/*
 * 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.jboss;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.PrivilegedActionException;
import java.util.Properties;

import org.jboss.logging.Logger;

/**
 * Common login module utility methods
 * 
 * @author Scott.Stark@jboss.org
 * @version $Revision: 68749 $
 */
public class Util {
	/**
	 * Utility method which loads the given properties file and returns a
	 * Properties object containing the key,value pairs in that file. The
	 * properties files should be in the class path as this method looks to the
	 * thread context class loader (TCL) to locate the resource. If the TCL is a
	 * URLClassLoader the findResource(String) method is first tried. If this
	 * fails or the TCL is not a URLClassLoader getResource(String) is tried. If
	 * not, an absolute path is tried.
	 * 
	 * @param propertiesName
	 *            - the name of the properties file resource
	 * @param log
	 *            - the logger used for trace level messages
	 * @return the loaded properties file if found
	 * @exception java.io.IOException
	 *                thrown if the properties file cannot be found or loaded
	 */
	static Properties loadProperties(String propertiesName, Logger log) throws IOException {
		ClassLoader loader = ResourceActions.getContextClassLoader();
		URL url = null;
		// First check for local visibility via a URLClassLoader.findResource
		if (loader instanceof URLClassLoader) {
			URLClassLoader ucl = (URLClassLoader) loader;
			url = ResourceActions.findResource(ucl, propertiesName);
			log.trace("findResource: " + url); //$NON-NLS-1$
		}
		if (url == null)
			url = loader.getResource(propertiesName);
		if (url == null) {
			url = new URL(propertiesName);
		}

		log.trace("Properties file=" + url); //$NON-NLS-1$

		Properties bundle = new Properties();
		InputStream is = null;
		try {
			is = ResourceActions.openStream(url);
		} catch (PrivilegedActionException e) {
			throw new IOException(e.getLocalizedMessage());
		}
		if (is != null) {
			bundle.load(is);
			is.close();
		} else {
			throw new IOException("Properties file " + propertiesName + " not available");//$NON-NLS-1$ //$NON-NLS-2$
		}
		log.debug("Loaded properties, users=" + bundle.keySet());//$NON-NLS-1$
		return bundle;
	}
}
