RemovrLeafSpec.java

/*
 * 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.removr.spec;

import com.bazaarvoice.jolt.common.pathelement.LiteralPathElement;
import com.bazaarvoice.jolt.common.pathelement.StarAllPathElement;
import com.bazaarvoice.jolt.common.pathelement.StarPathElement;

import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

/**
 * Spec for handling the leaf level of the Removr Transform.
 */
public class RemovrLeafSpec extends RemovrSpec {

    public RemovrLeafSpec( String rawKey ) {
        super( rawKey );
    }

    /**
     * Build a list of keys to remove from the input map, using the pathElement
     *  from the Spec.
     *
     * @param inputMap : Input map from which the spec key needs to be removed.
     */
    @Override
    public List<String> applyToMap( Map<String, Object> inputMap ) {
        if ( inputMap == null ) {
            return null;
        }

        List<String> keysToBeRemoved = new LinkedList<>();

        if ( pathElement instanceof LiteralPathElement ) {

            // if we are a literal, check to see if we match
            if ( inputMap.containsKey( pathElement.getRawKey() ) ) {
                keysToBeRemoved.add( pathElement.getRawKey() );
            }
        }
        else if ( pathElement instanceof StarPathElement ) {

            StarPathElement star = (StarPathElement) pathElement;

            // if we are a wildcard, check each input key to see if it matches us
            for( String key : inputMap.keySet() ) {

                if ( star.stringMatch( key ) ) {
                    keysToBeRemoved.add( key );
                }
            }
        }

        return keysToBeRemoved;
    }

    /**
     * @param inputList : Input List from which the spec key needs to be removed.
     */
    @Override
    public List<Integer> applyToList( List<Object> inputList ) {
        if ( inputList == null ) {
            return null;
        }

        if ( pathElement instanceof LiteralPathElement ) {

            Integer pathElementInt = getNonNegativeIntegerFromLiteralPathElement();

            if ( pathElementInt != null && pathElementInt < inputList.size() ) {
                return Collections.singletonList( pathElementInt );
            }
        }
        else if ( pathElement instanceof StarAllPathElement ) {

            // To be clear, this is kinda silly.
            // If you just wanted to remove the whole list, you could have just
            //  directly removed it, instead of stepping into it and using the "*".
            List<Integer> toReturn = new ArrayList<>( inputList.size() );
            for( int index = 0; index < inputList.size(); index++ ) {
                toReturn.add( index );
            }

            return toReturn;
        }
        // else the pathElement is some other kind which is not supported when running
        //  against arrays, aka "tuna*" makes no sense against a list.


        return Collections.emptyList();
    }
}