/*
* Copyright 2013 Bazaarvoice, Inc.
*
* Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0
*
* 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 com.bazaarvoice.jolt.cardinality;
import com.bazaarvoice.jolt.common.WalkedPath;
import com.bazaarvoice.jolt.common.pathelement.LiteralPathElement;
import com.bazaarvoice.jolt.exception.SpecException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
/**
* Leaf level CardinalitySpec object.
* <p/>
* If this CardinalitySpec's PathElement matches the input (successful parallel tree walk)
* this CardinalitySpec has the information needed to write the given data to the output object.
*/
public class CardinalityLeafSpec extends CardinalitySpec {
public enum CardinalityRelationship {
ONE,
MANY
}
private CardinalityRelationship cardinalityRelationship;
public CardinalityLeafSpec( String rawKey, Object rhs ) {
super( rawKey );
try {
cardinalityRelationship = CardinalityRelationship.valueOf( rhs.toString() );
}
catch( Exception e ) {
throw new SpecException( "Invalid Cardinality type :" + rhs.toString(), e );
}
}
/**
* If this CardinalitySpec matches the inputkey, then do the work of modifying the data and return true.
*
* @return true if this this spec "handles" the inputkey such that no sibling specs need to see it
*/
@Override
public boolean apply( String inputKey, Object input, WalkedPath walkedPath, Object parentContainer ) {
LiteralPathElement thisLevel = getMatch( inputKey, walkedPath );
if ( thisLevel == null ) {
return false;
}
performCardinalityAdjustment( inputKey, input, walkedPath, (Map) parentContainer, thisLevel );
return true;
}
/**
* This should only be used by composite specs with an '@' child
*
* @return null if no work was done, otherwise returns the re-parented data
*/
public Object applyToParentContainer ( String inputKey, Object input, WalkedPath walkedPath, Object parentContainer ) {
LiteralPathElement thisLevel = getMatch( inputKey, walkedPath );
if ( thisLevel == null ) {
return null;
}
return performCardinalityAdjustment( inputKey, input, walkedPath, (Map) parentContainer, thisLevel );
}
/**
*
* @return null if no work was done, otherwise returns the re-parented data
*/
private Object performCardinalityAdjustment( String inputKey, Object input, WalkedPath walkedPath, Map parentContainer, LiteralPathElement thisLevel ) {
// Add our the LiteralPathElement for this level, so that write path References can use it as &(0,0)
walkedPath.add( input, thisLevel );
Object returnValue = null;
if ( cardinalityRelationship == CardinalityRelationship.MANY ) {
if ( input instanceof List ) {
returnValue = input;
}
else if ( input instanceof Map || input instanceof String || input instanceof Number || input instanceof Boolean ) {
Object one = parentContainer.remove( inputKey );
returnValue = new ArrayList<Object>();
( (List) returnValue ).add( one );
}
else if ( input == null ) {
returnValue = Collections.emptyList();
}
parentContainer.put( inputKey, returnValue );
}
else if ( cardinalityRelationship == CardinalityRelationship.ONE ) {
if ( input instanceof List ) {
if (!( (List) input ).isEmpty()) {
returnValue = ( (List) input ).get( 0 );
}
parentContainer.put( inputKey, returnValue );
}
}
walkedPath.removeLast();
return returnValue;
}
private LiteralPathElement getMatch( String inputKey, WalkedPath walkedPath ) {
return pathElement.match( inputKey, walkedPath );
}
}