/*******************************************************************************
 * ============LICENSE_START====================================================
 * * org.onap.aaf
 * * ===========================================================================
 * * Copyright © 2017 AT&T Intellectual Property. All rights reserved.
 * * ===========================================================================
 * * 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.
 * * ============LICENSE_END====================================================
 * *
 * * ECOMP is a trademark and service mark of AT&T Intellectual Property.
 * *
 ******************************************************************************/
package org.onap.aaf.rosetta.marshal;

import java.util.Iterator;
import java.util.List;

import org.onap.aaf.rosetta.Ladder;
import org.onap.aaf.rosetta.Marshal;
import org.onap.aaf.rosetta.ParseException;
import org.onap.aaf.rosetta.Parsed;


public abstract class FieldArray<T,S> extends Marshal<T> {
	private DataWriter<S> dataWriter;
	private String name;

	public FieldArray(String name, DataWriter<S> dw) {
		this.name = name;
		dataWriter = dw;
	}
	
	@SuppressWarnings("unchecked")
	@Override
	public Parsed<State> parse(T t, Parsed<State> parsed) throws ParseException {
		Ladder<Iterator<?>> ladder = parsed.state.ladder;
		Iterator<?> iter = ladder.peek();
		if(iter==null) {
			List<S> list = data(t);
			if(list.isEmpty() && parsed.state.smallest) {
				ladder.push(DONE_ITERATOR);
			} else {
				ladder.push(new ListIterator<S>(list));
				parsed.event = START_ARRAY;
				parsed.name = name;
			}
		} else if (DONE_ITERATOR.equals(iter)) {
		} else {
			ladder.ascend(); // look at field info
				Iterator<?> memIter = ladder.peek();
				ListIterator<S> mems = (ListIterator<S>)iter;
				S mem;
				if(memIter==null) {
					mem=mems.next();
				} else if(!DONE_ITERATOR.equals(memIter)) {
					mem=mems.peek();
				} else if(iter.hasNext()) {
					mem=null;
					ladder.push(null);
				} else {
					mem=null;
				}
				
				if(mem!=null) {
					parsed.isString=dataWriter.write(mem, parsed.sb);
					parsed.event = NEXT;
				}
			ladder.descend();
			if(mem==null) {
				if(iter.hasNext()) {
					parsed.event = NEXT;
				} else {
					parsed.event = END_ARRAY;
					ladder.push(DONE_ITERATOR);
				}
			}
		}
		return parsed; // if unchanged, then it will end process
	}

	protected abstract List<S> data(T t);

}