path: root/services/presence/Buddy.py

# Copyright (C) 2006, Red Hat, Inc.
#
# 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 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

import base64
import logging

import gobject
import dbus, dbus.service
from sugar import profile


PRESENCE_SERVICE_TYPE = "_presence_olpc._tcp"
BUDDY_DBUS_OBJECT_PATH = "/org/laptop/Presence/Buddies/"
BUDDY_DBUS_INTERFACE = "org.laptop.Presence.Buddy"

_BUDDY_KEY_COLOR = 'color'
_BUDDY_KEY_CURACT = 'curact'

class NotFoundError(Exception):
    pass

class BuddyDBusHelper(dbus.service.Object):
    def __init__(self, parent, bus_name, object_path):
        self._parent = parent
        self._bus_name = bus_name
        self._object_path = object_path
        dbus.service.Object.__init__(self, bus_name, self._object_path)

    @dbus.service.signal(BUDDY_DBUS_INTERFACE,
                        signature="o")
    def ServiceAppeared(self, object_path):
        pass

    @dbus.service.signal(BUDDY_DBUS_INTERFACE,
                        signature="o")
    def ServiceDisappeared(self, object_path):
        pass

    @dbus.service.signal(BUDDY_DBUS_INTERFACE,
                        signature="")
    def Disappeared(self):
        pass

    @dbus.service.signal(BUDDY_DBUS_INTERFACE,
                        signature="ao")
    def CurrentActivityChanged(self, activities):
        pass

    @dbus.service.signal(BUDDY_DBUS_INTERFACE,
                        signature="")
    def IconChanged(self):
        pass

    @dbus.service.signal(BUDDY_DBUS_INTERFACE,
                        signature="o")
    def JoinedActivity(self, object_path):
        pass

    @dbus.service.signal(BUDDY_DBUS_INTERFACE,
                        signature="o")
    def LeftActivity(self, object_path):
        pass

    @dbus.service.signal(BUDDY_DBUS_INTERFACE,
                        signature="as")
    def PropertyChanged(self, prop_list):
        pass

    @dbus.service.method(BUDDY_DBUS_INTERFACE,
                        in_signature="", out_signature="ay")
    def getIcon(self):
        icon = self._parent.get_icon()
        if not icon:
            return ""
        return icon

    @dbus.service.method(BUDDY_DBUS_INTERFACE,
                        in_signature="so", out_signature="o")
    def getServiceOfType(self, stype, activity_op):
        activity = None
        # "/" is the placeholder for None
        if activity_op != "/":
            for act in self._parent.get_joined_activities():
                if act.object_path() == activity_op:
                    activity = act
            if not activity:
                raise NotFoundError("Not found")

        service = self._parent.get_service_of_type(stype, activity)
        if not service:
            raise NotFoundError("Not found")
        return service.object_path()

    @dbus.service.method(BUDDY_DBUS_INTERFACE,
                        in_signature="", out_signature="ao")
    def getJoinedActivities(self):
        acts = []
        for act in self._parent.get_joined_activities():
            acts.append(act.object_path())
        return acts

    @dbus.service.method(BUDDY_DBUS_INTERFACE,
                        in_signature="", out_signature="a{sv}")
    def getProperties(self):
        props = {}
        props['name'] = self._parent.get_name()
        addr = self._parent.get_address()
        if addr:
            props['ip4_address'] = addr
        props['owner'] = self._parent.is_owner()
        color = self._parent.get_color()
        if color:
            props[_BUDDY_KEY_COLOR] = self._parent.get_color()
        return props

    @dbus.service.method(BUDDY_DBUS_INTERFACE,
                        in_signature="", out_signature="o")
    def getCurrentActivity(self):
        activity = self._parent.get_current_activity()
        if not activity:
            raise NotFoundError()
        return activity.object_path()

class Buddy(object):
    """Represents another person on the network and keeps track of the
    activities and resources they make available for sharing."""

