# -*- coding: utf-8 -*-
##############################################################################
#
# Copyright (c) 2002, 2005 Nexedi SARL and Contributors. All Rights Reserved.
#                    Sebastien Robin <seb@nexedi.com>
#                    Jean-Paul Smets <jp@nexedi.com>
#                    Romain Courteaud <romain@nexedi.com>
#                    Nicolas Delaby <nicolas@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
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# Service Company
#
# This program is Free Software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
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# This program is distributed in the hope that it will be useful,
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# You should have received a copy of the GNU General Public License
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# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
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##############################################################################

from Products.CMFCore.Expression import Expression

from Products.ERP5Type import PropertySheet
from Products.ERP5Type.Utils import createExpressionContext
from Products.ERP5Type.Core.PropertyExistenceConstraint import \
		PropertyExistenceConstraint
from Products.ZSQLCatalog.SQLCatalog import Query, NegatedQuery

class AttributeUnicityConstraint(PropertyExistenceConstraint):
  """
    This constraint class allows to check
    attribute unicity.
  """
  meta_type = 'ERP5 Attribute Unicity Constraint'
  portal_type = 'Attribute Unicity Constraint'

  property_sheets = PropertyExistenceConstraint.property_sheets + \
                    (PropertySheet.AttributeUnicityConstraint,)

  _message_id_tuple = ('message_invalid_attribute_unicity',)


  def _checkConsistency(self, obj, fixit=0):
    """Check the object's consistency.
      We will make sure that each non None constraint_definition is 
      satisfied (unicity)
      This Constraint use portal_catalog
    """
    error_list = PropertyExistenceConstraint._checkConsistency(self, obj, 
                                                           fixit=fixit)
    attribute_name = self.getConstraintProperty()
    expression_criterion_dict = self.getFilterParameter()

    message_id = None
    mapping = dict(attribute_name=attribute_name)
    #Evaluate expression_criterion_dict
    expression = Expression(expression_criterion_dict)
    econtext = createExpressionContext(obj)
    criterion_dict = expression(econtext)
    # Add uid in criterion keys to avoid fetching current object.
    criterion_dict['query'] = NegatedQuery(Query(uid=obj.getUid()))
    portal = obj.getPortalObject()
    result = portal.portal_catalog.countResults(**criterion_dict)[0][0]
    if result >= 1:
      mapping['value'] = criterion_dict.get(attribute_name)
      message_id = 'message_invalid_attribute_unicity'
    # Generate error
    if message_id is not None:
      error_list.append(self._generateError(obj,
                      self._getMessage(message_id), mapping))

    return error_list