##      common/zeroconf/zeroconf.py
##
## Copyright (C) 2006 Stefan Bethge <stefan@lanpartei.de>
##
## This file is part of Gajim.
##
## Gajim 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; version 3 only.
##
## Gajim 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.
##
## You should have received a copy of the GNU General Public License
## along with Gajim.  If not, see <http://www.gnu.org/licenses/>.
##

import logging
log = logging.getLogger('gajim.c.z.zeroconf_avahi')

try:
	import dbus.glib
except ImportError, e:
	pass

from common.zeroconf.zeroconf import C_BARE_NAME, C_INTERFACE, C_PROTOCOL, C_DOMAIN

class Zeroconf:
	def __init__(self, new_serviceCB, remove_serviceCB, name_conflictCB,
		disconnected_CB, error_CB, name, host, port):
		self.avahi = None
		self.domain = None   # specific domain to browse
		self.stype = '_presence._tcp'
		self.port = port  # listening port that gets announced
		self.username = name
		self.host = host
		self.txt = {}		# service data

		#XXX these CBs should be set to None when we destroy the object
		# (go offline), because they create a circular reference
		self.new_serviceCB = new_serviceCB
		self.remove_serviceCB = remove_serviceCB
		self.name_conflictCB = name_conflictCB
		self.disconnected_CB = disconnected_CB
		self.error_CB = error_CB

		self.service_browser = None
		self.domain_browser = None
		self.bus = None
		self.server = None
		self.contacts = {}    # all current local contacts with data
		self.entrygroup = None
		self.connected = False
		self.announced = False
		self.invalid_self_contact = {}


	## handlers for dbus callbacks
	def entrygroup_commit_error_CB(self, err):
		# left blank for possible later usage
		pass

	def error_callback1(self, err):
		log.debug('Error while resolving: ' + str(err))

	def error_callback(self, err):
		log.debug(str(err))
		# timeouts are non-critical
		if str(err) != 'Timeout reached':
			self.disconnect()
			self.disconnected_CB()

	def new_service_callback(self, interface, protocol, name, stype, domain,
	flags):
		log.debug('Found service %s in domain %s on %i.%i.' % (name, domain,
			interface, protocol))
		if not self.connected:
		 	return

		# synchronous resolving
		self.server.ResolveService( int(interface), int(protocol), name, stype,
			domain, self.avahi.PROTO_UNSPEC, dbus.UInt32(0),
			reply_handler=self.service_resolved_callback,
			error_handler=self.error_callback1)

	def remove_service_callback(self, interface, protocol, name, stype, domain,
	flags):
		log.debug('Service %s in domain %s on %i.%i disappeared.' % (name,
			domain, interface, protocol))
		if not self.connected:
		 	return
		if name != self.name:
			for key in self.contacts.keys():
				if self.contacts[key][C_BARE_NAME] == name:
					del self.contacts[key]
					self.remove_serviceCB(key)
					return

	def new_service_type(self, interface, protocol, stype, domain, flags):
		# Are we already browsing this domain for this type?
		if self.service_browser:
			return

		object_path = self.server.ServiceBrowserNew(interface, protocol, \
				stype, domain, dbus.UInt32(0))

		self.service_browser = dbus.Interface(self.bus.get_object(
			self.avahi.DBUS_NAME, object_path),
			self.avahi.DBUS_INTERFACE_SERVICE_BROWSER)
		self.service_browser.connect_to_signal('ItemNew',
			self.new_service_callback)
		self.service_browser.connect_to_signal('ItemRemove',
			self.remove_service_callback)
		self.service_browser.connect_to_signal('Failure', self.error_callback)

	def new_domain_callback(self,interface, protocol, domain, flags):
		if domain != 'local':
			self.browse_domain(interface, protocol, domain)

	def txt_array_to_dict(self, txt_array):
		txt_dict = {}
		for els in txt_array:
			key, val = '', None
			for c in els:
					c = chr(c)
					if val is None:
						if c == '=':
							val = ''
						else:
							key += c
					else:
						val += c
			if val is None: # missing '='
				val = ''
			txt_dict[key] = val.decode('utf-8', 'ignore')
		return txt_dict

	def service_resolved_callback(self, interface, protocol, name, stype, domain,
	host, aprotocol, address, port, txt, flags):
		log.debug('Service data for service %s in domain %s on %i.%i:'
			% (name, domain, interface, protocol))
		log.debug('Host %s (%s), port %i, TXT data: %s' % (host, address,
			port, self.txt_array_to_dict(txt)))
		if not self.connected:
			return
		bare_name = name
		if name.find('@') == -1:
			name = name + '@' + name

