##   dispatcher_nb.py
##       based on dispatcher.py
##
##   Copyright (C) 2003-2005 Alexey "Snake" Nezhdanov
##       modified by Dimitur Kirov <dkirov@gmail.com>
##
##   This program is free software; you can redistribute it and/or modify
##   it under the terms of the GNU General Public License as published by
##   the Free Software Foundation; either version 2, 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 General Public License for more details.


'''
Main xmpp decision making logic. Provides library with methods to assign
different handlers to different XMPP stanzas and namespaces.
'''

import simplexml, sys, locale
from xml.parsers.expat import ExpatError
from plugin import PlugIn
from protocol import (NS_STREAMS, NS_XMPP_STREAMS, NS_HTTP_BIND, Iq, Presence,
	Message, Protocol, Node, Error, ERR_FEATURE_NOT_IMPLEMENTED, StreamError)
import logging
log = logging.getLogger('gajim.c.x.dispatcher_nb')

#: default timeout to wait for response for our id
DEFAULT_TIMEOUT_SECONDS = 25
outgoingID = 0

XML_DECLARATION = '<?xml version=\'1.0\'?>'

# FIXME: ugly
class Dispatcher():
	'''
	Why is this here - I needed to redefine Dispatcher for BOSH and easiest way
	was to inherit original Dispatcher (now renamed to XMPPDispatcher). Trouble
	is that reference used to access dispatcher instance is in Client attribute
	named by __class__.__name__ of the dispatcher instance .. long story short:

	I wrote following to avoid changing each client.Dispatcher.whatever() in xmpp

	If having two kinds of dispatcher will go well, I will rewrite the dispatcher
	references in other scripts
	'''
	def PlugIn(self, client_obj, after_SASL=False, old_features=None):
		if client_obj.protocol_type == 'XMPP':
			XMPPDispatcher().PlugIn(client_obj)
		elif client_obj.protocol_type == 'BOSH':
			BOSHDispatcher().PlugIn(client_obj, after_SASL, old_features)
		else:
			assert False # should never be reached

	@classmethod
	def get_instance(cls, *args, **kwargs):
		'''
		Factory Method for object creation.

		Use this instead of directly initializing the class in order to make
		unit testing much easier.
		'''
		return cls(*args, **kwargs)


class XMPPDispatcher(PlugIn):
	'''
	Handles XMPP stream and is the first who takes control over a fresh stanza.

	Is plugged into NonBlockingClient but can be replugged to restart handled
	stream headers (used by SASL f.e.).
	'''
	def __init__(self):
		PlugIn.__init__(self)
		self.handlers = {}
		self._expected = {}
		self._defaultHandler = None
		self._pendingExceptions = []
		self._eventHandler = None
		self._cycleHandlers = []
		self._exported_methods=[self.RegisterHandler, self.RegisterDefaultHandler,
			self.RegisterEventHandler, self.UnregisterCycleHandler,
			self.RegisterCycleHandler, self.RegisterHandlerOnce,
			self.UnregisterHandler, self.RegisterProtocol,
			self.SendAndWaitForResponse, self.SendAndCallForResponse,
			self.getAnID, self.Event, self.send]

	def getAnID(self):
		global outgoingID
		outgoingID += 1
		return repr(outgoingID)

	def dumpHandlers(self):
		'''
			Return set of user-registered callbacks in it's internal format.
			Used within the library to carry user handlers set over Dispatcher
			replugins.
		'''
		return self.handlers

	def restoreHandlers(self, handlers):
		'''
			Restores user-registered callbacks structure from dump previously
			obtained via dumpHandlers. Used within the library to carry user
			handlers set over Dispatcher replugins.
		'''
		self.handlers = handlers

	def _init(self):
		'''
			Registers default namespaces/protocols/handlers. Used internally.
		'''
		# FIXME: inject dependencies, do not rely that they are defined by our
		# owner
		self.RegisterNamespace('unknown')
		self.RegisterNamespace(NS_STREAMS)
		self.RegisterNamespace(self._owner.defaultNamespace)
		self.RegisterProtocol('iq', Iq)
		self.RegisterProtocol('presence', Presence)
		self.RegisterProtocol('message', Message)
		self.RegisterDefaultHandler(self.returnStanzaHandler)
		self.RegisterEventHandler(self._owner._caller._event_dispatcher)
		self.on_responses = {}

