/*******************************************************************************
 * Copyright 2017 Capital One Services, LLC and Bitwise, 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 hydrograph.engine.transformation.userfunctions.cumulate;

import hydrograph.engine.transformation.userfunctions.base.CumulateTransformBase;
import hydrograph.engine.transformation.userfunctions.base.ReusableRow;

import java.util.ArrayList;
import java.util.Properties;
/**
 * The Class StringAppend.
 *
 * @author Bitwise
 *
 */
public class StringAppend implements CumulateTransformBase {

	private String appended = null;
	public static final String DEFAULT_FILLER = ",";
	private String filler = DEFAULT_FILLER;

	@Override
	public void prepare(Properties props, ArrayList<String> inputFields,
			ArrayList<String> outputFields, ArrayList<String> keyFields) {
		if (props != null) {
		filler = props.getProperty("filler") == null ? filler : props
				.getProperty("filler");
		}
	}

	@Override
	public void cumulate(ReusableRow input, ReusableRow output) {
		if (appended == null) {
			appended = input.getString(0);
		} else {
			appended = appended + filler + input.getString(0);
		}
		output.setField(0, appended);

	}

	@Override
	public void onCompleteGroup() {
		appended = null;

	}

	@Override
	public void cleanup() {
		appended = null;

	}

}