package jmri.jmrit.audio;

import java.util.LinkedList;
import java.util.Queue;
import java.util.concurrent.ThreadLocalRandom;
import javax.annotation.Nonnull;
import javax.vecmath.Vector3f;
import jmri.Audio;
import jmri.AudioManager;
import jmri.InstanceManager;
import jmri.implementation.AbstractAudio;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Base implementation of the AudioSource class.
 * <p>
 * Specific implementations will extend this base class.
 * <br>
 * <hr>
 * This file is part of JMRI.
 * <p>
 * JMRI is free software; you can redistribute it and/or modify it under the
 * terms of version 2 of the GNU General Public License as published by the Free
 * Software Foundation. See the "COPYING" file for a copy of this license.
 * <p>
 * JMRI 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.
 *
 * @author Matthew Harris copyright (c) 2009
 */
public abstract class AbstractAudioSource extends AbstractAudio implements AudioSource {

    private Vector3f position = new Vector3f(0.0f, 0.0f, 0.0f);
    private Vector3f currentPosition = new Vector3f(0.0f, 0.0f, 0.0f);
    private Vector3f velocity = new Vector3f(0.0f, 0.0f, 0.0f);
    private float gain = 1.0f;
    private float pitch = 1.0f;
    private float referenceDistance = 1.0f;
    private float maximumDistance = Audio.MAX_DISTANCE;
    private float rollOffFactor = 1.0f;
    private int minLoops = LOOP_NONE;
    private int maxLoops = LOOP_NONE;
    private int numLoops = 0;
    // private int minLoopDelay = 0;
    // private int maxLoopDelay = 0;
    // private int loopDelay = 0;
    private int fadeInTime = 1000;
    private int fadeOutTime = 1000;
    private float fadeGain = 1.0f;
    private long timeOfLastFadeCheck = 0;
    private long timeOfLastPositionCheck = 0;
    private int fading = Audio.FADE_NONE;
    private boolean bound = false;
    private boolean positionRelative = false;
    private boolean queued = false;
    private long offset = 0;
    private AudioBuffer buffer;
    // private AudioSourceDelayThread asdt = null;
    private LinkedList<AudioBuffer> pendingBufferQueue = new LinkedList<>();

    private static final AudioFactory activeAudioFactory = InstanceManager.getDefault(jmri.AudioManager.class).getActiveAudioFactory();
    private static float metersPerUnit;

    /**
     * Abstract constructor for new AudioSource with system name
     *
     * @param systemName AudioSource object system name (e.g. IAS1)
     */
    public AbstractAudioSource(String systemName) {
        super(systemName);
        AudioListener al = activeAudioFactory.getActiveAudioListener();
        if (al != null) {
            storeMetersPerUnit(al.getMetersPerUnit());
        }
    }

    /**
     * Abstract constructor for new AudioSource with system name and user name
     *
     * @param systemName AudioSource object system name (e.g. IAS1)
     * @param userName   AudioSource object user name
     */
    public AbstractAudioSource(String systemName, String userName) {
        super(systemName, userName);
        AudioListener al = activeAudioFactory.getActiveAudioListener();
        if (al != null) {
            storeMetersPerUnit(al.getMetersPerUnit());
        }
    }

    private static void storeMetersPerUnit(float newVal) {
        metersPerUnit = newVal;
    }

    public boolean isAudioAlive() {
        return ((AudioThread) activeAudioFactory.getCommandThread()).isThreadAlive();
    }

    @Override
    public char getSubType() {
        return SOURCE;
    }

    @Override
    public boolean queueBuffers(Queue<AudioBuffer> audioBuffers) {
        // Note: Cannot queue buffers to a Source that has a bound buffer.
        if (!bound) {
            this.pendingBufferQueue = new LinkedList<>(audioBuffers);
            activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_QUEUE_BUFFERS));
            activeAudioFactory.getCommandThread().interrupt();
            if (log.isDebugEnabled() && (audioBuffers.peek() != null)) {
                log.debug("Queued Buffer {} to Source {}", audioBuffers.peek().getSystemName(), this.getSystemName());
            }
            return true;
        } else {
            if (audioBuffers.peek() != null) {
                log.error("Attempted to queue buffers {} (etc) to Bound Source {}", audioBuffers.peek().getSystemName(), this.getSystemName());
            }
            return false;
        }
    }

