/**
 * Copyright (c) 2011, The University of Southampton and the individual contributors.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *   *  Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *
 *   *  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.
 *
 *   *  Neither the name of the University of Southampton nor the names of its
 *      contributors may be used to endorse or promote products derived from this
 *      software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 THE COPYRIGHT OWNER 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.
 */
/**
 * 
 */
package org.openimaj.audio;

import java.util.ArrayList;
import java.util.List;

/**
 *      A class used to force a specific number of loops of an audio stream.
 *      The class can buffer the stream, if you consider that it will be small
 *      enough to fit within memory, otherwise it will reset the audio stream
 *      at each loop.
 *
 *      @author David Dupplaw (dpd@ecs.soton.ac.uk)
 *      
 *      @created 27 Nov 2011
 */
public class AudioLooper extends AudioStream
{
        /** The audio stream to loop */
        private AudioStream stream = null;
        
        /** The number of times to loop */
        private int nLoops = 1;
        
        /** The current loop being played */
        private int currentLoop = 0;
        
        /** If we're caching the stream, it will be put in this list */ 
        private List<SampleChunk> streamCache = null;
        
        /** The index into the cache if we're playing from the cache */
        private int currentCacheIndex = 0;

        /** Whether we're caching the stream or not */
        private boolean cacheStream = false;
        
        /**
         *      Create a new looper that will loop the given stream the given number
         *      of times.
         * 
         *      @param stream The stream to loop
         *      @param nLoops The number of times to loop the stream
         */
        public AudioLooper( AudioStream stream, int nLoops )
        {
                this( stream, nLoops, false );
        }
        
        /**
         *      Create a new looper that will loop the given stream the given number
         *      of times. Whether the stream is cached or not is able to be specified. 
         * 
         *      @param stream The stream to loop
         *      @param nLoops The number of loops to do
         *      @param cacheStream Whether to cache the stream or not
         */
        public AudioLooper( AudioStream stream, int nLoops, boolean cacheStream )
        {
                this.stream = stream;
                this.nLoops = nLoops;
                this.cacheStream  = cacheStream;
                this.format = stream.getFormat();
                
                if( cacheStream )
                        streamCache = new ArrayList<SampleChunk>();
        }

        /**
         *      {@inheritDoc}
         *      @see org.openimaj.audio.AudioStream#nextSampleChunk()
         */
        @Override
        public SampleChunk nextSampleChunk()
        {
                if( currentLoop == 0 || !cacheStream )
                {
                        SampleChunk sc = stream.nextSampleChunk();
                        
                        if( sc != null )
                        {
                                // Cache the chunk if necessary
                                if( cacheStream && nLoops > 1 )
                                        streamCache.add( sc.clone() );
                                
                                // We're on the first loop, so simply return this chunk
                                return sc;
                        }
                        else    
                        {
                                currentCacheIndex = 0;
                                currentLoop++;
                                
                                // If we're not caching the stream, we need to reset the
                                // stream.
                                if( !cacheStream )
                                {
                                        stream.reset();
                                        return stream.nextSampleChunk();
                                }
                        }
                }
                
                if( currentLoop < nLoops )
                {
                        SampleChunk sc = streamCache.get( currentCacheIndex );
                        currentCacheIndex++;
                        
                        if( currentCacheIndex == streamCache.size() )
                        {
                                currentCacheIndex = 0;
                                currentLoop++;
                        }
                
                        return sc; 
                }
                
                return null;
        }

        /**
         *      {@inheritDoc}
         *      @see org.openimaj.audio.AudioStream#reset()
         */
        @Override
        public void reset()
        {
        }
        
        /**
         *      {@inheritDoc}
         *      @see org.openimaj.audio.AudioStream#getLength()
         */
        @Override
        public long getLength()
        {
                return this.stream.getLength() * nLoops;
        }
}