/*
   Copyright (C) 2000 - 2007 Grid Systems, S.A.
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2, as
   published by the Free Software Foundation.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  GNU General Public License for more details.
  
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
  
  /*
   * Project: KernelConfigurator
   * Created on 24-feb-2004
   *
   * Copyright (c)2003 Grid Systems
   */
  package com.gridsystems.config.app;
  
  import java.awt.BorderLayout;
  import java.awt.Color;
  import java.awt.Component;
  import java.awt.Dimension;
  import java.awt.FlowLayout;
  import java.awt.Font;
  import java.awt.GridBagConstraints;
  import java.awt.GridBagLayout;
  import java.awt.Insets;
  import java.awt.event.ActionEvent;
  import java.text.MessageFormat;
  import java.util.Stack;
  
  import javax.swing.AbstractAction;
  import javax.swing.Action;
  import javax.swing.BorderFactory;
  import javax.swing.Icon;
  import javax.swing.InputVerifier;
  import javax.swing.JButton;
  import javax.swing.JComponent;
  import javax.swing.JLabel;
  import javax.swing.JPanel;
  import javax.swing.JProgressBar;
  import javax.swing.event.ChangeEvent;
  import javax.swing.event.ChangeListener;
  
  import com.gridsystems.config.Configurator;
  import com.gridsystems.config.ConfiguratorView;
  import com.gridsystems.config.ErrorListener;
  import com.gridsystems.config.SwingConfiguratorView;
  import com.gridsystems.config.tools.swing.SwingTools;
  
  /**
   * Specialized JPanel that handles the active configurator and its swing view.
   *
   * @author <a href="mailto:rruiz@gridsystems.com">Rodrigo Ruiz Aguayo</a>
   * @version 1.0
   */
  public class ConfigPanel extends JPanel implements ChangeListener, ErrorListener {
    /**
     * Configurator instance.
     */
    private Configurator cfg = null;
  
    /**
     * View instance.
     */
    private JComponent component = null;
  
    /**
     * Head banner.
     */
    private JPanel header = null;
  
    /**
     * Button panel.
     */
    private JPanel footer = null;
  
    /**
     * Configurator name.
     */
    private JLabel lblName = null;
  
    /**
     * Configurator description.
     */
    private JLabel lblDescription = null;
  
    /**
     * Configurator icon.
     */
    private JLabel lblIcon = null;
  
   /**
    * Apply button.
    */
   private JButton btnApply = new JButton();
 
   /**
    * Discard button.
    */
   private JButton btnDiscard = new JButton();
 
   /**
    * Apply action instance.
    */
   private Action actApply;
 
   /**
    * Discard action instance.
    */
   private Action actDiscard;
 
   /**
    * Progress bar to tell to wait.
    */
   private JProgressBar progressBar = null;
 
   /**
    * Stores the previous message (from a label) it it has to be temporally changed.
    */
   private String oldMessage = null;
 
   /**
    * Default constructor.
    */
   public ConfigPanel() {
     super(new BorderLayout());
     setPreferredSize(new Dimension(400, 400));
     JLabel label = new JLabel(UI.getString("lblSelectConfig"));
     label.setHorizontalAlignment(JLabel.CENTER);
     this.add(label, BorderLayout.CENTER);
     this.component = label;
 
     // Ensures Swing Mode is active
     Configurator.setViewMode(Configurator.MODE_SWING);
   }
 
   /**
    * Changes the configurator managed by this instance.
    *
    * @param c A configurator instance
    */
   public void setConfigurator(Configurator c) {
     if (this.cfg != null) {
       this.cfg.setErrorListener(null);
     }
 
     if (c != null) {
       this.cfg = c;
       this.cfg.setErrorListener(this);
       setComponent(cfg);
       updateHeader();
       updateFooter();
 
       this.validate();
       this.repaint();
     }
   }
 
   /**
    * Gets the current edition component.
    *
    * @return The current component
    */
   public JComponent getComponent() {
     return this.component;
   }
 