    @Override
    public boolean queueBuffer(AudioBuffer audioBuffer) {
        if (!bound) {
            //this.pendingBufferQueue.clear();
            this.pendingBufferQueue.add(audioBuffer);
            activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_QUEUE_BUFFERS));
            activeAudioFactory.getCommandThread().interrupt();
            if (log.isDebugEnabled()) {
                log.debug("Queued Buffer {} to Source {}", audioBuffer.getSystemName(), this.getSystemName());
            }
            return true;
        } else {
            log.error("Attempted to queue buffer {} to Bound Source {}", audioBuffer.getSystemName(), this.getSystemName());
            return false;
        }
    }

    @Override
    public boolean unqueueBuffers() {
        if (bound) {
            log.error("Attempted to unqueue buffers on Bound Source {}", this.getSystemName());
            return false;
        } else if (queued) {
            activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_UNQUEUE_BUFFERS));
            activeAudioFactory.getCommandThread().interrupt();
            if (log.isDebugEnabled()) {
                log.debug("Unqueued Processed Buffers on Source {}", this.getSystemName());
            }
            return true;
        } else {
            log.debug("Source neither queued nor bound. Not an error. {}", this.getSystemName());
            return false;
        }
    }

    public Queue<AudioBuffer> getQueuedBuffers() {
        return this.pendingBufferQueue;
    }

    @Override
    public void setAssignedBuffer(AudioBuffer audioBuffer) {
        if (!queued) {
            this.buffer = audioBuffer;
            // Ensure that the source is stopped
            this.stop(false);
            activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_BIND_BUFFER));
            activeAudioFactory.getCommandThread().interrupt();
            if (log.isDebugEnabled()) {
                log.debug("Assigned Buffer {} to Source {}", audioBuffer.getSystemName(), this.getSystemName());
            }
        } else {
            log.error("Attempted to assign buffer {} to Queued Source {}", audioBuffer.getSystemName(), this.getSystemName());
        }
    }

    @Override
    public void setAssignedBuffer(String bufferSystemName) {
        if (!queued) {
            AudioManager am = InstanceManager.getDefault(jmri.AudioManager.class);
            Audio a = am.getBySystemName(bufferSystemName);
            if (a != null && a.getSubType() == Audio.BUFFER) {
                setAssignedBuffer((AudioBuffer) a);
            } else {
                log.warn("Attempt to assign incorrect object type to buffer - AudioBuffer expected.");
                this.buffer = null;
                this.bound = false;
            }
        } else {
            log.error("Attempted to assign buffer {} to Queued Source {}", bufferSystemName, this.getSystemName());
        }
    }

    @Override
    public AudioBuffer getAssignedBuffer() {
        return this.buffer;
    }

    @Override
    public String getAssignedBufferName() {
        return (buffer != null) ? buffer.getSystemName() : "[none]";
    }

    @Override
    public void setPosition(Vector3f pos) {
        this.position = pos;
        this.currentPosition = pos;
        changePosition(pos);
        if (log.isDebugEnabled()) {
            log.debug("Set position of Source {} to {}", this.getSystemName(), pos);
        }
    }

    @Override
    public void setPosition(float x, float y, float z) {
        this.setPosition(new Vector3f(x, y, z));
    }

    @Override
    public void setPosition(float x, float y) {
        this.setPosition(new Vector3f(x, y, 0.0f));
    }

    @Override
    public Vector3f getPosition() {
        return this.position;
    }

    @Override
    public Vector3f getCurrentPosition() {
        return this.currentPosition;
    }

    @Override
    public void setPositionRelative(boolean relative) {
        this.positionRelative = relative;
    }

    @Override
    public boolean isPositionRelative() {
        return this.positionRelative;
    }

    @Override
    public void setVelocity(Vector3f vel) {
        this.velocity = vel;
        if (log.isDebugEnabled()) {
            log.debug("Set velocity of Source {} to {}", this.getSystemName(), vel);
        }
    }

    @Override
    public Vector3f getVelocity() {
        return this.velocity;
    }

    /**
     * Calculate current position based on velocity.
     */
    protected void calculateCurrentPosition() {

