/*
 * 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 de.unioninvestment.eai.portal.portlet.crud.domain.container;

import java.util.List;

import de.unioninvestment.eai.portal.portlet.crud.domain.model.TableColumn;
import de.unioninvestment.eai.portal.portlet.crud.domain.model.TableColumns;
import de.unioninvestment.eai.portal.portlet.crud.domain.model.ValuesRow;
import de.unioninvestment.eai.portal.portlet.crud.domain.model.container.StreamItem;
import de.unioninvestment.eai.portal.portlet.crud.domain.model.container.StreamItemValuesRow;

/**
 * Wrapper around {@link StreamItem} to add generated column values.
 * 
 * @author cmj
 */
public class GeneratedColumnsStreamItemWrapper implements StreamItem {

	private final StreamItem delegate;
	private final List<String> columnNames;
	private final TableColumns columns;

	private ValuesRow row;

	public GeneratedColumnsStreamItemWrapper(StreamItem delegate,
			List<String> columnNames, TableColumns columns) {
		this.delegate = delegate;
		this.columnNames = columnNames;
		this.columns = columns;
	}

	@Override
	public Object getValue(String columnName) {
		if (columns != null) {
			TableColumn tableColumn = columns.get(columnName);
			if (tableColumn != null && tableColumn.isGenerated()) {
				if (tableColumn.getGeneratedValueGenerator() != null) {
					if (row == null) {
						row = new StreamItemValuesRow(columnNames, delegate);
					}
					return tableColumn.getGeneratedValueGenerator().getValue(row);
				} else {
					return null;
				}
			}
		}
		return delegate.getValue(columnName);
	}
}