/*
This file is part of jpcsp.

Jpcsp is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Jpcsp 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.

You should have received a copy of the GNU General Public License
along with Jpcsp.  If not, see <http://www.gnu.org/licenses/>.
 */
package jpcsp.sound;

import java.nio.ByteBuffer;
import java.util.LinkedList;
import java.util.List;
import java.util.Stack;

import jpcsp.HLE.modules.sceAudio;

import org.apache.log4j.Logger;
import org.lwjgl.openal.AL10;

public class SoundBufferManager {
	private static Logger log = sceAudio.log;
	private static SoundBufferManager instance;
	private Stack<Integer> freeBuffers;
	private List<ByteBuffer> freeDirectBuffers;

	public static SoundBufferManager getInstance() {
		if (instance == null) {
			instance = new SoundBufferManager();
		}

		return instance;
	}

	private SoundBufferManager() {
		freeBuffers = new Stack<Integer>();
		freeDirectBuffers = new LinkedList<ByteBuffer>();
	}

	public int getBuffer() {
		if (freeBuffers.isEmpty()) {
			int alBuffer = AL10.alGenBuffers();
			freeBuffers.push(alBuffer);
		}

		return freeBuffers.pop();
	}

	public void checkFreeBuffers(int alSource) {
        while (true) {
        	int processedBuffers = AL10.alGetSourcei(alSource, AL10.AL_BUFFERS_PROCESSED);
        	if (processedBuffers <= 0) {
        		break;
        	}
    		int alBuffer = AL10.alSourceUnqueueBuffers(alSource);
    		if (log.isDebugEnabled()) {
    			log.debug(String.format("free buffer %d", alBuffer));
    		}
    		freeBuffers.push(alBuffer);
        }
	}

	public ByteBuffer getDirectBuffer(int size) {
		for (int i = 0; i < freeDirectBuffers.size(); i++) {
			ByteBuffer directBuffer = freeDirectBuffers.get(i);
			if (directBuffer.capacity() >= size) {
				freeDirectBuffers.remove(i);
				return directBuffer;
			}
		}

		ByteBuffer directBuffer = ByteBuffer.allocateDirect(size);
		return directBuffer;
	}

	public void releaseDirectBuffer(ByteBuffer directBuffer) {
		freeDirectBuffers.add(0, directBuffer);
	}
}