// This Source Code is in the Public Domain per: http://litesoft.org/License.txt
package org.litesoft.render;

import org.litesoft.commonfoundation.base.*;
import org.litesoft.core.delayed.*;

public class TicklerForRPM implements RenderProcessManager.Listener,
                                      TimedRunnable
{
    private final MillisecTimeSource mMillisecTimeSource;
    private final TimedRunner mTimedRunner;

    public TicklerForRPM( MillisecTimeSource pMillisecTimeSource, TimedRunner pTimedRunner )
    {
        mMillisecTimeSource = MillisecTimeSource.deNull( pMillisecTimeSource );
        mTimedRunner = pTimedRunner;
    }

    public TicklerForRPM( TimedRunner pTimedRunner )
    {
        this( null, pTimedRunner );
    }

    public Again runOnce()
    {
        if ( !mProcessing )
        {
            Long zNextTime = process();
            if ( zNextTime != null )
            {
                return new RunAgainOnOrAfter( zNextTime );
            }
        }
        return null;
    }

    public void processManagerNowHasProcesses()
    {
        if ( !mProcessing )
        {
            mTimedRunner.runIn( this, 1 ); // Defer queue processing until current thread is complete
            // Use to execute immediately - but that caused certain Callbacks to be added AFTER the process had completed!
            //Long zNextTime = process();
            //if ( zNextTime != null )
            //{
            //    mTimedRunner.runOnOrAfter( this, zNextTime );
            //}
        }
    }

    private boolean mProcessing = false;

    private Long process()
    {
        mProcessing = true;
        long zEnd, zStarted = mMillisecTimeSource.now();

        RenderProcessManager zRPM = RenderProcessManager.INSTANCE;

        do
        {
            for ( int i = 0; i < 100; i++ )
            {
                RenderHelperProcess zProcess = zRPM.first();
                if ( zProcess == null )
                {
                    mProcessing = false;
                    return zRPM.whenIsNextDeferredProcess();
                }
                zProcess.process();
            }
            zEnd = mMillisecTimeSource.now();
        }
        while ( (zEnd - zStarted) < 5000 ); // 5 Secs Max at a time!

        mProcessing = false;
        return (zEnd + 50); // 50 millisecs
    }
}