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

# SAT plugin for Pubsub Schemas
# Copyright (C) 2009-2017 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 import exceptions
from sat.core.constants import Const as C
from twisted.words.protocols.jabber import jid
from twisted.words.protocols.jabber.xmlstream import XMPPHandler
from sat.core.log import getLogger
log = getLogger(__name__)
from wokkel import disco, iwokkel
from wokkel import data_form
from wokkel import generic
from zope.interface import implements

NS_SCHEMA = 'https://salut-a-toi/protocol/schema:0'
NS_SCHEMA_FORM = 'https://salut-a-toi/protocol/schema#schema:0'

PLUGIN_INFO = {
    C.PI_NAME: "PubSub Schema",
    C.PI_IMPORT_NAME: "PUBSUB_SCHEMA",
    C.PI_TYPE: "EXP",
    C.PI_PROTOCOLS: [],
    C.PI_DEPENDENCIES: ["XEP-0060"],
    C.PI_MAIN: "PubsubSchema",
    C.PI_HANDLER: "yes",
    C.PI_DESCRIPTION: _("""Handle Pubsub data schemas""")
}


class PubsubSchema(object):

    def __init__(self, host):
        log.info(_(u"PubSub Schema initialization"))
        self.host = host
        host.bridge.addMethod("psSchemaGet", ".plugin",
                              in_sign='sss', out_sign='s',
                              method=self._getSchema,
                              async=True
                              )
        host.bridge.addMethod("psSchemaSet", ".plugin",
                              in_sign='ssss', out_sign='',
                              method=self._setSchema,
                              async=True
                              )

    def getHandler(self, client):
        return SchemaHandler()

    def _getSchemaBridgeCb(self, schema_elt):
        if schema_elt is None:
            return u''
        return schema_elt.toXml()

    def _getSchema(self, service, nodeIdentifier, profile_key=C.PROF_KEY_NONE):
        client = self.host.getClient(profile_key)
        service = None if not service else jid.JID(service)
        d = self.getSchema(client, service, nodeIdentifier)
        d.addCallback(self._getSchemaBridgeCb)
        return d

    def _getSchemaCb(self, iq_elt):
        try:
            schema_elt = next(iq_elt.elements(NS_SCHEMA, 'schema'))
        except StopIteration:
            raise exceptions.DataError('missing <schema> element')
        schema_form = data_form.findForm(schema_elt, NS_SCHEMA_FORM)
        if schema_form is None:
            # there is not schema on this node
            return None
        # we get again the form because we need all elements/namespaces
        # while schema_form.toElement while only keep XEP-0004 elements
        x_elt = next(schema_elt.elements(data_form.NS_X_DATA, 'x'))
        return x_elt

    def getSchema(self, client, service, nodeIdentifier):
        """retrieve PubSub node schema

        @param service(jid.JID, None): jid of PubSub service
            None to use our PEP
        @param nodeIdentifier(unicode): node to get schema from
        @return (domish.Element, None): schema (<x> element)
            None if not schema has been set on this node
        """
        iq_elt = client.IQ(u'get')
        if service is not None:
            iq_elt['to'] = service.full()
        pubsub_elt = iq_elt.addElement((NS_SCHEMA, 'pubsub'))
        schema_elt = pubsub_elt.addElement((NS_SCHEMA, 'schema'))
        schema_elt['node'] = nodeIdentifier
        d = iq_elt.send()
        d.addCallback(self._getSchemaCb)
        return d

    def _setSchema(self, service, nodeIdentifier, schema, profile_key=C.PROF_KEY_NONE):
        client = self.host.getClient(profile_key)
        service = None if not service else jid.JID(service)
        schema = generic.parseXml(schema.encode('utf-8'))
        return self.setSchema(client, service, nodeIdentifier, schema)

    def setSchema(self, client, service, nodeIdentifier, schema):
        """set or replace PubSub node schema

        @param schema(domish.Element, None): schema to set
            None if schema need to be removed
        """
        iq_elt = client.IQ()
        if service is not None:
            iq_elt['to'] = service.full()
        pubsub_elt = iq_elt.addElement((NS_SCHEMA, 'pubsub'))
        schema_elt = pubsub_elt.addElement((NS_SCHEMA, 'schema'))
        schema_elt['node'] = nodeIdentifier
        if schema is not None:
            schema_elt.addChild(schema)
        return iq_elt.send()


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

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

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