	def plugin(self, owner):
		'''
			Plug the Dispatcher instance into Client class instance and send
			initial stream header. Used internally.
		'''
		self._init()
		self._owner.lastErrNode = None
		self._owner.lastErr = None
		self._owner.lastErrCode = None
		if hasattr(self._owner, 'StreamInit'):
			self._owner.StreamInit()
		else:
			self.StreamInit()

	def plugout(self):
		''' Prepares instance to be destructed. '''
		self.Stream.dispatch = None
		self.Stream.features = None
		self.Stream.destroy()
		self._owner = None
		self.Stream = None

	def StreamInit(self):
		''' Send an initial stream header. '''
		self.Stream = simplexml.NodeBuilder()
		self.Stream.dispatch = self.dispatch
		self.Stream._dispatch_depth = 2
		self.Stream.stream_header_received = self._check_stream_start
		self.Stream.features = None
		self._metastream = Node('stream:stream')
		self._metastream.setNamespace(self._owner.Namespace)
		self._metastream.setAttr('version', '1.0')
		self._metastream.setAttr('xmlns:stream', NS_STREAMS)
		self._metastream.setAttr('to', self._owner.Server)
		if locale.getdefaultlocale()[0]:
			self._metastream.setAttr('xml:lang',
				locale.getdefaultlocale()[0].split('_')[0])
		self._owner.send("%s%s>" % (XML_DECLARATION, str(self._metastream)[:-2]))

	def _check_stream_start(self, ns, tag, attrs):
		if ns != NS_STREAMS or tag!='stream':
			raise ValueError('Incorrect stream start: (%s,%s). Terminating.'
				% (tag, ns))

	def ProcessNonBlocking(self, data):
		'''
		Check incoming stream for data waiting.

		:param data: data received from transports/IO sockets
		:return:
			1) length of processed data if some data were processed;
			2) '0' string if no data were processed but link is alive;
			3) 0 (zero) if underlying connection is closed.
		'''
		# FIXME:
		# When an error occurs we disconnect the transport directly. Client's
		# disconnect method will never be called.
		# Is this intended?
		# also look at transports start_disconnect()
		for handler in self._cycleHandlers:
			handler(self)
		if len(self._pendingExceptions) > 0:
			_pendingException = self._pendingExceptions.pop()
			raise _pendingException[0], _pendingException[1], _pendingException[2]
		try:
			self.Stream.Parse(data)
			# end stream:stream tag received
			if self.Stream and self.Stream.has_received_endtag():
				self._owner.disconnect(self.Stream.streamError)
				return 0
		except ExpatError:
			log.error('Invalid XML received from server. Forcing disconnect.')
			self._owner.Connection.disconnect()
			return 0
		except ValueError, e:
			log.debug('ValueError: %s' % str(e))
			self._owner.Connection.pollend()
			return 0
		if len(self._pendingExceptions) > 0:
			_pendingException = self._pendingExceptions.pop()
			raise _pendingException[0], _pendingException[1], _pendingException[2]
		if len(data) == 0:
			return '0'
		return len(data)

	def RegisterNamespace(self, xmlns, order='info'):
		'''
		Creates internal structures for newly registered namespace.
		You can register handlers for this namespace afterwards. By default
		one namespace is already registered
		(jabber:client or jabber:component:accept depending on context.
		'''
		log.debug('Registering namespace "%s"' % xmlns)
		self.handlers[xmlns] = {}
		self.RegisterProtocol('unknown', Protocol, xmlns=xmlns)
		self.RegisterProtocol('default', Protocol, xmlns=xmlns)

	def RegisterProtocol(self, tag_name, Proto, xmlns=None, order='info'):
		'''
		Used to declare some top-level stanza name to dispatcher.
		Needed to start registering handlers for such stanzas.

