/*
 * Copyright (C) 2011-2012, 2014-2015, 2017-2018, 2022-2024, 2026
 *           D. R. Commander
 *
 * 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 libjpeg-turbo Project 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 HOLDERS 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.
 */

// This program demonstrates how to use TurboJPEG/JNA to approximate the
// functionality of the IJG's djpeg program.  djpeg features that are not
// covered:
//
// - OS/2 BMP, GIF, and Targa output file formats [legacy feature]
// - Color quantization and dithering [legacy feature]
// - The floating-point IDCT method [legacy feature]
// - Extracting an ICC color management profile
// - Progress reporting
// - Skipping rows (i.e. exclusive rather than inclusive partial decompression)
// - Debug output

import java.io.*;
import java.nio.*;
import java.util.*;

import com.sun.jna.*;
import com.sun.jna.ptr.*;


final class TJDecomp {

  private TJDecomp() {}

  static final String CLASS_NAME =
    new TJDecomp().getClass().getName();


  private static boolean isCropped(TJ.Region cr) {
    return (cr.x != 0 || cr.y != 0 || cr.w != 0 || cr.h != 0);
  }


  private static String tjErrorMsg;
  private static int tjErrorCode = -1;

  static void handleTJException(TJ.Exception e, int stopOnWarning)
                                throws TJ.Exception {
    String errorMsg = e.getMessage();
    int errorCode = e.getErrorCode();

    if (stopOnWarning != 1 && errorCode == TJ.ERR_WARNING) {
      if (tjErrorMsg == null || !tjErrorMsg.equals(errorMsg) ||
          tjErrorCode != errorCode) {
        tjErrorMsg = errorMsg;
        tjErrorCode = errorCode;
        System.out.println("WARNING: " + errorMsg);
      }
    } else
      throw e;
  }


  private static TJ.ScalingFactor[] scalingFactors;
  private static int numScalingFactors = 0;


  static void usage() {
    System.out.println("\nUSAGE: java [Java options] " + CLASS_NAME +
                       " [options] <JPEG image> <Output image>\n");

    System.out.println("The output image will be in Windows BMP or PBMPLUS (PPM/PGM) format, depending");
    System.out.println("on the file extension.\n");

    System.out.println("GENERAL OPTIONS (CAN BE ABBREVBIATED)");
    System.out.println("-------------------------------------");
    System.out.println("-icc FILE");
    System.out.println("    Extract the ICC (International Color Consortium) color profile from the");
    System.out.println("    JPEG image to the specified file");
    System.out.println("-noicc");
    System.out.println("    Do not transfer the embedded ICC profile (if any) from the JPEG image to a");
    System.out.println("    PNG output image");
    System.out.println("-strict");
    System.out.println("    Treat all warnings as fatal; abort immediately if incomplete or corrupt");
    System.out.println("    data is encountered in the JPEG image, rather than trying to salvage the");
    System.out.println("    rest of the image\n");

    System.out.println("LOSSY JPEG OPTIONS (CAN BE ABBREVIATED)");
    System.out.println("---------------------------------------");
    System.out.println("-crop WxH+X+Y");
    System.out.println("    Decompress only the specified region of the JPEG image.  (W, H, X, and Y");
    System.out.println("    are the width, height, left boundary, and upper boundary of the region, all");
    System.out.println("    specified relative to the scaled image dimensions.)  If necessary, X will");
    System.out.println("    be shifted left to the nearest iMCU boundary, and W will be increased");
    System.out.println("    accordingly.");
    System.out.println("-dct fast");
    System.out.println("    Use less accurate IDCT algorithm [legacy feature]");
    System.out.println("-dct int");
    System.out.println("    Use more accurate IDCT algorithm [default]");
    System.out.println("-grayscale");
    System.out.println("    Decompress a full-color JPEG image into a grayscale output image");
    System.out.println("-maxmemory N");
    System.out.println("    Memory limit (in megabytes) for intermediate buffers used with progressive");
    System.out.println("    JPEG decompression [default = no limit]");
    System.out.println("-maxscans N");
    System.out.println("    Refuse to decompress progressive JPEG images that have more than N scans");
    System.out.println("-nosmooth");
    System.out.println("    Use the fastest chrominance upsampling algorithm available");
    System.out.println("-precision 12");
    System.out.println("    Decompress an 8-bit-per-sample JPEG image into a 12-bit-per-sample output");
    System.out.println("    image [useful for shadow recovery]");
    System.out.println("-rgb");
    System.out.println("    Decompress a grayscale JPEG image into a full-color output image");
    System.out.println("-scale M/N");
    System.out.println("    Scale the width/height of the JPEG image by a factor of M/N when");
    System.out.print("    decompressing it (M/N = ");
    for (int i = 0; i < numScalingFactors; i++) {
      System.out.format("%d/%d", scalingFactors[i].num,
                        scalingFactors[i].denom);
      if (numScalingFactors == 2 && i != numScalingFactors - 1)
        System.out.print(" or ");
      else if (numScalingFactors > 2) {
        if (i != numScalingFactors - 1)
          System.out.print(", ");
        if (i == numScalingFactors - 2)
          System.out.print("or ");
      }
      if (i % 8 == 0 && i != 0) System.out.print("\n    ");
    }
    System.out.println(")\n");

