/*
 * Copyright (c) 2003-2010 The Regents of the University of California.
 * All rights reserved.
 *
 * '$Author: barseghian $'
 * '$Date: 2013-01-16 23:42:20 +0000 (Wed, 16 Jan 2013) $' 
 * '$Revision: 31342 $'
 * 
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and its documentation for any purpose, provided that the above
 * copyright notice and the following two paragraphs appear in all copies
 * of this software.
 *
 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
 * FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * 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 OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
 * ENHANCEMENTS, OR MODIFICATIONS.
 *
 */

package org.kepler.authentication.gui;

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.IOException;
import java.util.Vector;

import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.UIManager;

import org.kepler.authentication.DomainList;
import org.kepler.authentication.ProxyRepository;

/**
 * LoginGUI pops up the login dialog to let user login, retrieves credential
 * from GAMA server, and stores the credential into ProxyRepository.
 * 
 * @author Zhijie Guan guan@sdsc.edu
 * 
 */

public class GAMALoginGUI extends JPanel implements ActionListener {
        private static ProxyRepository proxyRepository; // the proxyrepository got
                                                                                                        // from
                                                                                                        // AuthenticationManager
        private static JFrame controllingFrame; // The Frame of login dialog

        // Command button constants
        private String OK = "ok";
        private String RESET = "reset";

        // Input fields
        private JTextField userNameField;
        private JPasswordField passwordField;
        private JComboBox domainField;
        private static Vector domainList;

        private static String username = null;
        private static String password = null;
        
        // XXX magic string, get rid of this
        public static String USERNAME_BREAK = "BREAK";

        /**
         * The constructor is used to build all the display components
         * 
         */
        public GAMALoginGUI() {
                // Create everything.
                // User Name field, label, and pane
                try {
                        domainList = DomainList.getInstance().getDomainList();
                } catch (IOException ioe) {
                        JOptionPane.showMessageDialog(this, "There was an error "
                                        + "reading the domain list: " + ioe.getMessage());
                }
                userNameField = new JTextField(20);
                JLabel userNameLabel = new JLabel("Enter your user name: ");
                userNameLabel.setLabelFor(userNameField);
                JPanel userNamePane = new JPanel(new FlowLayout());
                userNamePane.add(userNameLabel);
                userNamePane.add(userNameField);

                // Password field, label, and pane
                passwordField = new JPasswordField(20);
                passwordField.setEchoChar('#');
                passwordField.setActionCommand(OK);
                passwordField.addActionListener(this);
                JLabel passwordLabel = new JLabel("Enter the password: ");
                passwordLabel.setLabelFor(passwordField);
                JPanel passwordPane = new JPanel(new FlowLayout());
                passwordPane.add(passwordLabel);
                passwordPane.add(passwordField);

                // Domain field, label, and pane

                domainField = new JComboBox(domainList);
                domainField.setSelectedIndex(0);
                ComboBoxRenderer renderer = new ComboBoxRenderer();
                domainField.setRenderer(renderer);
                JLabel domainLabel = new JLabel("Select the domain/subdomain: ");
                domainLabel.setLabelFor(domainField);
                JPanel domainPane = new JPanel(new FlowLayout());
                domainPane.add(domainLabel);
                domainPane.add(domainField);

                // Lay out input fields and labels on inputPane
                JPanel inputPane = new JPanel();
                inputPane.setLayout(new BoxLayout(inputPane, BoxLayout.Y_AXIS));
                inputPane.add(userNamePane);
                inputPane.add(passwordPane);
                inputPane.add(domainPane);

                // Buttons and their buttonPane
                JButton okButton = new JButton("OK");
                JButton resetButton = new JButton("Cancel");
                okButton.setActionCommand(OK);
                okButton.addActionListener(this);
                resetButton.setActionCommand(RESET);
                resetButton.addActionListener(this);
                JPanel buttonPane = new JPanel(new FlowLayout());
                buttonPane.add(okButton);
                buttonPane.add(resetButton);

                // Pane for the whole window
                setLayout(new BorderLayout());
                add(inputPane, BorderLayout.CENTER);
                add(buttonPane, BorderLayout.PAGE_END);
        }

        /**
         * Event listener
         */
        public void actionPerformed(ActionEvent e) {
                String cmd = e.getActionCommand();

                if (OK.equals(cmd)) { // User login and click OK button
                        char[] passwd = passwordField.getPassword();
                        password = new String(passwd);

                        // Zero out the possible password, for security.
                        for (int i = 0; i < passwd.length; i++) {
                                passwd[i] = 0;
                        }

                        username = userNameField.getText();
                } else if (RESET.equals(cmd)) { // CANCEL button is clicked.
                        controllingFrame.dispose();
                        username = USERNAME_BREAK;
                }
        }

        // Method to reset the focus of the login dialog
        // Must be called from the event-dispatching thread.
        protected void resetFocus() {
                userNameField.requestFocusInWindow();
        }

        /**
         * Create the GUI and show it. For thread safety, this method should be
         * invoked from the event-dispatching thread.
         */
        private static void createAndShowGUI() {
                // Make sure we have nice window decorations.
                try {
                        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (Exception e) {
                        e.printStackTrace();
                }

                // Create and set up the window.
                controllingFrame = new JFrame("GAMA Login");
                //controllingFrame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                controllingFrame.addWindowListener(new WindowAdapter(){
      public void windowClosing(WindowEvent e) {
        username = USERNAME_BREAK;
        controllingFrame.dispose();
      }
    }
    );

                // Create and set up the content pane.
                final GAMALoginGUI contentPane = new GAMALoginGUI();
                contentPane.setOpaque(true); // content panes must be opaque
                controllingFrame.setContentPane(contentPane);

                // Make sure the focus goes to the right component
                // whenever the frame is initially given the focus.
                controllingFrame.addWindowListener(new WindowAdapter() {
                        public void windowActivated(WindowEvent e) {
                                contentPane.resetFocus();
                        }
                });

                // Display the window.
                controllingFrame.pack();
                controllingFrame.setLocationRelativeTo(null); // stay in the center
                controllingFrame.setVisible(true);
        }

        /**
         * Function to show the login dialog It adds the login dialog into the
         * event-dispatching thread
         * 
         * @param p
         *            The ProxyRepository got from the AuthenticationManager
         */
        public static void fire() {
                // Schedule a job for the event-dispatching thread:
                // creating and showing this application's GUI.
                javax.swing.SwingUtilities.invokeLater(new Runnable() {
                        public void run() {
                                createAndShowGUI();
                        }
                });
        }

        /**
         * get the username from the gui
         */
        public static String getUsername() {
                return username;
        }

        /**
         * get the password from the gui
         */
        public static String getPassword() {
                return password;
        }
}