bridge.messageNew(data['uid'], data['timestamp'], data['from'].full(), data['to'].full(), data['message'], data['subject'], data['type'], data['extra'], profile=client.profile)
        return data

    def cancelErrorTrap(self, failure_):
        """A message sending can be cancelled by a plugin treatment"""
        failure_.trap(exceptions.CancelError)


class SatRosterProtocol(xmppim.RosterClientProtocol):

    def __init__(self, host):
        xmppim.RosterClientProtocol.__init__(self)
        self.host = host
        self.got_roster = defer.Deferred() # called when roster is received and ready
        #XXX: the two following dicts keep a local copy of the roster
        self._groups = {}  # map from groups to jids: key=group value=set of jids
        self._jids = None  # map from jids to RosterItem: key=jid value=RosterItem

    def rosterCb(self, roster):
        assert roster is not None # FIXME: must be managed with roster versioning
        self._groups.clear()
        self._jids = roster
        for item in roster.itervalues():
            if not item.subscriptionTo and not item.subscriptionFrom and not item.ask:
                #XXX: current behaviour: we don't want contact in our roster list
                # if there is no presence subscription
                # may change in the future
                log.info(u"Removing contact {} from roster because there is no presence subscription".format(item.jid))
                self.removeItem(item.entity) # FIXME: to be checked
            else:
                self._registerItem(item)

    def _registerItem(self, item):
        """Register item in local cache

        item must be already registered in self._jids before this method is called
        @param item (RosterIem): item added
        """
        log.debug(u"registering item: {}".format(item.entity.full()))
        if item.entity.resource:
            log.warning(u"Received a roster item with a resource, this is not common but not restricted by RFC 6121, this case may be not well tested.")
        if not item.subscriptionTo:
            if not item.subscriptionFrom:
                log.info(_(u"There's no subscription between you and [{}]!").format(item.entity.full()))
            else:
                log.info(_(u"You are not subscribed to [{}]!").format(item.entity.full()))
        if not item.subscriptionFrom:
            log.info(_(u"[{}] is not subscribed to you!").format(item.entity.full()))

        for group in item.groups:
            self._groups.setdefault(group, set()).add(item.entity)

    def requestRoster(self):
        """ ask the server for Roster list """
        log.debug("requestRoster")
        d = self.getRoster().addCallback(self.rosterCb)
        d.chainDeferred(self.got_roster)

    def removeItem(self, to_jid):
        """Remove a contact from roster list
        @param to_jid: a JID instance
        @return: Deferred
        """
        return xmppim.RosterClientProtocol.removeItem(self, to_jid)

    def getAttributes(self, item):
        """Return dictionary of attributes as used in bridge from a RosterItem

        @param item: RosterItem
        @return: dictionary of attributes
        """
        item_attr = {'to': unicode(item.subscriptionTo),
                     'from': unicode(item.subscriptionFrom),
                     'ask': unicode(item.ask)
                     }
        if item.name:
            item_attr['name'] = item.name
        return item_attr

    def setReceived(self, request):
        #TODO: implement roster versioning (cf RFC 6121 §2.6)
        item = request.item
        try:  # update the cache for the groups the contact has been removed from
            left_groups = set(self._jids[item.entity].groups).difference(item.groups)
            for group in left_groups:
                jids_set = self._groups[group]
                jids_set.remove(item.entity)
                if not jids_set:
                    del self._groups[group]
        except KeyError:
            pass  # no previous item registration (or it's been cleared)
        self._jids[item.entity] = item
        self._registerItem(item)
        self.host.bridge.newContact(item.entity.full(), self.getAttributes(item), item.groups, self.parent.profile)

    def removeReceived(self, request):
        entity = request.item.entity
        log.info(u"removing %s from roster list" % entity.full())

        # we first remove item from local cache (self._groups and self._jids)
        try:
            item = self._jids.pop(entity)
        except KeyError:
            log.error(u"Received a roster remove event for an item not in cache ({})".format(entity))
            return
        for group in item.groups:
            try:
                jids_set = self._groups[group]
                jids_set.remove(entity)
                if not jids_set:
                    del self._groups[group]
            except KeyError:
                log.warning(u"there is no cache for the group [%(group)s] of the removed roster item [%(jid)s]" %
                            {"group": group, "jid": entity})

        # then we send the bridge signal
        self.host.bridge.contactDeleted(entity.full(), self.parent.profile)

    def getGroups(self):
        """Return a list of groups"""
        return self._groups.keys()

    def getItem(self, entity_jid):
        """Return RosterItem for a given jid

        @param entity_jid(jid.JID): jid of the contact
        @return(RosterItem, None): RosterItem instance
            None if contact is not in cache
        """
        return self._jids.get(entity_jid, None)

    def getJids(self):
        """Return all jids of the roster"""
        return self._jids.keys()

    def isJidInRoster(self, entity_jid):
        """Return True if jid is in roster"""
        return entity_jid in self._jids

    def getItems(self):
        """Return all items of the roster"""
        return self._jids.values()

    def getJidsFromGroup(self, group):
        try:
            return self._groups[group]
        except KeyError:
            raise exceptions.UnknownGroupError(group)

    def getJidsSet(self, type_, groups=None):
        """Helper method to get a set of jids

