/**********************************************************************
 * Copyright (c) 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 *
 * Contributors:
 *    IBM - Initial API and implementation
 **********************************************************************/
package net.sourceforge.phpeclipse.wiki.internal;

import java.io.ByteArrayInputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import net.sourceforge.phpeclipse.webbrowser.internal.Trace;
import net.sourceforge.phpeclipse.wiki.editor.WikiEditorPlugin;

import org.eclipse.core.runtime.Preferences;
/**
 * 
 */
public class ConfigurationManager {
	private static final int ADD = 0;
	private static final int CHANGE = 1;
	private static final int REMOVE = 2;

	// configurations
	protected List configurations;
	protected Map threads = new HashMap();
	
	protected List monitorListeners = new ArrayList();
	
	private Preferences.IPropertyChangeListener pcl;
	protected boolean ignorePreferenceChanges = false;
	
	protected static ConfigurationManager instance;
	
	public static ConfigurationManager getInstance() {
		if (instance == null)
			instance = new ConfigurationManager();
		return instance;
	}
	
	private ConfigurationManager() {
		loadConfigurations();
		
		pcl = new Preferences.IPropertyChangeListener() {
			public void propertyChange(Preferences.PropertyChangeEvent event) {
				if (ignorePreferenceChanges)
					return;
				String property = event.getProperty();
				if (property.equals("configurations")) {
					loadConfigurations();
				}
			}
		};
		
		WikiEditorPlugin.getDefault().getPluginPreferences().addPropertyChangeListener(pcl);
	}
	
	protected void dispose() {
		WikiEditorPlugin.getDefault().getPluginPreferences().removePropertyChangeListener(pcl);
	}
	
	public IConfigurationWorkingCopy createConfiguration() {
		return new ConfigurationWorkingCopy();
	}
	
	public List getConfigurations() {
		return new ArrayList(configurations);
	}

	protected void addConfiguration(IConfiguration configuration) {
		if (!configurations.contains(configuration))
			configurations.add(configuration);
		fireConfigurationEvent(configuration, ADD);
		saveConfigurations();
	}
	
	protected boolean isActive(IConfiguration configuration) {
		return (threads.get(configuration) != null);
	}

	protected void removeConfiguration(IConfiguration configuration) {
		configurations.remove(configuration);
		fireConfigurationEvent(configuration, REMOVE);
		saveConfigurations();
	}
	
	protected void configurationChanged(IConfiguration configuration) {
		fireConfigurationEvent(configuration, CHANGE);
		saveConfigurations();
	}
	
	/**
	 * Add monitor listener.
	 * 
	 * @param listener
	 */
	public void addConfigurationListener(IConfigurationListener listener) {
		monitorListeners.add(listener);
	}

	/**
	 * Remove monitor listener.
	 * 
	 * @param listener
	 */
	public void removeConfigurationListener(IConfigurationListener listener) {
		monitorListeners.remove(listener);
	}
	
	/**
	 * Fire a monitor event.
	 * @param rr
	 * @param fType
	 */
	protected void fireConfigurationEvent(IConfiguration monitor, int type) {
		Object[] obj = monitorListeners.toArray();
		
		int size = obj.length;
		for (int i = 0; i < size; i++) {
			IConfigurationListener listener = (IConfigurationListener) obj[i];
			if (type == ADD)
				listener.monitorAdded(monitor);
			else if (type == CHANGE)
				listener.monitorChanged(monitor);
			else if (type == REMOVE)
				listener.monitorRemoved(monitor);
		}
	}
	
	
	
	
	protected void loadConfigurations() {
		Trace.trace(Trace.FINEST, "Loading Configurations");
		
		configurations = new ArrayList();
		Preferences prefs = WikiEditorPlugin.getDefault().getPluginPreferences();
		String xmlString = prefs.getString("configurations");
		if (xmlString != null && xmlString.length() > 0) {
			try {
				ByteArrayInputStream in = new ByteArrayInputStream(xmlString.getBytes());
				IMemento memento = XMLMemento.loadMemento(in);
		
				IMemento[] children = memento.getChildren("config");
				if (children != null) {
					int size = children.length;
					for (int i = 0; i < size; i++) {
						Configuration monitor = new Configuration();
						monitor.load(children[i]);
						configurations.add(monitor);
					}
				}
			} catch (Exception e) {
				Trace.trace(Trace.WARNING, "Could not load configurations: " + e.getMessage());
			}
		}
	}
	
	protected void saveConfigurations() {
		try {
			ignorePreferenceChanges = true;
			XMLMemento memento = XMLMemento.createWriteRoot("configurations");

			Iterator iterator = configurations.iterator();
			while (iterator.hasNext()) {
				Configuration monitor = (Configuration) iterator.next();
				IMemento child = memento.createChild("config");
				monitor.save(child);
			}
			
			String xmlString = memento.saveToString();
			Preferences prefs = WikiEditorPlugin.getDefault().getPluginPreferences();
			prefs.setValue("configurations", xmlString);
			WikiEditorPlugin.getDefault().savePluginPreferences();
		} catch (Exception e) {
			Trace.trace(Trace.SEVERE, "Could not save Configurations", e);
		}
		ignorePreferenceChanges = false;
	}
}