        // Calculate how long it's been since we lasted checked position
        long currentTime = System.currentTimeMillis();
        float timePassed = (currentTime - this.timeOfLastPositionCheck);
        this.timeOfLastPositionCheck = currentTime;

        log.debug("timePassed = {} metersPerUnit = {} source = {} state = {}", timePassed, metersPerUnit, this.getSystemName(), this.getState());
        if (this.velocity.length() != 0) {
            this.currentPosition.scaleAdd((timePassed / 1000) * metersPerUnit,
                    this.velocity,
                    this.currentPosition);
            changePosition(this.currentPosition);
            if (log.isDebugEnabled()) {
                log.debug("Set current position of Source {} to {}", this.getSystemName(), this.currentPosition);
            }
        }
    }

    @Override
    public void resetCurrentPosition() {
        activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_RESET_POSITION));
        activeAudioFactory.getCommandThread().interrupt();
    }

    /**
     * Reset the current position.
     */
    protected void doResetCurrentPosition() {
        this.currentPosition = this.position;
    }

    /**
     * Change the current position of this source.
     *
     * @param pos new position
     */
    abstract protected void changePosition(Vector3f pos);

    @Override
    public void setGain(float gain) {
        this.gain = gain;
        if (log.isDebugEnabled()) {
            log.debug("Set gain of Source {} to {}", this.getSystemName(), gain);
        }
    }

    @Override
    public float getGain() {
        return this.gain;
    }

    /**
     * Calculate the gain of this AudioSource based on distance from
     * listener and fade levels.
     */
    abstract protected void calculateGain();

    @Override
    public void setPitch(float pitch) {
        if (pitch < 0.5f) {
            pitch = 0.5f;
        }
        if (pitch > 2.0f) {
            pitch = 2.0f;
        }
        this.pitch = pitch;
        if (log.isDebugEnabled()) {
            log.debug("Set pitch of Source {} to {}", this.getSystemName(), pitch);
        }
    }

    @Override
    public float getPitch() {
        return this.pitch;
    }

    @Override
    public void setReferenceDistance(float referenceDistance) {
        if (referenceDistance < 0.0f) {
            referenceDistance = 0.0f;
        }
        this.referenceDistance = referenceDistance;
        if (log.isDebugEnabled()) {
            log.debug("Set reference distance of Source {} to {}", this.getSystemName(), referenceDistance);
        }
    }

    @Override
    public float getReferenceDistance() {
        return this.referenceDistance;
    }

    @Override
    public void setOffset(long offset) {
        if (offset < 0) {
            offset = 0;
        }
        if (offset > this.buffer.getLength()) {
            offset = this.buffer.getLength();
        }
        this.offset = offset;
        if (log.isDebugEnabled()) {
            log.debug("Set byte offset of Source {}to {}", this.getSystemName(), offset);
        }
    }

    @Override
    public long getOffset() {
        return this.offset;
    }

    @Override
    public void setMaximumDistance(float maximumDistance) {
        if (maximumDistance < 0.0f) {
            maximumDistance = 0.0f;
        }
        this.maximumDistance = maximumDistance;
        if (log.isDebugEnabled()) {
            log.debug("Set maximum distance of Source {} to {}", this.getSystemName(), maximumDistance);
        }
    }

    @Override
    public float getMaximumDistance() {
        return this.maximumDistance;
    }

    @Override
    public void setRollOffFactor(float rollOffFactor) {
        this.rollOffFactor = rollOffFactor;
        if (log.isDebugEnabled()) {
            log.debug("Set roll-off factor of Source {} to {}", this.getSystemName(), rollOffFactor);
        }
    }

    @Override
    public float getRollOffFactor() {
        return this.rollOffFactor;
    }

    @Override
    public void setLooped(boolean loop) {
        if (loop) {
            this.minLoops = LOOP_CONTINUOUS;
            this.maxLoops = LOOP_CONTINUOUS;
        } else {
            this.minLoops = LOOP_NONE;
            this.maxLoops = LOOP_NONE;
        }
        calculateLoops();
    }

    @Override
    public boolean isLooped() {
        return (this.minLoops != LOOP_NONE || this.maxLoops != LOOP_NONE);
    }

