##############################################################################
#
# Copyright (c) 2001 Zope Corporation and Contributors. All Rights
# Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL).  A copy of the ZPL should accompany this
# distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
""" Classes: ERP5GroupManager
"""

from Products.ERP5Type.Globals import InitializeClass
from AccessControl import ClassSecurityInfo
from AccessControl.SecurityManagement import newSecurityManager,\
    getSecurityManager, setSecurityManager
from Products.PageTemplates.PageTemplateFile import PageTemplateFile
from Products.PluggableAuthService.plugins.BasePlugin import BasePlugin
from Products.PluggableAuthService.utils import classImplements
from Products.PluggableAuthService.interfaces.plugins import IGroupsPlugin
from Products.ERP5Type.Cache import CachingMethod
from Products.ERP5Type.ERP5Type \
  import ERP5TYPE_SECURITY_GROUP_ID_GENERATION_SCRIPT
from Products.ERP5Type.UnrestrictedMethod import UnrestrictedMethod
from Products.ZSQLCatalog.SQLCatalog import SimpleQuery
from Products.PluggableAuthService.PropertiedUser import PropertiedUser
from ZODB.POSException import ConflictError

import sys

from zLOG import LOG, WARNING

from ERP5UserManager import SUPER_USER

# It can be useful to set NO_CACHE_MODE to 1 in order to debug
# complex security issues related to caching groups. For example,
# the use of scripts instead of external methods for
# assignment category lookup may make the system unstable and
# hard to debug. Setting NO_CACHE_MODE allows to debug such
# issues.
NO_CACHE_MODE = 0

class ConsistencyError(Exception): pass

manage_addERP5GroupManagerForm = PageTemplateFile(
    'www/ERP5Security_addERP5GroupManager', globals(),
    __name__='manage_addERP5GroupManagerForm' )

def addERP5GroupManager( dispatcher, id, title=None, REQUEST=None ):
  """ Add a ERP5GroupManager to a Pluggable Auth Service. """

  egm = ERP5GroupManager(id, title)
  dispatcher._setObject(egm.getId(), egm)

  if REQUEST is not None:
    REQUEST['RESPONSE'].redirect(
                              '%s/manage_workspace'
                              '?manage_tabs_message='
                              'ERP5GroupManager+added.'
                          % dispatcher.absolute_url())

class ERP5GroupManager(BasePlugin):

  """ PAS plugin for dynamically adding Groups
  based on Assignments in ERP5
  """
  meta_type = 'ERP5 Group Manager'

  security = ClassSecurityInfo()

  def __init__(self, id, title=None):

    self._id = self.id = id
    self.title = title

  #
  #   IGroupsPlugin implementation
  #
  def getGroupsForPrincipal(self, principal, request=None):
    """ See IGroupsPlugin.
    """
    # If this is the super user, skip the check.
    if principal.getId() == SUPER_USER:
      return ()

    @UnrestrictedMethod
    def _getGroupsForPrincipal(user_name, path):
      security_category_dict = {} # key is the base_category_list,
                                  # value is the list of fetched categories
      security_group_list = []
      security_definition_list = ()

      try:
        # To get the complete list of groups, we try to call the
        # ERP5Type_getSecurityCategoryMapping which should return a list
        # of lists of two elements (script, base_category_list) like :
        # (
        #   ('script_1', ['base_category_1', 'base_category_2', ...]),
        #   ('script_2', ['base_category_1', 'base_category_3', ...])
        # )
        #
        # else, if the script does not exist, falls back to a list containng
        # only one list :
        # (('ERP5Type_getSecurityCategoryFromAssignment',
        #   self.getPortalAssignmentBaseCategoryList() ),)

        mapping_method = getattr(self,
            'ERP5Type_getSecurityCategoryMapping', None)
        if mapping_method is None:
          security_definition_list = ((
              'ERP5Type_getSecurityCategoryFromAssignment',
              self.getPortalAssignmentBaseCategoryList()
          ),)
        else:
          security_definition_list = mapping_method()

        # get the person from its reference - no security check needed
        catalog_result = self.portal_catalog.unrestrictedSearchResults(
            portal_type="Person", query=SimpleQuery(reference=user_name))
        if len(catalog_result) != 1: # we won't proceed with groups
          if len(catalog_result) > 1: # configuration is screwed
            raise ConsistencyError, 'There is more than one Person whose \
                login is %s : %s' % (user_name,
                repr([r.getObject() for r in catalog_result]))
          else: # no person is linked to this user login
            return ()
        person_object = catalog_result[0].getObject()
        person_id = person_object.getId()

        # Fetch category values from defined scripts
        for (method_name, base_category_list) in security_definition_list:
          base_category_list = tuple(base_category_list)
          method = getattr(self, method_name)
          security_category_list = security_category_dict.setdefault(
                                            base_category_list, [])
          try:
            # The called script may want to distinguish if it is called
            # from here or from _updateLocalRolesOnSecurityGroups.
            # Currently, passing portal_type='' (instead of 'Person')
            # is the only way to make the difference.
            security_category_list.extend(
              method(base_category_list, user_name, person_object, '')
            )
          except ConflictError:
            raise
          except:
            LOG('ERP5GroupManager', WARNING,
                'could not get security categories from %s' % (method_name,),
                error = sys.exc_info())

        # Get group names from category values
        # XXX try ERP5Type_asSecurityGroupIdList first for compatibility
        generator_name = 'ERP5Type_asSecurityGroupIdList'
        group_id_list_generator = getattr(self, generator_name, None)
        if group_id_list_generator is None:
          generator_name = ERP5TYPE_SECURITY_GROUP_ID_GENERATION_SCRIPT
          group_id_list_generator = getattr(self, generator_name)
        for base_category_list, category_value_list in \
            security_category_dict.iteritems():
          for category_dict in category_value_list:
            try:
              group_id_list = group_id_list_generator(
                                        category_order=base_category_list,
                                        **category_dict)
              if isinstance(group_id_list, str):
                group_id_list = [group_id_list]
              security_group_list.extend(group_id_list)
            except ConflictError:
              raise
            except:
              LOG('ERP5GroupManager', WARNING,
                  'could not get security groups from %s' %
                  generator_name,
                  error = sys.exc_info())
      finally:
        pass
      return tuple(security_group_list)

    if not NO_CACHE_MODE:
      _getGroupsForPrincipal = CachingMethod(_getGroupsForPrincipal,
                                             id='ERP5GroupManager_getGroupsForPrincipal',
                                             cache_factory='erp5_content_short')

    return _getGroupsForPrincipal(
                user_name=principal.getId(),
                path=self.getPhysicalPath())


classImplements( ERP5GroupManager
               , IGroupsPlugin
               )

InitializeClass(ERP5GroupManager)
