package jaxe;

import java.awt.EventQueue;
import java.beans.*;
import javax.swing.event.SwingPropertyChangeSupport;
import javax.swing.JOptionPane;
import textbender.recombinant.common.awt.RunBuffer;
import textbender.recombinant.common.beans.PropertyListenerRegistryN;
import textbender.recombinant.common.hold.Spool0;
import textbender.recombinant.common.lang.*;
import textbender.recombinant.common.util.prefs.PreferencesX;


/** Common instances.
  * The single instance of Common itself is available via Common.i().
  *
  *     @author Michael Allan <mike@zelea.com>
  */
public final class Common

    implements PropertyListenerRegistryN, Thread.UncaughtExceptionHandler, ThrowableHolderModel
{

    /** The single instance of Common.
      * <p>
      *     It is not thread safe. Except where marked otherwise,
      *     clients are restricted to the AWT event dispatch thread.
      *     </p>
      */
    public static Common i() { return instance; }



    private Common()
    {
        Thread.setDefaultUncaughtExceptionHandler( Common.this );
    }



   // ````````````````````````````````````````````````````````````````````````````````````
   // First, so available during initialization below.


    private final SwingPropertyChangeSupport propertyChangeSupport
        = new SwingPropertyChangeSupport( /*source bean*/Common.this );


   // ------------------------------------------------------------------------------------


    /** A shared run buffer with a slow queue, invoking runs once per second.
      */
    public RunBuffer slowRunBuffer() { return slowRunBuffer; }


        private final RunBuffer slowRunBuffer = new RunBuffer
            ( /*interInvocationMilliseconds*/1000 );



   // - P r o p e r t y - L i s t e n e r - R e g i s t r y ------------------------------


    public void addPropertyChangeListener( PropertyChangeListener listener )
    {
        assert java.awt.EventQueue.isDispatchThread();
        propertyChangeSupport.addPropertyChangeListener( listener );
    }



    public void removePropertyChangeListener( PropertyChangeListener listener )
    {
        assert java.awt.EventQueue.isDispatchThread();
        propertyChangeSupport.removePropertyChangeListener( listener );
    }



   // - P r o p e r t y - L i s t e n e r - R e g i s t r y - N --------------------------


    public void addPropertyChangeListener( String propertyName, PropertyChangeListener listener )
    {
        assert java.awt.EventQueue.isDispatchThread();
        propertyChangeSupport.addPropertyChangeListener( propertyName, listener );
    }



    public void removePropertyChangeListener( String propertyName, PropertyChangeListener listener )
    {
        assert java.awt.EventQueue.isDispatchThread();
        propertyChangeSupport.removePropertyChangeListener( propertyName, listener );
    }



   // - T h r o w a b l e - H o l d e r --------------------------------------------------


    /** Returns the last throwable shown, per {@linkplain #showThrowable showThrowable}.
      * The return value is bound to property name <tt>throwable</tt>.
      */
    public Throwable getThrowable() { return throwable; }


        private Throwable throwable;


        private final ThrowableHolderV throwableView;
        {
            JOptionPane optionPane = new JOptionPane();
            {
                optionPane.setMessageType( JOptionPane.ERROR_MESSAGE );

                final String closeOption = "Close";
                optionPane.setOptions( new Object[]{ closeOption });
                optionPane.setInitialValue( closeOption );
            }
            throwableView = new ThrowableHolderV( optionPane, Spool0.i() ).init2 // Spool0, never released
            (
                Common.this, /*dialog parent*/null,
                PreferencesX.userNodeForClass( Common.class ), slowRunBuffer()
            );
        }


        /** Shows a throwable in a modal dialog.
          * Use this to display errors or exceptions that occur in response to user actions.
          *
          *     @throws NullPointerException if the throwable is null
          *
          *     @see #getThrowable
          */
        public final void showThrowable( Throwable newThrowable )
        {
            assert java.awt.EventQueue.isDispatchThread();
            final Throwable oldThrowable = throwable;
            if( newThrowable.equals( oldThrowable )) return;

            throwable = newThrowable;
            propertyChangeSupport.firePropertyChange( "throwable", oldThrowable, newThrowable );

            throwableView.dialog().setVisible( true );
        }



   // - U n c a u g h t - E x c e p t i o n - H a n d l e r ------------------------------


    /** Handles an otherwise uncaught exception. Thread safe, though other members are not.
      */
    public void uncaughtException( Thread thread, final Throwable throwable )
    {
        if( throwable instanceof ThreadDeath ) throw (ThreadDeath)throwable; // always let it die

        EventQueue.invokeLater( new Runnable()
        {
            public final void run() { showThrowable( throwable ); } // in AWT event dispatch thread
        });
    }



//////////////////////////////////////////////////////////////////////////////////////////
// Last, so static fields above initialize, and are available during instantiation below


    private static final Common instance = new Common();



}