/*
 * Copyright 2013 MovingBlocks
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.terasology.audio.openAL.staticSound;

import org.lwjgl.openal.AL10;
import org.lwjgl.openal.AL11;
import org.terasology.audio.openAL.BaseSoundSource;
import org.terasology.audio.openAL.OpenALException;
import org.terasology.audio.openAL.SoundPool;

import static org.lwjgl.openal.AL10.AL_FALSE;
import static org.lwjgl.openal.AL10.AL_LOOPING;
import static org.lwjgl.openal.AL10.AL_TRUE;
import static org.lwjgl.openal.AL10.alGetSourcei;
import static org.lwjgl.openal.AL10.alSourcei;

/**
 *
 */
public class OpenALSoundSource extends BaseSoundSource<OpenALSound> {

    private OpenALSound audio;
    
    public OpenALSoundSource(SoundPool<OpenALSound, OpenALSoundSource> pool) {
        super(pool);
    }

    public float getLength() {
        return audio.getLength();
    }

    /**
     * @return the playback position in second
     */
    public float getPlaybackPositionSeconds() {
        return (float) AL10.alGetSourcei(getSourceId(), AL11.AL_BYTE_OFFSET) / audio.getBufferSize();
    }

    // TODO: Work out what this method returns and rename it to fit
    public float getPlaybackPosition() {
        return (float) AL10.alGetSourcei(getSourceId(), AL11.AL_SAMPLE_OFFSET) / audio.getSamplingRate();
    }

    /**
     * Set playback position in seconds
     *
     * @param position
     */
    public OpenALSoundSource setPlaybackPositionInSeconds(float position) {
        boolean isPlaying = isPlaying();
        if (isPlaying) {
            AL10.alSourceStop(getSourceId());
        }

        AL10.alSourceRewind(getSourceId());
        AL10.alSourcei(getSourceId(), AL11.AL_SAMPLE_OFFSET, (int) (audio.getSamplingRate() * position));

        OpenALException.checkState("Setting sound playback absolute position");

        if (isPlaying) {
            play();
        }

        return this;
    }

    /**
     * Set relative playback position (0.0f - start, 1.0f - end)
     *
     * @param position
     */
    // TODO: This is broken for compressed streams - is this something that we need to worry about?
    public OpenALSoundSource setPlaybackPosition(float position) {
        boolean isPlaying = isPlaying();
        if (isPlaying()) {
            AL10.alSourceStop(getSourceId());
        }

        AL10.alSourceRewind(getSourceId());
        AL10.alSourcei(getSourceId(), AL11.AL_BYTE_OFFSET, (int) (audio.getBufferSize() * position));

        OpenALException.checkState("Setting sound playback relaive position");

        if (isPlaying) {
            play();
        }

        return this;
    }

    @Override
    public OpenALSound getAudio() {
        return audio;
    }

    @Override
    public boolean isLooping() {
        return alGetSourcei(getSourceId(), AL_LOOPING) == AL_TRUE;
    }

    @Override
    public OpenALSoundSource setLooping(boolean looping) {
        alSourcei(getSourceId(), AL_LOOPING, looping ? AL_TRUE : AL_FALSE);

        OpenALException.checkState("Setting sound looping");

        return this;
    }

    @Override
    public OpenALSoundSource setAudio(OpenALSound sound) {
        boolean isPlaying = isPlaying();
        if (isPlaying) {
            stop();
        }

        reset();

        audio = sound;
        AL10.alSourcei(getSourceId(), AL10.AL_BUFFER, audio.getBufferId());

        OpenALException.checkState("Assigning buffer to source");

        if (isPlaying) {
            play();
        }

        return this;
    }

    @Override
    public void purge() {
        boolean isPlaying = isPlaying();
        if (isPlaying) {
            stop();
        }

        reset();

        audio = null;
        AL10.alSourcei(getSourceId(), AL10.AL_BUFFER, 0);
        OpenALException.checkState("Clearing source");
    }
}