/**
 *
 * Copyright 2003-2004 The Apache Software Foundation
 *
 *  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.
 */

package javax.mail;

/**
 * The context in which a piece of message content is contained.
 *
 * @version $Rev$ $Date$
 */
public class MessageContext {
    private final Part part;

    /**
     * Create a MessageContext object describing the context of the supplied Part.
     *
     * @param part the containing part
     */
    public MessageContext(Part part) {
        this.part = part;
    }

    /**
     * Return the {@link Part} that contains the content.
     *
     * @return the part
     */
    public Part getPart() {
        return part;
    }

    /**
     * Return the message that contains the content; if the Part is a {@link Multipart}
     * then recurse up the chain until a {@link Message} is found.
     *
     * @return
     */
    public Message getMessage() {
        return getMessageFrom(part);
    }

    /**
     * Return the session associated with the Message containing this Part.
     *
     * @return the session associated with this context's root message
     */
    public Session getSession() {
        Message message = getMessage();
        if (message == null) {
            return null;
        } else {
            return message.session;
        }
    }

    // recurse up the chain of MultiPart/BodyPart paris until we hit a message
    private Message getMessageFrom(Part p) {
        while (p != null) {
            if (p instanceof Message) {
                return (Message) p;
            }
            Multipart mp = ((BodyPart) p).getParent();
            if (mp == null) {
                return null;
            }
            p = mp.getParent();
        }
        return null;
    }
}