/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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.googlecode.openbeans;

import com.googlecode.openbeans.DefaultPersistenceDelegate;
import com.googlecode.openbeans.Encoder;
import com.googlecode.openbeans.Expression;
import com.googlecode.openbeans.PersistenceDelegate;
import com.googlecode.openbeans.Statement;

import javax.swing.DefaultComboBoxModel;


class SwingDefaultComboBoxModelPersistenceDelegate extends
		DefaultPersistenceDelegate {
    @Override
    @SuppressWarnings({ "nls", "boxing" })
    protected void initialize(Class<?> type, Object oldInstance,
			Object newInstance, Encoder enc) {
		super.initialize(type, oldInstance, newInstance, enc);

		DefaultComboBoxModel model = (DefaultComboBoxModel) oldInstance;

		int count = model.getSize();
		Expression getterExp = null;
		for (int i = 0; i < count; i++) {
			getterExp = new Expression(model, "getElementAt", new Object[] { i });
			try {
				// Calculate the old value of the property
				Object oldVal = getterExp.getValue();
				// Write the getter expression to the encoder
				enc.writeExpression(getterExp);
				// Get the target value that exists in the new environment
				Object targetVal = enc.get(oldVal);
				// Get the current property value in the new environment
				Object newVal = null;
				try {
					newVal = new Expression(newInstance, "getElementAt",
							new Object[] { i }).getValue();
				} catch (IndexOutOfBoundsException ex) {
					// The newInstance has no elements, so current property
					// value remains null
				}
				/*
				 * Make the target value and current property value equivalent
				 * in the new environment
				 */
				Statement setterStm = null;
				if (null == targetVal) {
					if (null != newVal) {
						// Set to null
						setterStm = new Statement(oldInstance, "addElement",
								new Object[] { null });
						enc.writeStatement(setterStm);
					}
				} else {
					PersistenceDelegate pd = enc
							.getPersistenceDelegate(targetVal.getClass());
					if (!pd.mutatesTo(targetVal, newVal)) {
						setterStm = new Statement(oldInstance, "addElement",
								new Object[] { oldVal });
						enc.writeStatement(setterStm);
					}
				}
			} catch (Exception ex) {
				enc.getExceptionListener().exceptionThrown(ex);
			}
		}
	}
}