		Iq, message and presence protocols are registered by default.
		'''
		if not xmlns:
			xmlns=self._owner.defaultNamespace
		log.debug('Registering protocol "%s" as %s(%s)' %(tag_name, Proto, xmlns))
		self.handlers[xmlns][tag_name] = {type:Proto, 'default':[]}

	def RegisterNamespaceHandler(self, xmlns, handler, typ='', ns='',
	makefirst=0, system=0):
		'''
		Register handler for processing all stanzas for specified namespace.
		'''
		self.RegisterHandler('default', handler, typ, ns, xmlns, makefirst,
			system)

	def RegisterHandler(self, name, handler, typ='', ns='', xmlns=None,
			makefirst=False, system=False):
		'''
		Register user callback as stanzas handler of declared type.

		Callback must take (if chained, see later) arguments:
		dispatcher instance (for replying), incoming return of previous handlers.
		The callback must raise xmpp.NodeProcessed just before return if it wants
		other callbacks to be called with the same stanza as argument _and_, more
		importantly	library from returning stanza to sender with error set.

		:param name: name of stanza. F.e. "iq".
		:param handler: user callback.
		:param typ: value of stanza's "type" attribute. If not specified any
			value will match
		:param ns: namespace of child that stanza must contain.
		:param chained: chain together output of several handlers.
		:param makefirst: insert handler in the beginning of handlers list instea
			of	adding it to the end. Note that more common handlers i.e. w/o "typ"
			and " will be called first nevertheless.
		:param system: call handler even if NodeProcessed Exception were raised
			already.
		'''
		# FIXME: What does chain mean and where is it handled?
		if not xmlns:
			xmlns=self._owner.defaultNamespace
		log.debug('Registering handler %s for "%s" type->%s ns->%s(%s)' %
			(handler, name, typ, ns, xmlns))
		if not typ and not ns:
			typ='default'
		if xmlns not in self.handlers:
			self.RegisterNamespace(xmlns,'warn')
		if name not in self.handlers[xmlns]:
			self.RegisterProtocol(name,Protocol,xmlns,'warn')
		if typ+ns not in self.handlers[xmlns][name]:
			self.handlers[xmlns][name][typ+ns]=[]
		if makefirst:
			self.handlers[xmlns][name][typ+ns].insert(0,{'func':handler,
				'system':system})
		else:
			self.handlers[xmlns][name][typ+ns].append({'func':handler,
				'system':system})

	def RegisterHandlerOnce(self, name, handler, typ='', ns='', xmlns=None,
	makefirst=0, system=0):
		''' Unregister handler after first call (not implemented yet).	'''
		# FIXME Drop or implement
		if not xmlns:
			xmlns = self._owner.defaultNamespace
		self.RegisterHandler(name, handler, typ, ns, xmlns, makefirst, system)

	def UnregisterHandler(self, name, handler, typ='', ns='', xmlns=None):
		'''
		Unregister handler. "typ" and "ns" must be specified exactly the same as
		with registering.
		'''
		if not xmlns:
			xmlns = self._owner.defaultNamespace
		if not typ and not ns:
			typ='default'
		if xmlns not in self.handlers:
			return
		if name not in self.handlers[xmlns]:
			return
		if typ+ns not in self.handlers[xmlns][name]:
			return
		for pack in self.handlers[xmlns][name][typ+ns]:
			if pack['func'] == handler:
				try:
					self.handlers[xmlns][name][typ+ns].remove(pack)
				except ValueError:
					pass

	def RegisterDefaultHandler(self, handler):
		'''
		Specify the handler that will be used if no NodeProcessed exception were
		raised. This is returnStanzaHandler by default.
		'''
		self._defaultHandler = handler

	def RegisterEventHandler(self, handler):
		'''
		Register handler that will process events. F.e.
		"FILERECEIVED" event. See common/connection: _event_dispatcher()
		'''
		self._eventHandler = handler

	def returnStanzaHandler(self, conn, stanza):
		'''
		Return stanza back to the sender with <feature-not-implemented/> error set
		'''
		if stanza.getType() in ('get','set'):
			conn._owner.send(Error(stanza, ERR_FEATURE_NOT_IMPLEMENTED))

	def RegisterCycleHandler(self, handler):
		'''
		Register handler that will be called on every Dispatcher.Process() call.
		'''
		if handler not in self._cycleHandlers:
			self._cycleHandlers.append(handler)

	def UnregisterCycleHandler(self, handler):
		'''
		Unregister handler that will is called on every Dispatcher.Process() call
		'''
		if handler in self._cycleHandlers:
			self._cycleHandlers.remove(handler)

	def Event(self, realm, event, data):
		'''
		Raise some event.

