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# Source code for slixmpp.plugins.xep_0047.ibb

    # Slixmpp: The Slick XMPP Library
    # This file is part of Slixmpp
    # See the file LICENSE for copying permission
    import uuid
    import logging

    from typing import (
        Optional,
        Union,
    )

    from slixmpp import JID
    from slixmpp.stanza import Message, Iq
    from slixmpp.exceptions import XMPPError
    from slixmpp.xmlstream.handler import CoroutineCallback
    from slixmpp.xmlstream.matcher import StanzaPath
    from slixmpp.xmlstream import register_stanza_plugin
    from slixmpp.plugins import BasePlugin
    from slixmpp.plugins.xep_0047 import stanza, Open, Close, Data, IBBytestream

    log = logging.getLogger(__name__)

    class XEP_0047(BasePlugin):
        """
        XEP-0047: In-Band Bytestreams

        Events registered by this plugin:

        - :term:`ibb_stream_start`
        - :term:`ibb_stream_end`
        - :term:`ibb_stream_data`
        - :term:`stream:[stream id]:[peer jid]`

        Plugin Parameters:

        - ``block_size`` (default: ``4096``): default block size to negotiate
        - ``max_block_size`` (default: ``8192``): max block size to accept
        - ``auto_accept`` (default: ``False``): if incoming streams should be
            accepted automatically.

        - :term:`authorized (0047 version)`
        - :term:`authorized_sid (0047 version)`
        - :term:`preauthorize_sid (0047 version)`
        - :term:`get_stream`
        - :term:`set_stream`
        - :term:`del_stream`
        """

        name = 'xep_0047'
        description = 'XEP-0047: In-Band Bytestreams'
        dependencies = {'xep_0030'}
        stanza = stanza
        default_config = {
            'block_size': 4096,
            'max_block_size': 8192,
            'auto_accept': False,
        }

        def plugin_init(self):
            self._streams = {}
            self._preauthed_sids = {}

            register_stanza_plugin(Iq, Open)
            register_stanza_plugin(Iq, Close)
            register_stanza_plugin(Iq, Data)
            register_stanza_plugin(Message, Data)

            self.xmpp.register_handler(CoroutineCallback(
                'IBB Open',
                StanzaPath('iq@type=set/ibb_open'),
                self._handle_open_request))

            self.xmpp.register_handler(CoroutineCallback(
                'IBB Close',
                StanzaPath('iq@type=set/ibb_close'),
                self._handle_close))

            self.xmpp.register_handler(CoroutineCallback(
                'IBB Data',
                StanzaPath('iq@type=set/ibb_data'),
                self._handle_data))

            self.xmpp.register_handler(CoroutineCallback(
                'IBB Message Data',
                StanzaPath('message/ibb_data'),
                self._handle_data))

            self.api.register(self._authorized, 'authorized', default=True)
            self.api.register(self._authorized_sid, 'authorized_sid', default=True)
            self.api.register(self._preauthorize_sid, 'preauthorize_sid', default=True)
            self.api.register(self._get_stream, 'get_stream', default=True)
            self.api.register(self._set_stream, 'set_stream', default=True)
            self.api.register(self._del_stream, 'del_stream', default=True)

        def plugin_end(self):
            self.xmpp.remove_handler('IBB Open')
            self.xmpp.remove_handler('IBB Close')
            self.xmpp.remove_handler('IBB Data')
            self.xmpp.remove_handler('IBB Message Data')
            self.xmpp['xep_0030'].del_feature(feature='http://jabber.org/protocol/ibb')

        def session_bind(self, jid):
            self.xmpp['xep_0030'].add_feature('http://jabber.org/protocol/ibb')

        def _get_stream(self, jid, sid, peer_jid, data):
            return self._streams.get((jid, sid, peer_jid), None)

        def _set_stream(self, jid, sid, peer_jid, stream):
            self._streams[(jid, sid, peer_jid)] = stream

        def _del_stream(self, jid, sid, peer_jid, data):
            if (jid, sid, peer_jid) in self._streams:
                del self._streams[(jid, sid, peer_jid)]

        async def _accept_stream(self, iq):
            receiver = iq['to']
            sender = iq['from']
            sid = iq['ibb_open']['sid']

