/**
 *
 * Copyright (c) 2014, the Railo Company Ltd. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either 
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public 
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 * 
 **/
package lucee.runtime.cache.legacy;

import java.io.IOException;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import lucee.commons.io.res.Resource;
import lucee.commons.io.res.util.WildCardFilter;
import lucee.commons.lang.ExceptionUtil;
import lucee.runtime.converter.JavaConverter;

public class MetaData implements Serializable {
	
	private static Map<String,MetaData> instances=new HashMap<String,MetaData>();
	
	private HashMap<String,String> data=new HashMap<String,String>();
	private Resource file;
	
	private MetaData(Resource file) {
		this.file=file;
		data=new HashMap<String,String>();
	}
	
	public MetaData(Resource file,HashMap<String,String> data) {
		this.file=file;
		this.data=data;
	}

	public static MetaData getInstance(Resource directory) {
		MetaData instance=instances.get(directory.getAbsolutePath());
		
		if(instance==null) {
			Resource file = directory.getRealResource("meta");
			if(file.exists()){
				try {
					instance= new MetaData(file,(HashMap)JavaConverter.deserialize(file));
				}
				catch(Throwable t) {ExceptionUtil.rethrowIfNecessary(t);}
			}
			if(instance==null) instance=new MetaData(file);
			instances.put(directory.getAbsolutePath(), instance);
		}
		return instance;
	}
	
	public synchronized void add(String name, String raw) throws IOException {
		synchronized (data) {
			data.put(name, raw);
			JavaConverter.serialize(data, file);
		}
	}
	
	public synchronized List<String> get(String wildcard) throws IOException {
		synchronized (data) {
			List<String> list=new ArrayList<String>();
			Iterator<Entry<String, String>> it = data.entrySet().iterator();
			WildCardFilter filter=new WildCardFilter( wildcard);
			Entry<String, String> entry;
			String value;
			while(it.hasNext()) {
				entry = it.next();
				value= entry.getValue();
				if(filter.accept(value)){
					list.add(entry.getKey());
					it.remove();
				}
			}
			if(list.size()>0)JavaConverter.serialize(data, file);
			return list;
		}
	}
	
}