/*

  * Copyright 2011 The Kuali Foundation

  *

  * Licensed under the Educational Community License, Version 1.0 (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/ecl1.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 java.util.Collection;

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

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

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

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

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

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

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

 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;

 /**

  * This class validates attributes that are collection size constrained - ones that can only have between x and y number 

  * 

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

  */

 public class CollectionSizeConstraintProcessor implements CollectionConstraintProcessor<Collection<?>, CollectionSizeConstraint> {

         private static final String CONSTRAINT_NAME = "collection size constraint";

         /**

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

          */

         @Override

         public ProcessorResult process(DictionaryValidationResult result, Collection<?> collection, CollectionSizeConstraint 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 collection size constrained only provides a single max and minimum, there is effectively a single constraint

                 // being imposed.

         return new ProcessorResult(processSingleCollectionSizeConstraint(result, collection, 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 CollectionSizeConstraint.class;

         }

         /**

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

          */

         @Override

         public boolean isOptional() {

                 return false;

         }

         protected ConstraintValidationResult processSingleCollectionSizeConstraint(DictionaryValidationResult result, Collection<?> collection, CollectionSizeConstraint constraint, AttributeValueReader attributeValueReader) throws AttributeValidationException {

                 Integer sizeOfCollection = Integer.valueOf(collection.size());

                 Integer maxOccurances = constraint.getMaximumNumberOfElements();

                 Integer minOccurances = constraint.getMinimumNumberOfElements();

                 Result lessThanMax = ValidationUtils.isLessThanOrEqual(sizeOfCollection, maxOccurances);

                 Result greaterThanMin = ValidationUtils.isGreaterThanOrEqual(sizeOfCollection, minOccurances);

                 // It's okay for one end of the range to be undefined - that's not an error. It's only an error if one of them is invalid 

         if (lessThanMax != Result.INVALID && greaterThanMin != Result.INVALID) { 

                 // Of course, if they're both undefined then we didn't actually have a real constraint

                 if (lessThanMax == Result.UNDEFINED && greaterThanMin == Result.UNDEFINED)

                         return result.addNoConstraint(attributeValueReader, CONSTRAINT_NAME);

                 // In this case, we've succeeded

                 return result.addSuccess(attributeValueReader, CONSTRAINT_NAME);

         }

                 String maxErrorParameter = maxOccurances != null ? maxOccurances.toString() : null;

                 String minErrorParameter = minOccurances != null ? minOccurances.toString() : null;

         // If both comparisons happened then if either comparison failed we can show the end user the expected range on both sides.

         if (lessThanMax != Result.UNDEFINED && greaterThanMin != Result.UNDEFINED) 

                 return result.addError(attributeValueReader, CONSTRAINT_NAME, RiceKeyConstants.ERROR_QUANTITY_RANGE, minErrorParameter, maxErrorParameter);

         // If it's the max comparison that fails, then just tell the end user what the max can be

         else if (lessThanMax == Result.INVALID)

                 return result.addError(attributeValueReader, CONSTRAINT_NAME, RiceKeyConstants.ERROR_MAX_OCCURS, maxErrorParameter);

         // Otherwise, just tell them what the min can be

         else 

                 return result.addError(attributeValueReader, CONSTRAINT_NAME, RiceKeyConstants.ERROR_MIN_OCCURS, minErrorParameter);

         // Obviously the last else above is unnecessary, since anything after it is dead code, but keeping it seems clearer than dropping it

         }

 }