/**
 * MailArchiver is an application that provides services for storing and managing e-mail messages through a Web Services SOAP interface.
 * Copyright (C) 2012  Marcio Andre Scholl Levien and Fernando Alberto Reuter Wendt and Jose Ronaldo Nogueira Fonseca Junior
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/******************************************************************************\
*
*  This product was developed by
*
*        SERVIÇO FEDERAL DE PROCESSAMENTO DE DADOS (SERPRO),
*
*  a government company established under Brazilian law (5.615/70),
*  at Department of Development of Porto Alegre.
*
\******************************************************************************/

package serpro.mailarchiver.util;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.eclipse.jetty.rewrite.handler.RegexRule;
import org.eclipse.jetty.rewrite.handler.Rule;
import org.eclipse.jetty.server.Request;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Configurable;

import serpro.mailarchiver.session.Session;
import serpro.mailarchiver.session.SessionMap;

@Configurable
public class MailAccessRule
    extends RegexRule
    implements Rule.ApplyURI
{
    private static final Logger log = Logger.getLocalLogger();

    public MailAccessRule() {
        _handling = false;
        _terminating = false;

        setRegex("^/(.*)$");
    }

    @Autowired
    private UserAppConfig userAppConfig;

    private static final String messagePathRegex =
            "^([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})/" +
            "(([^/]+/)*([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})\\.eml)$";

    private static final Pattern messagePathPattern = Pattern.compile(messagePathRegex, Pattern.CASE_INSENSITIVE);

    @Override
    public String apply(
            String oldTarget,
            HttpServletRequest request,
            HttpServletResponse response,
            Matcher matcher) {

        Matcher m = messagePathPattern.matcher(matcher.group(1));

        if(m.matches()) {
            String sessionId = m.group(1);
            Session session = SessionMap.get(sessionId);
            if(session != null) {
                String relativeStrPath = session.getUserId() + "/" + m.group(2);
                Path absolutePath = userAppConfig.SERVER.getArchiveDir()
                        .resolve("mail")
                        .resolve(relativeStrPath);
                if(Files.exists(absolutePath)) {
                    return "/" + relativeStrPath;
                }
            }
            try {
                response.sendError(HttpServletResponse.SC_NOT_FOUND);
            }
            catch (IOException ex) {
            }
        }
        else {
            try {
                response.sendError(HttpServletResponse.SC_BAD_REQUEST);
            }
            catch (IOException ex) {
            }
        }

        return oldTarget;
    }

    @Override
    public void applyURI(
            Request request,
            String oldTarget,
            String newTarget) throws IOException {

        if( ! newTarget.equalsIgnoreCase(oldTarget)) {
            request.setRequestURI(request.getContextPath() + newTarget);
        }
    }
}