package ca.uhn.fhir.util;

/*
 * #%L
 * HAPI FHIR - Core Library
 * %%
 * Copyright (C) 2014 - 2017 University Health Network
 * %%
 * 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.
 * #L%
 */

import java.io.InputStream;
import java.util.Properties;

import org.apache.commons.io.IOUtils;

/**
 * Used internally by HAPI to log the version of the HAPI FHIR framework
 * once, when the framework is first loaded by the classloader.
 */
public class VersionUtil {

	private static final org.slf4j.Logger ourLog = org.slf4j.LoggerFactory.getLogger(VersionUtil.class);
	private static String ourVersion;

	static {
		initialize();
	}

	public static String getVersion() {
		return ourVersion;
	}

	private static void initialize() {
		InputStream is = null;
		try {
			is = VersionUtil.class.getResourceAsStream("/ca/uhn/fhir/hapi-version.properties");
			Properties p = new Properties();
			p.load(is);
			ourVersion = p.getProperty("version");
			ourLog.info("HAPI FHIR version is: " + ourVersion);
		} catch (Exception e) {
			ourLog.warn("Unable to determine HAPI version information", e);
		} finally {
			IOUtils.closeQuietly(is);
		}
	}
	
}