		# we don't want to see ourselves in the list
		if name != self.name:
			self.contacts[name] = (name, domain, interface, protocol, host,
				address, port, bare_name, txt)
			self.new_serviceCB(name)
		else:
			# remember data
			# In case this is not our own record but of another
			# gajim instance on the same machine,
			# it will be used when we get a new name.
			self.invalid_self_contact[name] = (name, domain, interface, protocol,
				host, address, port, bare_name, txt)


	# different handler when resolving all contacts
	def service_resolved_all_callback(self, interface, protocol, name, stype,
	domain, host, aprotocol, address, port, txt, flags):
		if not self.connected:
			return
		bare_name = name
		if name.find('@') == -1:
			name = name + '@' + name
		self.contacts[name] = (name, domain, interface, protocol, host, address,
			port, bare_name, txt)

	def service_added_callback(self):
		log.debug('Service successfully added')

	def service_committed_callback(self):
		log.debug('Service successfully committed')

	def service_updated_callback(self):
		log.debug('Service successfully updated')

	def service_add_fail_callback(self, err):
		log.debug('Error while adding service. %s' % str(err))
		if 'Local name collision' in str(err):
			alternative_name = self.server.GetAlternativeServiceName(self.username)
			self.name_conflictCB(alternative_name)
			return
		self.error_CB(_('Error while adding service. %s') % str(err))
		self.disconnect()

	def server_state_changed_callback(self, state, error):
		log.debug('server state changed to %s' % state)
		if state == self.avahi.SERVER_RUNNING:
			self.create_service()
		elif state in (self.avahi.SERVER_COLLISION,
		self.avahi.SERVER_REGISTERING):
			self.disconnect()
			self.entrygroup.Reset()
		elif state == self.avahi.CLIENT_FAILURE:
			# does it ever go here?
			log.debug('CLIENT FAILURE')

	def entrygroup_state_changed_callback(self, state, error):
		# the name is already present, so recreate
		if state == self.avahi.ENTRY_GROUP_COLLISION:
			log.debug('zeroconf.py: local name collision')
			self.service_add_fail_callback('Local name collision')
		elif state == self.avahi.ENTRY_GROUP_FAILURE:
			self.disconnect()
			self.entrygroup.Reset()
			log.debug('zeroconf.py: ENTRY_GROUP_FAILURE reached(that'
				' should not happen)')

	# make zeroconf-valid names
	def replace_show(self, show):
		if show in ['chat', 'online', '']:
			return 'avail'
		elif show == 'xa':
			return 'away'
		return show

	def avahi_txt(self):
		utf8_dict = {}
		for key in self.txt:
			val = self.txt[key]
			if isinstance(val, unicode):
				utf8_dict[key] = val.encode('utf-8')
			else:
				utf8_dict[key] = val
		return self.avahi.dict_to_txt_array(utf8_dict)

	def create_service(self):
		try:
			if not self.entrygroup:
				# create an EntryGroup for publishing
				self.entrygroup = dbus.Interface(self.bus.get_object(
					self.avahi.DBUS_NAME, self.server.EntryGroupNew()),
					self.avahi.DBUS_INTERFACE_ENTRY_GROUP)
				self.entrygroup.connect_to_signal('StateChanged',
					self.entrygroup_state_changed_callback)

			txt = {}

			# remove empty keys
			for key,val in self.txt.iteritems():
				if val:
					txt[key] = val

			txt['port.p2pj'] = self.port
			txt['version'] = 1
			txt['txtvers'] = 1

			# replace gajim's show messages with compatible ones
			if 'status' in self.txt:
				txt['status'] = self.replace_show(self.txt['status'])
			else:
				txt['status'] = 'avail'

			self.txt = txt
			log.debug('Publishing service %s of type %s' % (self.name,
				self.stype))
			self.entrygroup.AddService(self.avahi.IF_UNSPEC,
				self.avahi.PROTO_UNSPEC, dbus.UInt32(0), self.name, self.stype, '',
				'', dbus.UInt16(self.port), self.avahi_txt(),
				reply_handler=self.service_added_callback,
				error_handler=self.service_add_fail_callback)

			self.entrygroup.Commit(reply_handler=self.service_committed_callback,
				error_handler=self.entrygroup_commit_error_CB)

			return True

		except dbus.DBusException, e:
			log.debug(str(e))
			return False

	def announce(self):
		if not self.connected:
			return False

		state = self.server.GetState()
		if state == self.avahi.SERVER_RUNNING:
			self.create_service()
			self.announced = True
			return True

	def remove_announce(self):
		if self.announced == False:
			return False
		try:
			if self.entrygroup.GetState() != self.avahi.ENTRY_GROUP_FAILURE:
				self.entrygroup.Reset()
				self.entrygroup.Free()
				# .Free() has mem leaks
				self.entrygroup._obj._bus = None
				self.entrygroup._obj = None
				self.entrygroup = None
				self.announced = False

				return True
			else:
				return False
		except dbus.DBusException:
			log.debug("Can't remove service. That should not happen")

	def browse_domain(self, interface, protocol, domain):
		self.new_service_type(interface, protocol, self.stype, domain, '')

	def avahi_dbus_connect_cb(self, a, connect, disconnect):
		if connect != "":
			log.debug('Lost connection to avahi-daemon')
			self.disconnect()
			if self.disconnected_CB:
				self.disconnected_CB()
		else:
			log.debug('We are connected to avahi-daemon')