    @Override
    public void setMinLoops(int loops) {
        if (this.maxLoops < loops) {
            this.maxLoops = loops;
        }
        this.minLoops = loops;
        calculateLoops();
    }

    @Override
    public int getMinLoops() {
        return this.minLoops;
    }

    @Override
    public void setMaxLoops(int loops) {
        if (this.minLoops > loops) {
            this.minLoops = loops;
        }
        this.maxLoops = loops;
        calculateLoops();
    }

    /**
     * Calculate the number of times to loop playback of this sound.
     */
    protected void calculateLoops() {
        if (this.minLoops != this.maxLoops) {
            this.numLoops = this.minLoops + ThreadLocalRandom.current().nextInt(this.maxLoops - this.minLoops);
        } else {
            this.numLoops = this.minLoops;
        }
    }

    @Override
    public int getMaxLoops() {
        return this.maxLoops;
    }

    @Override
    public int getNumLoops() {
        // Call the calculate method each time so as to ensure
        // randomness when min and max are not equal
        calculateLoops();
        return this.numLoops;
    }

    @Override
    public int getLastNumLoops() {
        return this.numLoops;
    }

//    public void setMinLoopDelay(int loopDelay) {
//        if (this.maxLoopDelay < loopDelay) {
//            this.maxLoopDelay = loopDelay;
//        }
//        this.minLoopDelay = loopDelay;
//        calculateLoopDelay();
//    }
//
//    public int getMinLoopDelay() {
//        return this.minLoopDelay;
//    }
//
//    public void setMaxLoopDelay(int loopDelay) {
//        if (this.minLoopDelay > loopDelay) {
//            this.minLoopDelay = loopDelay;
//        }
//        this.maxLoopDelay = loopDelay;
//        calculateLoopDelay();
//    }
//
//    public int getMaxLoopDelay() {
//        return this.maxLoopDelay;
//    }
//
//    public int getLoopDelay() {
//        // Call the calculate method each time so as to ensure
//        // randomness when min and max are not equal
//        calculateLoopDelay();
//        return this.loopDelay;
//    }
//
//    /**
//     * Method to calculate the delay between subsequent loops of this source
//     */
//    protected void calculateLoopDelay() {
//        if (this.minLoopDelay != this.maxLoopDelay) {
//            Random r = new Random();
//            this.loopDelay = this.minLoopDelay + r.nextInt(this.maxLoopDelay-this.minLoopDelay);
//        } else {
//            this.loopDelay = this.minLoopDelay;
//        }
//    }
    @Override
    public void setFadeIn(int fadeInTime) {
        this.fadeInTime = fadeInTime;
    }

    @Override
    public int getFadeIn() {
        return this.fadeInTime;
    }

    @Override
    public void setFadeOut(int fadeOutTime) {
        this.fadeOutTime = fadeOutTime;
    }

    @Override
    public int getFadeOut() {
        return this.fadeOutTime;
    }

    /**
     * Used to return the current calculated fade gain for this AudioSource.
     *
     * @return current fade gain
     */
    protected float getFadeGain() {
        return this.fadeGain;
    }

    /**
     * Calculate the fade gains.
     */
    protected void calculateFades() {

        // Calculate how long it's been since we lasted checked fade gains
        long currentTime = System.currentTimeMillis();
        long timePassed = currentTime - this.timeOfLastFadeCheck;
        this.timeOfLastFadeCheck = currentTime;

        switch (this.fading) {
            case Audio.FADE_NONE:
                // Reset fade gain
                this.fadeGain = 1.0f;
                break;
            case Audio.FADE_OUT:
                // Calculate fade-out gain
                this.fadeGain -= roundDecimal(timePassed) / (this.getFadeOut());

                // Ensure that fade-out gain is not less than 0.0f
                if (this.fadeGain < 0.0f) {
                    this.fadeGain = 0.0f;

                    // If so, we're done fading
                    this.fading = Audio.FADE_NONE;
                }
                if (log.isDebugEnabled()) {
                    log.debug("Set fade out gain of AudioSource {} to {}", this.getSystemName(), this.fadeGain);
                }
                break;
            case Audio.FADE_IN:
                // Calculate fade-in gain
                this.fadeGain += roundDecimal(timePassed) / (this.getFadeIn());