		:param realm: scope of event. Usually a namespace.
		:param event: the event itself. F.e. "SUCCESSFUL SEND".
		:param data: data that comes along with event. Depends on event.
		'''
		if self._eventHandler:
			self._eventHandler(realm, event, data)
		else:
			log.warning('Received unhandled event: %s' % event)

	def dispatch(self, stanza, session=None, direct=0):
		'''
		Main procedure that performs XMPP stanza recognition and calling
		apppropriate handlers for it. Called by simplexml.
		'''
		# FIXME: Where do we set session and direct. Why? What are those intended
		# to do?

		#log.info('dispatch called: stanza = %s, session = %s, direct= %s'
		#	% (stanza, session, direct))
		if not session:
			session = self
		session.Stream._mini_dom = None
		name = stanza.getName()

		if name == 'features':
			self._owner.got_features = True
			session.Stream.features = stanza

		xmlns = stanza.getNamespace()

		# log.info('in dispatch, getting ns for %s, and the ns is %s'
		# % (stanza, xmlns))
		if xmlns not in self.handlers:
			log.warn("Unknown namespace: " + xmlns)
			xmlns = 'unknown'
		# features stanza has been handled before
		if name not in self.handlers[xmlns]:
			if name != 'features':
				log.warn("Unknown stanza: " + name)
			else:
				log.debug("Got %s/%s stanza" % (xmlns, name))
			name='unknown'
		else:
			log.debug("Got %s/%s stanza" % (xmlns, name))

		if stanza.__class__.__name__ == 'Node':
			# FIXME: this cannot work
			stanza=self.handlers[xmlns][name][type](node=stanza)

		typ = stanza.getType()
		if not typ:
			typ = ''
		stanza.props = stanza.getProperties()
		ID = stanza.getID()

		list_ = ['default'] # we will use all handlers:
		if typ in self.handlers[xmlns][name]:
			list_.append(typ) # from very common...
		for prop in stanza.props:
			if prop in self.handlers[xmlns][name]:
				list_.append(prop)
			if typ and typ+prop in self.handlers[xmlns][name]:
				list_.append(typ+prop)  # ...to very particular

		chain = self.handlers[xmlns]['default']['default']
		for key in list_:
			if key:
				chain = chain + self.handlers[xmlns][name][key]

		if ID in session._expected:
			user = 0
			if isinstance(session._expected[ID], tuple):
				cb, args = session._expected[ID]
				log.debug("Expected stanza arrived. Callback %s(%s) found!" %
					(cb, args))
				try:
					cb(session,stanza,**args)
				except Exception, typ:
					if typ.__class__.__name__ != 'NodeProcessed':
						raise
			else:
				log.debug("Expected stanza arrived!")
				session._expected[ID] = stanza
		else:
			user = 1
		for handler in chain:
			if user or handler['system']:
				try:
					handler['func'](session, stanza)
				except Exception, typ:
					if typ.__class__.__name__ != 'NodeProcessed':
						self._pendingExceptions.insert(0, sys.exc_info())
						return
					user=0
		if user and self._defaultHandler:
			self._defaultHandler(session, stanza)

	def _WaitForData(self, data):
		'''
		Internal wrapper around ProcessNonBlocking. Will check for
		'''
		if data is None:
			return
		res = self.ProcessNonBlocking(data)
		# 0 result indicates that we have closed the connection, e.g.
		# we have released dispatcher, so self._owner has no methods
		if not res:
			return
		for (_id, _iq) in self._expected.items():
			if _iq is None:
				# If the expected Stanza would have arrived, ProcessNonBlocking
				# would have placed the reply stanza in there
				continue
			if _id in self.on_responses:
				if len(self._expected) == 1:
					self._owner.onreceive(None)
				resp, args = self.on_responses[_id]
				del self.on_responses[_id]
				if args is None:
					resp(_iq)
				else:
					resp(self._owner, _iq, **args)
				del self._expected[_id]

	def SendAndWaitForResponse(self, stanza, timeout=None, func=None, args=None):
		'''
		Send stanza and wait for recipient's response to it. Will call transports
		on_timeout callback if response is not retrieved in time.

