/*******************************************************************************
 * 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.core.utilities;

import hydrograph.engine.core.component.utils.SafeResourceClose;
import hydrograph.engine.core.props.OrderedProperties;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.InputStream;

/**
 * The Class OrderedPropertiesHelper.
 *
 * @author Bitwise
 */
public class OrderedPropertiesHelper {
	private static Logger LOG = LoggerFactory
			.getLogger(OrderedPropertiesHelper.class);

	/**
	 * Constructor marked as private to disable instantiation
	 */
	private OrderedPropertiesHelper() {

	}

	/**
	 * Reads the property file and returns an object of
	 * {@link OrderedProperties} class for that property file.
	 * 
	 * @param propertyFileName
	 *            the properties file for whom the
	 *            <code>OrderedProperties</code> object is to be retrieved.
	 * @return an object of {@link OrderedProperties} class for that property
	 *         file.
	 * @throws IOException
	 *             if there is a problem reading the properties file.
	 */
	public static OrderedProperties getOrderedProperties(String propertyFileName)
			throws IOException {
		LOG.trace("Entering method : 'getProperties', file name: '"
				+ propertyFileName + "'");
		OrderedProperties properties = new OrderedProperties();
		InputStream in = ClassLoader
				.getSystemResourceAsStream(propertyFileName);
		try {
			properties.load(in);
			LOG.trace("Property file name: '" + propertyFileName
					+ "' successfully loaded.");
		} catch (IOException e) {
			LOG.error("Error reading properties file: '" + propertyFileName
					+ "'");
			throw new RuntimeException(e);
		} finally {
			try {
				SafeResourceClose.safeInputStreamClose(in);
			} catch (IOException e) {
				// Exception not thrown as properties file was already read. An
				// exception in closing input stream will
				// cause a memory leak, however, the desired functionality works
				LOG.warn("Exception in closing input stream for properties file: '"
						+ propertyFileName + "'", e);
			}
		}

		return properties;
	}

}