/* ================================================================

  * Cewolf : Chart enabling Web Objects Framework

  * ================================================================

  *

  * Project Info:  http://cewolf.sourceforge.net

  * Project Lead:  Guido Laures (guido@laures.de);

  *

  * (C) Copyright 2002, by Guido Laures

  *

  * 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,

  * Boston, MA 02111-1307, USA.

  */

 package de.laures.cewolf.storage;

 import java.io.File;

 import java.io.FileInputStream;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.io.ObjectInputStream;

 import java.io.ObjectOutputStream;

 import java.io.Serializable;

 import java.util.ArrayList;

 import java.util.List;

 import javax.servlet.ServletContext;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.jsp.PageContext;

 import de.laures.cewolf.CewolfException;

 import de.laures.cewolf.ChartImage;

 import de.laures.cewolf.Configuration;

 import de.laures.cewolf.Storage;

 import de.laures.cewolf.taglib.util.KeyGenerator;

 /**

  * Storage for storing images as files in the web application directory as files _chart-XXXXX.

  * Note that by default the files won't ever be removed. To remove saved images on VM exit set

  * the <code>FileStorage.deleteOnExit</code> configuration parameter to "true". For example:

  * 

  * <pre>

  *		<init-param>

  *			<param-name>storage</param-name>

  *			<param-value>de.laures.cewolf.storage.FileStorage</param-value>

  *		</init-param>

  *		<init-param>

  *				<param-name>FileStorage.deleteOnExit</param-name>

  *				<param-value>true</param-value>

  *		</init-param> 

  *	</pre> 

  * 

  * @author guido

  */

 public class FileStorage implements Storage {

 	String basePath = null;

 	List stored = new ArrayList();

 	private boolean deleteOnExit = false;

 	/**

 	 * @see de.laures.cewolf.Storage#storeChartImage(ChartImage, PageContext)

 	 */

 	public String storeChartImage(ChartImage cid, PageContext pageContext) {

 		if(contains(cid, pageContext)){

 			return getKey(cid);

 		}

 		String id = getKey(cid);

 		ObjectOutputStream oos = null;

 		try {

 			String fileName = getFileName(id);

 			pageContext.getServletContext().log("Storing image to file " + fileName);

 			File f = new File(fileName);

 			if (deleteOnExit) {

 				f.deleteOnExit();			

 			}

 			oos = new ObjectOutputStream(new FileOutputStream(f));

 			oos.writeObject(new SerializableChartImage(cid));

 			oos.close();

 		} catch(IOException ioex){

 			ioex.printStackTrace();

 		} catch(CewolfException cwex){

 			cwex.printStackTrace();

 		} finally {

 			if(oos != null){

 				try {

 					oos.close();

 				} catch(IOException ioex){

 					ioex.printStackTrace();

 				}

 			}

 		}

 		return id;		

 	}

 	/**

 	 * @see de.laures.cewolf.Storage#getChartImage(String, HttpServletRequest)

 	 */

 	public ChartImage getChartImage(String id, HttpServletRequest request) {

 		ChartImage res = null;

 		ObjectInputStream ois = null;

 		try {

 			ois = new ObjectInputStream(new FileInputStream(getFileName(id)));

 			res = (ChartImage)ois.readObject();

 			ois.close();

 		} catch(Exception ex){

 			ex.printStackTrace();

 		} finally {

 			if(ois != null){

 				try {

 					ois.close();

 				} catch(IOException ioex){

 					ioex.printStackTrace();

 				}

 			}

 		}

 		return res;

 	}

 	/**

 	 * @see de.laures.cewolf.Storage#contains(ChartImage, PageContext)

 	 */

 	public boolean contains(ChartImage chartImage, PageContext pageContext) {

 		return new File(getFileName(chartImage)).exists();

 	}

 	/**

 	 * @see de.laures.cewolf.Storage#getKey(ChartImage)

 	 */

 	public String getKey(ChartImage chartImage) {

 		return String.valueOf(KeyGenerator.generateKey((Serializable)chartImage));

 	}

 	/**

 	 * @see de.laures.cewolf.Storage#init(ServletContext)

 	 */

 	public void init(ServletContext servletContext) throws CewolfException {

 		basePath = servletContext.getRealPath("/");

 		Configuration config = Configuration.getInstance(servletContext);

 		deleteOnExit = "true".equalsIgnoreCase("" + config.getParameters().get("FileStorage.deleteOnExit"));

 		servletContext.log("FileStorage initialized, deleteOnExit=" + deleteOnExit);

 	}

 	private String getFileName(ChartImage chartImage){

 		return getFileName(getKey(chartImage));

 	}

 	private String getFileName(String id){

 		return basePath + "_chart" + id;

 	}

 	/**

 	 * @see de.laures.cewolf.Storage#removeChartImage(java.lang.String, javax.servlet.jsp.PageContext)

 	 */

 	public String removeChartImage(String imgKey, HttpServletRequest pageContext) throws CewolfException {

 		File file = new File(getFileName(imgKey));

 		if (file.exists())

 		{

 			if (!file.delete())

 			{

 				throw new CewolfException("Could not delete file " + file.getAbsolutePath());

 			}

 		}

 		return imgKey;

 	}

 }