/**
 * Copyright 2013 JogAmp Community. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 * 
 *    1. Redistributions of source code must retain the above copyright notice, this list of
 *       conditions and the following disclaimer.
 * 
 *    2. Redistributions in binary form must reproduce the above copyright notice, this list
 *       of conditions and the following disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * The views and conclusions contained in the software and documentation are those of the
 * authors and should not be interpreted as representing official policies, either expressed
 * or implied, of JogAmp Community.
 */
package jogamp.opengl.openal.av;


import jogamp.opengl.util.av.SyncedRingbuffer;

import com.jogamp.common.util.locks.LockFactory;
import com.jogamp.common.util.locks.RecursiveLock;
import com.jogamp.openal.AL;
import com.jogamp.openal.ALC;
import com.jogamp.openal.ALCcontext;
import com.jogamp.openal.ALCdevice;
import com.jogamp.openal.ALFactory;
import com.jogamp.opengl.util.av.AudioSink;

/***
 * OpenAL Audio Sink
 */
public class ALAudioSink implements AudioSink {

    /** Chunk of audio processed at one time. FIXME: Parameterize .. */
    public static final int BUFFER_SIZE = 4096;
    public static final int SAMPLES_PER_BUFFER = BUFFER_SIZE / 2;
    
    private static final ALC alc;
    private static final AL al;
    private static final boolean staticAvailable;    
    
    private String deviceSpecifier;
    private ALCdevice device;
    private ALCcontext context;
    // private static final ThreadLocal<GLContext> currentContext = new ThreadLocal<GLContext>();
    protected final RecursiveLock lock = LockFactory.createRecursiveLock();

    /** Sample period in seconds */
    public float samplePeriod;
    
    /** Playback speed, range [0.5 - 2.0], default 1.0. */
    public float playSpeed;
    
    static class ActiveBuffer {
        ActiveBuffer(Integer name, int pts, int size) {
            this.name = name;
            this.pts = pts;
            this.size = size;
        }
        public final Integer name;
        public final int pts;
        public final int size;
        public String toString() { return "ABuffer[name "+name+", pts "+pts+", size "+size+"]"; }
    }
    
    int[] alBuffers = null;
    private SyncedRingbuffer<Integer> alBufferAvail = null;
    private SyncedRingbuffer<ActiveBuffer> alBufferPlaying = null;
    private volatile int alBufferBytesQueued = 0;
    private volatile int ptsPlaying = 0;
    private volatile int enqueuedFrameCount;

    private int[] alSource = null;
    private AudioDataFormat chosenFormat;
    private int alFormat;    
    private boolean initialized;
    
    private volatile boolean playRequested = false;

    static {
        ALC _alc = null;
        AL _al = null;
        try {
            _alc = ALFactory.getALC();            
            _al = ALFactory.getAL();
        } catch(Throwable t) {
            if( DEBUG ) {
                System.err.println("ALAudioSink: Catched "+t.getClass().getName()+": "+t.getMessage());
                t.printStackTrace();
            }
        }
        alc = _alc;
        al = _al;
        staticAvailable = null != alc && null != al;
    }
    
    public ALAudioSink() {
        initialized = false;
        chosenFormat = null;
        
        if( !staticAvailable ) {
            return;
        }
        
        try {
            // Get handle to default device.
            device = alc.alcOpenDevice(null);
            if (device == null) {
                throw new RuntimeException("ALAudioSink: Error opening default OpenAL device");
            }
        
            // Get the device specifier.
            deviceSpecifier = alc.alcGetString(device, ALC.ALC_DEVICE_SPECIFIER);
            if (deviceSpecifier == null) {
                throw new RuntimeException("ALAudioSink: Error getting specifier for default OpenAL device");
            }
                
            // Create audio context.
            context = alc.alcCreateContext(device, null);
            if (context == null) {
                throw new RuntimeException("ALAudioSink: Error creating OpenAL context");
            }
        
            lockContext();
            try {
                // Check for an error.
                if ( alc.alcGetError(device) != ALC.ALC_NO_ERROR ) {
                    throw new RuntimeException("ALAudioSink: Error making OpenAL context current");
                }
                
