/**	Util.java
 *
 *	Utility routines related to directories for G4blGui and G4blData.
 **/

import java.io.*;
import java.net.URL;
import java.util.*;

public class Util {

static String osName = null;
static String g4bl_dir = null;
static String geant4_data = null;

/// findG4blDir() returns the absolute path of the G4beamline install directory.
/// Returns null if it cannot be determined.
public static String findG4blDir() {
	if(g4bl_dir != null) return g4bl_dir;

	osName = System.getProperty("os.name");
	String filesep = System.getProperty("file.separator");
	String pathsep = System.getProperty("path.separator");
	g4bl_dir = System.getenv("G4BL_DIR");
	if(g4bl_dir == null || g4bl_dir == "") {
		g4bl_dir = System.getProperty("java.class.path");
		int i = g4bl_dir.indexOf(pathsep);
		if(i >= 0) g4bl_dir = g4bl_dir.substring(0,i);
		File tmp = new File(g4bl_dir);
		g4bl_dir = tmp.getParentFile().getParentFile().getAbsolutePath();
	}
	if(g4bl_dir.endsWith("/") || g4bl_dir.endsWith("\\"))
		g4bl_dir = g4bl_dir.substring(0,g4bl_dir.length()-1);

	// verify g4bl_dir
	File dir = new File(g4bl_dir);
	String ext = "";
	if(osName.startsWith("Windows")) ext = ".exe";
	if(!new File(g4bl_dir+filesep+"bin"+filesep+"g4beamline"+ext).exists())
		g4bl_dir = null;
	System.out.printf("G4BL_DIR=%s\n",g4bl_dir);
	return g4bl_dir;
}

/// findGeant4Data() will find the directory and return its absolute path.
/// Returns null if not found.
public static String findGeant4Data() {
	if(geant4_data != null) return geant4_data;

	if(findG4blDir() == null) return null;

	File d = new File(g4bl_dir);
	if(!d.isDirectory()) return null;
	d = new File(d,"Geant4Data");
	System.out.printf("Looking for Geant4Data in '%s'",d.toString());
	if(d.exists() && d.isDirectory()) {
		System.out.printf(" found.\n");
		geant4_data = d.getAbsolutePath();
		return geant4_data;
	}
	System.out.printf(" not found.\n");

	d = new File(System.getProperty("user.home"));
	if(!d.isDirectory()) return null;
	d = new File(d,"Geant4Data");
	System.out.printf("Looking for Geant4Data in '%s'",d.toString());
	if(d.exists() && d.isDirectory()) {
		System.out.printf(" found.\n");
		geant4_data = d.getAbsolutePath();
		return geant4_data;
	}
	System.out.printf(" not found.\n");

	return null;
}

/// findOrCreateGeant4Data() will find the directory, creating it if not found.
/// Returns its absolute path, or null if it cannot be created.
public static String findOrCreateGeant4Data() {
	String s = findGeant4Data();
	if(s != null) return s;

	File d = new File(g4bl_dir);
	if(!d.isDirectory()) return null;
	d = new File(d,"Geant4Data");
	try {
		if(d.mkdir()) {
			geant4_data = d.getAbsolutePath();
			return geant4_data;
		}
	} catch(Exception e) { }

	d = new File(System.getProperty("user.home"));
	if(!d.isDirectory()) return null;
	d = new File(d,"Geant4Data");
	try {
		if(d.mkdir()) {
			geant4_data = d.getAbsolutePath();
			return geant4_data;
		}
	} catch(Exception e) { }

	return null;
}

};