#!/usr/bin/python
# -*- coding: utf-8 -*-

# SAT plugin for Message Archive Management (XEP-0313)
# Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014 Jérôme Poisson (goffi@goffi.org)
# Copyright (C) 2013, 2014 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.constants import Const as C
from sat.core.i18n import _
from sat.core.log import getLogger
log = getLogger(__name__)

from wokkel import disco, iwokkel, compat, data_form
from wokkel.rsm import RSMRequest
from wokkel.generic import parseXml
try:
    from twisted.words.protocols.xmlstream import XMPPHandler
except ImportError:
    from wokkel.subprotocols import XMPPHandler
from twisted.words.xish import domish
from zope.interface import implements

from dateutil.tz import tzutc


NS_MAM = 'urn:xmpp:mam:0'
NS_SF = 'urn:xmpp:forward:0'
NS_DD = 'urn:xmpp:delay'
NS_CLIENT = 'jabber:client'

PLUGIN_INFO = {
    "name": "Message Archive Management",
    "import_name": "XEP-0313",
    "type": "XEP",
    "protocols": ["XEP-0313"],
    "dependencies": ["XEP-0059", "XEP-0297", "XEP-0203"],
    "recommendations": ["XEP-0334"],
    "main": "XEP_0313",
    "handler": "yes",
    "description": _("""Implementation of Message Archive Management""")
}


class XEP_0313(object):

    def __init__(self, host):
        log.info(_("Message Archive Management plugin initialization"))
        self.host = host
        host.bridge.addMethod("MAMqueryFields", ".plugin", in_sign='s', out_sign='s',
                              method=self.queryFields,
                              async=True,
                              doc={})
        host.bridge.addMethod("MAMqueryArchive", ".plugin", in_sign='ssss', out_sign='s',
                              method=self._queryArchive,
                              async=True,
                              doc={})
        host.trigger.add("MessageReceived", self.messageReceivedTrigger)

    def getHandler(self, profile):
        return XEP_0313_handler(self, profile)

    def _queryArchive(self, form=None, rsm=None, node=None, profile_key=C.PROF_KEY_NONE):
        form_elt = parseXml(form) if form else None
        rsm_inst = RSMRequest(**rsm) if rsm else None
        return self.queryArchive(form_elt, rsm_inst, node, profile_key)

    def queryArchive(self, form=None, rsm=None, node=None, profile_key=C.PROF_KEY_NONE):
        """Query a user, MUC or pubsub archive.

        @param form (domish.Element): data form to filter the request
        @param rsm (RSMRequest): RSM request instance
        @param node (unicode): pubsub node to query, or None if inappropriate
        @param profile_key (unicode): %(doc_profile_key)s
        @return: a Deferred when the message has been sent
        """
        client = self.host.getClient(profile_key)
        iq = compat.IQ(client.xmlstream, 'set')
        query_elt = iq.addElement((NS_MAM, 'query'))
        if form:
            query_elt.addChild(form)
        if rsm:
            rsm.render(query_elt)
        if node:
            query_elt['node'] = node
        d = iq.send()

        def eb(failure):
            # typically StanzaError with condition u'service-unavailable'
            log.error(failure.getErrorMessage())
            return ''

        return d.addCallbacks(lambda elt: elt.toXml(), eb)

    def queryFields(self, profile_key=C.PROF_KEY_NONE):
        """Ask the server about additional supported fields.

        @param profile_key (unicode): %(doc_profile_key)s
        @return: the server response as a Deferred domish.Element
        """
        # http://xmpp.org/extensions/xep-0313.html#query-form
        client = self.host.getClient(profile_key)
        iq = compat.IQ(client.xmlstream, 'get')
        iq.addElement((NS_MAM, 'query'))
        d = iq.send()

        def eb(failure):
            # typically StanzaError with condition u'service-unavailable'
            log.error(failure.getErrorMessage())
            return ''

        return d.addCallbacks(lambda elt: elt.toXml(), eb)

    def queryPrefs(self, profile_key=C.PROF_KEY_NONE):
        """Retrieve the current user preferences.