                // Ensure that fade-in gain is not greater than 1.0f
                if (this.fadeGain >= 1.0f) {
                    this.fadeGain = 1.0f;

                    // If so, we're done fading
                    this.fading = Audio.FADE_NONE;
                }
                if (log.isDebugEnabled()) {
                    log.debug("Set fade in gain of AudioSource {} to {}", this.getSystemName(), this.fadeGain);
                }
                break;
            default:
                throw new IllegalArgumentException();
        }
    }

    // Probably aught to be abstract, but I don't want to force the non-JOAL Source
    // types to implement this (yet).  So default to failing.
    public boolean queueAudioBuffers(Queue<AudioBuffer> audioBuffers) {
        log.debug("Abstract queueAudioBuffers() called.");
        return false;
    }

    // Probably aught to be abstract, but I don't want to force the non-JOAL Source
    // types to implement this (yet).  So default to failing.
    public boolean queueAudioBuffer(AudioBuffer audioBuffer) {
        return false;
    }

    public boolean unqueueAudioBuffers() {
        return false;
    }

    // Probably aught to be abstract, but I don't want to force the non-JOAL Source
    // types to implement this (yet).  So default to failing.
    @Override
    public int numQueuedBuffers() {
        return 0;
    }

    // Probably aught to be abstract, but I don't want to force the non-JOAL Source
    // types to implement this (yet).  So default to failing.
    @Override
    public int numProcessedBuffers() {
        return 0;
    }

    /**
     * Binds this AudioSource with the specified AudioBuffer.
     * <p>
     * Applies only to sub-types:
     * <ul>
     * <li>Source
     * </ul>
     *
     * @param buffer The AudioBuffer to bind to this AudioSource
     * @return true if successful
     */
    abstract boolean bindAudioBuffer(AudioBuffer buffer);

    /**
     * Method to define if this AudioSource has been bound to an AudioBuffer.
     *
     * @param bound True if bound to an AudioBufferr
     */
    protected void setBound(boolean bound) {
        this.bound = bound;
    }

    protected void setQueued(boolean queued) {
        this.queued = queued;
    }

    @Override
    public boolean isBound() {
        return this.bound;
    }

    @Override
    public boolean isQueued() {
        return this.queued;
    }

    @Override
    public void stateChanged(int oldState) {
        // Get the current state
        int i = this.getState();

        // Check if the current state has changed to playing
        if (i != oldState && i == STATE_PLAYING) {
            // We've changed to playing so start the move thread
            this.timeOfLastPositionCheck = System.currentTimeMillis();
            AudioSourceMoveThread asmt = new AudioSourceMoveThread(this);
            asmt.start();
        }

//        // Check if the current state has changed to stopped
//        if (i!=oldState && i==STATE_STOPPED) {
//            // We've changed to stopped so determine if we need to start the
//            // loop delay thread
//            if (isLooped() && getMinLoops()!=LOOP_CONTINUOUS) {
//                // Yes, we need to
//                if (asdt!=null) {
//                    asdt.cleanup();
//                    asdt = null;
//                }
//                asdt = new AudioSourceDelayThread(this);
//                asdt.start();
//            }
//        }
    }

    @Override
    public void play() {
        this.fading = Audio.FADE_NONE;
//        if (asdt!=null) {
//            asdt.interrupt();
//        }
        if (this.getState() != STATE_PLAYING) {
            this.setState(STATE_PLAYING);
            activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_PLAY));
            activeAudioFactory.getCommandThread().interrupt();
        }
    }

    /**
     * Play the clip from the beginning. If looped, start looping.
     */
    abstract protected void doPlay();

    @Override
    public void stop() {
        stop(true);
    }

    private void stop(boolean interruptThread) {
        this.fading = Audio.FADE_NONE;
        this.setState(STATE_STOPPED);
        activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_STOP));
        if (interruptThread) {
            activeAudioFactory.getCommandThread().interrupt();
        }
    }

    /**
     * Stop playing the clip and rewind to the beginning.
     */
    abstract protected void doStop();

    @Override
    public void togglePlay() {
        this.fading = Audio.FADE_NONE;
        activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_PLAY_TOGGLE));
        activeAudioFactory.getCommandThread().interrupt();
    }

