package nom.tam.image.compression.hdu;
   
   import java.io.IOException;
   import java.nio.Buffer;
   import java.nio.ByteBuffer;
   import java.util.Arrays;
   import java.util.HashMap;
   import java.util.List;
   import java.util.Map;
  
  import nom.tam.fits.BinaryTableHDU;
  import nom.tam.fits.FitsException;
  import nom.tam.fits.FitsUtil;
  import nom.tam.fits.Header;
  import nom.tam.fits.HeaderCard;
  import nom.tam.fits.HeaderCardException;
  import nom.tam.fits.ImageData;
  import nom.tam.fits.ImageHDU;
  import nom.tam.fits.compression.algorithm.api.ICompressOption;
  import nom.tam.fits.header.Compression;
  import nom.tam.fits.header.GenericKey;
  import nom.tam.fits.header.IFitsHeader;
  import nom.tam.fits.header.Standard;
  import nom.tam.image.compression.CompressedImageTiler;
  import nom.tam.util.ByteBufferInputStream;
  import nom.tam.util.ByteBufferOutputStream;
  import nom.tam.util.Cursor;
  import nom.tam.util.FitsInputStream;
  import nom.tam.util.FitsOutputStream;
  
  /*
   * #%L
   * nom.tam FITS library
   * %%
   * Copyright (C) 1996 - 2024 nom-tam-fits
   * %%
   * This is free and unencumbered software released into the public domain.
   *
   * Anyone is free to copy, modify, publish, use, compile, sell, or
   * distribute this software, either in source code form or as a compiled
   * binary, for any purpose, commercial or non-commercial, and by any
   * means.
   *
   * In jurisdictions that recognize copyright laws, the author or authors
   * of this software dedicate any and all copyright interest in the
   * software to the public domain. We make this dedication for the benefit
   * of the public at large and to the detriment of our heirs and
   * successors. We intend this dedication to be an overt act of
   * relinquishment in perpetuity of all present and future rights to this
   * software under copyright law.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
   * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
   * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
   * OTHER DEALINGS IN THE SOFTWARE.
   * #L%
   */
  
  import static nom.tam.fits.header.Compression.ZIMAGE;
  import static nom.tam.fits.header.Standard.BLANK;
  
  /**
   * <p>
   * A header-data unit (HDU) containing a compressed image. A compressed image is a normal binary table with some
   * additional constraints. The original image is divided into tiles and each tile is compressed on its own. The
   * compressed data is then stored in the 3 data columns of this binary table (compressed, gzipped and uncompressed)
   * depending on the compression type used in the tile. Additional data columns may contain specific compression or
   * quantization options for each tile (i.e. compressed table row) individually. Table keywords, which conflict with
   * those in the original image are 'saved' under standard alternative names, so they may be restored with the image as
   * appropriate.
   * </p>
   * <p>
   * Compressing an image HDU is typically a multi-step process:
   * </p>
   * <ol>
   * <li>Create a <code>CompressedImageHDU</code>, e.g. with {@link #fromImageHDU(ImageHDU, int...)}.</li>
   * <li>Set up the compression algorithm, including quantization (if desired) via {@link #setCompressAlgorithm(String)}
   * and {@link #setQuantAlgorithm(String)}, and optionally the compressiomn method used for preserving the blank values
   * via {@link #preserveNulls(String)}.</li>
   * <li>Set compression (and quantization) options, via calling on {@link #getCompressOption(Class)}</li>
   * <li>Perform the compression via {@link #compress()}</li>
   * </ol>
   * <p>
   * For example to compress an image HDU:
   * </p>
   * 
   * <pre>
   *   ImageHDU image = ...
   *   
   *   // 1. Create compressed HDU
   *   CompressedImageHDU compressed = CompressedImageHDU.fromImageHDU(image, 60, 40);
   *   
   *   // 2. Set compression (and optional qunatizaiton) algorithm(s)
   *   compressed.setCompressAlgorithm(Compression.ZCMPTYPE_RICE_1)
   *             .setQuantAlgorithm(Compression.ZQUANTIZ_SUBTRACTIVE_DITHER_1)
   *             .preserveNulls(Compression.ZCMPTYPE_HCOMPRESS_1);
  *             
  *   // 3. Set compression (and quantizaiton) options
  *   compressed.getCompressOption(RiceCompressOption.class).setBlockSize(32);
  *   compressed.getCompressOption(QuantizeOption.class).setBZero(3.0).setBScale(0.1).setBNull(-999);
  *                    
  *   // 4. Perform the compression.
  *   compressed.compress();
  * </pre>
  * <p>
  * After the compression, the compressed image HDU can be handled just like any other HDU, and written to a file or
  * stream, for example.
  * </p>
  * <p>
  * The reverse process is simply via the {@link #asImageHDU()} method. E.g.:
  * </p>
  * 
  * <pre>
  *    CompressedImageHDU compressed = ...
  *    ImageHDU image = compressed.asImageHDU();
  * </pre>
  * 
  * @see CompressedImageData
  * @see nom.tam.image.compression.CompressedImageTiler
  */
 @SuppressWarnings("deprecation")
 public class CompressedImageHDU extends BinaryTableHDU {
     /** The maximum number of table columns FITS supports */
     public static final int MAX_NAXIS_ALLOWED = 999;
 
