/*
 * 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
 *
 *      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 org.apache.lenya.cms.metadata.dublincore;

import org.apache.lenya.cms.metadata.MetaData;
import org.apache.lenya.cms.metadata.MetaDataException;
import org.apache.lenya.cms.metadata.MetaDataOwner;
import org.apache.lenya.cms.publication.Document;

/**
 * Helper class to access dublin core meta data.
 */
public class DublinCoreHelper {

    /**
     * @param owner The owner.
     * @return The dublin core title or <code>null</code> if the title is not set.
     * @throws MetaDataException if the owner has no dublin core meta data.
     */
    public static String getTitle(MetaDataOwner owner) throws MetaDataException {
        return getDublinCore(owner).getFirstValue(DublinCore.ELEMENT_TITLE);
    }
    
    /**
     * @param doc The document.
     * @param fallbackToUuid If the dublin core title is <code>null</code>, the document's UUID is returned.
     * @return The dublin core title.
     * @throws MetaDataException if the document has no dublin core meta data.
     */
    public static String getTitle(Document doc, boolean fallbackToUuid) throws MetaDataException {
        String title = DublinCoreHelper.getTitle(doc);
        return title == null ? doc.getUUID() : title;
    }
    
    protected static MetaData getDublinCore(MetaDataOwner owner) throws MetaDataException {
        return owner.getMetaData(DublinCore.DC_NAMESPACE);
    }
    
}