        @param type_(unicode): one of:
            C.ALL: get all jids from roster
            C.GROUP: get jids from groups (listed in "groups")
        @groups(list[unicode]): list of groups used if type_==C.GROUP
        @return (set(jid.JID)): set of selected jids
        """
        if type_ == C.ALL and groups is not None:
            raise ValueError('groups must not be set for {} type'.format(C.ALL))

        if type_ == C.ALL:
            return set(self.getJids())
        elif type_ == C.GROUP:
            jids = set()
            for group in groups:
                jids.update(self.getJidsFromGroup(group))
            return jids
        else:
            raise ValueError(u'Unexpected type_ {}'.format(type_))

    def getNick(self, entity_jid):
        """Return a nick name for an entity

        return nick choosed by user if available
        else return user part of entity_jid
        """
        item = self.getItem(entity_jid)
        if item is None:
            return entity_jid.user
        else:
            return item.name or entity_jid.user


class SatPresenceProtocol(xmppim.PresenceClientProtocol):

    def __init__(self, host):
        xmppim.PresenceClientProtocol.__init__(self)
        self.host = host

    def send(self, obj):
        if not self.host.trigger.point("Presence send", self.parent, obj):
            return
        super(SatPresenceProtocol, self).send(obj)

    def availableReceived(self, entity, show=None, statuses=None, priority=0):
        log.debug(_(u"presence update for [%(entity)s] (available, show=%(show)s statuses=%(statuses)s priority=%(priority)d)") % {'entity': entity, C.PRESENCE_SHOW: show, C.PRESENCE_STATUSES: statuses, C.PRESENCE_PRIORITY: priority})

        if not statuses:
            statuses = {}

        if None in statuses:  # we only want string keys
            statuses[C.PRESENCE_STATUSES_DEFAULT] = statuses.pop(None)

        if not self.host.trigger.point("presenceReceived", entity, show, priority, statuses, self.parent.profile):
            return

        self.host.memory.setPresenceStatus(entity, show or "",
                                           int(priority), statuses,
                                           self.parent.profile)

        # now it's time to notify frontends
        self.host.bridge.presenceUpdate(entity.full(), show or "",
                                        int(priority), statuses,
                                        self.parent.profile)

    def unavailableReceived(self, entity, statuses=None):
        log.debug(_(u"presence update for [%(entity)s] (unavailable, statuses=%(statuses)s)") % {'entity': entity, C.PRESENCE_STATUSES: statuses})

        if not statuses:
            statuses = {}

        if None in statuses:  # we only want string keys
            statuses[C.PRESENCE_STATUSES_DEFAULT] = statuses.pop(None)

        if not self.host.trigger.point("presenceReceived", entity, "unavailable", 0, statuses, self.parent.profile):
            return

        # now it's time to notify frontends
        # if the entity is not known yet in this session or is already unavailable, there is no need to send an unavailable signal
        try:
            presence = self.host.memory.getEntityDatum(entity, "presence", self.parent.profile)
        except (KeyError, exceptions.UnknownEntityError):
            # the entity has not been seen yet in this session
            pass
        else:
            if presence.show != C.PRESENCE_UNAVAILABLE:
                self.host.bridge.presenceUpdate(entity.full(), C.PRESENCE_UNAVAILABLE, 0, statuses, self.parent.profile)

        self.host.memory.setPresenceStatus(entity, C.PRESENCE_UNAVAILABLE, 0, statuses, self.parent.profile)

    def available(self, entity=None, show=None, statuses=None, priority=None):
        """Set a presence and statuses.

        @param entity (jid.JID): entity
        @param show (unicode): value in ('unavailable', '', 'away', 'xa', 'chat', 'dnd')
        @param statuses (dict{unicode: unicode}): multilingual statuses with
            the entry key beeing a language code on 2 characters or "default".
        """
        if priority is None:
            try:
                priority = int(self.host.memory.getParamA("Priority", "Connection", profile_key=self.parent.profile))
            except ValueError:
                priority = 0

        if statuses is None:
            statuses = {}

        # default for us is None for wokkel
        # so we must temporarily switch to wokkel's convention...
        if C.PRESENCE_STATUSES_DEFAULT in statuses:
            statuses[None] = statuses.pop(C.PRESENCE_STATUSES_DEFAULT)

        presence_elt = xmppim.AvailablePresence(entity, show, statuses, priority)

        # ... before switching back
        if None in statuses:
            statuses['default'] = statuses.pop(None)

        if not self.host.trigger.point("presence_available", presence_elt, self.parent):
            return
        self.send(presence_elt)

