package org.jcodec.common;

import java.nio.ByteBuffer;
import java.nio.FloatBuffer;
import org.jcodec.api.NotSupportedException;
import org.jcodec.common.tools.MathUtil;

public class AudioUtil {
  private static final float f24 = 8388607.0F;
  
  private static final float f16 = 32767.0F;
  
  public static final float r16 = 3.0517578E-5F;
  
  public static final float r24 = 1.1920929E-7F;
  
  public static void toFloat(AudioFormat format, ByteBuffer buf, FloatBuffer floatBuf) {
    if (!format.isSigned())
      throw new NotSupportedException("Unsigned PCM is not supported ( yet? )."); 
    if (format.getSampleSizeInBits() != 16 && format.getSampleSizeInBits() != 24)
      throw new NotSupportedException("" + format.getSampleSizeInBits() + " bit PCM is not supported ( yet? )."); 
    if (format.isBigEndian()) {
      if (format.getSampleSizeInBits() == 16) {
        toFloat16BE(buf, floatBuf);
      } else {
        toFloat24BE(buf, floatBuf);
      } 
    } else if (format.getSampleSizeInBits() == 16) {
      toFloat16LE(buf, floatBuf);
    } else {
      toFloat24LE(buf, floatBuf);
    } 
  }
  
  public static void fromFloat(FloatBuffer floatBuf, AudioFormat format, ByteBuffer buf) {
    if (!format.isSigned())
      throw new NotSupportedException("Unsigned PCM is not supported ( yet? )."); 
    if (format.getSampleSizeInBits() != 16 && format.getSampleSizeInBits() != 24)
      throw new NotSupportedException("" + format.getSampleSizeInBits() + " bit PCM is not supported ( yet? )."); 
    if (format.isBigEndian()) {
      if (format.getSampleSizeInBits() == 16) {
        fromFloat16BE(buf, floatBuf);
      } else {
        fromFloat24BE(buf, floatBuf);
      } 
    } else if (format.getSampleSizeInBits() == 16) {
      fromFloat16LE(buf, floatBuf);
    } else {
      fromFloat24LE(buf, floatBuf);
    } 
  }
  
  private static void toFloat24LE(ByteBuffer buf, FloatBuffer out) {
    while (buf.remaining() >= 3 && out.hasRemaining())
      out.put(1.1920929E-7F * (float)(((buf.get() & 0xFF) << 8 | (buf.get() & 0xFF) << 16 | (buf.get() & 0xFF) << 24) >> 8)); 
  }
  
  private static void toFloat16LE(ByteBuffer buf, FloatBuffer out) {
    while (buf.remaining() >= 2 && out.hasRemaining())
      out.put(3.0517578E-5F * (float)(short)(buf.get() & 0xFF | (buf.get() & 0xFF) << 8)); 
  }
  
  private static void toFloat24BE(ByteBuffer buf, FloatBuffer out) {
    while (buf.remaining() >= 3 && out.hasRemaining())
      out.put(1.1920929E-7F * (float)(((buf.get() & 0xFF) << 24 | (buf.get() & 0xFF) << 16 | (buf.get() & 0xFF) << 8) >> 8)); 
  }
  
  private static void toFloat16BE(ByteBuffer buf, FloatBuffer out) {
    while (buf.remaining() >= 2 && out.hasRemaining())
      out.put(3.0517578E-5F * (float)(short)((buf.get() & 0xFF) << 8 | buf.get() & 0xFF)); 
  }
  
  private static void fromFloat24LE(ByteBuffer buf, FloatBuffer _in) {
    while (buf.remaining() >= 3 && _in.hasRemaining()) {
      int val = MathUtil.clip((int)(_in.get() * 8388607.0F), -8388608, 8388607) & 0xFFFFFF;
      buf.put((byte)val);
      buf.put((byte)(val >> 8));
      buf.put((byte)(val >> 16));
    } 
  }
  
  private static void fromFloat16LE(ByteBuffer buf, FloatBuffer _in) {
    while (buf.remaining() >= 2 && _in.hasRemaining()) {
      int val = MathUtil.clip((int)(_in.get() * 32767.0F), -32768, 32767) & 0xFFFF;
      buf.put((byte)val);
      buf.put((byte)(val >> 8));
    } 
  }
  
  private static void fromFloat24BE(ByteBuffer buf, FloatBuffer _in) {
    while (buf.remaining() >= 3 && _in.hasRemaining()) {
      int val = MathUtil.clip((int)(_in.get() * 8388607.0F), -8388608, 8388607) & 0xFFFFFF;
      buf.put((byte)(val >> 16));
      buf.put((byte)(val >> 8));
      buf.put((byte)val);
    } 
  }
  
  private static void fromFloat16BE(ByteBuffer buf, FloatBuffer _in) {
    while (buf.remaining() >= 2 && _in.hasRemaining()) {
      int val = MathUtil.clip((int)(_in.get() * 32767.0F), -32768, 32767) & 0xFFFF;
      buf.put((byte)(val >> 8));
      buf.put((byte)val);
    } 
  }
  
