# Source code for slixmpp.stanza.iq

    """
        Slixmpp: The Slick XMPP Library
        Copyright (C) 2010  Nathanael C. Fritz
        This file is part of Slixmpp.

        See the file LICENSE for copying permission.
    """

    from slixmpp.stanza.rootstanza import RootStanza
    from slixmpp.xmlstream import StanzaBase, ET
    from slixmpp.xmlstream.handler import Waiter, Callback, CoroutineCallback
    from slixmpp.xmlstream.asyncio import asyncio
    from slixmpp.xmlstream.matcher import MatchIDSender, MatcherId
    from slixmpp.exceptions import IqTimeout, IqError

    class Iq(RootStanza):

        """
        XMPP <iq> stanzas, or info/query stanzas, are XMPP's method of
        requesting and modifying information, similar to HTTP's GET and
        POST methods.

        Each <iq> stanza must have an 'id' value which associates the
        stanza with the response stanza. XMPP entities must always
        be given a response <iq> stanza with a type of 'result' after
        sending a stanza of type 'get' or 'set'.

        Most uses cases for <iq> stanzas will involve adding a <query>
        element whose namespace indicates the type of information
        desired. However, some custom XMPP applications use <iq> stanzas
        as a carrier stanza for an application-specific protocol instead.

        Example <iq> Stanzas:

        .. code-block:: xml

            <iq to="user@example.com" type="get" id="314">
              <query xmlns="http://jabber.org/protocol/disco#items" />
            </iq>

            <iq to="user@localhost" type="result" id="17">
              <query xmlns='jabber:iq:roster'>
                <item jid='otheruser@example.net'
                      name='John Doe'
                      subscription='both'>
                  <group>Friends</group>
                </item>
              </query>
            </iq>

        Stanza Interface:
            - **query**: The namespace of the <query> element if one exists.
        Attributes:
            - **types**: May be one of: get, set, result, or error.
        """

        namespace = 'jabber:client'
        name = 'iq'
        interfaces = set(('type', 'to', 'from', 'id', 'query'))
        types = set(('get', 'result', 'set', 'error'))
        plugin_attrib = name

        def __init__(self, *args, **kwargs):
            """
            Initialize a new <iq> stanza with an 'id' value.

            Overrides StanzaBase.__init__.
            """
            StanzaBase.__init__(self, *args, **kwargs)
            if self['id'] == '':
                if self.stream is not None:
                    self['id'] = self.stream.new_id()
                else:
                    self['id'] = '0'

        def unhandled(self):
            """
            Send a feature-not-implemented error if the stanza is not handled.

            Overrides StanzaBase.unhandled.
            """
            if self['type'] in ('get', 'set'):
                reply = self.reply()
                reply['error']['condition'] = 'feature-not-implemented'
                reply['error']['text'] = 'No handlers registered for this request.'
                reply.send()

        def set_payload(self, value):
            """
            Set the XML contents of the <iq> stanza.

            :param value: An XML object or a list of XML objects to use as the <iq>
                          stanza's contents
            :type value: list or XML object
            """
            self.clear()
            StanzaBase.set_payload(self, value)
            return self

        def set_query(self, value):
            """
            Add or modify a <query> element.

            Query elements are differentiated by their namespace.

            :param str value: The namespace of the <query> element.
            """
            query = self.xml.find("{%s}query" % value)
            if query is None and value:
                plugin = self.plugin_tag_map.get('{%s}query' % value, None)
                if plugin:
                    self.enable(plugin.plugin_attrib)
                else:
                    self.clear()
                    query = ET.Element("{%s}query" % value)
                    self.xml.append(query)
            return self

        def get_query(self):
            """Return the namespace of the <query> element.