                // Create source
                {
                    alSource = new int[1];
                    al.alGenSources(1, alSource, 0);
                    final int err = al.alGetError();
                    if( err != AL.AL_NO_ERROR ) {
                        alSource = null;
                        throw new RuntimeException("ALAudioSink: Error generating Source: 0x"+Integer.toHexString(err));
                    }       
                }
                
                if( DEBUG ) {                
                    System.err.println("ALAudioSink: Using device: " + deviceSpecifier);
                }
                initialized = true;
            } finally {
                unlockContext();
            }
            return;
        } catch ( Exception e ) {
            if( DEBUG ) {
                System.err.println(e.getMessage());
            }
            destroy();
        }
    }
    
    private final void lockContext() {
        lock.lock();
        alc.alcMakeContextCurrent(context);
    }
    private final void unlockContext() {
        alc.alcMakeContextCurrent(null);
        lock.unlock();
    }
    private final void destroyContext() {
        lock.lock();
        try {
            if( null != context ) {
                try {
                    alc.alcDestroyContext(context);
                } catch (Throwable t) {
                    if( DEBUG ) {
                        System.err.println("Catched "+t.getClass().getName()+": "+t.getMessage());
                        t.printStackTrace();
                    }
                }
                context = null;
            }
            // unroll lock !
            while(lock.getHoldCount() > 1) {
                lock.unlock();
            }
        } finally {
            lock.unlock();
        }
    }
    
    @Override
    public final String toString() {
        final int alSrcName = null != alSource ? alSource[0] : 0;
        final int alBuffersLen = null != alBuffers ? alBuffers.length : 0;
        final int ctxHash = context != null ? context.hashCode() : 0; 
        return "ALAudioSink[init "+initialized+", playRequested "+playRequested+", device "+deviceSpecifier+", ctx "+toHexString(ctxHash)+", alSource "+alSrcName+
               ", chosen "+chosenFormat+", alFormat "+toHexString(alFormat)+
               ", playSpeed "+playSpeed+", buffers[total "+alBuffersLen+", avail "+alBufferAvail.size()+", "+
               "queued["+alBufferPlaying.size()+", apts "+ptsPlaying+", "+getQueuedTime() + " ms, " + alBufferBytesQueued+" bytes]";
    }
    public final String getPerfString() {
        final int alBuffersLen = null != alBuffers ? alBuffers.length : 0;
        return "Play [buffer "+alBufferPlaying.size()+"/"+alBuffersLen+", apts "+ptsPlaying+", "+getQueuedTime() + " ms, " + alBufferBytesQueued+" bytes]";
    }
    
    @Override
    public final AudioDataFormat getPreferredFormat() {
        return DefaultFormat;
    }
    
    @Override
    public final AudioDataFormat initSink(AudioDataFormat requestedFormat, int frameCount) {
        if( !staticAvailable ) {
            return null;
        }
        if( !requestedFormat.fixedP ||
            !requestedFormat.littleEndian ||
            ( 1 != requestedFormat.channelCount && requestedFormat.channelCount != 2 ) ||
            ( 8 != requestedFormat.sampleSize  && requestedFormat.sampleSize != 16 )
          ) {
            return null; // not supported w/ OpenAL
        }
        samplePeriod = 1.0f / requestedFormat.sampleRate;
        switch( requestedFormat.channelCount ) {
            case 1: { 
                switch ( requestedFormat.sampleSize ) {
                    case 8: 
                        alFormat = AL.AL_FORMAT_MONO8; break;
                    case 16:
                        alFormat = AL.AL_FORMAT_MONO16; break;
                }
            } break;
            case 2: 
                switch ( requestedFormat.sampleSize ) {
                    case 8: 
                        alFormat = AL.AL_FORMAT_STEREO8; break;
                    case 16:
                        alFormat = AL.AL_FORMAT_STEREO16; break;
                }
        }
        lockContext();
        try {
            // Allocate buffers
            destroyBuffers();
            {
                alBuffers = new int[frameCount];
                al.alGenBuffers(frameCount, alBuffers, 0);
                final int err = al.alGetError();
                if( err != AL.AL_NO_ERROR ) {
                    alBuffers = null;
                    throw new RuntimeException("ALAudioSink: Error generating Buffers: 0x"+Integer.toHexString(err));
                }
                final Integer[] alBufferRingArray = new Integer[frameCount];
                for(int i=0; i<frameCount; i++) {
                    alBufferRingArray[i] = Integer.valueOf(alBuffers[i]);
                }
                alBufferAvail = new SyncedRingbuffer<Integer>(alBufferRingArray, true /* full */);
                alBufferPlaying = new SyncedRingbuffer<ActiveBuffer>(new ActiveBuffer[frameCount], false /* full */);
            }
        } finally {
            unlockContext();
        }
        
