package org.greenstone.gsdl3.util;

import java.util.Properties;
import java.io.File;
import java.io.InputStream;

import org.apache.log4j.*;

/** holds some global properties for the application. Read from a properties file */
public class GlobalProperties {


     static Logger logger = Logger.getLogger(org.greenstone.gsdl3.util.GlobalProperties.class.getName());
    private static Properties properties = null;
    private static String properties_filename = "global.properties";
    private static String gsdl3_home = null;
    private static String gsdl3_web_address = null;
    
    // Note, that if the servlet is reloadable, then it is reloaded each time the file is changed.
    static {
	//load in the properties
	properties = new Properties();
	reload();	
    }
    
    /** get the value of the property 'key'. returns null if not found */
    public static String getProperty(String key) {
	return properties.getProperty(key);
    }

    /** get the value of the property 'key'. 
     * returns default_value if not found */
    public static String getProperty(String key, String default_value) {
	return properties.getProperty(key, default_value);
    }

    /** some special ones */
    public static String getGSDL3Home() {
	return gsdl3_home;
    }

    public static String getGSDL3WebAddress() {
	return gsdl3_web_address;
    }
    
    public static void reload() {
	try {
	    InputStream in = Class.forName("org.greenstone.gsdl3.util.GlobalProperties").getClassLoader().getResourceAsStream(properties_filename);
	    if (in != null) {
		logger.error("loading global properties");
		properties.load(in);
		in.close();
	    } else {
		logger.error("couldn't load global properties!");
	    }
	    gsdl3_home = properties.getProperty("gsdl3.home");
	    // make sure the path separators are correct
	    File gs3_file = new File(gsdl3_home);
	    gsdl3_home = gs3_file.getPath();
	    gsdl3_web_address = "http://"+ properties.getProperty("tomcat.server")+":"+ properties.getProperty("tomcat.port")+"/"+properties.getProperty("tomcat.context");
	} catch (Exception e) {
	    logger.error("Exception trying to reload global.properties: "+e);
	}
	
    }
}