    @defer.inlineCallbacks
    def subscribed(self, entity):
        yield self.parent.roster.got_roster
        xmppim.PresenceClientProtocol.subscribed(self, entity)
        self.host.memory.delWaitingSub(entity.userhost(), self.parent.profile)
        item = self.parent.roster.getItem(entity)
        if not item or not item.subscriptionTo:  # we automatically subscribe to 'to' presence
            log.debug(_('sending automatic "from" subscription request'))
            self.subscribe(entity)

    def unsubscribed(self, entity):
        xmppim.PresenceClientProtocol.unsubscribed(self, entity)
        self.host.memory.delWaitingSub(entity.userhost(), self.parent.profile)

    def subscribedReceived(self, entity):
        log.debug(_(u"subscription approved for [%s]") % entity.userhost())
        self.host.bridge.subscribe('subscribed', entity.userhost(), self.parent.profile)

    def unsubscribedReceived(self, entity):
        log.debug(_(u"unsubscription confirmed for [%s]") % entity.userhost())
        self.host.bridge.subscribe('unsubscribed', entity.userhost(), self.parent.profile)

    @defer.inlineCallbacks
    def subscribeReceived(self, entity):
        log.debug(_(u"subscription request from [%s]") % entity.userhost())
        yield self.parent.roster.got_roster
        item = self.parent.roster.getItem(entity)
        if item and item.subscriptionTo:
            # We automatically accept subscription if we are already subscribed to contact presence
            log.debug(_('sending automatic subscription acceptance'))
            self.subscribed(entity)
        else:
            self.host.memory.addWaitingSub('subscribe', entity.userhost(), self.parent.profile)
            self.host.bridge.subscribe('subscribe', entity.userhost(), self.parent.profile)

    @defer.inlineCallbacks
    def unsubscribeReceived(self, entity):
        log.debug(_(u"unsubscription asked for [%s]") % entity.userhost())
        yield self.parent.roster.got_roster
        item = self.parent.roster.getItem(entity)
        if item and item.subscriptionFrom:  # we automatically remove contact
            log.debug(_('automatic contact deletion'))
            self.host.delContact(entity, self.parent.profile)
        self.host.bridge.subscribe('unsubscribe', entity.userhost(), self.parent.profile)


class SatDiscoProtocol(disco.DiscoClientProtocol):
    def __init__(self, host):
        disco.DiscoClientProtocol.__init__(self)


class SatFallbackHandler(generic.FallbackHandler):
    def __init__(self, host):
        generic.FallbackHandler.__init__(self)

    def iqFallback(self, iq):
        if iq.handled is True:
            return
        log.debug(u"iqFallback: xml = [%s]" % (iq.toXml()))
        generic.FallbackHandler.iqFallback(self, iq)


class RegisteringAuthenticator(xmlstream.ConnectAuthenticator):

    def __init__(self, host, jabber_host, user_login, user_pass, email, deferred, profile):
        xmlstream.ConnectAuthenticator.__init__(self, jabber_host)
        self.host = host
        self.jabber_host = jabber_host
        self.user_login = user_login
        self.user_pass = user_pass
        self.user_email = email
        self.deferred = deferred
        self.profile = profile
        log.debug(_(u"Registration asked for %(user)s@%(host)s") % {'user': user_login, 'host': jabber_host})

    def connectionMade(self):
        log.debug(_(u"Connection made with %s" % self.jabber_host))
        self.xmlstream.namespace = C.NS_CLIENT
        self.xmlstream.sendHeader()

        iq = xmlstream.IQ(self.xmlstream, 'set')
        iq["to"] = self.jabber_host
        query = iq.addElement(('jabber:iq:register', 'query'))
        _user = query.addElement('username')
        _user.addContent(self.user_login)
        _pass = query.addElement('password')
        _pass.addContent(self.user_pass)
        if self.user_email:
            _email = query.addElement('email')
            _email.addContent(self.user_email)
        d = iq.send(self.jabber_host).addCallbacks(self.registrationAnswer, self.registrationFailure)
        d.chainDeferred(self.deferred)

    def registrationAnswer(self, answer):
        log.debug(_(u"Registration answer: %s") % answer.toXml())
        self.xmlstream.sendFooter()

    def registrationFailure(self, failure_):
        log.info(_("Registration failure: %s") % unicode(failure_.value))
        self.xmlstream.sendFooter()
        raise failure_.value


class SatVersionHandler(generic.VersionHandler):

    def getDiscoInfo(self, requestor, target, node):
        #XXX: We need to work around wokkel's behaviour (namespace not added if there is a
        # node) as it cause issues with XEP-0115 & PEP (XEP-0163): there is a node when server
        # ask for disco info, and not when we generate the key, so the hash is used with different
        # disco features, and when the server (seen on ejabberd) generate its own hash for security check
        # it reject our features (resulting in e.g. no notification on PEP)
        return generic.VersionHandler.getDiscoInfo(self, requestor, target, None)

class SatIdentityHandler(XMPPHandler):
    """ Manage disco Identity of SàT. Currently, we use "client/pc/Salut à Toi", but as
    SàT is multi-frontends and can be used on mobile devices, as a bot, with a web frontend,
    etc, we should implement a way to dynamically update identities through the bridge """
    #TODO: dynamic identity update (see docstring). Note that a XMPP entity can have several identities
    implements(iwokkel.IDisco)

    def getDiscoInfo(self, requestor, target, nodeIdentifier=''):
        return [disco.DiscoIdentity(u"client", u"pc", C.APP_NAME)]

    def getDiscoItems(self, requestor, target, nodeIdentifier=''):
        return []