##############################################################################
#
# Copyright (c) 2006 Nexedi SARL and Contributors. All Rights Reserved.
#             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
# 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.
#
##############################################################################

from Products.ERP5Type.mixin.constraint import ConstraintMixin

class TransactionQuantityValueFeasabilityConstraint(ConstraintMixin):
  """
  Check if the quantity of the transaction is possible
  for the source and the destination

  This is only relevant for ZODB Property Sheets (filesystem Property
  Sheets rely on Products.ERP5.Constraint.TransactionQuantityValueFeasability
  instead).
  """
  meta_type = 'ERP5 Transaction Quantity Value Feasability Constraint'
  portal_type = 'Transaction Quantity Value Feasability Constraint'

  def _checkConsistency(self, obj, fixit=0, **_):
    """
    Check if the quantity of the transaction is possible
    for the source and the destination
    """
    errors = []
    source_cell = obj.getSourceValue()
    destination_cell = obj.getDestinationValue()
    # Check for source and destination
    for node, sign, node_title in ((source_cell, 1, 'source'),
                                   (destination_cell, -1, 'destination')):
      # As the quantity can change a few lines letter,
      # we need to get it each time.
      object_quantity = obj.getQuantity()
      quantity = object_quantity * sign
      if node is not None:
        balance = node.getCurrentBalance()
        is_transaction_ok = 1
        # Check if balance and quantity have the same sign
        if ((balance < 0) and (quantity < 0)):
          if balance > quantity:
            is_transaction_ok = 0
        elif ((balance >= 0) and (quantity >= 0)):
          if balance < quantity:
            is_transaction_ok = 0
        # Raise error
        if not is_transaction_ok:
          if fixit != 0:
            obj.setQuantity(balance)
          else:
            error_message = 'The quantity "%s" of the transaction is not ' \
                            'compatible with budget "%s" defined on the ' \
                            '%s "%s".' % \
                            (object_quantity, balance, node_title, node)
            # Add error
            errors.append(self._generateError(obj, error_message))
    return errors