    System.exit(1);
  }


  static boolean matchArg(String arg, String string, int minChars) {
    if (arg.length() > string.length() || arg.length() < minChars)
      return false;

    int cmpChars = Math.max(arg.length(), minChars);
    string = string.substring(0, cmpChars);

    return arg.equalsIgnoreCase(string);
  }


  public static void main(String[] argv) {
    int exitStatus = 0;

    try {

      int i;
      int colorspace, fastDCT = -1, fastUpsample = -1, jpegPrecision,
        maxMemory = -1, maxScans = -1, pixelFormat = TJ.PF_UNKNOWN,
        precision = -1, stopOnWarning = -1, subsamp;
      boolean lossless, noICC = false;
      TJ.Region croppingRegion = TJ.UNCROPPED;
      TJ.ScalingFactor scalingFactor = TJ.UNSCALED;
      String iccFilename = null;
      NativeLong jpegSize;
      long sampleSize;
      int width, height;
      Pointer jpegBuf, dstBuf;
      IntByReference numSF = new IntByReference();

      scalingFactors = TJ.getScalingFactors(numSF);
      numScalingFactors = numSF.getValue();

      for (i = 0; i < argv.length; i++) {
        if (matchArg(argv[i], "-crop", 2) && i < argv.length - 1) {
          int tempWidth = -1, tempHeight = -1, tempX = -1, tempY = -1;
          Scanner scanner = new Scanner(argv[++i]).useDelimiter("x|X|\\+");

          try {
            tempWidth = scanner.nextInt();
            tempHeight = scanner.nextInt();
            tempX = scanner.nextInt();
            tempY = scanner.nextInt();
          } catch (Exception e) {}

          if (tempWidth < 1 || tempHeight < 1 || tempX < 0 || tempY < 0)
            usage();
          croppingRegion.w = tempWidth;
          croppingRegion.h = tempHeight;
          croppingRegion.x = tempX;
          croppingRegion.y = tempY;
        } else if (matchArg(argv[i], "-dct", 2) && i < argv.length - 1) {
          i++;
          if (matchArg(argv[i], "fast", 1))
            fastDCT = 1;
          else if (!matchArg(argv[i], "int", 1))
            usage();
        } else if (matchArg(argv[i], "-grayscale", 2) ||
                   matchArg(argv[i], "-greyscale", 2))
          pixelFormat = TJ.PF_GRAY;
        else if (matchArg(argv[i], "-icc", 2) && i < argv.length - 1)
          iccFilename = argv[++i];
        else if (matchArg(argv[i], "-maxscans", 5) && i < argv.length - 1) {
          int temp = -1;

          try {
            temp = Integer.parseInt(argv[++i]);
          } catch (NumberFormatException e) {}
          if (temp < 0)
            usage();
          maxScans = temp;
        } else if (matchArg(argv[i], "-maxmemory", 2) && i < argv.length - 1) {
          int temp = -1;

          try {
            temp = Integer.parseInt(argv[++i]);
          } catch (NumberFormatException e) {}
          if (temp < 0)
            usage();
          maxMemory = temp;
        } else if (matchArg(argv[i], "-noicc", 4))
          noICC = true;
        else if (matchArg(argv[i], "-nosmooth", 2))
          fastUpsample = 1;
        else if (matchArg(argv[i], "-precision", 4) && i < argv.length - 1) {
          int temp = 0;

          try {
            temp = Integer.parseInt(argv[++i]);
          } catch (NumberFormatException e) {}
          if (temp != 12)
            usage();
          precision = temp;
        } else if (matchArg(argv[i], "-rgb", 2))
          pixelFormat = TJ.PF_RGB;
        else if (matchArg(argv[i], "-strict", 3))
          stopOnWarning = 1;
        else if (matchArg(argv[i], "-scale", 2) && i < argv.length - 1) {
          int tempNum = 0, tempDenom = 0;
          boolean match = false, scanned = true;
          Scanner scanner = new Scanner(argv[++i]).useDelimiter("/");

          try {
            tempNum = scanner.nextInt();
            tempDenom = scanner.nextInt();
          } catch (Exception e) {}

          if (tempNum < 1 || tempDenom < 1)
            usage();

          for (int j = 0; j < numScalingFactors; j++) {
            if ((double)tempNum / (double)tempDenom ==
                (double)scalingFactors[j].num /
                (double)scalingFactors[j].denom) {
              scalingFactor = scalingFactors[j];
              match = true;  break;
            }
          }
          if (!match) usage();
        } else break;
      }

      if (i != argv.length - 2)
        usage();

      try (TJ.Handle tjInstance = new TJ.Handle(TJ.INIT_DECOMPRESS)) {

        if (stopOnWarning >= 0)
          TJ.set(tjInstance, TJ.PARAM_STOPONWARNING, stopOnWarning);
        if (fastUpsample >= 0)
          TJ.set(tjInstance, TJ.PARAM_FASTUPSAMPLE, fastUpsample);
        if (fastDCT >= 0)
          TJ.set(tjInstance, TJ.PARAM_FASTDCT, fastDCT);
        if (maxScans >= 0)
          TJ.set(tjInstance, TJ.PARAM_SCANLIMIT, maxScans);
        if (maxMemory >= 0)
          TJ.set(tjInstance, TJ.PARAM_MAXMEMORY, maxMemory);

