/*
 * Copyright Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags and
 * the COPYRIGHT.txt file distributed with this work.
 *
 * 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 org.teiid.json.simple;

import java.io.IOException;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Stack;

public class SimpleContentHandler implements ContentHandler {
	
	private Stack<Object> stack = new Stack<Object>();
	private Stack<String> nameStack = new Stack<String>();
	private Object result;

	@Override
	public void startJSON() throws ParseException, IOException {
		
	}

	@Override
	public void endJSON() throws ParseException, IOException {
		
	}

	@Override
	public boolean startObject() throws ParseException, IOException {
		Map<String, Object> current = new LinkedHashMap<String, Object>();
		stack.add(current);
		return true;
	}

	@Override
	public boolean endObject() throws ParseException, IOException {
		end(stack.pop());
		return true;
	}

	private void end(Object current) {
		if (!stack.isEmpty() && stack.lastElement() instanceof List) {
			((List)stack.lastElement()).add(current);
		} else {
			result = current;
		}
	}

	@Override
	public boolean startObjectEntry(String key) throws ParseException,
			IOException {
		nameStack.push(key);
		return true;
	}

	@Override
	public boolean endObjectEntry() throws ParseException, IOException {
		Object parent = stack.lastElement();
		((Map<String, Object>)parent).put(nameStack.pop(), result);
		return true;
	}

	@Override
	public boolean startArray() throws ParseException, IOException {
		List<Object> current = new ArrayList<Object>();
		stack.add(current);
		return true;
	}

	@Override
	public boolean endArray() throws ParseException, IOException {
		end(stack.pop());
		return true;
	}

	@Override
	public boolean primitive(Object value) throws ParseException, IOException {
		end(value);
		return true;
	}
	
	public Object getResult() {
		return result;
	}
	
}