    def __init__(self, bus_name, object_id, service, icon_cache):
        if not bus_name:
            raise ValueError("DBus bus name must be valid")
        if not object_id or not isinstance(object_id, int):
            raise ValueError("object id must be a valid number")
        # Normal Buddy objects must be created with a valid service,
        # owner objects do not
        if not isinstance(self, Owner):
            if not isinstance(service, Service.Service):
                raise ValueError("service must be a valid service object")

        self._services = {}
        self._activities = {}

        self._icon_cache = icon_cache

        self._nick_name = None
        self._address = None
        if service is not None:
            self._nick_name = service.get_name()
            self._address = service.get_source_address()
        self._color = None
        self._current_activity = None
        self._valid = False
        self._icon = None
        self._icon_tries = 0

        self._object_id = object_id
        self._object_path = BUDDY_DBUS_OBJECT_PATH + str(self._object_id)
        self._dbus_helper = BuddyDBusHelper(self, bus_name, self._object_path)

        self._buddy_presence_service = None
        if service is not None:
            self.add_service(service)

    def object_path(self):
        return dbus.ObjectPath(self._object_path)

    def _request_buddy_icon_cb(self, result_status, response, user_data):
        """Callback when icon request has completed."""
        from sugar.p2p import network
        icon = response
        service = user_data
        if result_status == network.RESULT_SUCCESS:
            if icon and len(icon):
                icon = base64.b64decode(icon)
                self._set_icon(icon)
                self._icon_cache.add_icon(icon)

        if (result_status == network.RESULT_FAILED or not icon) and self._icon_tries < 3:
            self._icon_tries = self._icon_tries + 1
            if self._icon_tries >= 3:
                logging.debug("Failed to retrieve buddy icon for '%s'." % self._nick_name)
            gobject.timeout_add(1000, self._get_buddy_icon, service, True)
        return False

    def _get_buddy_icon(self, service, retry=False):
        """Get the buddy's icon.  Check the cache first, if its
        not there get the icon from the buddy over the network."""
        if retry != True:
            # Only hit the cache once
            icon_hash = service.get_one_property('icon-hash')
            if icon_hash is not None:
                icon = self._icon_cache.get_icon(icon_hash)
                if icon:
                    logging.debug("%s: icon cache hit for %s." % (self._nick_name, icon_hash))
                    self._set_icon(icon)
                    return False
            logging.debug("%s: icon cache miss, fetching icon from buddy..." % self._nick_name)

        from sugar.p2p import Stream
        buddy_stream = Stream.Stream.new_from_service(service, start_reader=False)
        writer = buddy_stream.new_writer(service)
        success = writer.custom_request("get_buddy_icon", self._request_buddy_icon_cb, service)
        if not success:
            del writer, buddy_stream
            gobject.timeout_add(1000, self._get_buddy_icon, service, True)
        return False

    def _get_service_key(self, service):
        return (service.get_type(), service.get_activity_id())

    def add_service(self, service):
        """Adds a new service to this buddy's service list, returning
        True if the service was successfully added, and False if it was not."""
        if service.get_name() != self._nick_name:
            logging.error("Service and buddy nick names doesn't match: " \
                    "%s %s" % (service.get_name(), self._nick_name))
            return False

        source_addr = service.get_source_address()
        if source_addr != self._address:
            logging.error("Service source and buddy address doesn't " \
                    "match: %s %s" % (source_addr, self._address))
            return False        
        return self._internal_add_service(service)

    def _internal_add_service(self, service):
        service_key = self._get_service_key(service)
        if service_key in self._services.keys():
            logging.error("Service already known: %s %s" % (service_key[0],
                    service_key[1]))
            return False

        if service.get_type() == PRESENCE_SERVICE_TYPE and self._buddy_presence_service:
            # already have a presence service for this buddy
            logging.debug("!!! Tried to add a buddy presence service when " \
                    "one already existed.")
            return False

        logging.debug("Buddy %s added service type %s id %s" % (self._nick_name,
                service.get_type(), service.get_activity_id()))
        self._services[service_key] = service
        service.set_owner(self)

        if service.get_type() == PRESENCE_SERVICE_TYPE:
            self._buddy_presence_service = service
            # A buddy isn't valid until its official presence
            # service has been found and resolved
            self._valid = True
            self._get_buddy_icon(service)
            self._color = service.get_one_property(_BUDDY_KEY_COLOR)
            self._current_activity = service.get_one_property(_BUDDY_KEY_CURACT)
            # Monitor further buddy property changes, like current activity
            # and color
            service.connect('property-changed',
                    self.__buddy_presence_service_property_changed_cb)

