/*
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999-2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Commons", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
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 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.commons.discovery.resource.names;

import java.util.Dictionary;
import java.util.Hashtable;

import org.apache.commons.discovery.ResourceNameDiscover;
import org.apache.commons.discovery.ResourceNameIterator;
import org.apache.commons.discovery.log.DiscoveryLogFactory;
import org.apache.commons.logging.Log;


/**
 * Recover resources from a Dictionary.  This covers Properties as well,
 * since <code>Properties extends Hashtable extends Dictionary</code>.
 * 
 * The recovered value is expected to be either a <code>String</code>
 * or a <code>String[]</code>.
 * 
 * @author Richard A. Sitze
 */
public class DiscoverNamesInDictionary
    extends ResourceNameDiscoverImpl
    implements ResourceNameDiscover
{
    private static Log log = DiscoveryLogFactory.newLog(DiscoverNamesInDictionary.class);
    public static void setLog(Log _log) {
        log = _log;
    }

    private Dictionary dictionary;
    
    /** Construct a new resource discoverer
     */
    public DiscoverNamesInDictionary() {
        setDictionary(new Hashtable());
    }
    
    /** Construct a new resource discoverer
     */
    public DiscoverNamesInDictionary(Dictionary dictionary) {
        setDictionary(dictionary);
    }

    protected Dictionary getDictionary() {
        return dictionary;
    }

    /**
     * Specify set of class loaders to be used in searching.
     */
    public void setDictionary(Dictionary table) {
        this.dictionary = table;
    }
    
    public void addResource(String resourceName, String resource) {
        dictionary.put(resourceName, resource);
    }
    
    public void addResource(String resourceName, String[] resources) {
        dictionary.put(resourceName, resources);
    }

    /**
     * @return Enumeration of ResourceInfo
     */
    public ResourceNameIterator findResourceNames(final String resourceName) {
        if (log.isDebugEnabled())
            log.debug("find: resourceName='" + resourceName + "'");

        Object baseResource = dictionary.get(resourceName);

        final String[] resources;
        if (baseResource instanceof String) {
            resources = new String[] { (String)baseResource };
        } else if (baseResource instanceof String[]) {
            resources = (String[])baseResource;
        } else {
            resources = null;
        }

        return new ResourceNameIterator() {
            private int idx = 0;
            
            public boolean hasNext() {
                if (resources != null) {
                    while (idx < resources.length  &&  resources[idx] == null) {
                        idx++;
                    }
                    return idx < resources.length;
                }
                return false;
            }
            
            public String nextResourceName() {
                return hasNext() ? resources[idx++] : null;
            }
        };
    }
}