        chosenFormat = requestedFormat;
        return chosenFormat;
    }
    
    private void destroyBuffers() {
        if( !staticAvailable ) {
            return;
        }
        if( null != alBuffers ) {
            try {
                al.alDeleteBuffers(alBufferAvail.capacity(), alBuffers, 0);
            } catch (Throwable t) {
                if( DEBUG ) {
                    System.err.println("Catched "+t.getClass().getName()+": "+t.getMessage());
                    t.printStackTrace();
                }
            }
            alBufferAvail.clear(true);
            alBufferAvail = null;
            alBufferPlaying.clear(true);
            alBufferPlaying = null;
            alBufferBytesQueued = 0;
            alBuffers = null;
        }
    }
    
    @Override
    public final void destroy() {
        initialized = false;
        if( !staticAvailable ) {
            return;
        }
        if( null != context ) {
            lockContext();
        }
        try {
            stopImpl();
            if( null != alSource ) {
                try {
                    al.alDeleteSources(1, alSource, 0);
                } catch (Throwable t) {
                    if( DEBUG ) {
                        System.err.println("Catched "+t.getClass().getName()+": "+t.getMessage());
                        t.printStackTrace();
                    }
                }
                alSource = null;
            }
            
            destroyBuffers();
        } finally {
            destroyContext();
        }
        if( null != device ) {
            try {
                alc.alcCloseDevice(device);
            } catch (Throwable t) {
                if( DEBUG ) {
                    System.err.println("Catched "+t.getClass().getName()+": "+t.getMessage());
                    t.printStackTrace();
                }
            }
            device = null;            
        }
        chosenFormat = null;
    }
    
    @Override
    public final boolean isInitialized() {
        return initialized;
    }
    
    private final int dequeueBuffer(boolean all, boolean wait) {
        if( !lock.isLocked() ) {
            throw new InternalError("XXX");
        }
        int alErr = AL.AL_NO_ERROR;
        final int releaseBufferCount;
        if( all ) {
            releaseBufferCount = alBufferPlaying.size();
        } else if( alBufferBytesQueued > 0 ) {
            final int[] val=new int[1];
            int i=0;
            do {
                al.alGetSourcei(alSource[0], AL.AL_BUFFERS_PROCESSED, val, 0);
                alErr = al.alGetError();
                if( AL.AL_NO_ERROR != alErr ) {
                    throw new RuntimeException("ALError "+toHexString(alErr)+" while quering processed buffers at source. "+this);
                }
                if( wait && val[0] <= 0 ) {
                    i++;
                    // clip wait at 60Hz - min 1ms
                    final int sleep = Math.max(1, Math.min(15, getQueuedTimeImpl( alBufferBytesQueued / alBufferPlaying.size() ) ));
                    if( DEBUG ) {
                        System.err.println(getThreadName()+": ALAudioSink: Dequeue.wait["+i+"]: sleep "+sleep+" ms, playImpl "+isPlayingImpl1()+", processed "+val[0]+", "+this);
                    }                
                    unlockContext();
                    try {
                        Thread.sleep(sleep);
                    } catch (InterruptedException e) {
                    } finally {
                        lockContext();
                    }
                }
            } while ( wait && val[0] <= 0 && alBufferBytesQueued > 0 );
            releaseBufferCount = val[0];
        } else {
            releaseBufferCount = 0;
        }

        if( releaseBufferCount > 0 ) {
            int[] buffers=new int[releaseBufferCount];
            al.alSourceUnqueueBuffers(alSource[0], releaseBufferCount, buffers, 0);
            alErr = al.alGetError();
            if( AL.AL_NO_ERROR != alErr ) {
                throw new RuntimeException("ALError "+toHexString(alErr)+" while dequeueing "+releaseBufferCount+" buffers. "+this);                 
            }
            for ( int i=0; i<releaseBufferCount; i++ ) {
                final ActiveBuffer releasedBuffer = alBufferPlaying.get(true /* clearRef */);
                if( null == releasedBuffer ) {
                    throw new InternalError("Internal Error: "+this);
                }
                if( releasedBuffer.name.intValue() != buffers[i] ) {                    
                    throw new InternalError("Buffer name mismatch: dequeued: "+buffers[i]+", released "+releasedBuffer);
                    // System.err.println("XXX ["+i+"]: dequeued: "+buffers[i]+", released "+releasedBuffer);
                }
                alBufferBytesQueued -= releasedBuffer.size;
                if( !alBufferAvail.put(releasedBuffer.name) ) {
                    throw new InternalError("Internal Error: "+this);
                }
            }
        }
        return releaseBufferCount;
    }
    
    private static final String toHexString(int v) { return "0x"+Integer.toHexString(v); }
    private static final String getThreadName() { return Thread.currentThread().getName(); }
        
    @Override
    public final void enqueueData(AudioFrame audioFrame) {
        if( !initialized || null == chosenFormat ) {
            return;
        }
        int alErr = AL.AL_NO_ERROR;
            
        // OpenAL consumes buffers in the background
        // we first need to initialize the OpenAL buffers then
        // start continuous playback.
        lockContext();
        try {
            alErr = al.alGetError();
            if(al.alGetError() != AL.AL_NO_ERROR) {
                throw new RuntimeException("ALError "+toHexString(alErr)+" while makeCurrent. "+this);
            }
            
            if( isPlayingImpl0() ) { // dequeue only possible if playing ..
                final boolean wait = alBufferAvail.size() <= 1;
                if( DEBUG ) {
                    System.err.println(getThreadName()+": ALAudioSink: Dequeue: playImpl "+isPlayingImpl1()+", wait "+wait+", "+this);
                }
                final int dequeuedBufferCount = dequeueBuffer( false /* all */, wait );        
                final ActiveBuffer currentBuffer = alBufferPlaying.peek();
                ptsPlaying = null != currentBuffer ? currentBuffer.pts : audioFrame.pts;
                if( DEBUG ) {
                    System.err.println(getThreadName()+": ALAudioSink: Write "+audioFrame.pts+", "+getQueuedTimeImpl(audioFrame.dataSize)+" ms, dequeued "+dequeuedBufferCount+", wait "+wait+", "+getPerfString());
                }
            }
            
            final Integer alBufferName = alBufferAvail.get(true /* clearRef */);
            if( null == alBufferName ) {
                throw new InternalError("Internal Error: "+this);
            }
            if( !alBufferPlaying.put( new ActiveBuffer(alBufferName, audioFrame.pts, audioFrame.dataSize) ) ) {
                throw new InternalError("Internal Error: "+this);
            }
            al.alBufferData(alBufferName.intValue(), alFormat, audioFrame.data, audioFrame.dataSize, chosenFormat.sampleRate);
            final int[] alBufferNames = new int[] { alBufferName.intValue() };
            al.alSourceQueueBuffers(alSource[0], 1, alBufferNames, 0);
            alErr = al.alGetError();
            if(al.alGetError() != AL.AL_NO_ERROR) {
                throw new RuntimeException("ALError "+toHexString(alErr)+" while queueing buffer "+toHexString(alBufferNames[0])+". "+this);
            }
            alBufferBytesQueued += audioFrame.dataSize;
            enqueuedFrameCount++;
            
            playImpl(); // continue playing, fixes issue where we ran out of enqueued data!
        } finally {
            unlockContext();
        }
    }

    @Override
    public final boolean isPlaying() {
        if( !initialized || null == chosenFormat ) {
            return false;
        }
        if( playRequested ) {
            lockContext();
            try {
                return isPlayingImpl0();
            } finally {
                unlockContext();
            }                            
        } else {
            return false;
        }
    }
    private final boolean isPlayingImpl0() {
        if( playRequested ) {
            return isPlayingImpl1();
        } else {
            return false;
        }
    }
    private final boolean isPlayingImpl1() {
        final int[] val = new int[1];
        al.alGetSourcei(alSource[0], AL.AL_SOURCE_STATE, val, 0);
        final int alErr = al.alGetError();
        if(al.alGetError() != AL.AL_NO_ERROR) {
            throw new RuntimeException("ALError "+toHexString(alErr)+" while querying isPlaying. "+this);
        }
        return val[0] == AL.AL_PLAYING;
    }
    
    @Override
    public final void play() {
        if( !initialized || null == chosenFormat ) {
            return;
        }
        playRequested = true;
        lockContext();
        try {
            playImpl();
            if( DEBUG ) {
                System.err.println(getThreadName()+": ALAudioSink: PLAY playImpl "+isPlayingImpl1()+", "+this);
            }        
        } finally {
            unlockContext();
        }                
    }
    private final void playImpl() {
        if( playRequested && !isPlayingImpl1() ) {
            al.alSourcePlay(alSource[0]);
            final int alErr = al.alGetError();
            if(al.alGetError() != AL.AL_NO_ERROR) {
                throw new RuntimeException("ALError "+toHexString(alErr)+" while start playing. "+this);
            }
        }        
    }
    
    @Override
    public final void pause() {
        if( !initialized || null == chosenFormat ) {
            return;
        }
        if( playRequested ) {
            lockContext();
            try {
                pauseImpl();
                if( DEBUG ) {
                    System.err.println(getThreadName()+": ALAudioSink: PAUSE playImpl "+isPlayingImpl1()+", "+this);
                }        
            } finally {
                unlockContext();
            }
        }
    }
    private final void pauseImpl() {
        if( isPlayingImpl0() ) {
            playRequested = false;
            al.alSourcePause(alSource[0]);
            final int alErr = al.alGetError();
            if(al.alGetError() != AL.AL_NO_ERROR) {
                throw new RuntimeException("ALError "+toHexString(alErr)+" while pausing. "+this);
            }
        }
    }
    private final void stopImpl() {
        if( isPlayingImpl0() ) {
            playRequested = false;
            al.alSourceStop(alSource[0]);
            final int alErr = al.alGetError();
            if(al.alGetError() != AL.AL_NO_ERROR) {
                throw new RuntimeException("ALError "+toHexString(alErr)+" while pausing. "+this);
            }
        }
    }
    
    @Override
    public final float getPlaySpeed() { return playSpeed; }
    
    @Override
    public final boolean setPlaySpeed(float rate) { 
        if( !initialized || null == chosenFormat ) {
            return false;
        }
        lockContext();
        try {
            if( Math.abs(1.0f - rate) < 0.01f ) {
                rate = 1.0f;
            }
            if( 0.5f <= rate && rate <= 2.0f ) { // OpenAL limits 
                playSpeed = rate;
                al.alSourcef(alSource[0], AL.AL_PITCH, playSpeed);
                return true;
            } 
        } finally {
            unlockContext();
        }
        return false; 
    }
    
    @Override
    public final void flush() {
        if( !initialized || null == chosenFormat ) {
            return;
        }
        lockContext();
        try {
            // pauseImpl();
            stopImpl();
            dequeueBuffer( true /* all */, false /* wait */ );
            if( alBuffers.length != alBufferAvail.size() || alBufferPlaying.size() != 0 ) {
                throw new InternalError("XXX: "+this);
            }
            if( DEBUG ) {
                System.err.println(getThreadName()+": ALAudioSink: FLUSH playImpl "+isPlayingImpl1()+", "+this);
            }        
        } finally {
            unlockContext();
        }                
    }
    
    @Override
    public final int getEnqueuedFrameCount() {
        return enqueuedFrameCount;
    }
    
    @Override
    public final int getFrameCount() {
        return null != alBuffers ? alBuffers.length : 0;
    }
    
    @Override
    public final int getQueuedFrameCount() {
        if( !initialized || null == chosenFormat ) {
            return 0;
        }
        return alBufferPlaying.size();
    }
    
    @Override
    public final int getFreeFrameCount() {
        if( !initialized || null == chosenFormat ) {
            return 0;
        }
        return alBufferAvail.size();
    }
    
    @Override
    public final int getQueuedByteCount() {
        if( !initialized || null == chosenFormat ) {
            return 0;
        }
        return alBufferBytesQueued;
    }
    
    @Override
    public final int getQueuedTime() {
        if( !initialized || null == chosenFormat ) {
            return 0;
        }
        return getQueuedTimeImpl(alBufferBytesQueued);
    }
    private final int getQueuedTimeImpl(int byteCount) {
        final int bytesPerSample = chosenFormat.sampleSize >>> 3; // /8
        return byteCount / ( chosenFormat.channelCount * bytesPerSample * ( chosenFormat.sampleRate / 1000 ) );        
    }
    
    @Override
    public final int getPTS() { return ptsPlaying; }
}