/**

  * Copyright 2005-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  * http://www.opensource.org/licenses/ecl2.php

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.kuali.rice.krad.datadictionary.validation.processor;

 import org.kuali.rice.core.api.util.RiceKeyConstants;

 import org.kuali.rice.krad.datadictionary.DataObjectEntry;

 import org.kuali.rice.krad.datadictionary.exception.AttributeValidationException;

 import org.kuali.rice.krad.datadictionary.validation.AttributeValueReader;

 import org.kuali.rice.krad.datadictionary.validation.DictionaryObjectAttributeValueReader;

 import org.kuali.rice.krad.datadictionary.validation.ValidationUtils;

 import org.kuali.rice.krad.datadictionary.validation.constraint.Constraint;

 import org.kuali.rice.krad.datadictionary.validation.constraint.ExistenceConstraint;

 import org.kuali.rice.krad.datadictionary.validation.result.ConstraintValidationResult;

 import org.kuali.rice.krad.datadictionary.validation.result.DictionaryValidationResult;

 import org.kuali.rice.krad.datadictionary.validation.result.ProcessorResult;

 /**

  * 

  * @author Kuali Rice Team (rice.collab@kuali.org) 

  */

 public class ExistenceConstraintProcessor extends OptionalElementConstraintProcessor<ExistenceConstraint> {

         private static final String CONSTRAINT_NAME = "existence constraint";

         /**

          * @see org.kuali.rice.krad.datadictionary.validation.processor.ConstraintProcessor#process(DictionaryValidationResult, Object, org.kuali.rice.krad.datadictionary.validation.Validatable, org.kuali.rice.krad.datadictionary.validation.AttributeValueReader)

          */

         @Override

         public ProcessorResult process(DictionaryValidationResult result, Object value, ExistenceConstraint constraint, AttributeValueReader attributeValueReader) throws AttributeValidationException {

                 // To accommodate the needs of other processors, the ConstraintProcessor.process() method returns a list of ConstraintValidationResult objects

                 // but since a definition that is existence constrained only provides a single isRequired field, there is effectively a single constraint

                 // being imposed.

                 return new ProcessorResult(processSingleExistenceConstraint(result, value, constraint, attributeValueReader));

         }

         @Override 

         public String getName() {

                 return CONSTRAINT_NAME;

         }

         /**

          * @see org.kuali.rice.krad.datadictionary.validation.processor.ConstraintProcessor#getConstraintType()

          */

         @Override

         public Class<? extends Constraint> getConstraintType() {

                 return ExistenceConstraint.class;

         }

         protected ConstraintValidationResult processSingleExistenceConstraint(DictionaryValidationResult result, Object value, ExistenceConstraint constraint, AttributeValueReader attributeValueReader) throws AttributeValidationException {

                 // If it's not set, then there's no constraint

                 if (constraint.isRequired() == null)

                         return result.addNoConstraint(attributeValueReader, CONSTRAINT_NAME);

                 if (constraint.isRequired().booleanValue() && !skipConstraint(attributeValueReader)) {

                         // If this attribute is required and the value is null then 

                         if (ValidationUtils.isNullOrEmpty(value)) 

                                 return result.addError(attributeValueReader, CONSTRAINT_NAME, RiceKeyConstants.ERROR_REQUIRED);

                         return result.addSuccess(attributeValueReader, CONSTRAINT_NAME);

                 }

                 return result.addSkipped(attributeValueReader, CONSTRAINT_NAME);

         }

     /**

      * Checks to see if existence constraint should be skipped.  Required constraint should be skipped if it is an attribute of a complex

      * attribute and the complex attribute is not required.

      * 

      * @param attributeValueReader

      * @return

      */

     private boolean skipConstraint(AttributeValueReader attributeValueReader) {

         boolean skipConstraint = false;

         if (attributeValueReader instanceof DictionaryObjectAttributeValueReader){

             DictionaryObjectAttributeValueReader dictionaryValueReader = (DictionaryObjectAttributeValueReader)attributeValueReader;

             skipConstraint = dictionaryValueReader.isNestedAttribute() && dictionaryValueReader.isParentAttributeNull();

         }

         return skipConstraint;

     }

 }