/**
 * Copyright (c) 2009 - 2012 Red Hat, Inc.
 *
 * This software is licensed to you under the GNU General Public License,
 * version 2 (GPLv2). There is NO WARRANTY for this software, express or
 * implied, including the implied warranties of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. You should have received a copy of GPLv2
 * along with this software; if not, see
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * Red Hat trademarks are not licensed under GPLv2. No permission is
 * granted to use or replicate Red Hat trademarks that are incorporated
 * in this software or its documentation.
 */
package org.candlepin.servlet.filter;

import com.google.inject.Inject;
import com.google.inject.persist.UnitOfWork;

import java.io.IOException;

import javax.inject.Singleton;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

/**
 * CandlepinPersistFilter Custom servlet filter for guice-persist that doesn't
 * initialize the persistence service
 */
@Singleton
public class CandlepinPersistFilter implements Filter {
    private UnitOfWork unitOfWork;

    @Inject
    public CandlepinPersistFilter(UnitOfWork unitOfWork) {
        this.unitOfWork = unitOfWork;
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
        FilterChain chain) throws IOException, ServletException {
        unitOfWork.begin();
        try {
            chain.doFilter(request, response);
        }
        finally {
            unitOfWork.end();
        }
    }

    @Override
    public void init(FilterConfig arg0) throws ServletException {
    }

    @Override
    public void destroy() {
    }
}