  public static int fromInt(int[] data, int len, AudioFormat format, ByteBuffer buf) {
    if (!format.isSigned())
      throw new NotSupportedException("Unsigned PCM is not supported ( yet? )."); 
    if (format.getSampleSizeInBits() != 16 && format.getSampleSizeInBits() != 24)
      throw new NotSupportedException("" + format.getSampleSizeInBits() + " bit PCM is not supported ( yet? )."); 
    if (format.isBigEndian()) {
      if (format.getSampleSizeInBits() == 16)
        return fromInt16BE(buf, data, len); 
      return fromInt24BE(buf, data, len);
    } 
    if (format.getSampleSizeInBits() == 16)
      return fromInt16LE(buf, data, len); 
    return fromInt24LE(buf, data, len);
  }
  
  private static int fromInt24LE(ByteBuffer buf, int[] out, int len) {
    int samples = 0;
    while (buf.remaining() >= 3 && samples < len) {
      int val = out[samples++];
      buf.put((byte)val);
      buf.put((byte)(val >> 8));
      buf.put((byte)(val >> 16));
    } 
    return samples;
  }
  
  private static int fromInt16LE(ByteBuffer buf, int[] out, int len) {
    int samples = 0;
    while (buf.remaining() >= 2 && samples < len) {
      int val = out[samples++];
      buf.put((byte)val);
      buf.put((byte)(val >> 8));
    } 
    return samples;
  }
  
  private static int fromInt24BE(ByteBuffer buf, int[] out, int len) {
    int samples = 0;
    while (buf.remaining() >= 3 && samples < len) {
      int val = out[samples++];
      buf.put((byte)(val >> 16));
      buf.put((byte)(val >> 8));
      buf.put((byte)val);
    } 
    return samples;
  }
  
  private static int fromInt16BE(ByteBuffer buf, int[] out, int len) {
    int samples = 0;
    while (buf.remaining() >= 2 && samples < len) {
      int val = out[samples++];
      buf.put((byte)(val >> 8));
      buf.put((byte)val);
    } 
    return samples;
  }
  
  public static int toInt(AudioFormat format, ByteBuffer buf, int[] samples) {
    if (!format.isSigned())
      throw new NotSupportedException("Unsigned PCM is not supported ( yet? )."); 
    if (format.getSampleSizeInBits() != 16 && format.getSampleSizeInBits() != 24)
      throw new NotSupportedException("" + format.getSampleSizeInBits() + " bit PCM is not supported ( yet? )."); 
    if (format.isBigEndian()) {
      if (format.getSampleSizeInBits() == 16)
        return toInt16BE(buf, samples); 
      return toInt24BE(buf, samples);
    } 
    if (format.getSampleSizeInBits() == 16)
      return toInt16LE(buf, samples); 
    return toInt24LE(buf, samples);
  }
  
  private static int toInt24LE(ByteBuffer buf, int[] out) {
    int samples = 0;
    while (buf.remaining() >= 3 && samples < out.length)
      out[samples++] = ((buf.get() & 0xFF) << 8 | (buf.get() & 0xFF) << 16 | (buf.get() & 0xFF) << 24) >> 8; 
    return samples;
  }
  
  private static int toInt16LE(ByteBuffer buf, int[] out) {
    int samples = 0;
    while (buf.remaining() >= 2 && samples < out.length)
      out[samples++] = (short)(buf.get() & 0xFF | (buf.get() & 0xFF) << 8); 
    return samples;
  }
  
  private static int toInt24BE(ByteBuffer buf, int[] out) {
    int samples = 0;
    while (buf.remaining() >= 3 && samples < out.length)
      out[samples++] = ((buf.get() & 0xFF) << 24 | (buf.get() & 0xFF) << 16 | (buf.get() & 0xFF) << 8) >> 8; 
    return samples;
  }
  
  private static int toInt16BE(ByteBuffer buf, int[] out) {
    int samples = 0;
    while (buf.remaining() >= 2 && samples < out.length)
      out[samples++] = (short)((buf.get() & 0xFF) << 8 | buf.get() & 0xFF); 
    return samples;
  }
  
  public static void interleave(AudioFormat format, ByteBuffer[] ins, ByteBuffer outb) {
    int bytesPerSample = format.getSampleSizeInBits() >> 3;
    int bytesPerFrame = bytesPerSample * ins.length;
    int max = 0;
    for (int i = 0; i < ins.length; i++) {
      if (ins[i].remaining() > max)
        max = ins[i].remaining(); 
    } 
    for (int frames = 0; frames < max && outb.remaining() >= bytesPerFrame; frames++) {
      for (int j = 0; j < ins.length; j++) {
        if (ins[j].remaining() < bytesPerSample) {
          for (int k = 0; k < bytesPerSample; k++)
            outb.put((byte)0); 
        } else {
          for (int k = 0; k < bytesPerSample; k++)
            outb.put(ins[j].get()); 
        } 
      } 
    } 
  }
  
  public static void deinterleave(AudioFormat format, ByteBuffer inb, ByteBuffer[] outs) {
    int bytesPerSample = format.getSampleSizeInBits() >> 3;
    int bytesPerFrame = bytesPerSample * outs.length;
    while (inb.remaining() >= bytesPerFrame) {
      for (int j = 0; j < outs.length; j++) {
        for (int i = 0; i < bytesPerSample; i++)
          outs[j].put(inb.get()); 
      } 
    } 
  }
}