    /**
     * Toggle the current playing status. Will always start at/return to the
     * beginning of the sample.
     */
    protected void doTogglePlay() {
        if (this.getState() == STATE_PLAYING) {
            stop();
        } else {
            play();
        }
    }

    @Override
    public void pause() {
        this.fading = Audio.FADE_NONE;
        this.setState(STATE_STOPPED);
        activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_PAUSE));
        activeAudioFactory.getCommandThread().interrupt();
    }

    /**
     * Stop playing the clip but retain the current position.
     */
    abstract protected void doPause();

    @Override
    public void resume() {
        this.fading = Audio.FADE_NONE;
        this.setState(STATE_PLAYING);
        activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_RESUME));
        activeAudioFactory.getCommandThread().interrupt();
    }

    /**
     * Play the clip from the current position.
     */
    abstract protected void doResume();

    @Override
    public void togglePause() {
        this.fading = Audio.FADE_NONE;
        activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_PAUSE_TOGGLE));
        activeAudioFactory.getCommandThread().interrupt();
    }

    /**
     * Toggle the current playing status. Will retain the playback position of
     * the sample.
     */
    protected void doTogglePause() {
        if (this.getState() == STATE_PLAYING) {
            pause();
        } else {
            resume();
        }
    }

    @Override
    public void rewind() {
        this.fading = Audio.FADE_NONE;
        this.setState(STATE_STOPPED);
        activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_REWIND));
        activeAudioFactory.getCommandThread().interrupt();
    }

    /**
     * Rewind clip to the beginning.
     */
    abstract protected void doRewind();

    @Override
    public void fadeIn() {
        if (this.getState() != STATE_PLAYING && this.fading != Audio.FADE_IN) {
            this.fading = Audio.FADE_IN;
            this.fadeGain = 0.0f;
            this.timeOfLastFadeCheck = System.currentTimeMillis();
            this.setState(STATE_PLAYING);
            activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_FADE_IN));
            activeAudioFactory.getCommandThread().interrupt();
        }
    }

    /**
     * Fade in then play this AudioSource.
     */
    abstract protected void doFadeIn();

    @Override
    public void fadeOut() {
        if (this.getState() == STATE_PLAYING && this.fading != Audio.FADE_OUT) {
            this.fading = Audio.FADE_OUT;
            this.fadeGain = 1.0f;
            this.timeOfLastFadeCheck = System.currentTimeMillis();
            this.setState(STATE_PLAYING);
            activeAudioFactory.audioCommandQueue(new AudioCommand(this, Audio.CMD_FADE_OUT));
            activeAudioFactory.getCommandThread().interrupt();
        }
    }

    /**
     * Fade out then stop this AudioSource.
     */
    abstract protected void doFadeOut();

    /**
     * Get the current fading status.
     *
     * @return fading status
     */
    protected int getFading() {
        return this.fading;
    }

    @Override
    @Nonnull
    public String getDebugString() {
        return "Pos: " + this.getPosition().toString()
                + ", bound to: " + this.getAssignedBufferName()
                + ", loops: "
                + ((this.getMinLoops() == LOOP_CONTINUOUS) ? "infinite"
                        : ((!this.isLooped()) ? "none"
                                : "(min=" + this.getMinLoops() + " max=" + this.getMaxLoops() + ")"));
    }

    private static final Logger log = LoggerFactory.getLogger(AbstractAudioSource.class);

    /**
     * An internal class used to create a new thread to monitor and maintain
     * fade in and fade out levels.
     * <p>
     * Will exist only as long as this source is in the process of fading in or
     * out.
     */
    protected static class AudioSourceFadeThread extends AbstractAudioThread {

        /**
         * Reference to the AudioSource object being monitored.
         */
        private AbstractAudioSource audioSource;

        /**
         * Internal variable to hold the fade direction.
         */
        private final int fadeDirection;

        /**
         * Constructor that takes handle to looping AudioSource to monitor.
         *
         * @param audioSource looping AudioSource to monitor
         */
        AudioSourceFadeThread(AbstractAudioSource audioSource) {
            super();
            this.setName("fadesrc-" + super.getName());
            this.audioSource = audioSource;
            this.fadeDirection = audioSource.getFading();
            if (log.isDebugEnabled()) {
                log.debug("Created AudioSourceFadeThread for AudioSource {}", audioSource.getSystemName());
            }
        }