            :rtype: str"""
            for child in self.xml:
                if child.tag.endswith('query'):
                    ns = child.tag.split('}')[0]
                    if '{' in ns:
                        ns = ns[1:]
                    return ns
            return ''

        def del_query(self):
            """Remove the <query> element."""
            for child in self.xml:
                if child.tag.endswith('query'):
                    self.xml.remove(child)
            return self

        def reply(self, clear=True):
            """
            Create a new <iq> stanza replying to ``self``.

            Overrides StanzaBase.reply

            Sets the 'type' to 'result' in addition to the default
            StanzaBase.reply behavior.

            :param bool clear: Indicates if existing content should be
                               removed before replying. Defaults to True.
            """
            new_iq = StanzaBase.reply(self, clear=clear)
            new_iq['type'] = 'result'
            return new_iq

        def send(self, callback=None, timeout=None, timeout_callback=None):
            """Send an <iq> stanza over the XML stream.

            A callback handler can be provided that will be executed when the Iq
            stanza's result reply is received.

            Returns a future which result will be set to the result Iq if it is of type 'get' or 'set'
            (when it is received), or a future with the result set to None if it has another type.

            Overrides StanzaBase.send

            :param function callback: Optional reference to a stream handler
                                      function. Will be executed when a reply
                                      stanza is received.
            :param int timeout: The length of time (in seconds) to wait for a
                                response before the timeout_callback is called,
                                instead of the regular callback
            :param function timeout_callback: Optional reference to a stream handler
                                              function.  Will be executed when the
                                              timeout expires before a response has
                                              been received for the originally-sent
                                              IQ stanza.
            :rtype: asyncio.Future
            """
            if self.stream.session_bind_event.is_set():
                matcher = MatchIDSender({
                    'id': self['id'],
                    'self': self.stream.boundjid,
                    'peer': self['to']
                })
            else:
                matcher = MatcherId(self['id'])

            future = asyncio.Future()

            def callback_success(result):
                if result['type'] == 'error':
                    future.set_exception(IqError(result))
                else:
                    future.set_result(result)

                if timeout is not None:
                    self.stream.cancel_schedule('IqTimeout_%s' % self['id'])
                if callback is not None:
                    callback(result)

            def callback_timeout():
                future.set_exception(IqTimeout(self))
                self.stream.remove_handler('IqCallback_%s' % self['id'])
                if timeout_callback is not None:
                    timeout_callback(self)

            if self['type'] in ('get', 'set'):
                handler_name = 'IqCallback_%s' % self['id']
                if asyncio.iscoroutinefunction(callback):
                    constr = CoroutineCallback
                else:
                    constr = Callback
                if timeout is not None:
                    self.stream.schedule('IqTimeout_%s' % self['id'],
                                         timeout,
                                         callback_timeout,
                                         repeat=False)
                handler = constr(handler_name,
                                 matcher,
                                 callback_success,
                                 once=True)
                self.stream.register_handler(handler)
            else:
                future.set_result(None)
            StanzaBase.send(self)
            return future

        def _handle_result(self, iq):
            # we got the IQ, so don't fire the timeout
            self.stream.cancel_schedule('IqTimeout_%s' % self['id'])
            self.callback(iq)

        def _fire_timeout(self):
            # don't fire the handler for the IQ, if it finally does come in
            self.stream.remove_handler('IqCallback_%s' % self['id'])
            self.timeout_callback(self)

        def _set_stanza_values(self, values):
            """
            Set multiple stanza interface values using a dictionary.

            Stanza plugin values may be set usind nested dictionaries.

            If the interface 'query' is given, then it will be set
            last to avoid duplication of the <query /> element.

            Overrides ElementBase._set_stanza_values.

            Arguments:
                values -- A dictionary mapping stanza interface with values.
                          Plugin interfaces may accept a nested dictionary that
                          will be used recursively.
            """
            query = values.get('query', '')
            if query:
                del values['query']
                StanzaBase._set_stanza_values(self, values)
                self['query'] = query
            else:
                StanzaBase._set_stanza_values(self, values)
            return self