##############################################################################
#
# Copyright (c) 2002, 2005 Nexedi SARL and Contributors. All Rights Reserved.
#                    Sebastien Robin <seb@nexedi.com>
#                    Romain Courteaud <romain@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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# 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
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# 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.
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# 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.
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##############################################################################

from Constraint import Constraint

class CategoryMembershipArity(Constraint):
  """
    This constraint checks if an object respects the arity.

    For example we can check if every Order has at least one source.
    Configuration example:
    { 'id'            : 'source',
      'description'   : '',
      'type'          : 'CategoryMembershipArity',
      'min_arity'     : '1',
      'max_arity'     : '1',
      'portal_type'   : ('Organisation', ),
      'base_category' : ('source',)
      'condition'     : 'python: object.getPortalType() == 'Foo',
    },
  """

  _message_id_list = ['message_arity_too_small',
                   'message_arity_not_in_range',
                   'message_arity_with_portal_type_to_small',
                   'message_arity_with_portal_type_not_in_range']

  message_arity_too_small = "Arity Error for Relation ${base_category}"\
                          ", arity is equal to ${current_arity} but "\
                          "should be at least ${min_arity}"
  message_arity_not_in_range = "Arity Error for Relation ${base_category}"\
                          ", arity is equal to ${current_arity} but "\
                          "should be between ${min_arity} and ${max_arity}"
  message_arity_with_portal_type_to_small = "Arity Error for Relation"\
                          " ${base_category} and Type ${portal_type}"\
                          ", arity is equal to ${current_arity} but "\
                          "should be at least ${min_arity}"

  message_arity_with_portal_type_not_in_range = "Arity Error for Relation"\
                          " ${base_category} and Type ${portal_type}"\
                          ", arity is equal to ${current_arity} but "\
                          "should be between ${min_arity} and ${max_arity}"

  def _calculateArity(self, obj):
    base_category = self.constraint_definition['base_category']
    portal_type = self.constraint_definition['portal_type']
    return len(obj.getCategoryMembershipList(base_category,
                                              portal_type=portal_type))

  def _checkConsistency(self, obj, fixit=0):
    """Check the object's consistency.
      We are looking the definition of the constraing where
      are defined the minimum and the maximum arity, and the
      list of objects we wants to check the arity.
    """
    error_list = []
    # Retrieve configuration values from PropertySheet (_constraints)
    base_category = self.constraint_definition['base_category']
    min_arity = int(self.constraint_definition['min_arity'])
    max_arity = None
    if 'max_arity' in self.constraint_definition:
      max_arity = int(self.constraint_definition['max_arity'])
    portal_type = self.constraint_definition['portal_type']
    # Check arity and compare it with the min and max
    arity = self._calculateArity(obj)
    if not (max_arity is None and (min_arity <= arity)
        or (min_arity <= arity <= max_arity)):
      mapping = dict(base_category=base_category,
                     portal_type=str(portal_type),
                     current_arity=arity,
                     min_arity=min_arity,
                     max_arity=max_arity,)
      # Generate error message
      if portal_type is not ():
        if max_arity is None:
          message_id = 'message_arity_with_portal_type_to_small'
        else:
          message_id = 'message_arity_with_portal_type_not_in_range'
      else:
        if max_arity is None:
          message_id = 'message_arity_too_small'
        else:
          message_id = 'message_arity_not_in_range'

      # Add error
      error_list.append(self._generateError(obj,
                              self._getMessage(message_id), mapping))
    return error_list