   /**
    * Adds an error to the component error stack.
    *
    * @param id  The error id
    * @param msg The error message
    * @param add The error action
    */
   public void updateError(String id, String msg, boolean add) {
     Stack<String> stack = getErrorStack();
     stack.remove(msg);
     if (add) {
       stack.push(msg);
     }
     updateHeader();
     updateFooter();
   }
 
   /**
    * @see ErrorListener#clearErrors()
    */
   public void clearErrors() {
     Stack stack = getErrorStack();
     stack.clear();
     updateHeader();
     updateFooter();
   }
 
   /**
    * Gets the error stack from the current component.
    *
    * @return The current component stack, or null if there is no current component
    */
   private Stack<String> getErrorStack() {
     Stack<String> stack = null;
     if (component != null) {
       stack = (Stack<String>)component.getClientProperty("error.messages");
       if (stack == null) {
         stack = new Stack<String>();
         component.putClientProperty("error.messages", stack);
       }
     }
     return stack;
   }
 
   /**
    * Changes the active view to the one returned by the specified configurator.
    *
    * @param c The configurator
    */
   private void setComponent(Configurator c) {
     SwingConfiguratorView view = (SwingConfiguratorView) c.getView();
 
     remove(component);
     if (component == this.progressBar) {
       progressBar = null;
     }
     component = view.getComponent();
     add(component, BorderLayout.CENTER);
 
     view.addChangeListener(this);
   }
 
   /**
    * Refreshes the header displayed information with data obtained from the
    * active view.
    */
   private void updateHeader() {
     if (header == null) {
       header = new JPanel(new GridBagLayout());
       header.setBorder(BorderFactory.createMatteBorder(0, 0, 1, 0, Color.GRAY));
       header.setBackground(Color.WHITE);
       header.setPreferredSize(new Dimension(100, 60));
       this.add(header, BorderLayout.NORTH);
 
       lblName = new JLabel();
       header.add(lblName, new GridBagConstraints(0, 0, 1, 1, 1.0, 0,
           GridBagConstraints.WEST, GridBagConstraints.BOTH,
           new Insets(2, 2, 2, 2), 0, 0));
 
       lblName.setFont(Font.decode("Sans Serif-BOLD-22"));
 
       lblDescription = new JLabel();
       header.add(lblDescription, new GridBagConstraints(0, 1, 1, 1, 1.0, 0,
           GridBagConstraints.WEST, GridBagConstraints.BOTH,
           new Insets(2, 2, 2, 2), 0, 0));
 
       lblDescription.setFont(Font.decode("Sans Serif-ITALIC-12"));
 
       lblIcon = new JLabel();
       header.add(lblIcon, new GridBagConstraints(1, 0, 1, 2, 0, 0,
           GridBagConstraints.CENTER, GridBagConstraints.BOTH,
           new Insets(2, 2, 2, 2), 0, 0));
     }
 
     String name = cfg.getView().getTitle();
     lblName.setText(name == null ? "" : name);
 
     Stack stack = getErrorStack();
     if (stack == null || stack.isEmpty()) {
       String description = cfg.getView().getSubtitle();
       lblDescription.setText(description == null ? "" : description);
       lblDescription.setIcon(null);
       lblDescription.setForeground(Color.BLACK);
     } else {
       String msg = (String)stack.peek();
       lblDescription.setText(msg);
       lblDescription.setForeground(Color.RED);
     }
 
     ConfiguratorView view = cfg.getView();
     if (view != null && view instanceof SwingConfiguratorView) {
       Icon icon = ((SwingConfiguratorView) view).getIcon();
       lblIcon.setIcon(icon);
     }
   }
 