        if self._valid:
            self._dbus_helper.ServiceAppeared(service.object_path())
        return True

    def __buddy_presence_service_property_changed_cb(self, service, keys):
        if _BUDDY_KEY_COLOR in keys:
            new_color = service.get_one_property(_BUDDY_KEY_COLOR)
            if new_color and self._color != new_color:
                self._color = new_color
                self._dbus_helper.PropertyChanged([_BUDDY_KEY_COLOR])
        if _BUDDY_KEY_CURACT in keys:
            # Three cases here:
            # 1) Buddy didn't publish a 'curact' key at all; we do nothing
            # 2) Buddy published a blank/zero-length 'curact' key; we send
            #        a current-activity-changed signal for no activity
            # 3) Buddy published a non-zero-length 'curact' key; we send
            #        a current-activity-changed signal if we know about the
            #        activity already, if not we postpone until the activity
            #        is found on the network and added to the buddy
            new_curact = service.get_one_property(_BUDDY_KEY_CURACT)
            if new_curact and self._current_activity != new_curact:
                if not len(new_curact):
                    new_curact = None
                self._current_activity = new_curact
                if self._activities.has_key(self._current_activity):
                    # Case (3) above, valid activity id
                    activity = self._activities[self._current_activity]
                    if activity.is_valid():
                        self._dbus_helper.CurrentActivityChanged([activity.object_path()])
                elif not self._current_activity:
                    # Case (2) above, no current activity
                    self._dbus_helper.CurrentActivityChanged([])

    def __find_service_by_activity_id(self, actid):
        for serv in self._services.values():
            if serv.get_activity_id() == actid:
                return serv
        return None

    def add_activity(self, activity):
        if activity in self._activities.values():
            return
        actid = activity.get_id()
        if not self.__find_service_by_activity_id(actid):
            raise RuntimeError("Tried to add activity for which we had no service")
        self._activities[actid] = activity
        if activity.is_valid():
            self._dbus_helper.JoinedActivity(activity.object_path())

            # If when we received a current activity update from the buddy,
            # but didn't know about that activity yet, and now we do know about
            # it, we need to send out the changed activity signal
            if actid == self._current_activity:
                self._dbus_helper.CurrentActivityChanged([activity.object_path()])

    def remove_service(self, service):
        """Remove a service from a buddy; ie, the activity was closed
        or the buddy went away."""
        if service.get_source_address() != self._address:
            return
        if service.get_name() != self._nick_name:
            return

        if service.get_type() == PRESENCE_SERVICE_TYPE \
                and self._buddy_presence_service \
                and service != self._buddy_presence_service:
            logging.debug("!!! Tried to remove a spurious buddy presence service.")
            return

        service_key = self._get_service_key(service)
        if self._services.has_key(service_key):
            if self._valid:
                self._dbus_helper.ServiceDisappeared(service.object_path())
            del self._services[service_key]

        if service.get_type() == PRESENCE_SERVICE_TYPE:
            self._valid = False
            self._dbus_helper.Disappeared()

    def remove_activity(self, activity):
        actid = activity.get_id()
        if not self._activities.has_key(actid):
            return
        del self._activities[actid]
        if activity.is_valid():
            self._dbus_helper.LeftActivity(activity.object_path())

        # If we just removed the buddy's current activity,
        # send out a signal
        if actid == self._current_activity:
            self._current_activity = None
            self._dbus_helper.CurrentActivityChanged([])

    def get_joined_activities(self):
        acts = []
        for act in self._activities.values():
            if act.is_valid():
                acts.append(act)
        return acts

    def get_service_of_type(self, stype, activity=None):
        """Return a service of a certain type, or None if the buddy
        doesn't provide that service."""
        if not stype:
            raise RuntimeError("Need to specify a service type.")

        if activity and not activity.is_valid():
            raise RuntimeError("Activity is not yet valid.")