     /**
      * keys that are only valid in tables and should not go into the uncompressed image.
      */
     private static final List<IFitsHeader> TABLE_COLUMN_KEYS = Arrays.asList(binaryTableColumnKeyStems());
 
     static final Map<IFitsHeader, CompressedCard> COMPRESSED_HEADER_MAPPING = new HashMap<>();
 
     static final Map<IFitsHeader, CompressedCard> UNCOMPRESSED_HEADER_MAPPING = new HashMap<>();
 
     /**
      * Prepare a compressed image hdu for the specified image. the tile axis that are specified with -1 default to
      * tiling by rows. To actually perform the compression, you will next have to select the compression algorithm (and
      * optinally a quantization algorithm), then configure options for these, and finally call {@link #compress()} to
      * perform the compression. See the description of this class for more details.
      *
      * @param  imageHDU      the image to compress
      * @param  tileAxis      the requested tile sizes in pixels in x, y, z... order (i.e. opposite of the Java array
      *                           indexing order!). The actual tile sizes that are set might be different, e.g. to fit
      *                           within the image bounds and/or to conform to tiling conventions (esp. in more than 2
      *                           dimensions).
      *
      * @return               the prepared compressed image hdu.
      *
      * @throws FitsException if the image could not be used to create a compressed image.
      * 
      * @see                  #asImageHDU()
      * @see                  #setCompressAlgorithm(String)
      * @see                  #setQuantAlgorithm(String)
      * @see                  #getCompressOption(Class)
      * @see                  #compress()
      */
     public static CompressedImageHDU fromImageHDU(ImageHDU imageHDU, int... tileAxis) throws FitsException {
         Header header = new Header();
         CompressedImageData compressedData = new CompressedImageData();
         int[] size = imageHDU.getAxes();
         int[] tileSize = new int[size.length];
 
         compressedData.setAxis(size);
 
         // Start with the default tile size.
         int nm1 = size.length - 1;
         Arrays.fill(tileSize, 1);
         tileSize[nm1] = size[nm1];
 
         // Check and apply the requested tile sizes.
         int n = Math.min(size.length, tileAxis.length);
         for (int i = 0; i < n; i++) {
             if (tileAxis[i] > 0) {
                 tileSize[nm1 - i] = Math.min(tileAxis[i], size[nm1 - i]);
             }
         }
 
         compressedData.setTileSize(tileSize);
 
         compressedData.fillHeader(header);
         Cursor<String, HeaderCard> iterator = header.iterator();
         Cursor<String, HeaderCard> imageIterator = imageHDU.getHeader().iterator();
         while (imageIterator.hasNext()) {
             HeaderCard card = imageIterator.next();
             CompressedCard.restore(card, iterator);
         }
         CompressedImageHDU compressedImageHDU = new CompressedImageHDU(header, compressedData);
         compressedData.prepareUncompressedData(imageHDU.getData().getData(), header);
         return compressedImageHDU;
     }
 
     /**
      * Check that this HDU has a valid header for this type.
      * 
      * @deprecated     (<i>for internal use</i>) Will reduce visibility in the future
      *
      * @param      hdr header to check
      *
      * @return         <CODE>true</CODE> if this HDU has a valid header.
      */
     @Deprecated
     public static boolean isHeader(Header hdr) {
         return hdr.getBooleanValue(ZIMAGE, false);
     }
 
     /**
      * Returns an empty compressed image data object based on its description in a FITS header.
      * 
      * @param      hdr           the FITS header containing a description of the compressed image
      * 
      * @return                   an empty compressed image data corresponding to the header description.
      * 
      * @throws     FitsException if the header does not sufficiently describe a compressed image
      * 
      * @deprecated               (<i>for internal use</i>) Will reduce visibility in the future
      */
     @Deprecated
     public static CompressedImageData manufactureData(Header hdr) throws FitsException {
         return new CompressedImageData(hdr);
     }
 
     /**
      * Creates an new compressed image HDU with the specified header and compressed data.
      * 
      * @param hdr   the header
      * @param datum the compressed image data. The data may not be actually compressed at this point, int which case you
      *                  may need to call {@link #compress()} before writing the new compressed HDU to a stream.
      * 
      * @see         #compress()
      */
     public CompressedImageHDU(Header hdr, CompressedImageData datum) {
         super(hdr, datum);
     }
 
     /**
      * Restores the original image HDU by decompressing the data contained in this compresed image HDU.
      * 
      * @return               The uncompressed Image HDU.
      * 
      * @throws FitsException If there was an issue with the decompression.
      * 
      * @see                  #getTileHDU(int[], int[])
      * @see                  #fromImageHDU(ImageHDU, int...)
      */
     public ImageHDU asImageHDU() throws FitsException {
         final Header header = getImageHeader();
         ImageData data = ImageHDU.manufactureData(header);
         ImageHDU imageHDU = new ImageHDU(header, data);
         data.setBuffer(getUncompressedData());
         return imageHDU;
     }
 