            if await self.api['authorized_sid'](receiver, sid, sender, iq):
                return True
            return await self.api['authorized'](receiver, sid, sender, iq)

        def _authorized(self, jid, sid, ifrom, iq):
            if self.auto_accept:
                return True
            return False

        def _authorized_sid(self, jid, sid, ifrom, iq):
            if (jid, sid, ifrom) in self._preauthed_sids:
                del self._preauthed_sids[(jid, sid, ifrom)]
                return True
            return False

        def _preauthorize_sid(self, jid, sid, ifrom, data):
            self._preauthed_sids[(jid, sid, ifrom)] = True

        async def open_stream(self, jid: JID, *, block_size: Optional[int] = None,
                              sid: Optional[str] = None, use_messages: bool = False,
                              ifrom: Optional[JID] = None,
                              **iqkwargs) -> IBBytestream:
            """Open an IBB stream with a peer JID.

            .. versionchanged:: 1.8.0
                This function is now a coroutine and must be awaited.
                All parameters except ``jid`` are keyword-args only.

            :param jid: The remote JID to initiate the stream with.
            :param block_size: The block size to advertise.
            :param sid: The IBB stream id (if not provided, will be auto-generated).
            :param use_messages: If the stream should use message stanzas instead of iqs.
            :returns: The opened byte stream with the remote JID
            :raises .IqError: When the remote entity denied the stream.
            """
            if sid is None:
                sid = str(uuid.uuid4())
            if block_size is None:
                block_size = self.block_size

            iq = self.xmpp.make_iq_set(ito=jid, ifrom=ifrom)
            iq['ibb_open']['block_size'] = block_size
            iq['ibb_open']['sid'] = sid
            iq['ibb_open']['stanza'] = 'message' if use_messages else 'iq'

            stream = IBBytestream(self.xmpp, sid, block_size,
                                  iq['from'], iq['to'], use_messages)

            callback = iqkwargs.pop('callback', None)
            result = await iq.send(**iqkwargs)

            log.debug('IBB stream (%s) accepted by %s', stream.sid, result['from'])
            stream.self_jid = result['to']
            stream.peer_jid = result['from']
            stream.stream_started = True
            await self.api['set_stream'](stream.self_jid, stream.sid, stream.peer_jid, stream)
            if callback is not None:
                self.xmpp.add_event_handler('ibb_stream_start', callback, disposable=True)
            self.xmpp.event('ibb_stream_start', stream)
            self.xmpp.event('stream:%s:%s' % (stream.sid, stream.peer_jid), stream)
            return stream

        async def _handle_open_request(self, iq: Iq):
            sid = iq['ibb_open']['sid']
            size = iq['ibb_open']['block_size'] or self.block_size

            log.debug('Received IBB stream request from %s', iq['from'])

            if not sid:
                raise XMPPError(etype='modify', condition='bad-request')

            if not await self._accept_stream(iq):
                raise XMPPError(etype='cancel', condition='not-acceptable')

            if size > self.max_block_size:
                raise XMPPError('resource-constraint')

            stream = IBBytestream(self.xmpp, sid, size,
                                  iq['to'], iq['from'])
            stream.stream_started = True
            await self.api['set_stream'](stream.self_jid, stream.sid, stream.peer_jid, stream)
            iq.reply().send()

            self.xmpp.event('ibb_stream_start', stream)
            self.xmpp.event('stream:%s:%s' % (sid, stream.peer_jid), stream)

        async def _handle_data(self, stanza: Union[Iq, Message]):
            sid = stanza['ibb_data']['sid']
            stream = await self.api['get_stream'](stanza['to'], sid, stanza['from'])
            if stream is not None and stanza['from'] == stream.peer_jid:
                stream._recv_data(stanza)
            else:
                raise XMPPError('item-not-found')

        async def _handle_close(self, iq: Iq):
            sid = iq['ibb_close']['sid']
            stream = await self.api['get_stream'](iq['to'], sid, iq['from'])
            if stream is not None and iq['from'] == stream.peer_jid:
                stream._closed(iq)
                await self.api['del_stream'](stream.self_jid, stream.sid, stream.peer_jid)
            else:
                raise XMPPError('item-not-found')