        /**
         * Main processing loop.
         */
        @Override
        public void run() {

            while (!dying()) {

                // Recalculate the fade levels
                audioSource.calculateFades();

                // Recalculate the gain levels
                audioSource.calculateGain();

                // Check if we've done fading
                if (audioSource.getFading() == Audio.FADE_NONE) {
                    die();
                }

                // sleep for a while so as not to overload CPU
                snooze(20);
            }

            // Reset fades
            audioSource.calculateFades();

            // Check if we were fading out and, if so, stop.
            // Otherwise reset gain
            if (this.fadeDirection == Audio.FADE_OUT) {
                audioSource.doStop();
            } else {
                audioSource.calculateGain();
            }

            // Finish up
            if (log.isDebugEnabled()) {
                log.debug("Clean up thread {}", this.getName());
            }
            cleanup();
        }

        /**
         * Shut down this thread and clear references to created objects.
         */
        @Override
        protected void cleanup() {
            // Thread is to shutdown
            die();

            // Clear references to objects
            this.audioSource = null;

            // Finalise cleanup in super-class
            super.cleanup();
        }
    }

    /**
     * An internal class used to create a new thread to monitor and maintain
     * current source position with respect to velocity.
     */
    protected static class AudioSourceMoveThread extends AbstractAudioThread {

        /**
         * Reference to the AudioSource object being monitored.
         */
        private AbstractAudioSource audioSource;

        /**
         * Constructor that takes handle to looping AudioSource to monitor.
         *
         * @param audioSource looping AudioSource to monitor
         */
        AudioSourceMoveThread(AbstractAudioSource audioSource) {
            super();
            this.setName("movesrc-" + super.getName());
            this.audioSource = audioSource;
            if (log.isDebugEnabled()) {
                log.debug("Created AudioSourceMoveThread for AudioSource {}", audioSource.getSystemName());
            }
        }

        /**
         * Main processing loop.
         */
        @Override
        public void run() {

            while (!dying()) {

                // Recalculate the position
                audioSource.calculateCurrentPosition();

                // Check state and die if not playing
                if (audioSource.getState() != STATE_PLAYING) {
                    die();
                }

                // sleep for a while so as not to overload CPU
                snooze(100);
            }

//            // Reset the current position
//            audioSource.resetCurrentPosition();
            // Finish up
            if (log.isDebugEnabled()) {
                log.debug("Clean up thread {}", this.getName());
            }
            cleanup();
        }

        /**
         * Shuts this thread down and clears references to created objects.
         */
        @Override
        protected void cleanup() {
            // Thread is to shutdown
            die();

            // Clear references to objects
            this.audioSource = null;

            // Finalise cleanup in super-class
            super.cleanup();
        }
    }

//    /**
//     * An internal class used to create a new thread to delay subsequent
//     * playbacks of a non-continuous looped source.
//     */
//    private class AudioSourceDelayThread extends Thread {
//
//        /**
//         * Reference to the AudioSource object being monitored
//         */
//        private AbstractAudioSource audioSource;
//
//        /**
//         * Constructor that takes handle to looping AudioSource to monitor
//         *
//         * @param audioSource looping AudioSource to monitor
//         */
//        AudioSourceDelayThread(AbstractAudioSource audioSource) {
//            super();
//            this.setName("delaysrc-"+super.getName());
//            this.audioSource = audioSource;
//            if (log.isDebugEnabled()) log.debug("Created AudioSourceDelayThread for AudioSource " + audioSource.getSystemName());
//        }
//
//        /**
//         * Main processing loop
//         */
//        @Override
//        public void run() {
//
//            // Sleep for the required period of time
//            try {
//                Thread.sleep(audioSource.getLoopDelay());
//            } catch (InterruptedException ex) {}
//
//            // Restart playing this AudioSource
//            this.audioSource.play();
//
//            // Finish up
//            if (log.isDebugEnabled()) log.debug("Clean up thread " + this.getName());
//            cleanup();
//        }
//
//        /**
//         * Shuts this thread down and clears references to created objects
//         */
//        protected void cleanup() {
//            // Clear references to objects
//            this.audioSource = null;
//        }
//    }

}