/*
 * (c) Copyright Rosella Software, 2005-. All rights reserved.
 *
 *  Rosella Software
 *  http://www.roselladb.com
 *  Sydney, Australia
 */

// package your.package.name;

import java.io.*;
import java.lang.*;

public class SwtJdbcInstaller {

    /**
     * Checks if a JAR file with the name of the 1st argument
     * is already installed into the Java Runtime running the
     * application. For example, SWT package has a "swt.jar" file.
     * You can check whether SWT package is installed or not as
     * follows;
     *
     *    if (!isJarInstalled("swt.jar")) {
     *       // install SWT here!
     *    }
     */
    static public boolean isJarInstalled(String jarfilename) {
	SwtJdbcInstaller sji = new SwtJdbcInstaller();
	ClassLoader cl  = sji.getClass().getClassLoader();
        String extdirs  = System.getProperty("java.ext.dirs");
	File f = new File(extdirs, jarfilename);
	return f.exists();
    }

    /**
     * This install a Jar file into the JVM's jar directory.
     * Jar files can be JDBC drivers and SWT package or your own
     * packages! This assumes that your main JAR file contains
     * the JAR file to install to JVM directory! 
     * The 1st argument is the path that the jar to be installed
     * is stored in the main JAR file. If stored at root level,
     * just use "". The 2nd argument is the name of the file.
     * For example, to install SWT package file located at "windows";
     *
     *   installJarFile("windows", "swt.jar");
     */
    static public void installJarFile(String pathname, 
				      String jarfilename) {
	SwtJdbcInstaller sji = new SwtJdbcInstaller();
	ClassLoader cl  = sji.getClass().getClassLoader();
        String extdirs  = System.getProperty("java.ext.dirs");

	String st = null;
	if (pathname==null || pathname.equals("")) {
	    st = jarfilename;
	} else {
	    if (pathname.endsWith("/")) {
		st = pathname+jarfilename;
	    } else {
		st = pathname+"/"+jarfilename;
	    }
	}
	InputStream stream = null;
	if (cl!=null) {
	    stream = cl.getResourceAsStream(st);
	} else {
	    stream = ClassLoader.getSystemResourceAsStream(st);
	}
	copyFile(stream, new File(extdirs, jarfilename));
    }

    /**
     * Same as the previous one except that this accept input 
     * file instead.
     */
    static public void installJarFile(File in, 
				      String jarfilename) {
        String extdirs = System.getProperty("java.ext.dirs");
	try {
	    InputStream stream = new FileInputStream(in);;
	    copyFile(stream, new File(extdirs, jarfilename));
	} catch (Throwable t) {
	    t.printStackTrace();
	}
    }

    /**
     * This install a DLL file into the JVM's DLL directory.
     * DLL files can be JDBC drivers and SWT package or your own
     * native packages! This assumes that your main JAR file contains
     * the DLL file to install to JVM directory! 
     * The 1st argument is the path that the DLL to be installed
     * is stored in the main JAR file. If stored at root level,
     * just use "". The 2nd argument is the name of the file.
     * For example, to install SWT package file located at "windows";
     *
     *   installDllFile("windows", "swt-aswt-win32-3123.DLL");
     *   installDllFile("windows", "swt-gdip-win32-3123.DLL");
     *   installDllFile("windows", "swt-win32-3123.DLL);
     */
    static public void installDllFile(String pathname, 
				      String dllfilename) {
	SwtJdbcInstaller sji = new SwtJdbcInstaller();
	ClassLoader cl  = sji.getClass().getClassLoader();
        String javahome = System.getProperty("java.home");
	String dllhome  = javahome+File.separator+"bin";

	String st = null;
	if (pathname==null || pathname.equals("")) {
	    st = dllfilename;
	} else {
	    if (pathname.endsWith("/")) {
		st = pathname+dllfilename;
	    } else {
		st = pathname+"/"+dllfilename;
	    }
	}
	InputStream stream = null;
	if (cl!=null) {
	    stream = cl.getResourceAsStream(st);
	} else {
	    stream = ClassLoader.getSystemResourceAsStream(st);
	}
	copyFile(stream, new File(dllhome, dllfilename));
    }

    /**
     * Same as the previous one except that this accept input 
     * file instead.
     */
    static public void installDllFile(File in, 
				      String dllfilename) {
        String javahome = System.getProperty("java.home");
	String dllhome  = javahome+File.separator+"bin";
	try {
	    InputStream stream = new FileInputStream(in);;
	    copyFile(stream, new File(dllhome, dllfilename));
	} catch (Throwable t) {
	    t.printStackTrace();
	}
    }

    /**
     * Copy files from input stream to output file.
     */
    private static void copyFile(InputStream input, File output0) {
	int    length = 512; // buffer block size
	int    read_length;
	long   sleeping = 1;
	byte[] buffer = new byte[length];

	// make sure that existing files deleted on Windows!
	while (true) {
	    if (!output0.exists()) {
		break;
	    }
	    try {Thread.sleep(sleeping);} catch (Exception e) {};
	    sleeping *= 2;
	    output0.delete();
	}

	FileOutputStream output = null;
	try {
	    output = new FileOutputStream(output0);
	    while (true) {
		read_length = input.read(buffer, 0, length);
		if (read_length <= 0) {
		    break;
		}
		output.write(buffer, 0, read_length);
	    }
	} catch (Throwable e) {
	    e.printStackTrace();
	}
	try {input.close();}  catch (Throwable t) {};
	try {output.close();} catch (Throwable t) {};
    }
}