        @param profile_key (unicode): %(doc_profile_key)s
        @return: the server response as a Deferred domish.Element
        """
        # http://xmpp.org/extensions/xep-0313.html#prefs
        client = self.host.getClient(profile_key)
        iq = compat.IQ(client.xmlstream, 'get')
        iq.addElement((NS_MAM, 'prefs'))
        d = iq.send()

        def eb(failure):
            # typically StanzaError with condition u'service-unavailable'
            log.error(failure.getErrorMessage())
            return ''

        return d.addCallbacks(lambda elt: elt.toXml(), eb)

    def setPrefs(self, default='roster', always=None, never=None, profile_key=C.PROF_KEY_NONE):
        """Set news user preferences.

        @param default (unicode): a value in ('always', 'never', 'roster')
        @param always (list): a list of JID instances
        @param never (list): a list of JID instances
        @param profile_key (unicode): %(doc_profile_key)s
        @return: the server response as a Deferred domish.Element
        """
        # http://xmpp.org/extensions/xep-0313.html#prefs
        assert(default in ('always', 'never', 'roster'))
        client = self.host.getClient(profile_key)
        iq = compat.IQ(client.xmlstream, 'set')
        prefs = iq.addElement((NS_MAM, 'prefs'))
        prefs['default'] = default

        for var, attr in ((always, 'always'), (never, 'never')):
            if var is not None:
                elt = prefs.addElement((None, attr))
                for entity in var:
                    elt.addElement((None, 'jid')).addContent(entity.full())
        d = iq.send()

        def eb(failure):
            # typically StanzaError with condition u'service-unavailable'
            log.error(failure.getErrorMessage())
            return ''

        return d.addCallbacks(lambda elt: elt.toXml(), eb)

    @classmethod
    def datetime2utc(cls, datetime):
        """Convert a datetime to a XEP-0082 compliant UTC datetime.

        @param datetime (datetime): offset-aware timestamp to convert.
        @return: unicode
        """
        # receipt from wokkel.delay.Delay.toElement
        stampFormat = '%Y-%m-%dT%H:%M:%SZ'
        return datetime.astimezone(tzutc()).strftime(stampFormat)

    @classmethod
    def buildForm(cls, start=None, end=None, with_jid=None, extra=None):
        """Prepare a data form for MAM query.

        @param start (datetime): offset-aware timestamp to filter out older messages.
        @param end (datetime): offset-aware timestamp to filter out later messages.
        @param with_jid (JID): JID against which to match messages.
        @param extra (list): list of extra fields that are not defined by the
            specification. Each element must be a 3-tuple containing the field
            type, name and value.
        @return: a XEP-0004 data form as domish.Element
        """
        form = data_form.Form('submit', formNamespace=NS_MAM)
        if start:
            form.addField(data_form.Field('text-single', 'start', XEP_0313.datetime2utc(start)))
        if end:
            form.addField(data_form.Field('text-single', 'end', XEP_0313.datetime2utc(end)))
        if with_jid:
            form.addField(data_form.Field('jid-single', 'with', with_jid.full()))
        if extra is not None:
            for field in extra:
                form.addField(data_form.Field(*field))
        return form.toElement()

    def messageReceivedTrigger(self, message, post_treat, profile):
        """Check if the message is a MAM result. If so, extract the original
        message, stop processing the current message and process the original
        message instead.
        """
        try:
            result = domish.generateElementsQNamed(message.elements(), "result", NS_MAM).next()
        except StopIteration:
            return True
        try:
            forwarded = domish.generateElementsQNamed(result.elements(), "forwarded", NS_SF).next()
        except StopIteration:
            log.error(_("MAM result misses its <forwarded/> mandatory element!"))
            return False
        try:
            # TODO: delay is not here for nothing, get benefice of it!
            delay = domish.generateElementsQNamed(forwarded.elements(), "delay", NS_DD).next()
            msg = domish.generateElementsQNamed(forwarded.elements(), "message", NS_CLIENT).next()
        except StopIteration:
            log.error(_("<forwarded/> element misses a mandatory child!"))
            return False
        log.debug(_("MAM found a forwarded message"))
        client = self.host.getClient(profile)
        client.messageProt.onMessage(msg)
        return False


class XEP_0313_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_MAM)]

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