        if activity:
            key = (stype, activity.get_id())
        else:
            key = (stype, None)
        if self._services.has_key(key):
            return self._services[key]
        return None

    def is_valid(self):
        """Return whether the buddy is valid or not.  A buddy is
        not valid until its official presence service has been found
        and successfully resolved."""
        return self._valid

    def get_icon(self):
        """Return the buddies icon, if any."""
        return self._icon
        
    def get_address(self):
        return self._address

    def get_name(self):
        return self._nick_name

    def get_color(self):
        return self._color

    def get_current_activity(self):
        if not self._current_activity:
            return None
        if not self._activities.has_key(self._current_activity):
            return None
        return self._activities[self._current_activity]

    def _set_icon(self, icon):
        """Can only set icon for other buddies.  The Owner
        takes care of setting it's own icon."""
        if icon != self._icon:
            self._icon = icon
            self._dbus_helper.IconChanged()

    def is_owner(self):
        return False


class Owner(Buddy):
    """Class representing the owner of the machine.  This is the client
    portion of the Owner, paired with the server portion in Owner.py."""
    def __init__(self, ps, bus_name, object_id, icon_cache):
        Buddy.__init__(self, bus_name, object_id, None, icon_cache)
        self._nick_name = profile.get_nick_name()
        self._color = profile.get_color()
        self._ps = ps

    def add_service(self, service):
        """Adds a new service to this buddy's service list, returning
        True if the service was successfully added, and False if it was not."""
        if service.get_name() != self._nick_name:
            logging.error("Service and buddy nick names doesn't match: " \
                    "%s %s" % (service.get_name(), self._nick_name))
            return False

        # The Owner initially doesn't have an address, so the first
        # service added to the Owner determines the owner's address
        source_addr = service.get_source_address()
        if self._address is None and service.is_local():
            self._address = source_addr
            self._dbus_helper.PropertyChanged(['ip4_address'])

        # The owner bypasses address checks and only cares if
        # avahi says the service is a local service
        if not service.is_local():
            logging.error("Cannot add remote service to owner object.")
            return False

        logging.debug("Adding owner service %s.%s at %s:%d." % (service.get_name(),
                service.get_type(), service.get_source_address(),
                service.get_port()))
        return self._internal_add_service(service)

    def is_owner(self):
        return True


#################################################################
# Tests
#################################################################

import unittest
import Service

__objid_seq = 0
def _next_objid():
    global __objid_seq
    __objid_seq = __objid_seq + 1
    return __objid_seq


class BuddyTestCase(unittest.TestCase):
    _DEF_NAME = u"Tommy"
    _DEF_STYPE = unicode(PRESENCE_SERVICE_TYPE)
    _DEF_DOMAIN = u"local"
    _DEF_ADDRESS = u"1.1.1.1"
    _DEF_PORT = 1234

    def __init__(self, name):
        self._bus = dbus.SessionBus()
        self._bus_name = dbus.service.BusName('org.laptop.Presence', bus=self._bus)        
        unittest.TestCase.__init__(self, name)

    def __del__(self):
        del self._bus_name
        del self._bus

    def _test_init_fail(self, service, fail_msg):
        """Test something we expect to fail."""
        try:
            objid = _next_objid()
            buddy = Buddy(self._bus_name, objid, service, owner=False)
        except ValueError, exc:
            pass
        else:
            self.fail("expected a ValueError for %s." % fail_msg)

    def testService(self):
        service = None
        self._test_init_fail(service, "invalid service")

    def testGoodInit(self):
        objid = _next_objid()
        service = Service.Service(self._bus_name, objid, self._DEF_NAME, self._DEF_STYPE, self._DEF_DOMAIN,
                self._DEF_ADDRESS, self._DEF_PORT)
        objid = _next_objid()
        buddy = Buddy(self._bus_name, objid, service)
        assert buddy.get_name() == self._DEF_NAME, "buddy name wasn't correct after init."
        assert buddy.get_address() == self._DEF_ADDRESS, "buddy address wasn't correct after init."
        assert buddy.object_path() == BUDDY_DBUS_OBJECT_PATH + str(objid)

    def addToSuite(suite):
        suite.addTest(BuddyTestCase("testService"))
        suite.addTest(BuddyTestCase("testGoodInit"))
    addToSuite = staticmethod(addToSuite)


def main():
    suite = unittest.TestSuite()
    BuddyTestCase.addToSuite(suite)
    runner = unittest.TextTestRunner()
    runner.run(suite)

if __name__ == "__main__":
    main()