/*

  * 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.List;

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

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

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

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

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

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

 import org.kuali.rice.krad.datadictionary.validation.capability.Constrainable;

 import org.kuali.rice.krad.datadictionary.validation.capability.HierarchicallyConstrainable;

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

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

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

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

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

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

 import org.kuali.rice.krad.service.KRADServiceLocatorWeb;

 /**

  * This object processes 'case constraints', which are constraints that are imposed only in specific cases, for example, when a value is

  * equal to some constant, or greater than some limit. 

  * 

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

  */

 public class CaseConstraintProcessor extends MandatoryElementConstraintProcessor<CaseConstraint> {

         private static final String CONSTRAINT_NAME = "case constraint";

         /**

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

          */

         @Override

         public ProcessorResult process(DictionaryValidationResult result, Object value, CaseConstraint caseConstraint, AttributeValueReader attributeValueReader) throws AttributeValidationException {

                 // Don't process this constraint if it's null

         if (null == caseConstraint) {

             return new ProcessorResult(result.addNoConstraint(attributeValueReader, CONSTRAINT_NAME));

         }

         String operator = (ValidationUtils.hasText(caseConstraint.getOperator())) ? caseConstraint.getOperator() : "EQUALS";

         AttributeValueReader nestedReader = (ValidationUtils.hasText(caseConstraint.getFieldPath())) ? getChildAttributeValueReader(caseConstraint.getFieldPath(), attributeValueReader) : attributeValueReader;

         // TODO: What happens when the field is not in the dataProvider?

         Constrainable caseField = (null != nestedReader) ? nestedReader.getDefinition(nestedReader.getAttributeName()) : null;

         Object fieldValue = (null != nestedReader) ? nestedReader.getValue(nestedReader.getAttributeName()) : value;

         DataType fieldDataType = (null != caseField && caseField instanceof DataTypeConstraint) ? ((DataTypeConstraint)caseField).getDataType() : null;

         // Default to a string comparison

         if (fieldDataType == null)

                 fieldDataType = DataType.STRING;

         // If fieldValue is null then skip Case check

         if (null == fieldValue) {

                 // FIXME: not sure if the definition and attribute value reader should change under this case

             return new ProcessorResult(result.addSkipped(attributeValueReader, CONSTRAINT_NAME), caseField, nestedReader);

         }

         // Extract value for field Key

         for (WhenConstraint wc : caseConstraint.getWhenConstraint()) {

                 List<Object> whenValueList = wc.getValues();

                 for (Object whenValue : whenValueList) {

                         if (ValidationUtils.compareValues(fieldValue, whenValue, fieldDataType, operator, caseConstraint.isCaseSensitive(), dateTimeService) && null != wc.getConstraint()) {

                                 if (nestedReader != null && wc.getValuePath() != null)

                                         nestedReader.setAttributeName(wc.getValuePath());

                                 return new ProcessorResult(result.addSuccess(nestedReader, CONSTRAINT_NAME), null, nestedReader, wc.getConstraint());

                         }

                 }

         }

         // Assuming that not finding any case constraints is equivalent to 'skipping' the constraint

         return new ProcessorResult(result.addSkipped(attributeValueReader, CONSTRAINT_NAME));

         }

         @Override 

         public String getName() {

                 return CONSTRAINT_NAME;

         }

         /**

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

          */

         @Override

         public Class<? extends Constraint> getConstraintType() {

                 return CaseConstraint.class;

         }

         private AttributeValueReader getChildAttributeValueReader(String key, AttributeValueReader attributeValueReader) throws AttributeValidationException {

                 String[] lookupPathTokens = ValidationUtils.getPathTokens(key);

                 AttributeValueReader localAttributeValueReader = attributeValueReader;

                 for(int i = 0; i < lookupPathTokens.length; i++) {

                         for (Constrainable definition : localAttributeValueReader.getDefinitions()) {

                                 String attributeName = definition.getName();

                                 if (attributeName.equals(lookupPathTokens[i])) {

                                         if(i==lookupPathTokens.length-1){

                                                 localAttributeValueReader.setAttributeName(attributeName);

                                                 return localAttributeValueReader;

                                         }

                                         if (definition instanceof HierarchicallyConstrainable) {

                                                 String childEntryName = ((HierarchicallyConstrainable)definition).getChildEntryName();

                                                 DataDictionaryEntry entry = KRADServiceLocatorWeb.getDataDictionaryService().getDataDictionary().getDictionaryObjectEntry(childEntryName);

                                                 Object value = attributeValueReader.getValue(attributeName);

                                                 attributeValueReader.setAttributeName(attributeName);

                                                 String attributePath = attributeValueReader.getPath();

                                                 localAttributeValueReader = new DictionaryObjectAttributeValueReader(value, childEntryName, entry, attributePath);

                                         } 

                                         break;

                                 }

                         }

                  }

                 return null;

         }

 }