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 * Licensed to the Apache Software Foundation (ASF) under one   *
 * or more contributor license agreements.  See the NOTICE file *
 * distributed with this work for additional information        *
 * regarding copyright ownership.  The ASF licenses this file   *
 * to you 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   *
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 *   http://www.apache.org/licenses/LICENSE-2.0                 *
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 * 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.                                           *
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package org.apache.james.transport.util;

import java.util.Optional;

import javax.mail.MessagingException;

import org.apache.james.core.MailAddress;
import org.apache.james.transport.mailets.redirect.SpecialAddress;
import org.apache.mailet.Mail;

public class SenderUtils {

    public static SenderUtils from(Optional<MailAddress> sender) {
        return new SenderUtils(sender);
    }

    private final Optional<MailAddress> sender;

    private SenderUtils(Optional<MailAddress> sender) {
        this.sender = sender;
    }

    public Optional<MailAddress> getSender(Mail originalMail) throws MessagingException {
        if (sender.isPresent()) {
            if (isUnalteredOrSender(sender.get())) {
                return originalMail.getMaybeSender().asOptional();
            }
        }
        return sender;
    }

    private boolean isUnalteredOrSender(MailAddress sender) {
        return sender.equals(SpecialAddress.UNALTERED) || sender.equals(SpecialAddress.SENDER);
    }
}
