// This Source Code is in the Public Domain per: http://unlicense.org
package org.litesoft.GWT.client.nonpublic;

import java.util.*;

import org.litesoft.GWT.client.*;

import com.google.gwt.core.client.*;
import com.google.gwt.event.logical.shared.*;
import com.google.gwt.user.client.*;
import com.google.gwt.user.client.ui.*;

public class AbstractPopupManager implements CloseHandler<PopupPanel>
{
    protected static void show( AbstractEntry pEntry )
    {
        INSTANCE.addAndShow( pEntry );
    }

    private static final AbstractPopupManager INSTANCE = new AbstractPopupManager();

    private void addAndShow( AbstractEntry pEntry )
    {
        if ( add( pEntry ) && !showing() )
        {
            pEntry = getEntry();
            if ( pEntry != null )
            {
                pEntry.show( this );
            }
        }
    }

    @Override
    public void onClose( CloseEvent<PopupPanel> event )
    {
        AbstractEntry zEntry = nextEntry();
        if ( zEntry != null )
        {
            zEntry.show( this );
        }
    }

    private synchronized boolean add( AbstractEntry pEntry )
    {
        String zFrom = pEntry.getFrom();
        if ( mFromsInQueue.contains( zFrom ) )
        {
            return false;
        }
        mFromsInQueue.add( zFrom );
        mFromQueue.add( pEntry );
        return true;
    }

    private boolean mShowing = false;
    private List<AbstractEntry> mFromQueue = new ArrayList<AbstractEntry>();
    private Set<String> mFromsInQueue = new HashSet<String>();

    /**
     * Will "manage" the mShowing flag
     */
    private synchronized boolean showing()
    {
        boolean rv = mShowing;
        mShowing = true;
        return rv;
    }

    /**
     * Will "manage" the mShowing flag in conjunction w/ the mFromQueue
     */
    private synchronized AbstractEntry getEntry()
    {
        if ( !mFromQueue.isEmpty() )
        {
            return mFromQueue.get( 0 );
        }
        mShowing = false;
        return null;
    }

    private synchronized AbstractEntry nextEntry()
    {
        if ( !mFromQueue.isEmpty() )
        {
            AbstractEntry entry = mFromQueue.remove( 0 );
            mFromsInQueue.remove( entry.getFrom() );
        }
        return getEntry();
    }

    protected abstract static class AbstractEntry
    {
        private String mFrom;
        protected String mTitle, mBody;
        protected DialogCloseCallBack mCloseCallBack;

        public AbstractEntry( String pFrom, String pTitle, String pBody, DialogCloseCallBack pCloseCallBack )
        {
            mFrom = pFrom;
            mTitle = pTitle;
            mBody = pBody;
            mCloseCallBack = pCloseCallBack;
        }

        public String getFrom()
        {
            return mFrom;
        }

        public void show( CloseHandler<PopupPanel> pCloseHandler )
        {
            final AbstractMessageDialog zDialog = create();
            zDialog.addCloseHandler( pCloseHandler );
            Scheduler.get().scheduleDeferred( new Command()
            {
                @Override
                public void execute()
                {
                    zDialog.show();
                }
            } );
        }

        abstract protected AbstractMessageDialog create();
    }

    public static void prefetchImages()
    {
        Image.prefetch( "common/images/misc/InfoIcon.gif" );
        Image.prefetch( "common/images/misc/ConfirmIcon.gif" );
        Image.prefetch( "common/images/misc/AlertError.gif" );

        Image.prefetch( "common/images/misc/dialogShadow/ShadowTopLeft.png" );
        Image.prefetch( "common/images/misc/dialogShadow/ShadowUpStraight.png" );
        Image.prefetch( "common/images/misc/dialogShadow/ShadowTopRight.png" );
        Image.prefetch( "common/images/misc/dialogShadow/ShadowLeftStraight.png" );
        Image.prefetch( "common/images/misc/dialogShadow/ShadowRightStraight.png" );
        Image.prefetch( "common/images/misc/dialogShadow/ShadowBottomLeft.png" );
        Image.prefetch( "common/images/misc/dialogShadow/ShadowDownStraight.png" );
        Image.prefetch( "common/images/misc/dialogShadow/ShadowBottomRight.png" );

        // Both LnFs are prefetched, need to only load once per theme
        Image.prefetch( "common/lnf/classic/Dialog/CornerBottomLeft.png" );
        Image.prefetch( "common/lnf/classic/Dialog/CornerBottomLeftDown.png" );
        Image.prefetch( "common/lnf/classic/Dialog/CornerBottomLeftUp.png" );
        Image.prefetch( "common/lnf/classic/Dialog/CornerBottomRight.png" );
        Image.prefetch( "common/lnf/classic/Dialog/CornerBottomRightDown.png" );
        Image.prefetch( "common/lnf/classic/Dialog/CornerBottomRightUp.png" );
        Image.prefetch( "common/lnf/classic/Dialog/CornerTopLeft.png" );
        Image.prefetch( "common/lnf/classic/Dialog/CornerTopLeftDown.png" );
        Image.prefetch( "common/lnf/classic/Dialog/CornerTopLeftUp.png" );
        Image.prefetch( "common/lnf/classic/Dialog/CornerTopRight.png" );
        Image.prefetch( "common/lnf/classic/Dialog/CornerTopRightDown.png" );
        Image.prefetch( "common/lnf/classic/Dialog/CornerTopRightUp.png" );
        Image.prefetch( "common/lnf/classic/Dialog/StraightBottom.png" );
        Image.prefetch( "common/lnf/classic/Dialog/StraightLeftCaption.png" );
        Image.prefetch( "common/lnf/classic/Dialog/StraightLeftContent.png" );
        Image.prefetch( "common/lnf/classic/Dialog/StraightRightCaption.png" );
        Image.prefetch( "common/lnf/classic/Dialog/StraightRightContent.png" );
        Image.prefetch( "common/lnf/classic/Dialog/StraightTop.png" );

        Image.prefetch( "common/lnf/classic_rounded/Dialog/CornerBottomLeft.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/CornerBottomLeftDown.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/CornerBottomLeftUp.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/CornerBottomRight.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/CornerBottomRightDown.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/CornerBottomRightUp.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/CornerTopLeft.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/CornerTopLeftDown.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/CornerTopLeftUp.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/CornerTopRight.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/CornerTopRightDown.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/CornerTopRightUp.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/StraightBottom.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/StraightLeftCaption.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/StraightLeftContent.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/StraightRightCaption.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/StraightRightContent.png" );
        Image.prefetch( "common/lnf/classic_rounded/Dialog/StraightTop.png" );
    }
}