/*
 * Copyright (c) 2014 tabletoptool.com team.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/gpl.html
 * 
 * Contributors:
 *     rptools.com team - initial implementation
 *     tabletoptool.com team - further development
 */
package com.t3.swing.preference;

import java.awt.EventQueue;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;
import java.util.prefs.Preferences;

import javax.swing.JTree;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.TreePath;

public class TreePreferences implements TreeSelectionListener {

    private JTree tree;
    private Preferences prefs;
    
    private static final String PREF_PATH_KEY = "path";
    
    private static final String PATH_DELIMITER = "|";
    
    public TreePreferences(String appName, String controlName, JTree tree) {
        this.tree = tree;
        
        prefs = Preferences.userRoot().node(appName + "/control/" + controlName);        
        
        tree.getSelectionModel().addTreeSelectionListener(this);

        // Wait until the UI has been built to do this
        EventQueue.invokeLater(new Runnable() {
        	@Override
			public void run() {
                restorePreferences();
        	}
        });
    }
    
    private void restorePreferences() {
        
        String path = prefs.get(PREF_PATH_KEY, "");
        if (path == null || path.length() == 0) {
            // First time usage
            return;
        }

        StringTokenizer strtok = new StringTokenizer(path, PATH_DELIMITER);
        List<Object> pathList = new ArrayList<Object>();
        pathList.add(tree.getModel().getRoot());
        Object currentStep = tree.getModel().getRoot();
        while (strtok.hasMoreElements()) {

        	boolean found = false;
        	String nextStep = strtok.nextToken();
        	for (int i = 0; i < tree.getModel().getChildCount(currentStep); i++) {
        		Object element = tree.getModel().getChild(currentStep, i);
        		if (element != null && element.toString().equals(nextStep)) {
        			pathList.add(element);
        			currentStep = element;
        			found = true;
        			break;
        		}
        	}
        	if (!found) {
        		break;
        	}
        }

        if (pathList.size() > 0) {
        	TreePath treePath = new TreePath(pathList.toArray());
        	tree.expandPath(treePath);
        	tree.setSelectionPath(treePath);
        }
    }
    
    private void savePreferences() {

    	StringBuilder builder = new StringBuilder();
    	TreePath path = tree.getSelectionPath();
    	if (path == null) {
    		return;
    	}
    	
    	for (int i = 0; i < path.getPathCount(); i++) {
    		Object o = path.getPathComponent(i);
    		
    		builder.append(o).append(PATH_DELIMITER);
    	}
    	if (builder.length() > 0) {
    		// Kill the last delimiter
    		builder.setLength(builder.length() - 1);
    	}

    	String composedPath = builder.toString();
    	if (composedPath.startsWith(PATH_DELIMITER)) {
    		composedPath = composedPath.substring(1);
    	}
        prefs.put(PREF_PATH_KEY, composedPath);
    }
    
    ////
    // TREE SELECTION LISTENER
    @Override
	public void valueChanged(TreeSelectionEvent e) {
        savePreferences();
    }
}