// $Id: ConfigurationProperties.java,v 1.14 2004/08/08 11:29:44 mvw Exp $
// Copyright (c) 1996-2004 The Regents of the University of California. All
// Rights Reserved. Permission to use, copy, modify, and distribute this
// software and its documentation without fee, and without a written
// agreement is hereby granted, provided that the above copyright notice
// and this paragraph appear in all copies.  This software program and
// documentation are copyrighted by The Regents of the University of
// California. The software program and documentation are supplied "AS
// IS", without any accompanying services from The Regents. The Regents
// does not warrant that the operation of the program will be
// uninterrupted or error-free. The end-user understands that the program
// was developed for research purposes and is advised not to rely
// exclusively on the program for any reason.  IN NO EVENT SHALL THE
// UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
// SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,
// ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
// THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY
// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
// PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
// CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,
// UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

package org.argouml.application.configuration;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URL;
import java.util.Properties;

import org.apache.log4j.Logger;

/**
 *  This class provides a user configuration based upon properties files.
 * Eventually this configuration file will be
 * available to users via a GUI interface to
 * set keyboards
 * memory allocations
 * which modules to load
 * user preferences
 * font sizes
 * user names and data
 * etc.*
 * @author Thierry Lach
 */
public class ConfigurationProperties extends ConfigurationHandler {
    /** logger */
    private static final Logger LOG = 
	Logger.getLogger(ConfigurationProperties.class);

    /** The location of Argo's default properties resource.
     */
    private static String propertyLocation =
        "/org/argouml/resource/default.properties";
    
    /** The primary property bundle.
     */
    private Properties propertyBundle = null;

    /** Flag to ensure that only the first load failure is reported
     *  even though we keep trying because the file or URL may only
     *  be temporarily unavailable.
     */
    private boolean canComplain = true;

    /** Anonymous constructor.
     */
    public ConfigurationProperties() {
	super(true);
	Properties defaults = new Properties();
	try {
	    defaults.load(getClass().getResourceAsStream(propertyLocation));
	    LOG.debug("Configuration loaded from " + propertyLocation);
	}
	catch (Exception ioe) {
	    // TODO:  What should we do here?
	    LOG.warn("Configuration not loaded from " + propertyLocation, ioe);
	}
	propertyBundle = new Properties(defaults);
    }

    /** Returns the default path for user properties.
     *
     *  @return a generic path string.
     */
    public String getDefaultPath() {
	return System.getProperty("user.home") + "/argo.user.properties";
    }


    /** Load the configuration from a specified location.
     * 
     * @param file  the path to load the configuration from.
     *
     * @return true if the load was successful, false if not.
     */
    public boolean loadFile(File file) {
        try {
            propertyBundle.load(new FileInputStream(file));
            LOG.info("Configuration loaded from " + file);
            return true;
        }
        catch (Exception e) {
            if (canComplain) {
                LOG.warn("Unable to load configuration " + file);
            }
            // Try to create an empty file.
            try {
                file.createNewFile();
                if (file.exists() && file.isFile()) {
                    LOG.info("New configuration created as " + file);
                    // Pretend we loaded the file correctly
                    return true;
                }
            }
            catch (IOException e1) {
                // Ignore an error here
                LOG.warn("Unable to create configuration " + file, e1);
            }
            canComplain = false;
        }

        return false;
    }

    /** Save the configuration to a specified location.
     * 
     * @param file  the path to save the configuration at.
     *
     * @return true if the save was successful, false if not.
     */
    boolean saveFile(File file) {
	try {
	    propertyBundle.store(new FileOutputStream(file), "Argo properties");
	    LOG.info("Configuration saved to " + file);
	    return true;
	}
	catch (Exception e) {
	    if (canComplain)
		LOG.warn("Unable to save configuration " + file + "\n");
	    canComplain = false;
	}

	return false;
    }
    /** Load the configuration from a specified location.
     * 
     * @param url  the path to load the configuration from.
     *
     * @return true if the load was successful, false if not.
     */
    public boolean loadURL(URL url) {
	try {
	    propertyBundle.load(url.openStream());
	    LOG.info("Configuration loaded from " + url + "\n");
	    return true;
	}
	catch (Exception e) {
	    if (canComplain) {
		LOG.warn("Unable to load configuration " + url + "\n");
	    }
	    canComplain = false;
	    return false;
	}
    }

    /** Save the configuration to a specified location.
     * 
     * @param url  the path to save the configuration at.
     *
     * @return true if the save was successful, false if not.
     */
    boolean saveURL(URL url) {
	// LOG.info("Configuration saved to " + url + "\n");
	return false;
    }

    /** Returns the string value of a configuration property.
     *
     *  @param key the key to return the value of.
     *  @param defaultValue the value to return if the key was not found.
     *
     *  @return the string value of the key if found, otherwise null;
     */
    public String getValue(String key, String defaultValue) {
	String result = "";
	try {
	    result = propertyBundle.getProperty(key, defaultValue);
	}
	catch (Exception e) {
	    result = defaultValue;
	}
	if (LOG.isDebugEnabled()) {
	    LOG.debug("key '" + key + "' returns '" + result + "'");
	}
	return result;
    }

    /** Sets the string value of a configuration property.
     *
     *  @param key the key to set.
     *  @param value the value to set the key to.
     */
    public void setValue(String key, String value) {
	LOG.debug("key '" + key + "' set to '" + value + "'");
	propertyBundle.setProperty(key, value);
    }
}