/**
 * 
 */
package com.onaro.sanscreen.client.prefs;

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.util.List;

import javax.swing.AbstractButton;
import javax.swing.BorderFactory;
import javax.swing.JButton;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.eclipse.core.runtime.IConfigurationElement;

import com.jidesoft.dialog.ButtonPanel;
import com.onaro.client.leekui.jface.preferences.IPreferenceNode;
import com.onaro.client.leekui.jface.preferences.PreferenceDialog;
import com.onaro.client.leekui.ui.IConfigurationFilter;
import com.onaro.sanscreen.client.MainDirector;
import com.onaro.sanscreen.client.error.CentralErrorHandler;
import com.onaro.sanscreen.client.features.FeatureManager;
import com.onaro.sanscreen.client.help.HelpManager;
import com.onaro.sanscreen.client.help.HelpManagerFactory;
import com.onaro.sanscreen.client.help.IHelpManager;
import com.onaro.util.IllegalInitException;
import com.onaro.util.jfc.ConfigurableAction;

/**
 * Class that specializes PreferenceDialog to support
 * context-sensitive help.
 * 
 * @author barrykl
 */
public class SettingsDialog extends PreferenceDialog {
    
    private static final long serialVersionUID = 1L;
    private static final String HELP_BUTTON_RESOURCE = "main.help"; //$NON-NLS-1$
    private static Logger logger = LogManager.getLogger (SettingsDialog.class);

    /**
     * Class used to filter our preferences whose required features are not enabled.
     */
    private static class PreferenceFilter implements IConfigurationFilter {
        @Override
        public List<IConfigurationElement> filter (IConfigurationElement... elements) {
            return FeatureManager.getInstance().filterByEnabledFeatures (elements);
        }
    }
    /**
     * Filter to exclude preferences whose required features are not enabled.
     * Is public only so
     * {@link com.onaro.sanscreen.client.test.PluginTestVisibilityByLicense PluginTestVisibilityByLicense}
     * can reference it.
     */
    public static final PreferenceFilter preferenceFilter = new PreferenceFilter();
    
    private ButtonPanel dialogButtonPanel;
    private JButton helpButton;

    // Help context that should be used as root context by all pages added to the dialog.
    public static String SANSCREEN_SETTINGS_CONTEXT = HelpManager.SANSCREEN_CLIENT_ROOT_CONTEXT + ".settings"; //$NON-NLS-1$

    /**
     * 
     */
    public SettingsDialog (String title) {
        super (preferenceFilter);
        setTitle (title);
        setPreferenceStore (ClientPrefs.getSettings());
        setExceptionListener (CentralErrorHandler.getInstance());
        
        // Set default help context for dialog. Enable F1 key to invoke help.
        final IHelpManager helpManager = HelpManagerFactory.getHelpManager();
        helpManager.setHelpContext (getContentPane(), SANSCREEN_SETTINGS_CONTEXT);
        helpManager.enableHelpKey (getContentPane(), SANSCREEN_SETTINGS_CONTEXT);
    }

    /**
     * Set context help ID to page's context when a page is shown.
     * 
     * @see com.onaro.client.leekui.jface.preferences.PreferenceDialog#showPage(com.onaro.client.leekui.jface.preferences.IPreferenceNode)
     */
    @Override
    protected boolean showPage (final IPreferenceNode node) {
        boolean isShown = super.showPage (node);
        if (isShown) {
            
            // Set help context for newly shown page. Enable F1 key to invoke help.
            String helpContext = SANSCREEN_SETTINGS_CONTEXT + "." + node.getId();  //$NON-NLS-1$
            logger.debug ("Help context set to "  //$NON-NLS-1$
                          + helpContext
                          + " for page "  //$NON-NLS-1$
                          + node.getLabelText());            
            final IHelpManager helpManager = HelpManagerFactory.getHelpManager();
            helpManager.setHelpContext (getContentPane(), helpContext);
            helpManager.enableHelpKey (getContentPane(), helpContext);
        }
        return isShown;
    }
    
    /**
     * This method creates a button panel with a help button.
     *     
     * @return com.jidesoft.dialog.ButtonPanel    
     */
    protected ButtonPanel getButtonPanel() {
        if (dialogButtonPanel == null) {
            dialogButtonPanel = new ButtonPanel();
            dialogButtonPanel.setBorder (BorderFactory.createCompoundBorder (
                    BorderFactory.createMatteBorder (1, 0, 0, 0, Color.gray),
                    BorderFactory.createEmptyBorder (5, 5, 5, 5)));
            dialogButtonPanel.add (getHelpButton(), ButtonPanel.HELP_BUTTON);
            dialogButtonPanel.add (getOkButton(), ButtonPanel.AFFIRMATIVE_BUTTON);
            dialogButtonPanel.add (getCancelButton(), ButtonPanel.CANCEL_BUTTON);
        }
        return dialogButtonPanel;
    }

    protected AbstractButton getHelpButton() {
        if (helpButton == null) {
            final IHelpManager helpManager = HelpManagerFactory.getHelpManager();
            
            // Load button action.
            ConfigurableAction action;
            try {
                action = new ConfigurableAction (HELP_BUTTON_RESOURCE, MainDirector.resources) {
                    @Override
                    public void actionPerformed (ActionEvent e) {
                        // Do nothing. Action handled by Help Manager listener.
                    }
                    private static final long serialVersionUID = 1L;
                    };
            }
            catch (IllegalInitException e) {
                logger.warn ("Could not load help button; " + e); //$NON-NLS-1$
                return null;
            }
            
            // Create button. Add Help Manager listener.
            helpButton = new JButton (action);
            helpManager.registerHelpInvoker (helpButton);
        }
        return helpButton;
    }
}