        File jpegFile = new File(argv[i++]);
        try (FileInputStream fis = new FileInputStream(jpegFile)) {
          jpegSize = new NativeLong(fis.available());
          if (jpegSize.longValue() < 1)
            throw new Exception("Input file contains no data");
          jpegBuf = new Memory(jpegSize.longValue());
          fis.getChannel().read(jpegBuf.getByteBuffer(0,
                                                      jpegSize.longValue()));
        }

        try {
          TJ.decompressHeader(tjInstance, jpegBuf, jpegSize);
        } catch (TJ.Exception e) { handleTJException(e, stopOnWarning); }
        subsamp = TJ.get(tjInstance, TJ.PARAM_SUBSAMP);
        width = TJ.get(tjInstance, TJ.PARAM_JPEGWIDTH);
        height = TJ.get(tjInstance, TJ.PARAM_JPEGHEIGHT);
        jpegPrecision = TJ.get(tjInstance, TJ.PARAM_PRECISION);
        colorspace = TJ.get(tjInstance, TJ.PARAM_COLORSPACE);
        lossless = TJ.get(tjInstance, TJ.PARAM_LOSSLESS) == 1;
        if (precision == -1 || lossless || jpegPrecision != 8)
          precision = jpegPrecision;
        sampleSize = (precision <= 8 ? 1 : 2);
        if (noICC)
          TJ.set(tjInstance, TJ.PARAM_SAVEMARKERS, 0);

        if (iccFilename != null) {
          NativeLongByReference iccSize = new NativeLongByReference();
          PointerByReference iccBuf = new PointerByReference();

          try {
            try {
              TJ.getICCProfile(tjInstance, iccBuf, iccSize);
            } catch (TJ.Exception e) { handleTJException(e, stopOnWarning); }
            if (iccBuf.getValue() != null) {
              File iccFile = new File(iccFilename);
              try (FileOutputStream fos = new FileOutputStream(iccFile)) {
                Pointer iccPtr = iccBuf.getValue();
                ByteBuffer bb =
                  iccPtr.getByteBuffer(0, iccSize.getValue().longValue());
                fos.getChannel().write(bb);
              }
            }
          } finally {
            TJ.free(iccBuf.getValue());
          }
        }

        if (pixelFormat == TJ.PF_UNKNOWN) {
          if (colorspace == TJ.CS_GRAY)
            pixelFormat = TJ.PF_GRAY;
          else if (colorspace == TJ.CS_CMYK || colorspace == TJ.CS_YCCK)
            pixelFormat = TJ.PF_CMYK;
          else
            pixelFormat = TJ.PF_RGB;
        }

        if (!lossless) {
          TJ.setScalingFactor(tjInstance, scalingFactor);
          width = TJ.scaled(width, scalingFactor);
          height = TJ.scaled(height, scalingFactor);

          if (isCropped(croppingRegion)) {
            int adjustment;

            if (subsamp == TJ.SAMP_UNKNOWN)
              throw new Exception("Could not determine subsampling level of JPEG image");
            adjustment = croppingRegion.x % TJ.scaled(TJ.MCU_WIDTH[subsamp],
                                                      scalingFactor);
            croppingRegion.x -= adjustment;
            croppingRegion.w += adjustment;
            TJ.setCroppingRegion(tjInstance, croppingRegion);
            width = croppingRegion.w;
            height = croppingRegion.h;
          }
        }

        dstBuf =
          new Memory(width * height * TJ.PIXEL_SIZE[pixelFormat] * sampleSize);

        try {
          if (precision <= 8)
            TJ.decompress8(tjInstance, jpegBuf, jpegSize, dstBuf, 0,
                           pixelFormat);
          else if (precision <= 12)
            TJ.decompress12(tjInstance, jpegBuf, jpegSize, dstBuf, 0,
                            pixelFormat);
          else
            TJ.decompress16(tjInstance, jpegBuf, jpegSize, dstBuf, 0,
                            pixelFormat);
        } catch (TJ.Exception e) { handleTJException(e, stopOnWarning); }

        if (precision <= 8)
          TJ.saveImage8(tjInstance, argv[i], dstBuf, width, 0, height,
                        pixelFormat);
        else if (precision <= 12)
          TJ.saveImage12(tjInstance, argv[i], dstBuf, width, 0, height,
                         pixelFormat);
        else
          TJ.saveImage16(tjInstance, argv[i], dstBuf, width, 0, height,
                         pixelFormat);

      }  // try (tjInstance)

    } catch (Exception e) {
      e.printStackTrace();
      exitStatus = -1;
    }

    System.exit(exitStatus);
  }
};