/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 *
 * http://www.gnu.org/copyleft/gpl.html
 */
package com.l2jfrozen.gameserver.scripting;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Map;
import java.util.logging.Logger;

import javax.script.Compilable;
import javax.script.CompiledScript;
import javax.script.ScriptEngine;
import javax.script.ScriptException;

import javolution.util.FastMap;

import com.l2jfrozen.Config;

/**
 * Cache of Compiled Scripts
 * 
 * @author KenM
 */
public class CompiledScriptCache implements Serializable
{
	/**
	 * Version 1
	 */
	private static final long serialVersionUID = 1L;

	private static final Logger LOG = Logger.getLogger(CompiledScriptCache.class.getName());

	private Map<String, CompiledScriptHolder> _compiledScriptCache = new FastMap<String, CompiledScriptHolder>();
	private transient boolean _modified = false;

	public CompiledScript loadCompiledScript(ScriptEngine engine, File file) throws FileNotFoundException, ScriptException
	{
		int len = L2ScriptEngineManager.SCRIPT_FOLDER.getPath().length() + 1;
		String relativeName = file.getPath().substring(len);

		CompiledScriptHolder csh = _compiledScriptCache.get(relativeName);
		if(csh != null && csh.matches(file))
		{
			if(Config.DEBUG)
			{
				LOG.fine("Reusing cached compiled script: " + file);
			}
			return csh.getCompiledScript();
		}
		else
		{
			if(Config.DEBUG)
			{
				LOG.info("Compiling script: " + file);
			}
			Compilable eng = (Compilable) engine;
			BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(file)));

			// TODO lock file
			CompiledScript cs = eng.compile(reader);
			if(cs instanceof Serializable)
			{
				synchronized (_compiledScriptCache)
				{
					_compiledScriptCache.put(relativeName, new CompiledScriptHolder(cs, file));
					_modified = true;
				}
			}

			return cs;
		}
	}

	public boolean isModified()
	{
		return _modified;
	}

	public void purge()
	{
		synchronized (_compiledScriptCache)
		{
			for(String path : _compiledScriptCache.keySet())
			{
				File file = new File(L2ScriptEngineManager.SCRIPT_FOLDER, path);
				if(!file.isFile())
				{
					_compiledScriptCache.remove(path);
					_modified = true;
				}
			}
		}
	}

	public void save() throws FileNotFoundException, IOException
	{
		synchronized (_compiledScriptCache)
		{
			ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(new File(L2ScriptEngineManager.SCRIPT_FOLDER, "CompiledScripts.cache")));
			oos.writeObject(this);
			_modified = false;
		}
	}
}