		Be aware: Only timeout of latest call of SendAndWait is active.
		'''
		if timeout is None:
			timeout = DEFAULT_TIMEOUT_SECONDS
		_waitid = self.send(stanza)
		if func:
			self.on_responses[_waitid] = (func, args)
		if timeout:
			self._owner.set_timeout(timeout)
		self._owner.onreceive(self._WaitForData)
		self._expected[_waitid] = None
		return _waitid

	def SendAndCallForResponse(self, stanza, func=None, args=None):
		''' Put stanza on the wire and call back when recipient replies.
			Additional callback arguments can be specified in args. '''
		self.SendAndWaitForResponse(stanza, 0, func, args)

	def send(self, stanza, now=False):
		'''
		Wraps transports send method when plugged into NonBlockingClient.
		Makes sure stanzas get ID and from tag.
		'''
		ID = None
		if type(stanza) not in [type(''), type(u'')]:
			if isinstance(stanza, Protocol):
				ID = stanza.getID()
				if ID is None:
					stanza.setID(self.getAnID())
					ID = stanza.getID()
				if self._owner._registered_name and not stanza.getAttr('from'):
					stanza.setAttr('from', self._owner._registered_name)
		self._owner.Connection.send(stanza, now)
		return ID


class BOSHDispatcher(XMPPDispatcher):

	def PlugIn(self, owner, after_SASL=False, old_features=None):
		self.old_features = old_features
		self.after_SASL = after_SASL
		XMPPDispatcher.PlugIn(self, owner)

	def StreamInit(self):
		''' Send an initial stream header. '''
		self.Stream = simplexml.NodeBuilder()
		self.Stream.dispatch = self.dispatch
		self.Stream._dispatch_depth = 2
		self.Stream.stream_header_received = self._check_stream_start
		self.Stream.features = self.old_features

		self._metastream = Node('stream:stream')
		self._metastream.setNamespace(self._owner.Namespace)
		self._metastream.setAttr('version', '1.0')
		self._metastream.setAttr('xmlns:stream', NS_STREAMS)
		self._metastream.setAttr('to', self._owner.Server)
		if locale.getdefaultlocale()[0]:
			self._metastream.setAttr('xml:lang',
				locale.getdefaultlocale()[0].split('_')[0])

		self.restart = True
		self._owner.Connection.send_init(after_SASL=self.after_SASL)

	def StreamTerminate(self):
		''' Send a stream terminator. '''
		self._owner.Connection.send_terminator()

	def ProcessNonBlocking(self, data=None):
		if self.restart:
			fromstream = self._metastream
			fromstream.setAttr('from', fromstream.getAttr('to'))
			fromstream.delAttr('to')
			data = '%s%s>%s' % (XML_DECLARATION,str(fromstream)[:-2] ,data)
			self.restart = False
		return XMPPDispatcher.ProcessNonBlocking(self, data)

	def dispatch(self, stanza, session=None, direct=0):
		if stanza.getName() == 'body' and stanza.getNamespace() == NS_HTTP_BIND:

			stanza_attrs = stanza.getAttrs()
			if 'authid' in stanza_attrs:
				# should be only in init response
				# auth module expects id of stream in document attributes
				self.Stream._document_attrs['id'] = stanza_attrs['authid']
			self._owner.Connection.handle_body_attrs(stanza_attrs)

			children = stanza.getChildren()
			if children:
				for child in children:
					# if child doesn't have any ns specified, simplexml (or expat)
					# thinks it's of parent's (BOSH body) namespace, so we have to
					# rewrite it to jabber:client
					if child.getNamespace() == NS_HTTP_BIND:
						child.setNamespace(self._owner.defaultNamespace)
					XMPPDispatcher.dispatch(self, child, session, direct)
		else:
			XMPPDispatcher.dispatch(self, stanza, session, direct)

# vim: se ts=3:
