##############################################################################
#
# Copyright (c) 2002 Nexedi SARL and Contributors. All Rights Reserved.
#                    Jean-Paul Smets-Solanes <jp@nexedi.com>
#
# WARNING: This program as such is intended to be used by professional
# programmers who take the whole responsability of assessing all potential
# consequences resulting from its eventual inadequacies and bugs
# End users who are looking for a ready-to-use solution with commercial
# garantees and support are strongly adviced to contract a Free Software
# Service Company
#
# 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
#
##############################################################################

import socket
import urllib
import threading
import sys
from types import TupleType, StringType
import re

from Products.CMFCore import CMFCorePermissions
from Products.ERP5Type.Core.Folder import Folder
from Products.CMFActivity.ActiveResult import ActiveResult
from Products.PythonScripts.Utility import allow_class
from AccessControl import ClassSecurityInfo, Permissions
from AccessControl.SecurityManagement import newSecurityManager
from AccessControl.SecurityManagement import noSecurityManager
from AccessControl.SecurityManagement import setSecurityManager
from AccessControl.SecurityManagement import getSecurityManager
from Products.CMFCore.utils import UniqueObject, _getAuthenticatedUser, getToolByName
from Globals import InitializeClass, DTMLFile
from Acquisition import aq_base
from Acquisition import aq_inner
from Products.CMFActivity.ActiveObject import DISTRIBUTABLE_STATE, INVOKE_ERROR_STATE, VALIDATE_ERROR_STATE
from ActivityBuffer import ActivityBuffer
from zExceptions import ExceptionFormatter

from ZODB.POSException import ConflictError
from Products.MailHost.MailHost import MailHostError

from zLOG import LOG, INFO, WARNING

try:
  from Products.TimerService import getTimerService
except ImportError:
  def getTimerService(self):
    pass

# minimal IP:Port regexp
NODE_RE = re.compile('^\d+\.\d+\.\d+\.\d+:\d+$')

# Using a RAM property (not a property of an instance) allows
# to prevent from storing a state in the ZODB (and allows to restart...)
active_threads = 0
max_active_threads = 1 # 2 will cause more bug to appear (he he)
is_initialized = 0
tic_lock = threading.Lock() # A RAM based lock to prevent too many concurrent tic() calls
timerservice_lock = threading.Lock() # A RAM based lock to prevent TimerService spamming when busy
first_run = 1

# Activity Registration
activity_dict = {}
activity_list = []

def registerActivity(activity):
  # Must be rewritten to register
  # class and create instance for each activity
  #LOG('Init Activity', 0, str(activity.__name__))
  activity_instance = activity()
  activity_list.append(activity_instance)
  activity_dict[activity.__name__] = activity_instance

class Message:
  """Activity Message Class.

  Message instances are stored in an activity queue, inside the Activity Tool.
  """
  def __init__(self, obj, active_process, activity_kw, method_id, args, kw):
    if isinstance(obj, str):
      self.object_path = obj.split('/')
    else:
      self.object_path = obj.getPhysicalPath()
    if type(active_process) is StringType:
      self.active_process = active_process.split('/')
    elif active_process is None:
      self.active_process = None
    else:
      self.active_process = active_process.getPhysicalPath()
      self.active_process_uid = active_process.getUid()
    self.activity_kw = activity_kw
    self.method_id = method_id
    self.args = args
    self.kw = kw
    self.is_executed = 0
    self.exc_type = None
    self.processing = None
    self.user_name = str(_getAuthenticatedUser(self))
    # Store REQUEST Info ?

  def getObject(self, activity_tool):
    """return the object referenced in this message."""
    return activity_tool.unrestrictedTraverse(self.object_path)

  def getObjectList(self, activity_tool):
    """return the list of object that can be expanded from this message."""
    try:
      expand_method_id = self.activity_kw['expand_method_id']
      obj = self.getObject(activity_tool)
      # FIXME: how to pass parameters?
      object_list = getattr(obj, expand_method_id)()
    except KeyError:
      object_list = [self.getObject(activity_tool)]

    return object_list

  def hasExpandMethod(self):
    """return true if the message has an expand method.
    An expand method is used to expand the list of objects and to turn a
    big recursive transaction affecting many objects into multiple
    transactions affecting only one object at a time (this can prevent
    duplicated method calls)."""
    return self.activity_kw.has_key('expand_method_id')

  def changeUser(self, user_name, activity_tool):
    """restore the security context for the calling user."""
    uf = activity_tool.getPortalObject().acl_users
    user = uf.getUserById(user_name)
    # if the user is not found, try to get it from a parent acl_users
    # XXX this is still far from perfect, because we need to store all
    # informations about the user (like original user folder, roles) to
    # replay the activity with exactly the same security context as if
    # it had been executed without activity.
    if user is None:
      uf = activity_tool.getPortalObject().aq_parent.acl_users
      user = uf.getUserById(user_name)
    if user is not None:
      user = user.__of__(uf)
      newSecurityManager(None, user)
    else :
      LOG("CMFActivity", WARNING,
          "Unable to find user %s in the portal" % user_name)
      noSecurityManager()
    return user

  def activateResult(self, activity_tool, result, object):
    if self.active_process is not None:
      active_process = activity_tool.unrestrictedTraverse(self.active_process)
      if isinstance(result,ActiveResult):
        result.edit(object_path=object)
        result.edit(method_id=self.method_id)
        # XXX Allow other method_id in future
        active_process.activateResult(result)
      else:
        active_process.activateResult(
                    ActiveResult(object_path=object,
                          method_id=self.method_id,
                          result=result)) # XXX Allow other method_id in future

  def __call__(self, activity_tool):
    try:
      obj = self.getObject(activity_tool)
      # Change user if required (TO BE DONE)
      # We will change the user only in order to execute this method
      current_user = str(_getAuthenticatedUser(self))
      user = self.changeUser(self.user_name, activity_tool)
      try:
        result = getattr(obj, self.method_id)(*self.args, **self.kw)
      finally:
        # Use again the previous user
        if user is not None:
          self.changeUser(current_user, activity_tool)
      self.activateResult(activity_tool, result, obj)
      self.is_executed = 1
    except:
      self.is_executed = 0
      self.exc_type = sys.exc_info()[0]
      self.exc_value = str(sys.exc_info()[1])
      self.traceback = ''.join(ExceptionFormatter.format_exception(
                               *sys.exc_info()))
      LOG('ActivityTool', WARNING,
          'Could not call method %s on object %s' % (
          self.method_id, self.object_path), error=sys.exc_info())
      # push the error in ZODB error_log
      if hasattr(activity_tool, 'error_log'):
        activity_tool.error_log.raising(sys.exc_info())

  def validate(self, activity, activity_tool, check_order_validation=1):
    return activity.validate(activity_tool, self,
                             check_order_validation=check_order_validation,
                             **self.activity_kw)

  def getDependentMessageList(self, activity, activity_tool):
    return activity.getDependentMessageList(activity_tool, self, **self.activity_kw)

  def notifyUser(self, activity_tool, message="Failed Processing Activity"):
    """Notify the user that the activity failed."""
    portal = activity_tool.getPortalObject()
    user_email = None
    user = portal.portal_membership.getMemberById(self.user_name)
    if user is not None:
      user_email = user.getProperty('email')
    if user_email in ('', None):
      user_email = portal.getProperty('email_to_address',
                       portal.getProperty('email_from_address'))
    mail_text = """From: %s
To: %s
Subject: %s

%s

Document: %s
Method: %s
Exception: %s %s

%s
""" % (activity_tool.email_from_address, user_email, message,
       message, '/'.join(self.object_path), self.method_id,
       self.exc_type, self.exc_value, self.traceback)
    try:
      activity_tool.MailHost.send( mail_text )
    except (socket.error, MailHostError), message:
      LOG('ActivityTool.notifyUser', WARNING, 'Mail containing failure information failed to be sent: %s' % (message, ))

  def reactivate(self, activity_tool):
    # Reactivate the original object.
    obj= self.getObject(activity_tool)
    # Change user if required (TO BE DONE)
    # We will change the user only in order to execute this method
    current_user = str(_getAuthenticatedUser(self))
    user = self.changeUser(self.user_name, activity_tool)
    try:
      active_obj = obj.activate(**self.activity_kw)
      getattr(active_obj, self.method_id)(*self.args, **self.kw)
    finally:
      # Use again the previous user
      if user is not None:
        self.changeUser(current_user, activity_tool)

class Method:

  def __init__(self, passive_self, activity, active_process, kw, method_id):
    self.__passive_self = passive_self
    self.__activity = activity
    self.__active_process = active_process
    self.__kw = kw
    self.__method_id = method_id

  def __call__(self, *args, **kw):
    m = Message(self.__passive_self, self.__active_process, self.__kw, self.__method_id, args, kw)
    activity_dict[self.__activity].queueMessage(self.__passive_self.portal_activities, m)

allow_class(Method)

class ActiveWrapper:

  def __init__(self, passive_self, activity, active_process, **kw):
    self.__dict__['__passive_self'] = passive_self
    self.__dict__['__activity'] = activity
    self.__dict__['__active_process'] = active_process
    self.__dict__['__kw'] = kw

  def __getattr__(self, id):
    return Method(self.__dict__['__passive_self'], self.__dict__['__activity'],
                  self.__dict__['__active_process'],
                  self.__dict__['__kw'], id)

class ActivityTool (Folder, UniqueObject):
    """
    ActivityTool is the central point for activity management.

    Improvement to consider to reduce locks:

      Idea 1: create an SQL tool which accumulate queries and executes them at the end of a transaction,
              thus allowing all SQL transaction to happen in a very short time
              (this would also be a great way of using MyISAM tables)

      Idea 2: do the same at the level of ActivityTool

      Idea 3: do the same at the level of each activity (ie. queueMessage
              accumulates and fires messages at the end of the transactino)
    """
    id = 'portal_activities'
    meta_type = 'CMF Activity Tool'
    portal_type = 'Activity Tool'
    allowed_types = ( 'CMF Active Process', )
    security = ClassSecurityInfo()

    _distributingNode = ''
    _nodes = ()

    manage_options = tuple(
                     [ { 'label' : 'Overview', 'action' : 'manage_overview' }
                     , { 'label' : 'Activities', 'action' : 'manageActivities' }
                     , { 'label' : 'LoadBalancing', 'action' : 'manageLoadBalancing'}
                     , { 'label' : 'Advanced', 'action' : 'manageActivitiesAdvanced' }
                     ,
                     ] + list(Folder.manage_options))

    security.declareProtected( CMFCorePermissions.ManagePortal , 'manageActivities' )
    manageActivities = DTMLFile( 'dtml/manageActivities', globals() )

    security.declareProtected( CMFCorePermissions.ManagePortal , 'manageActivitiesAdvanced' )
    manageActivitiesAdvanced = DTMLFile( 'dtml/manageActivitiesAdvanced', globals() )

    security.declareProtected( CMFCorePermissions.ManagePortal , 'manage_overview' )
    manage_overview = DTMLFile( 'dtml/explainActivityTool', globals() )
    
    security.declareProtected( CMFCorePermissions.ManagePortal , 'manageLoadBalancing' )
    manageLoadBalancing = DTMLFile( 'dtml/manageLoadBalancing', globals() )
    
    distributingNode = ''
    _nodes = ()

    def __init__(self):
        return Folder.__init__(self, ActivityTool.id)

    # Filter content (ZMI))
    def filtered_meta_types(self, user=None):
        # Filters the list of available meta types.
        all = ActivityTool.inheritedAttribute('filtered_meta_types')(self)
        meta_types = []
        for meta_type in self.all_meta_types():
            if meta_type['name'] in self.allowed_types:
                meta_types.append(meta_type)
        return meta_types

    def initialize(self):
      global is_initialized
      from Activity import RAMQueue, RAMDict, SQLQueue, SQLDict
      # Initialize each queue
      for activity in activity_list:
        activity.initialize(self)
      is_initialized = 1
      
    security.declareProtected(Permissions.manage_properties, 'isSubscribed')
    def isSubscribed(self):
        """
        return True, if we are subscribed to TimerService.
        Otherwise return False.
        """
        service = getTimerService(self)
        if not service:
            LOG('ActivityTool', INFO, 'TimerService not available')
            return False
        
        path = '/'.join(self.getPhysicalPath())
        if path in service.lisSubscriptions():
            return True
        return False

    security.declareProtected(Permissions.manage_properties, 'subscribe')
    def subscribe(self, REQUEST=None, RESPONSE=None):
        """ subscribe to the global Timer Service """
        service = getTimerService(self)
        url = '%s/manageLoadBalancing?manage_tabs_message=' %self.absolute_url()
        if not service:
            LOG('ActivityTool', INFO, 'TimerService not available')
            url += urllib.quote('TimerService not available')
        else:
            service.subscribe(self)
            url += urllib.quote("Subscribed to Timer Service")
        if RESPONSE is not None:
            RESPONSE.redirect(url)

    security.declareProtected(Permissions.manage_properties, 'unsubscribe')
    def unsubscribe(self, REQUEST=None, RESPONSE=None):
        """ unsubscribe from the global Timer Service """
        service = getTimerService(self)
        url = '%s/manageLoadBalancing?manage_tabs_message=' %self.absolute_url()
        if not service:
            LOG('ActivityTool', INFO, 'TimerService not available')
            url += urllib.quote('TimerService not available')
        else:
            service.unsubscribe(self)
            url += urllib.quote("Unsubscribed from Timer Service")
        if RESPONSE is not None:
            RESPONSE.redirect(url)

    def manage_beforeDelete(self, item, container):
        self.unsubscribe()
        Folder.inheritedAttribute('manage_beforeDelete')(self, item, container)
    
    def manage_afterAdd(self, item, container):
        self.subscribe()
        Folder.inheritedAttribute('manage_afterAdd')(self, item, container)
       
    def getCurrentNode(self):
        """ Return current node in form ip:port """
        port = ''
        from asyncore import socket_map
        for k, v in socket_map.items():
            if hasattr(v, 'port'):
                # see Zope/lib/python/App/ApplicationManager.py: def getServers(self)
                type = str(getattr(v, '__class__', 'unknown'))
                if type == 'ZServer.HTTPServer.zhttp_server':
                    port = v.port
                    break
        ip = socket.gethostbyname(socket.gethostname())
        currentNode = '%s:%s' %(ip, port)
        return currentNode
        
    security.declarePublic('getDistributingNode')
    def getDistributingNode(self):
        """ Return the distributingNode """
        return self.distributingNode

    security.declarePublic('getNodeList getNodes')
    def getNodes(self):
        """ Return all nodes """
        return self._nodes
    getNodeList = getNodes

    def _isValidNodeName(self, node_name) :
      """Check we have been provided a good node name"""
      return isinstance(node_name, str) and NODE_RE.match(node_name)
      
    security.declarePublic('manage_setDistributingNode')
    def manage_setDistributingNode(self, distributingNode, REQUEST=None):
        """ set the distributing node """   
        if not distributingNode or self._isValidNodeName(distributingNode):
          self.distributingNode = distributingNode
          if REQUEST is not None:
              REQUEST.RESPONSE.redirect(
                  REQUEST.URL1 +
                  '/manageLoadBalancing?manage_tabs_message=' +
                  urllib.quote("Distributing Node successfully changed."))
        else :
          if REQUEST is not None:
              REQUEST.RESPONSE.redirect(
                  REQUEST.URL1 +
                  '/manageLoadBalancing?manage_tabs_message=' +
                  urllib.quote("Malformed Distributing Node."))

    security.declarePublic('manage_addNode')
    def manage_addNode(self, node, REQUEST=None):
        """ add a node """
        if not self._isValidNodeName(node) :
            if REQUEST is not None:
                REQUEST.RESPONSE.redirect(
                    REQUEST.URL1 +
                    '/manageLoadBalancing?manage_tabs_message=' +
                    urllib.quote("Malformed node."))
            return
        
        if node in self._nodes:
            if REQUEST is not None:
                REQUEST.RESPONSE.redirect(
                    REQUEST.URL1 +
                    '/manageLoadBalancing?manage_tabs_message=' +
                    urllib.quote("Node exists already."))
            return
            
        self._nodes = self._nodes + (node,)
        
        if REQUEST is not None:
            REQUEST.RESPONSE.redirect(
                REQUEST.URL1 +
                '/manageLoadBalancing?manage_tabs_message=' +
                urllib.quote("Node successfully added."))
                        
    security.declarePublic('manage_delNode')
    def manage_delNode(self, deleteNodes, REQUEST=None):
        """ delete nodes """
        nodeList = list(self._nodes)
        for node in deleteNodes:
            if node in self._nodes:
                nodeList.remove(node)
        self._nodes = tuple(nodeList)
        if REQUEST is not None:
            REQUEST.RESPONSE.redirect(
                REQUEST.URL1 +
                '/manageLoadBalancing?manage_tabs_message=' +
                urllib.quote("Node(s) successfully deleted."))

    def process_timer(self, tick, interval, prev="", next=""):
        """
        Call distribute() if we are the Distributing Node and call tic()
        with our node number.
        This method is called by TimerService in the interval given
        in zope.conf. The Default is every 5 seconds.
        """
        # Prevent TimerService from starting multiple threads in parallel
        acquired = timerservice_lock.acquire(0)
        if not acquired:
          return

        old_sm = getSecurityManager()
        try:
          # get owner of portal_catalog, so normally we should be able to
          # have the permission to invoke all activities
          user = self.portal_catalog.getWrappedOwner()
          newSecurityManager(self.REQUEST, user)

          currentNode = self.getCurrentNode()

          # only distribute when we are the distributingNode or if it's empty
          if (self.distributingNode == currentNode):
            self.distribute(len(self._nodes))

          elif not self.distributingNode:
            self.distribute(1)

          # SkinsTool uses a REQUEST cache to store skin objects, as
          # with TimerService we have the same REQUEST over multiple
          # portals, we clear this cache to make sure the cache doesn't
          # contains skins from another portal.
          stool = getToolByName(self, 'portal_skins', None)
          if stool is not None:
            stool.changeSkin(None)

          # call tic for the current processing_node
          # the processing_node numbers are the indices of the elements in the node tuple +1
          # because processing_node starts form 1
          if currentNode in self._nodes:
            self.tic(list(self._nodes).index(currentNode)+1)

          elif len(self._nodes) == 0:
            self.tic(1)

        finally:
          timerservice_lock.release()
          setSecurityManager(old_sm)

    security.declarePublic('distribute')
    def distribute(self, node_count=1):
      """
        Distribute load
      """
      # Initialize if needed
      global is_initialized
      if not is_initialized: self.initialize()

      # Call distribute on each queue
      for activity in activity_list:
        try:
          activity.distribute(aq_inner(self), node_count)
        except ConflictError:
          raise
        except:
          LOG('CMFActivity:', 100, 'Core call to distribute failed for activity %s' % activity, error=sys.exc_info())

    security.declarePublic('tic')
    def tic(self, processing_node=1, force=0):
      """
        Starts again an activity
        processing_node starts from 1 (there is not node 0)
      """
      global active_threads, is_initialized, first_run

      # return if the number of threads is too high
      # else, increase the number of active_threads and continue
      tic_lock.acquire()
      too_many_threads = (active_threads >= max_active_threads)
      if not too_many_threads or force:
        active_threads += 1
      else:
        tic_lock.release()
        raise RuntimeError, 'Too many threads'
      tic_lock.release()

      # Initialize if needed
      if not is_initialized: self.initialize()

      inner_self = aq_inner(self)

      # If this is the first tic after zope is started, reset the processing
      # flag for activities of this node
      if first_run:
        inner_self.SQLDict_clearProcessingFlag(
                                processing_node=processing_node)
        inner_self.SQLQueue_clearProcessingFlag(
                                processing_node=processing_node)
        first_run = 0

      try:
        # Wakeup each queue
        for activity in activity_list:
          try:
            activity.wakeup(inner_self, processing_node)
          except ConflictError:
            raise
          except:
            LOG('CMFActivity:', 100, 'Core call to wakeup failed for activity %s' % activity)

        # Process messages on each queue in round robin
        has_awake_activity = 1
        while has_awake_activity:
          has_awake_activity = 0
          for activity in activity_list:
            try:
              activity.tic(inner_self, processing_node) # Transaction processing is the responsability of the activity
              has_awake_activity = has_awake_activity or activity.isAwake(inner_self, processing_node)
            except ConflictError:
              raise
            except:
              LOG('CMFActivity:', 100, 'Core call to tic or isAwake failed for activity %s' % activity, error=sys.exc_info())
      finally:
        # decrease the number of active_threads
        tic_lock.acquire()
        active_threads -= 1
        tic_lock.release()

    def hasActivity(self, *args, **kw):
      # Check in each queue if the object has deferred tasks
      # if not argument is provided, then check on self
      if len(args) > 0:
        obj = args[0]
      else:
        obj = self
      for activity in activity_list:
        if activity.hasActivity(aq_inner(self), obj, **kw):
          return 1
      return 0

    security.declarePrivate('activateObject')
    def activateObject(self, object, activity, active_process, **kw):
      global is_initialized
      if not is_initialized: self.initialize()
      if getattr(self, '_v_activity_buffer', None) is None:
        self._v_activity_buffer = ActivityBuffer(activity_tool=self)
      return ActiveWrapper(object, activity, active_process, **kw)

    def deferredQueueMessage(self, activity, message):
      self._v_activity_buffer.deferredQueueMessage(self, activity, message)

    def deferredDeleteMessage(self, activity, message):
      if getattr(self, '_v_activity_buffer', None) is None:
        self._v_activity_buffer = ActivityBuffer(activity_tool=self)
      self._v_activity_buffer.deferredDeleteMessage(self, activity, message)

    def getRegisteredMessageList(self, activity):
      activity_buffer = getattr(self, '_v_activity_buffer', None)
      if activity_buffer is not None:
        activity_buffer._register() # This is required if flush flush is called outside activate
        return activity.getRegisteredMessageList(self._v_activity_buffer,
                                                 aq_inner(self))
      else:
        return []

    def unregisterMessage(self, activity, message):
      self._v_activity_buffer._register() # Required if called by flush, outside activate
      return activity.unregisterMessage(self._v_activity_buffer, aq_inner(self), message)

    def flush(self, obj, invoke=0, **kw):
      global is_initialized
      if not is_initialized: self.initialize()
      if getattr(self, '_v_activity_buffer', None) is None:
        self._v_activity_buffer = ActivityBuffer(activity_tool=self)
      if isinstance(obj, tuple):
        object_path = obj
      else:
        object_path = obj.getPhysicalPath()
      for activity in activity_list:
        activity.flush(aq_inner(self), object_path, invoke=invoke, **kw)

    def start(self, **kw):
      global is_initialized
      if not is_initialized: self.initialize()
      for activity in activity_list:
        activity.start(aq_inner(self), **kw)

    def stop(self, **kw):
      global is_initialized
      if not is_initialized: self.initialize()
      for activity in activity_list:
        activity.stop(aq_inner(self), **kw)

    def invoke(self, message):
      message(self)

    def invokeGroup(self, method_id, message_list):
      # Invoke a group method.
      object_list = []
      expanded_object_list = []
      new_message_list = []
      path_dict = {}
      # Filter the list of messages. If an object is not available, ignore such a message.
      # In addition, expand an object if necessary, and make sure that no duplication happens.
      for m in message_list:
        # alternate method is used to segregate objects which cannot be grouped.
        alternate_method_id = m.activity_kw.get('alternate_method_id')
        try:
          obj = m.getObject(self)
          i = len(new_message_list) # This is an index of this message in new_message_list.
          if m.hasExpandMethod():
            for subobj in m.getObjectList(self):
              path = subobj.getPath()
              if path not in path_dict:
                path_dict[path] = i
                if alternate_method_id is not None \
                   and hasattr(aq_base(subobj), alternate_method_id):
                  # if this object is alternated, generate a new single active object.
                  activity_kw = m.activity_kw.copy()
                  if 'group_method_id' in activity_kw:
                    del activity_kw['group_method_id']
                  if 'group_id' in activity_kw:
                    del activity_kw['group_id']                    
                  active_obj = subobj.activate(**activity_kw)
                  getattr(active_obj, alternate_method_id)(*m.args, **m.kw)
                else:
                  expanded_object_list.append(subobj)
          else:
            path = obj.getPath()
            if path not in path_dict:
              path_dict[path] = i
              if alternate_method_id is not None \
                  and hasattr(aq_base(obj), alternate_method_id):
                # if this object is alternated, generate a new single active object.
                activity_kw = m.activity_kw.copy()
                if 'group_method_id' in activity_kw:
                  del activity_kw['group_method_id']
                active_obj = obj.activate(**activity_kw)
                getattr(active_obj, alternate_method_id)(*m.args, **m.kw)
              else:
                expanded_object_list.append(obj)
          object_list.append(obj)
          new_message_list.append(m)
        except:
          m.is_executed = 0
          m.exc_type = sys.exc_info()[0]
          LOG('WARNING ActivityTool', 0,
              'Could not call method %s on object %s' %
              (m.method_id, m.object_path), error=sys.exc_info())

      try:
        if len(expanded_object_list) > 0:
          method = self.unrestrictedTraverse(method_id)
          # FIXME: how to apply security here?
          # NOTE: expanded_object_list must be set to failed objects by the callee.
          #       If it fully succeeds, expanded_object_list must be empty when returning.
          result = method(expanded_object_list, **m.kw)
        else:
          result = None
      except:
        # In this case, the group method completely failed.
        for m in new_message_list:
          m.is_executed = 0
          m.exc_type = sys.exc_info()[0]
        LOG('WARNING ActivityTool', 0,
            'Could not call method %s on objects %s' %
            (method_id, expanded_object_list), error=sys.exc_info())
      else:
        # Obtain all indices of failed messages. Note that this can be a partial failure.
        failed_message_dict = {}
        for obj in expanded_object_list:
          path = obj.getPath()
          i = path_dict[path]
          failed_message_dict[i] = None

        # Only for succeeded messages, an activity process is invoked (if any).
        for i in xrange(len(object_list)):
          object = object_list[i]
          m = new_message_list[i]
          if i in failed_message_dict:
            m.is_executed = 0
            LOG('ActivityTool', WARNING,
                'the method %s partially failed on object %s' %
                (m.method_id, m.object_path,))
          else:
            try:
              m.activateResult(self, result, object)
              m.is_executed = 1
            except:
              m.is_executed = 0
              m.exc_type = sys.exc_info()[0]
              LOG('ActivityTool', WARNING,
                  'Could not call method %s on object %s' % (
                  m.method_id, m.object_path), error=sys.exc_info())

    def newMessage(self, activity, path, active_process,
                   activity_kw, method_id, *args, **kw):
      # Some Security Cheking should be made here XXX
      global is_initialized
      if not is_initialized: self.initialize()
      if getattr(self, '_v_activity_buffer', None) is None:
        self._v_activity_buffer = ActivityBuffer(activity_tool=self)
      activity_dict[activity].queueMessage(aq_inner(self),
        Message(path, active_process, activity_kw, method_id, args, kw))

    security.declareProtected( CMFCorePermissions.ManagePortal, 'manageInvoke' )
    def manageInvoke(self, object_path, method_id, REQUEST=None):
      """
        Invokes all methods for object "object_path"
      """
      if type(object_path) is type(''):
        object_path = tuple(object_path.split('/'))
      self.flush(object_path,method_id=method_id,invoke=1)
      if REQUEST is not None:
        return REQUEST.RESPONSE.redirect('%s/%s' %
                (self.absolute_url(), 'manageActivities'))

    security.declareProtected( CMFCorePermissions.ManagePortal, 'manageCancel' )
    def manageCancel(self, object_path, method_id, REQUEST=None):
      """
        Cancel all methods for object "object_path"
      """
      if type(object_path) is type(''):
        object_path = tuple(object_path.split('/'))
      self.flush(object_path,method_id=method_id,invoke=0)
      if REQUEST is not None:
        return REQUEST.RESPONSE.redirect('%s/%s' %
                (self.absolute_url(), 'manageActivities'))

    security.declareProtected( CMFCorePermissions.ManagePortal,
                               'manageClearActivities' )
    def manageClearActivities(self, keep=1, REQUEST=None):
      """
        Clear all activities and recreate tables.
      """
      folder = getToolByName(self, 'portal_skins').activity

      # Obtain all pending messages.
      message_list = []
      if keep:
        for activity in activity_list:
          if hasattr(activity, 'dumpMessageList'):
            try:
              message_list.extend(activity.dumpMessageList(self))
            except ConflictError:
              raise
            except:
              LOG('ActivityTool', WARNING,
                  'could not dump messages from %s' %
                  (activity,), error=sys.exc_info())

      if getattr(folder, 'SQLDict_createMessageTable', None) is not None:
        try:
          folder.SQLDict_dropMessageTable()
        except ConflictError:
          raise
        except:
          LOG('CMFActivity', WARNING,
              'could not drop the message table',
              error=sys.exc_info())
        folder.SQLDict_createMessageTable()

      if getattr(folder, 'SQLQueue_createMessageTable', None) is not None:
        try:
          folder.SQLQueue_dropMessageTable()
        except ConflictError:
          raise
        except:
          LOG('CMFActivity', WARNING,
              'could not drop the message queue table',
              error=sys.exc_info())
        folder.SQLQueue_createMessageTable()

      # Reactivate the messages.
      for m in message_list:
        try:
          m.reactivate(aq_inner(self))
        except ConflictError:
          raise
        except:
          LOG('ActivityTool', WARNING,
              'could not reactivate the message %r, %r' %
              (m.object_path, m.method_id), error=sys.exc_info())

      if REQUEST is not None:
        return REQUEST.RESPONSE.redirect('%s/%s' % (self.absolute_url(),
          'manageActivitiesAdvanced?manage_tabs_message=Activities%20Cleared'))

    security.declarePublic('getMessageList')
    def getMessageList(self,**kw):
      """
        List messages waiting in queues
      """
      # Initialize if needed
      if not is_initialized: self.initialize()

      message_list = []
      for activity in activity_list:
        try:
          message_list += activity.getMessageList(aq_inner(self),**kw)
        except AttributeError:
          LOG('getMessageList, could not get message from Activity:',0,activity)
      return message_list

    security.declarePublic('countMessageWithTag')
    def countMessageWithTag(self, value):
      """
        Return the number of messages which match the given tag.
      """
      message_count = 0
      for activity in activity_list:
        message_count += activity.countMessageWithTag(aq_inner(self), value)
      return message_count

    security.declarePublic('countMessage')
    def countMessage(self, **kw):
      """
        Return the number of messages which match the given parameter.

        Parameters allowed:

        method_id : the id of the method
        path : for activities on a particular object
        tag : activities with a particular tag
        message_uid : activities with a particular uid
      """
      message_count = 0
      for activity in activity_list:
        message_count += activity.countMessage(aq_inner(self), **kw)
      return message_count

    security.declareProtected( CMFCorePermissions.ManagePortal , 'newActiveProcess' )
    def newActiveProcess(self, **kw):
      from ActiveProcess import addActiveProcess
      new_id = str(self.generateNewId())
      addActiveProcess(self, new_id)
      active_process = self._getOb(new_id)
      active_process.edit(**kw)
      return active_process

    def reindexObject(self):
      self.immediateReindexObject()

    # Active synchronisation methods
    security.declarePrivate('validateOrder')
    def validateOrder(self, message, validator_id, validation_value):
      message_list = self.getDependentMessageList(message, validator_id, validation_value)
      return len(message_list) > 0

    security.declarePrivate('getDependentMessageList')
    def getDependentMessageList(self, message, validator_id, validation_value):
      global is_initialized
      if not is_initialized: self.initialize()
      message_list = []
      method_id = "_validate_%s" % validator_id
      for activity in activity_list:
        method = getattr(activity, method_id, None)
        if method is not None:
          result = method(aq_inner(self), message, validation_value)
          if result:
            message_list.extend([(activity, m) for m in result])
      return message_list

    # Required for tests (time shift)
    def timeShift(self, delay):
      global is_initialized
      if not is_initialized: self.initialize()
      for activity in activity_list:
        activity.timeShift(aq_inner(self), delay)

InitializeClass(ActivityTool)