/*
 * 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.publication;

import java.io.File;

/**
 * Default DocumentIdToPathMapper implementation.
 * 
 * @version $Id$
 */
public class DefaultDocumentIdToPathMapper implements DocumentIdToPathMapper {

    /**
     * The file name.
     */
    public static final String BASE_FILENAME_PREFIX = "index";

    /**
     * @see org.apache.lenya.cms.publication.DocumentIdToPathMapper#getPath(java.lang.String,
     *      java.lang.String)
     */
    public String getPath(String uuid, String language) {
        if (uuid.startsWith("/")) {
            return uuid.substring(1) + "/" + getFilename(language);
        }
        else {
            return uuid + "/" + language;
        }
    }

    /**
     * Constructs the filename for a given language.
     * 
     * @param language The language.
     * @return A string value.
     */
    protected String getFilename(String language) {
        String languageSuffix = "";
        if (language != null && !"".equals(language)) {
            languageSuffix = "_" + language;
        }
        return BASE_FILENAME_PREFIX + languageSuffix;
    }

    /**
     * Returns the language for a certain file
     * 
     * @param file the document file
     * 
     * @return the language for the given document file or null if the file has no language.
     */
    public String getLanguage(File file) {
        String fileName = file.getName();
        String language = null;

        int lastDotIndex = fileName.lastIndexOf(".");
        String suffix = fileName.substring(lastDotIndex);

        // check if the file is of the form index.html or index_en.html

        if (fileName.startsWith(BASE_FILENAME_PREFIX) && fileName.endsWith(suffix)) {
            String languageSuffix = fileName.substring(BASE_FILENAME_PREFIX.length(),
                    fileName.indexOf(suffix));
            if (languageSuffix.length() > 0) {
                // trim the leading '_'
                language = languageSuffix.substring(1);
            }
        }
        return language;
    }
}