/**
*    Copyright (C)  DataMelt project. The jHPLot package by S.Chekanov and Work.ORG
*    All rights reserved.
*
*    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 3 of the License, or 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, see .
*
*    Additional permission under GNU GPL version 3 section 7:
*    If you have received this program as a library with written permission from the DataMelt team,
*    you can link or combine this library with your non-GPL project to convey the resulting work.
*    In this case, this library should be considered as released under the terms of
*    GNU Lesser public license (see ),
*    provided you include this license notice and a URL through which recipients can access the
*    Corresponding Source.
**/

package jhplot.io;

import java.io.*;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.xml.DomDriver;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

import jhplot.gui.HelpBrowser;


/**
 * 
 * Methods used for serialization. Includes write (read) for the standard
 * serialization. Objects can be compressed on-fly using GZip. Also, one can use
 * XML format for serialization (writeXML(), readXML()). XML serialization is
 * based on XSream and not compressed. Files can be read from URL.
 * 
 * @author S.Chekanov
 * 
 */

public class Serialized {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	/**
	 * Write an object to a serialized file. Use the method read() to read it
	 * back.
	 * 
	 * @param o
	 *            object to serialize into a file
	 * 
	 * @param name
	 *            serialized file name for output.
	 * @param compression
	 * 
	 *            set true if file should be compressed.
	 * 
	 * @return zero if no errors
	 */
	public static int write(Object o, String name, boolean compressed) {

		try {
			FileOutputStream outFile = new FileOutputStream(name);
			ObjectOutputStream outStream;
			if (compressed == true) {
				outStream = new ObjectOutputStream(
						new GZIPOutputStream(outFile));
			} else {
				outStream = new ObjectOutputStream(outFile);
			}

			outStream.writeObject(o);
			outStream.close();
			outFile.close();
		} catch (FileNotFoundException e) {
			ErrorMessage(e.toString());
			return 2;
		} catch (IOException e) {
			ErrorMessage(e.toString());
			return 1;
		}

		return 0;
	}

	/**
	 * Write an object to a serialized file. Use the method read() to read it
	 * back. File will be compressed.
	 * 
	 * @param o
	 *            object to serialize into a file
	 * 
	 * @param name
	 *            serialized file name for output.
	 * 
	 * @return zero if no errors
	 */
	public static int write(Object o, String name) {

		return write(o, name, true);

	}

	/**
	 * Write an object to a serialized XML file. Use the method readXML() to get
	 * it back.
	 * 
	 * @param o
	 *            object to serialize into a file
	 * 
	 * @param name
	 *            serialized file name for the output.
	 * 
	 * @return zero if no errors
	 */
	public static int writeXML(Object o, String name) {

		try {
			XStream xstream = new XStream(new DomDriver());
			ObjectOutputStream out = xstream
					.createObjectOutputStream(new FileOutputStream(name));
			out.writeObject(o);
			out.close();

		} catch (IOException e) {

			ErrorMessage(e.toString());
			return 1;
		}

		return 0;

	}

	/**
	 * Read an object from a file. It can read a file from URL if the string starts from
	 * http or ftp, otherwise a file on the file system is assumed.
	 * 
	 * @param sfile
	 *            file name. Can be URL location of the file.
	 * @param compressed
	 *            true if compressed
	 * @return object from the file
	 */

	private static Object read(String sfile, boolean compressed) {

		sfile = sfile.trim();

		if (sfile.startsWith("http") || sfile.startsWith("ftp")) {

			try {
				return read(new URL(sfile), compressed);
			} catch (MalformedURLException e) {
				ErrorMessage(e.toString());
			}

		} else {
			return read(new File(sfile), compressed);
		}

		return null;

	}

	/**
	 * Read an object from a serialized file
	 * 
	 * @param file
	 *            serialized file for input.
	 * 
	 * @return object
	 * 
	 * @param compressed
	 *            set true if file is compressed.
	 * 
	 */
	public static Object read(File file, boolean compressed) {

		Object p0 = null;

		try {

			FileInputStream fileIn = new FileInputStream(file);
			ObjectInputStream in;

			if (compressed == true) {
				in = new ObjectInputStream(new GZIPInputStream(fileIn));
			} else {
				in = new ObjectInputStream(fileIn);
			}

			p0 = in.readObject();
			in.close();
			fileIn.close();

		} catch (ClassNotFoundException e) {
			ErrorMessage(e.toString());
		} catch (FileNotFoundException e) {
			ErrorMessage(e.toString());
		} catch (IOException e) {
			ErrorMessage(e.toString());
		}

		return p0;

	}

	/**
	 * Read an object from an URL
	 * 
	 * @param name
	 *            serialized file name for input from URL
	 * 
	 * @param compressed
	 *            set true if file is compressed.
	 *            
	 *  @return object          
	 * 
	 */
	public static Object read(URL url, boolean compressed) {

		Object p0 = null;

		try {
			URLConnection urlConn = url.openConnection();
			urlConn.setDoInput(true);
			urlConn.setUseCaches(false);

			ObjectInputStream in;
			if (compressed == true) {
				in = new ObjectInputStream(new GZIPInputStream(urlConn
						.getInputStream()));
			} else {
				in = new ObjectInputStream(urlConn.getInputStream());
			}

			p0 = in.readObject();
			in.close();

		} catch (ClassNotFoundException e) {
			ErrorMessage(e.toString());
		} catch (IOException e) {
			ErrorMessage(e.toString());
		}

		return p0;

	}

	/**
	 * Read an object from a serialized file. File is assumed to be compressed,
	 * i.e when it was saved using write(obj,name) method.
	 * 
	 * @param name
	 *            serialized file name for input.
	 * 
	 * @return object
	 * 
	 */
	public static Object read(String name) {

		return read(name, true);

	}

	/**
	 * Read an object from a serialized XML file (should be written using
	 * writeXML() method).
	 * 
	 * @param name
	 *            serialized XML file name for the input.
	 * 
	 * @return object
	 */
	public static Object readXML(String name) {

		Object p0 = null;

		try {
			XStream xstream = new XStream(new DomDriver());
			FileInputStream fileIn = new FileInputStream(name);
			ObjectInputStream ino = xstream.createObjectInputStream(fileIn);
			try {
				p0 = ino.readObject();
			} catch (ClassNotFoundException e) {
				// TODO Auto-generated catch block
				ErrorMessage(e.toString());
				return 2;
			}
			ino.close();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			ErrorMessage(e.toString());
			return 1;
		}

		return p0;

	}

	/**
	 * Convert object to XML using XSream package
	 * 
	 * @param ob
	 * @return XML string
	 */
	public static String toXML(Object ob) {

		XStream xstream = new XStream(new DomDriver());
		String xml = xstream.toXML(ob);
		return xml;
	}

	/**
	 * Get object to XML using XSream package
	 * 
	 * @param xml
	 *            XML string
	 * @return object
	 */
	public static Object fromXML(String xml) {

		XStream xstream = new XStream(new DomDriver());
		return xstream.fromXML(xml);

	}

	/**
	 * Generate error message
	 * 
	 * @param a
	 *            Message
	 */

	static private void ErrorMessage(String a) {
              jhplot.utils.Util.ErrorMessage(a);
	}
	 /**
     * Show online documentation.
     */
    public void doc() {

            String a = this.getClass().getName();
            a = a.replace(".", "/") + ".html";
            new HelpBrowser(HelpBrowser.JHPLOT_HTTP + a);

    }
}