package com.armedia.acm.services.email.service;

/*-
 * #%L
 * ACM Service: Email
 * %%
 * Copyright (C) 2014 - 2020 ArkCase LLC
 * %%
 * This file is part of the ArkCase software. 
 * 
 * If the software was purchased under a paid ArkCase license, the terms of 
 * the paid license agreement will prevail.  Otherwise, the software is 
 * provided under the following open source license terms:
 * 
 * ArkCase is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *  
 * ArkCase 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 Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with ArkCase. If not, see <http://www.gnu.org/licenses/>.
 * #L%
 */

import com.armedia.acm.service.MimeMessageParser;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import javax.mail.Message;
import javax.mail.Part;
import javax.mail.Session;
import javax.mail.internet.MimeMessage;

import java.util.List;
import java.util.Optional;

/**
 * Created by Aleksandar Acevski <aleksandar.acevski@armedia.com> on October, 2020
 */
public class ForwardedAsAttachmentEmailExtractor implements OriginalEmailExtractorStrategy
{
    private transient final Logger log = LogManager.getLogger(getClass());

    /**
     *
     * Finds and returns the original email if one is sent as an attachment
     *
     * @param message
     *            Email message
     * @return Original forwarded email or empty optional
     */
    @Override
    public Optional<Message> getForwardedMessage(Message message)
    {
        try
        {
            List<Part> attachments = MimeMessageParser.getAttachments(message);

            if (MimeMessageParser.hasForwardedEmailAsAttachment(attachments))
            {
                Part attachment = attachments.get(0);

                MimeMessage originalMessage = new MimeMessage(
                        Session.getDefaultInstance(System.getProperties()),
                        attachment.getInputStream());

                return Optional.of(originalMessage);
            }
        }
        catch (Exception e)
        {
            log.error("Couldn't read the email body and contents while extracting forwarded as attachment email!", e);
        }

        return Optional.empty();
    }
}