import java.util.Properties;
import java.io.FileOutputStream;

/**
 * Simple, generic class to load up or save properties for an application.
 *  (eg user preferences)
 *
 * While reading in values, it will automatically convert from string format,
 * to your choice of int or boolean, if desired.
 *
 * We assume that you want properties stored in a file named
 * $HOME/.yourappname, where $HOME represents the users "home directory"
 *
 * Feel free to email comments or suggestions to the author
 *
 * @version 1.0, 09/16/1997
 * @author Philip Brown phil@bolthole.com
 */

public class UserPrefs extends Properties {
	String userhome=null; //This will have fileseperator on end if it
	String pref_file;
	String AppName;
	
	Properties systemprops;
	

	/**
	 * We try to read in a preferences file, from the user's "HOME"
	 * directory. We base the name of the file, on the name of the
	 * application we are in.
	 * Use the getUserHome() call if you want to know what directory
	 * this is in.
	 *
	 * @param appname name of application calling this class
	 */
	public UserPrefs(String appname) {
		AppName = appname;
		
		systemprops=System.getProperties();
		// This is guaranteed as always being some valid directory,
		// according to spec.
		userhome=(String)systemprops.get("user.home")+
			(String)systemprops.get("file.separator");
		pref_file=userhome+"."+appname;
		try {
			load(new java.io.FileInputStream(pref_file));
		} catch (Exception err)	{
	//		if(err instanceOf java.io.FileNotFoundException)
	//			return;
				
			System.out.println("Error opening prefs file:"+err.getMessage());
		}
		
	}

	// Strip off any comments
	String trimValue(String prop) {
		if(prop==null)
			return null;
		
		int lastpos;
		lastpos=prop.indexOf('#');
		if(lastpos==-1)
			lastpos=prop.length()-1;
		while((prop.charAt(lastpos)==' ') ||
		      (prop.charAt(lastpos)=='\t'))	{
			lastpos--;
			if(lastpos==0)
				break;
		}
		      
		return prop.substring(0, lastpos+1);
	}

	/**
	 * The java spec guarantees that a "home" directory be
	 * specified. We look it up for our own uses at initialization
	 * If you want to do other things in the user's home dir,
	 * this routine is an easy way to find out where it is.
	 *
	 *  This returns string that will have trailing fileseparator, eg "/")
	 *  so you can slap together a filename directly after it, and
	 *  not worry about that sort of junk.
	 */
	public String getUserHome() {
		return userhome;
	}

	/**
	 * way to directly set a preference. You'll have to
	 * do your own type conversion.
	 * @param prefname name of property
	 * @param value string value of property
	 */
	public void setPref(String prefname, String value) {
		put(prefname, value);
	}

	
	/**
	 * Gets named resource, as a string value.
	 * returns null if no such resource defined.
	 * @param name name of property
	 */
	public String getString(String name) {
		return trimValue(getProperty(name));
	}
	/**
	 * Gets named resource, as a string value.
	 *
	 * @param name name of property
	 * @param defval default value to remember and return , if
	 *   no existing property name found.
	 */
	public String getString(String name, String defstr) {
		String val = trimValue(getProperty(name));
		if(val==null) {
			setPref(name, defstr);
			return defstr;
		}
		return val;
	}

	/**
	 * look up property that is an int value
	 * @param name name of property
	 */	
	public int getInt(String name) {
		String strint = trimValue(getProperty(name));
		int val=0;
		try {
			val = Integer.parseInt(strint);
		} catch (NumberFormatException err) {
			//we dont care
		}
		return val;
	}

	/**
	 * look up property that is an int value
	 * @param name name of property
	 * @param defval default value to remember and return , if
	 *   no existing property name found.
	 */	
	public int getInt(String name, int defval) {
		String strint = trimValue(getProperty(name));
		if(strint==null) {
			setPref(name, String.valueOf(defval));
			return defval;
		}
		int val=0;
		try {
			val = Integer.parseInt(strint);
		} catch (NumberFormatException err) {
			//we dont care
		}
		return val;
	}

	/**
	 * look up property that is a boolean value
	 * @param name name of property
	 * @param defval default value to remember and return , if
	 *   no existing property name found.
	 */	
	public boolean getBool(String name) {
		String strval = trimValue(getProperty(name));
		if(strval.equals("true"))
			return true;

		return false;
	}

	/**
	 * @param name name of property
	 * @param defval default value to remember and return , if
	 *   no existing property name found.
	 */	
	public boolean getBool(String name, boolean defval) {
		String strval = trimValue(getProperty(name));
		if(strval==null) {
			setPref(name, String.valueOf(defval));
			return defval;
		}

		if(strval.equals("true"))
			return true;

		return false;
	}

	/**
	* save user preferences to default file. Duh.
	*/
	public void Save() throws java.io.IOException {
		
		save(new FileOutputStream(pref_file), AppName+"prefs");
	}
}