/**

  * 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.kim.impl.common.attribute;

 import org.kuali.rice.core.api.criteria.CriteriaValue;

 import org.kuali.rice.core.api.criteria.LookupCustomizer;

 import org.kuali.rice.core.api.criteria.MultiValuedPredicate;

 import org.kuali.rice.core.api.criteria.Predicate;

 import org.kuali.rice.core.api.criteria.PropertyPathPredicate;

 import org.kuali.rice.core.api.criteria.SingleValuedPredicate;

 import java.util.ArrayList;

 import java.util.List;

 import java.util.Set;

 import java.util.regex.Matcher;

 import java.util.regex.Pattern;

 import static org.kuali.rice.core.api.criteria.PredicateFactory.*;

 /**

  * this is an internal class used by kim service implementations that have generic lookup methods for classes

  * with "attributes".

  */

 public final class AttributeTransform implements LookupCustomizer.Transform<Predicate, Predicate> {

     private static final LookupCustomizer.Transform<Predicate, Predicate> INSTANCE = new AttributeTransform();

     private static final String ATTRIBUTE_DETAILS_ATTRIBUTE_VALUE = "attributeDetails.attributeValue";

     private static final String ATTRIBUTE_DETAILS_ATTRIBUTE_NAME = "attributeDetails.kimAttribute.attributeName";

     private static final String ATTRIBUTES_REGEX = "^attributes\\[\\w*\\]$";

     private static final Pattern ATTRIBUTES_PATTERN = Pattern.compile(ATTRIBUTES_REGEX);

     private AttributeTransform() {

     }

     @Override

     public Predicate apply(final Predicate input) {

         if (input instanceof PropertyPathPredicate) {

             String pp = ((PropertyPathPredicate) input).getPropertyPath();

             if (isAttributesPredicate(pp)) {

                 final String attributeName = pp.substring(pp.indexOf('[') + 1, pp.indexOf(']'));

                 final Predicate attrValue;

                 if (input instanceof SingleValuedPredicate) {

                     final CriteriaValue<?> value = ((SingleValuedPredicate) input).getValue();

                     attrValue = dynConstruct(input.getClass().getSimpleName(), ATTRIBUTE_DETAILS_ATTRIBUTE_VALUE, value.getValue());

                 } else if (input instanceof MultiValuedPredicate) {

                     final Set<? extends CriteriaValue<?>> values = ((MultiValuedPredicate) input).getValues();

                     List<Object> l = new ArrayList<Object>();

                     for (CriteriaValue<?> v : values) {

                         l.add(v.getValue());

                     }

                     attrValue = dynConstruct(input.getClass().getSimpleName(), ATTRIBUTE_DETAILS_ATTRIBUTE_VALUE, l.toArray());

                 } else {

                     attrValue = dynConstruct(input.getClass().getSimpleName(), ATTRIBUTE_DETAILS_ATTRIBUTE_VALUE);

                 }

                 return and(equal(ATTRIBUTE_DETAILS_ATTRIBUTE_NAME, attributeName), attrValue);

             }

         }

         return input;

     }

     private boolean isAttributesPredicate(String pp) {

         Matcher matcher = ATTRIBUTES_PATTERN.matcher(pp);

         return matcher.matches();

     }

     public static LookupCustomizer.Transform<Predicate, Predicate> getInstance() {

         return INSTANCE;

     }

 }