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

# SAT plugin for Extended Stanza Addressing (xep-0033)
# Copyright (C) 2013-2016 Adrien Cossa (souliane@mailoo.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.log import getLogger
log = getLogger(__name__)
from sat.core import exceptions
from wokkel import disco, iwokkel
from zope.interface import implements
from twisted.words.protocols.jabber.jid import JID
from twisted.python import failure
import copy
try:
    from twisted.words.protocols.xmlstream import XMPPHandler
except ImportError:
    from wokkel.subprotocols import XMPPHandler
from twisted.words.xish import domish
from twisted.internet import defer

from sat.tools import trigger
from time import time

# TODO: fix Prosody "addressing" plugin to leave the concerned bcc according to the spec:
#
# http://xmpp.org/extensions/xep-0033.html#addr-type-bcc
# "This means that the server MUST remove these addresses before the stanza is delivered to anyone other than the given bcc addressee or the multicast service of the bcc addressee."
#
# http://xmpp.org/extensions/xep-0033.html#multicast
# "Each 'bcc' recipient MUST receive only the <address type='bcc'/> associated with that addressee."

# TODO: fix Prosody "addressing" plugin to determine itself if remote servers supports this XEP


NS_XMPP_CLIENT = "jabber:client"
NS_ADDRESS = "http://jabber.org/protocol/address"
ATTRIBUTES = ["jid", "uri", "node", "desc", "delivered", "type"]
ADDRESS_TYPES = ["to", "cc", "bcc", "replyto", "replyroom", "noreply"]

PLUGIN_INFO = {
    "name": "Extended Stanza Addressing Protocol Plugin",
    "import_name": "XEP-0033",
    "type": "XEP",
    "protocols": ["XEP-0033"],
    "dependencies": [],
    "main": "XEP_0033",
    "handler": "yes",
    "description": _("""Implementation of Extended Stanza Addressing""")
}


class XEP_0033(object):
    """
    Implementation for XEP 0033
    """
    def __init__(self, host):
        log.info(_("Extended Stanza Addressing plugin initialization"))
        self.host = host
        self.internal_data = {}
        host.trigger.add("sendMessage", self.sendMessageTrigger, trigger.TriggerManager.MIN_PRIORITY)
        host.trigger.add("MessageReceived", self.messageReceivedTrigger)

    def sendMessageTrigger(self, mess_data, pre_xml_treatments, post_xml_treatments, profile):
        """Process the XEP-0033 related data to be sent"""

        def treatment(mess_data):
            if not 'address' in mess_data['extra']:
                return mess_data

            def discoCallback(entities):
                if not entities:
                    log.warning(_("XEP-0033 is being used but the server doesn't support it!"))
                    raise failure.Failure(exceptions.CancelError())
                if mess_data["to"] not in entities:
                    expected = _(' or ').join([entity.userhost() for entity in entities])
                    log.warning(_(u"Stanzas using XEP-0033 should be addressed to %(expected)s, not %(current)s!") % {'expected': expected, 'current': mess_data["to"]})
                    log.warning(_(u"TODO: addressing has been fixed by the backend... fix it in the frontend!"))
                    mess_data["to"] = list(entities)[0].userhostJID()
                element = mess_data['xml'].addElement('addresses', NS_ADDRESS)
                entries = [entry.split(':') for entry in mess_data['extra']['address'].split('\n') if entry != '']
                for type_, jid_ in entries:
                    element.addChild(domish.Element((None, 'address'), None, {'type': type_, 'jid': jid_}))
                # when the prosody plugin is completed, we can immediately return mess_data from here
                self.sendAndStoreMessage(mess_data, entries, profile)
                log.debug("XEP-0033 took over")
                raise failure.Failure(exceptions.CancelError())
            d = self.host.findFeaturesSet([NS_ADDRESS], profile=profile)
            d.addCallbacks(discoCallback, lambda dummy: discoCallback(None))
            return d

        post_xml_treatments.addCallback(treatment)
        return True

    def sendAndStoreMessage(self, mess_data, entries, profile):
        """Check if target servers support XEP-0033, send and store the messages
        @return: a friendly failure to let the core know that we sent the message already

        Later we should be able to remove this method because:
        # XXX: sending the messages should be done by the local server
        # FIXME: for now we duplicate the messages in the history for each recipient, this should change
        # FIXME: for now we duplicate the echoes to the sender, this should also change
        Ideas:
        - fix Prosody plugin to check if target server support the feature
        - redesign the database to save only one entry to the database
        - change the newMessage signal to eventually pass more than one recipient
        """
        def send(mess_data, skip_send=False):
            client = self.host.profiles[profile]
            d = defer.Deferred()
            if not skip_send:
                d.addCallback(self.host._sendMessageToStream, client)
            d.addCallback(self.host._storeMessage, client)
            d.addCallback(self.host.sendMessageToBridge, client)
            d.addErrback(lambda failure: failure.trap(exceptions.CancelError))
            return d.callback(mess_data)

        def discoCallback(entities, to_jid_s):
            history_data = copy.deepcopy(mess_data)
            history_data['to'] = JID(to_jid_s)
            history_data['xml']['to'] = to_jid_s
            if entities:
                if entities not in self.internal_data[timestamp]:
                    sent_data = copy.deepcopy(mess_data)
                    sent_data['to'] = JID(JID(to_jid_s).host)
                    sent_data['xml']['to'] = JID(to_jid_s).host
                    send(sent_data)
                    self.internal_data[timestamp].append(entities)
                # we still need to fill the history and signal the echo...
                send(history_data, skip_send=True)
            else:
                # target server misses the addressing feature
                send(history_data)

        def errback(failure, to_jid):
            discoCallback(None, to_jid)

        timestamp = time()
        self.internal_data[timestamp] = []
        defer_list = []
        for type_, jid_ in entries:
            d = defer.Deferred()
            d.addCallback(self.host.findFeaturesSet, jid_=JID(JID(jid_).host), profile=profile)
            d.addCallbacks(discoCallback, errback, callbackArgs=[jid_], errbackArgs=[jid_])
            d.callback([NS_ADDRESS])
            defer_list.append(d)
        d = defer.Deferred().addCallback(lambda dummy: self.internal_data.pop(timestamp))
        defer.DeferredList(defer_list).chainDeferred(d)

    def messageReceivedTrigger(self, message, post_treat, profile):
        """In order to save the addressing information in the history"""
        def post_treat_addr(data, addresses):
            data['extra']['addresses'] = ""
            for address in addresses:
                # Depending how message has been constructed, we could get here
                # some noise like "\n        " instead of an address element.
                if isinstance(address, domish.Element):
                    data['extra']['addresses'] += '%s:%s\n' % (address['type'], address['jid'])
            return data

        try:
            addresses = message.elements(NS_ADDRESS, 'addresses').next()
            post_treat.addCallback(post_treat_addr, addresses.children)
        except StopIteration:
            pass  # no addresses
        return True

    def getHandler(self, profile):
        return XEP_0033_handler(self, profile)


class XEP_0033_handler(XMPPHandler):
    implements(iwokkel.IDisco)

    def __init__(self, plugin_parent, profile):
        self.plugin_parent = plugin_parent
        self.host = plugin_parent.host
        self.profile = profile

    def getDiscoInfo(self, requestor, target, nodeIdentifier=''):
        return [disco.DiscoFeature(NS_ADDRESS)]

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