	# connect to dbus
	def connect_dbus(self):
		try:
			import dbus
		except ImportError:
			log.debug('Error: python-dbus needs to be installed. No '
				'zeroconf support.')
			return False
		if self.bus:
			return True
		try:
			self.bus = dbus.SystemBus()
			self.bus.add_signal_receiver(self.avahi_dbus_connect_cb,
				'NameOwnerChanged', 'org.freedesktop.DBus',
				arg0='org.freedesktop.Avahi')
		except Exception, e:
			# System bus is not present
			self.bus = None
			log.debug(str(e))
			return False
		else:
			return True

	# connect to avahi
	def connect_avahi(self):
		if not self.connect_dbus():
			return False
		try:
			import avahi
			self.avahi = avahi
		except ImportError:
			log.debug('Error: python-avahi needs to be installed. No '
				'zeroconf support.')
			return False

		if self.server:
			return True
		try:
			self.server = dbus.Interface(self.bus.get_object(self.avahi.DBUS_NAME,
				self.avahi.DBUS_PATH_SERVER), self.avahi.DBUS_INTERFACE_SERVER)
			self.server.connect_to_signal('StateChanged',
				self.server_state_changed_callback)
		except Exception, e:
			# Avahi service is not present
			self.server = None
			log.debug(str(e))
			return False
		else:
			return True

	def connect(self):
		self.name = self.username + '@' + self.host # service name
		if not self.connect_avahi():
			return False

		self.connected = True
		# start browsing
		if self.domain is None:
			# Explicitly browse .local
			self.browse_domain(self.avahi.IF_UNSPEC, self.avahi.PROTO_UNSPEC,
				'local')

			# Browse for other browsable domains
			self.domain_browser = dbus.Interface(self.bus.get_object(
				self.avahi.DBUS_NAME, self.server.DomainBrowserNew(
				self.avahi.IF_UNSPEC, self.avahi.PROTO_UNSPEC, '',
				self.avahi.DOMAIN_BROWSER_BROWSE, dbus.UInt32(0))),
				self.avahi.DBUS_INTERFACE_DOMAIN_BROWSER)
			self.domain_browser.connect_to_signal('ItemNew',
				self.new_domain_callback)
			self.domain_browser.connect_to_signal('Failure', self.error_callback)
		else:
			self.browse_domain(self.avahi.IF_UNSPEC, self.avahi.PROTO_UNSPEC,
				self.domain)

		return True

	def disconnect(self):
		if self.connected:
			self.connected = False
			if self.service_browser:
				self.service_browser.Free()
				self.service_browser._obj._bus = None
				self.service_browser._obj = None
			if self.domain_browser:
				self.domain_browser.Free()
				self.domain_browser._obj._bus = None
				self.domain_browser._obj = None
			self.remove_announce()
			self.server._obj._bus = None
			self.server._obj = None
		self.server = None
		self.service_browser = None
		self.domain_browser = None

	# refresh txt data of all contacts manually (no callback available)
	def resolve_all(self):
		if not self.connected:
			return
		for val in self.contacts.values():
			self.server.ResolveService(int(val[C_INTERFACE]), int(val[C_PROTOCOL]),
				val[C_BARE_NAME], self.stype, val[C_DOMAIN],
				self.avahi.PROTO_UNSPEC, dbus.UInt32(0),
				reply_handler=self.service_resolved_all_callback,
				error_handler=self.error_callback)

	def get_contacts(self):
		return self.contacts

	def get_contact(self, jid):
		if not jid in self.contacts:
			return None
		return self.contacts[jid]

	def update_txt(self, show = None):
		if show:
			self.txt['status'] = self.replace_show(show)

		txt = self.avahi_txt()
		if self.connected and self.entrygroup:
			self.entrygroup.UpdateServiceTxt(self.avahi.IF_UNSPEC,
				self.avahi.PROTO_UNSPEC, dbus.UInt32(0), self.name, self.stype, '',
				txt, reply_handler=self.service_updated_callback,
				error_handler=self.error_callback)
			return True
		else:
			return False


# END Zeroconf

# vim: se ts=3:
