/*
 * The contents of this file are subject to the terms of the Common Development and
 * Distribution License (the License). You may not use this file except in compliance with the
 * License.
 *
 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
 * specific language governing permission and limitations under the License.
 *
 * When distributing Covered Software, include this CDDL Header Notice in each file and include
 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
 * Header, with the fields enclosed by brackets [] replaced by your own identifying
 * information: "Portions Copyrighted [year] [name of copyright owner]".
 *
 * Copyright © 2010–2011 ApexIdentity Inc. All rights reserved.
 * Portions Copyrighted 2011 ForgeRock AS.
 */

package org.forgerock.openig.header;

// OpenIG Core
import org.forgerock.openig.http.Message;

/**
 * Processes the <strong>{@code Content-Length}</strong> message header. For more information,
 * see <a href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</a> §14.13.
 *
 * @author Paul C. Bryan
 */
public class ContentLengthHeader implements Header {

    /** The name of the header that this object represents. */
    public static final String NAME = "Content-Length";

    /** The content length, or {@code -1} if not specified. */
    public long length = -1;

    /**
     * Constructs a new empty header.
     */
    public ContentLengthHeader() {
    }

    /**
     * Constructs a new header, initialized from the specified message.
     *
     * @param message the message to initialize the header from.
     */
    public ContentLengthHeader(Message message) {
        fromMessage(message);
    }

    /**
     * Constructs a new header, initialized from the specified string value.
     *
     * @param string the value to initialize the header from. 
     */
    public ContentLengthHeader(String string) {
        fromString(string);
    }

    @Override
    public void clear() {
        length = -1;
    }

    @Override
    public String getKey() {
        return NAME;
    }

    @Override
    public void fromMessage(Message message) {
        if (message != null && message.headers != null) {
            fromString(message.headers.getFirst(NAME)); // expect only one header value
        }
    }

    @Override
    public void fromString(String string) {
        clear();
        if (string != null) {
            try {
                length = Long.parseLong(string);
            } catch (NumberFormatException nfe) {
                // will remain default of -1 from clear() call above
            }
        }
    }

    @Override
    public void toMessage(Message message) {
        String value = toString();
        if (value != null) {
            message.headers.putSingle(NAME, value);
        }
    }

    @Override
    public String toString() {
        return (length >= 0 ? Long.toString(length) : null);
    }

    @Override
    public boolean equals(Object o) {
        return (o == this || (o != null && o instanceof ContentLengthHeader &&
         this.length == ((ContentLengthHeader)o).length));
    }

    @Override
    public int hashCode() {
        return (int)(length ^ (length >>> 32));
    }
}