/*
   Copyright (C) 2005-2012, by the President and Fellows of Harvard College.

   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.

   Dataverse Network - A web application to share, preserve and analyze research data.
   Developed at the Institute for Quantitative Social Science, Harvard University.
   Version 3.0.
*/
/* MPL License text (see http://www.mozilla.org/MPL/) */
package edu.harvard.iq.dvn.core.web.util;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;
import java.io.File;
import java.io.Serializable;


/**
 * <p>The InputFileSessionCleaner is responsible for cleaning up any files
 * that may have been uploaded by a session.  The InputFile component by
 * default stores files in an upload folder in the root directory of the
 * deployed application in a child folder named after session id.</p>
 * <p>In most deployment scenarios there is no need to keep files that
 * where uploaded during the session.  This class implements
 * HttpSessionListener and will clean up any uploaded files when the
 * #sessionDestroyed method is called be the Servlet container </p>
 * <p>Make sure that this been is properly register as a listener in the
 * application web.xml descriptor file.</p>
 *
 * @since 1.7
 */
public class InputFileSessionCleaner implements HttpSessionListener, Serializable {

    public static final Log log = LogFactory.getLog(InputFileSessionCleaner.class);

    public static final String FILE_UPLOAD_DIRECTORY = "upload";

    /**
     * This method is called by the servlet container when the session
     * is about to expire. This method will attempt to delete all files that
     * where uploaded into the folder which has the same name as the session
     * id.
     *
     * @param event JSF session event.
     */
    public void sessionDestroyed(HttpSessionEvent event) {
        // get the session id, so we know which folder to remove
        String sessionId = event.getSession().getId();

        String applicationPath = event.getSession().getServletContext().getRealPath(
                event.getSession().getServletContext().getServletContextName());

        String sessionFileUploadPath =
                applicationPath + FILE_UPLOAD_DIRECTORY + sessionId;

        File sessionfileUploadDirectory = new File(sessionFileUploadPath);

        if (sessionfileUploadDirectory.isDirectory()) {
            try {
                sessionfileUploadDirectory.delete();
            }
            catch (SecurityException e) {
                log.error("Error deleting file upload directory: ", e);
            }
        }

    }

    public void sessionCreated(HttpSessionEvent event) {

    }

}