   /**
    * Refreshes the bottom buttons depending on the "modified" state of the
    * active view.
    */
   private void updateFooter() {
     if (footer == null) {
       footer = new JPanel(new FlowLayout(FlowLayout.TRAILING));
       footer.setBorder(BorderFactory.createMatteBorder(1, 0, 0, 0, Color.BLACK));
 
       footer.add(btnApply);
       footer.add(btnDiscard);
 
       actApply = new ApplyAction();
       btnApply.setAction(actApply);
 
       actDiscard = new DiscardAction();
       btnDiscard.setAction(actDiscard);
 
       this.add(footer, BorderLayout.SOUTH);
     }
 
     ConfiguratorView view = cfg.getView();
     if (view != null && view instanceof SwingConfiguratorView) {
       Stack stack = getErrorStack();
       boolean modified = true;
       boolean error = stack != null && !stack.isEmpty();
       actApply.setEnabled(modified && !error);
       actDiscard.setEnabled(modified || error);
     }
   }
 
   /**
    * Action to be performed on "Apply" button press.
    *
    * @author <a href="mailto:rruiz@gridsystems.com">Rodrigo Ruiz Aguayo</a>
    * @version 1.0
    */
   private class ApplyAction extends AbstractAction {
     /**
      * Creates an instance.
      */
     public ApplyAction() {
       super(UI.getString("btnApply.text"));
     }
 
     /**
      * {@inheritDoc}
      */
     public void actionPerformed(ActionEvent event) {
       Configurator config = ConfigPanel.this.cfg;
       try {
         if (config != null) {
           config.apply();
           SwingTools.showInformation(UI.getString("lblChangesApplied"));
         }
       } catch (Exception e) {
         String pattern = UI.getString("errors.apply_error");
         Object[] params = { config.getName()};
         String message = MessageFormat.format(pattern, params);
         SwingTools.showError(message, e);
       }
     }
   }
 
   /**
    * Action to be performed on "Discard" button press.
    *
    * @author <a href="mailto:rruiz@gridsystems.com">Rodrigo Ruiz Aguayo</a>
    * @version 1.0
    */
   private class DiscardAction extends AbstractAction {
     /**
      * Default constructor.
      */
     public DiscardAction() {
       super(UI.getString("btnDiscard.text"));
     }
 
     /**
      * {@inheritDoc}
      */
     public void actionPerformed(ActionEvent event) {
       ConfigPanel.this.cfg.discard();
       verifyAll(ConfigPanel.this.component);
     }
   }
 
   /**
    * {@inheritDoc}
    */
   public void stateChanged(ChangeEvent e) {
     updateFooter();
   }
 
   /**
    * Forces a verify on all components in the specified component.
    *
    * @param c  The component to verify
    */
   private void verifyAll(JComponent c) {
     if (c.isEnabled()) {
       InputVerifier verifier = c.getInputVerifier();
       if (verifier != null) {
         verifier.verify(c);
       }
 
       Component[] children = c.getComponents();
       int count = children == null ? 0 : children.length;
       for (int i = 0; i < count; i++) {
         if (children[i] instanceof JComponent) {
           verifyAll((JComponent)children[i]);
         }
       }
     }
   }
 
   /**
    * Shows a message telling that the configurator tree is being expanded.
    *
    * Shows a message telling that the configurator tree is being expanded. The
    * previous message is stored at <code>oldMessage</code> to be shown again
    * when the expansion finishes.
    */
   public void showExpansionMessage() {
     if (this.component instanceof JLabel) {
       JLabel jlabel = (JLabel) this.component;
       this.oldMessage = jlabel.getText();
       jlabel.setText(UI.getString("lblExpandTree"));
       jlabel.validate();
       jlabel.paintImmediately(this.getVisibleRect());
     } else {
       this.oldMessage = null;
     }
   }
 
   /**
    * Hides the message showed by <code>showExpansionMessage</code>.
    *
    * Hides the message showed by <code>showExpansionMessage</code> and restores
    * the message stored at <code>oldMessage</code>.
    */
   public void hideExpansionMessage() {
     if ((this.oldMessage != null) && (this.component instanceof JLabel)) {
       JLabel jlabel = (JLabel) this.component;
       jlabel.setText(this.oldMessage);
       jlabel.validate();
       jlabel.paintImmediately(this.getVisibleRect());
     }
   }
 }