/*
 * Copyright 2005-2014 the original author or authors.
 *
 * 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.springframework.ws.soap.security.x509.cache;

import java.security.cert.X509Certificate;

import net.sf.ehcache.CacheException;
import net.sf.ehcache.Ehcache;
import net.sf.ehcache.Element;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.dao.DataRetrievalFailureException;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.util.Assert;


/**
 * Caches {@code User} objects using a Spring IoC defined <a
 * href="http://ehcache.sourceforge.net">EHCACHE</a>.
 * <p>Migrated from Spring Security 2 since it has been removed in Spring Security 3.</p>
 *
 * @author Luke Taylor
 * @author Ben Alex
 */
public class EhCacheBasedX509UserCache implements X509UserCache, InitializingBean {
	//~ Static fields/initializers =====================================================================================

	private static final Log logger = LogFactory.getLog(EhCacheBasedX509UserCache.class);

	//~ Instance fields ================================================================================================

	private Ehcache cache;

	//~ Methods ========================================================================================================

	@Override
	public void afterPropertiesSet() throws Exception {
		Assert.notNull(cache, "cache is mandatory");
	}

	@Override
	public UserDetails getUserFromCache(X509Certificate userCert) {
		Element element = null;

		try {
			element = cache.get(userCert);
		} catch (CacheException cacheException) {
			throw new DataRetrievalFailureException("Cache failure: " + cacheException.getMessage());
		}

		if (logger.isDebugEnabled()) {
			String subjectDN = "unknown";

			if ((userCert != null) && (userCert.getSubjectDN() != null)) {
				subjectDN = userCert.getSubjectDN().toString();
			}

			logger.debug("X.509 Cache hit. SubjectDN: " + subjectDN);
		}

		if (element == null) {
			return null;
		} else {
			return (UserDetails) element.getObjectValue();
		}
	}

	@Override
	public void putUserInCache(X509Certificate userCert, UserDetails user) {
		Element element = new Element(userCert, user);

		if (logger.isDebugEnabled()) {
			logger.debug("Cache put: " + userCert.getSubjectDN());
		}

		cache.put(element);
	}

	@Override
	public void removeUserFromCache(X509Certificate userCert) {
		if (logger.isDebugEnabled()) {
			logger.debug("Cache remove: " + userCert.getSubjectDN());
		}

		cache.remove(userCert);
	}

	public void setCache(Ehcache cache) {
		this.cache = cache;
	}
}