/*******************************************************************************
 * sdr-trunk
 * Copyright (C) 2014-2018 Dennis Sheirer
 *
 * This program 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.
 *
 * This program 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 this program.
 * If not, see <http://www.gnu.org/licenses/>
 *
 ******************************************************************************/
package io.github.dsheirer.source.wave;

import io.github.dsheirer.sample.ConversionUtils;
import io.github.dsheirer.sample.Listener;
import io.github.dsheirer.sample.buffer.ReusableComplexBuffer;
import io.github.dsheirer.sample.buffer.ReusableComplexBufferQueue;
import io.github.dsheirer.source.ComplexSource;
import io.github.dsheirer.source.IControllableFileSource;
import io.github.dsheirer.source.IFrameLocationListener;
import io.github.dsheirer.source.SourceEvent;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.UnsupportedAudioFileException;
import java.io.File;
import java.io.IOException;
import java.util.Arrays;

public class ComplexWaveSource extends ComplexSource implements IControllableFileSource, AutoCloseable
{
    private final static Logger mLog = LoggerFactory.getLogger(ComplexWaveSource.class);

    private IFrameLocationListener mFrameLocationListener;
    private int mBytesPerFrame;
    private int mFrameCounter = 0;
    private long mFrequency = 0;
    private Listener<ReusableComplexBuffer> mListener;
    private AudioInputStream mInputStream;
    private File mFile;
    private ReusableComplexBufferQueue mReusableComplexBufferQueue = new ReusableComplexBufferQueue("ComplexWaveSource");

    public ComplexWaveSource(File file) throws IOException
    {
        mFile = file;
    }

    @Override
    public void setSourceEventListener(Listener<SourceEvent> listener)
    {
        //Not implemented
    }

    @Override
    public void removeSourceEventListener()
    {
        //Not implemented
    }

    @Override
    public Listener<SourceEvent> getSourceEventListener()
    {
        //Not implemented
        return null;
    }

    @Override
    public void reset()
    {
        stop();
        start();
    }

    @Override
    public void start()
    {
        try
        {
            open();
        }
        catch(IOException | UnsupportedAudioFileException e)
        {
            mLog.error("Error starting complex wave source");
        }
    }

    @Override
    public void stop()
    {
        try
        {
            close();
        }
        catch(IOException e)
        {
            mLog.error("Error stopping complex wave source");
        }
    }

    @Override
    public long getFrameCount() throws IOException
    {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public double getSampleRate()
    {
        if(mInputStream != null)
        {
            return mInputStream.getFormat().getSampleRate();
        }

        return 0;
    }

    /**
     * Returns the frequency set for this file.  Normally returns zero, but
     * the value can be set with setFrequency() method.
     */
    public long getFrequency()
    {
        return mFrequency;
    }

    /**
     * Changes the value returned from getFrequency() for this source.
     */
    public void setFrequency(long frequency)
    {
        mFrequency = frequency;
    }

    /**
     * Closes the source file
     */
    public void close() throws IOException
    {
        if(mInputStream != null)
        {
            mInputStream.close();
            mInputStream = null;
        }
    }

    /**
     * Opens the source file for reading
     */
    public void open() throws IOException, UnsupportedAudioFileException
    {
        if(mInputStream == null)
        {
            mInputStream = AudioSystem.getAudioInputStream(mFile);
        }
        else
        {
            throw new IOException("Can't open wave source - is already opened");
        }


        AudioFormat format = mInputStream.getFormat();

        mBytesPerFrame = format.getFrameSize();

        if(format.getChannels() != 2 || format.getSampleSizeInBits() != 16)
        {
            throw new IOException("Unsupported Wave Format - EXPECTED: 2 " +
                "channels 16-bit samples FOUND: " +
                mInputStream.getFormat().getChannels() + " channels " +
                mInputStream.getFormat().getSampleSizeInBits() + "-bit samples");
        }

        /* Broadcast that we're at frame location 0 */
        broadcast(0);
    }

    /**
     * Reads the number of frames and sends a buffer to the listener
     */
    @Override
    public void next(int frames) throws IOException
    {
        next(frames, true);
    }

    /**
     * Reads the number of frames and optionally sends the buffer to the listener
     */
    public void next(int frames, boolean broadcast) throws IOException
    {
        if(mInputStream != null)
        {
            byte[] buffer = new byte[mBytesPerFrame * frames];

        	/* Fill the buffer with samples from the file */
            int samplesRead = mInputStream.read(buffer);

            mFrameCounter += samplesRead;

            broadcast(mFrameCounter);

            if(broadcast && mListener != null)
            {
                if(samplesRead < buffer.length)
                {
                    buffer = Arrays.copyOf(buffer, samplesRead);
                }

                float[] samples = ConversionUtils.convertFromSigned16BitSamples(buffer);

                ReusableComplexBuffer reusableBuffer = mReusableComplexBufferQueue.getBuffer(samples.length);
                reusableBuffer.reloadFrom(samples, System.currentTimeMillis());
                mListener.receive(reusableBuffer);
            }
        }
    }

    /**
     * Registers the listener to receive sample buffers as they are read from
     * the wave file
     */
    @Override
    public void setListener(Listener<ReusableComplexBuffer> listener)
    {
        mListener = listener;
    }

    /**
     * Unregisters the listener from receiving sample buffers
     */
    public void removeListener(Listener<ReusableComplexBuffer> listener)
    {
        mListener = null;
    }

    @Override
    public void dispose()
    {
        mListener = null;
    }

    @Override
    public File getFile()
    {
        return mFile;
    }

    private void broadcast(int byteLocation)
    {
        int frameLocation = (int)(byteLocation / mBytesPerFrame);

        if(mFrameLocationListener != null)
        {
            mFrameLocationListener.frameLocationUpdated(frameLocation);
        }
    }

    @Override
    public void setListener(IFrameLocationListener listener)
    {
        mFrameLocationListener = listener;
    }

    @Override
    public void removeListener(IFrameLocationListener listener)
    {
        mFrameLocationListener = null;
    }

    /**
     * Indicates if the file is a supported audio file type
     */
    public static boolean supports(File file)
    {
        try(AudioInputStream ais = AudioSystem.getAudioInputStream(file))
        {
            AudioFormat format = ais.getFormat();

            if(format.getChannels() == 2 && format.getSampleSizeInBits() == 16)
            {
                return true;
            }
        }
        catch(Exception e)
        {
            //Do nothing, we'll return a default of false
        }

        return false;
    }
}