     /**
      * Returns an <code>ImageHDU</code>, with the specified decompressed image area. The HDU's header will be adjusted
      * as necessary to reflect the correct size and coordinate system of the image cutout.
      * 
      * @param  corners                  the location in pixels where the tile begins in the full (uncompressed) image.
      *                                      The number of elements in the array must match the image dimnesion.
      * @param  lengths                  the size of the tile in pixels. The number of elements in the array must match
      *                                      the image dimnesion.
      * 
      * @return                          a new image HDU containing the selected area of the uncompresed image, including
      *                                      the adjusted header for the selected area,
      * 
      * @throws IOException              If the tiling operation itself could not be performed
      * @throws FitsException            If the compressed image itself if invalid or imcomplete
      * @throws IllegalArgumentException if the tile area is not fully contained inside the uncompressed image or if the
      *                                      lengths are not positive definite.
      * 
      * @see                             #asImageHDU()
      * @see                             CompressedImageTiler#getTile(int[], int[])
      * 
      * @since                           1.18
      */
     public ImageHDU getTileHDU(int[] corners, int[] lengths) throws IOException, FitsException, IllegalArgumentException {
         Header h = getImageHeader();
 
         int dim = h.getIntValue(Standard.NAXIS);
 
         if (corners.length != lengths.length || corners.length != dim) {
             throw new IllegalArgumentException("arguments for mismatched dimensions");
         }
 
         // Edit the image bound for the tile
         for (int i = 0; i < corners.length; i++) {
             int naxis = h.getIntValue(Standard.NAXISn.n(dim - i));
 
             if (lengths[0] <= 0) {
                 throw new IllegalArgumentException("Illegal tile size in dim " + i + ": " + lengths[i]);
             }
 
             if (corners[i] < 0 || corners[i] + lengths[i] > naxis) {
                 throw new IllegalArgumentException("tile out of bounds in dim " + i + ": [" + corners[i] + ":"
                         + (corners[i] + lengths[i]) + "] in " + naxis);
             }
 
             h.addValue(Standard.NAXISn.n(dim - i), lengths[i]);
 
             // Adjust the CRPIXn values
             HeaderCard crpix = h.getCard(Standard.CRPIXn.n(dim - i));
             if (crpix != null) {
                 crpix.setValue(crpix.getValue(Double.class, Double.NaN) - corners[i]);
             }
 
             // Adjust CRPIXna values
             for (char c = 'A'; c <= 'Z'; c++) {
                 crpix = h.getCard("CRPIX" + (dim - i) + Character.toString(c));
                 if (crpix != null) {
                     crpix.setValue(crpix.getValue(Double.class, Double.NaN) - corners[i]);
                 }
             }
         }
 
         ImageData im = ImageHDU.manufactureData(h);
         ByteBuffer buf = ByteBuffer.wrap(new byte[(int) FitsUtil.addPadding(im.getSize())]);
 
         try (FitsOutputStream out = new FitsOutputStream(new ByteBufferOutputStream(buf))) {
             new CompressedImageTiler(this).getTile(out, corners, lengths);
             out.close();
         }
 
         // Rewind buffer for reading, including padding.
         buf.limit(buf.capacity());
         buf.position(0);
 
         try (FitsInputStream in = new FitsInputStream(new ByteBufferInputStream(buf))) {
             im.read(in);
             in.close();
         }
 
         return new ImageHDU(h, im);
     }
 
     /**
      * Given this compressed HDU, get the original (decompressed) axes.
      *
      * @return               the dimensions of the axis.
      *
      * @throws FitsException if the axis are configured wrong.
      *
      * @since                1.18
      */
     public int[] getImageAxes() throws FitsException {
         int nAxis = myHeader.getIntValue(Compression.ZNAXIS);
         if (nAxis < 0) {
             throw new FitsException("Negative ZNAXIS (or NAXIS) value " + nAxis);
         }
         if (nAxis > CompressedImageHDU.MAX_NAXIS_ALLOWED) {
             throw new FitsException("ZNAXIS/NAXIS value " + nAxis + " too large");
         }
 
         if (nAxis == 0) {
             return null;
         }
 
         final int[] axes = new int[nAxis];
         for (int i = 1; i <= nAxis; i++) {
             axes[nAxis - i] = myHeader.getIntValue(Compression.ZNAXISn.n(i));
         }
 
         return axes;
     }
 
     /**
      * Obtain a header representative of a decompressed ImageHDU.
      *
      * @return                     Header with decompressed cards.
      *
      * @throws HeaderCardException if the card could not be copied
      *
      * @since                      1.18
      */
     public Header getImageHeader() throws HeaderCardException {
         Header header = new Header();
 
         Cursor<String, HeaderCard> imageIterator = header.iterator();
         Cursor<String, HeaderCard> iterator = getHeader().iterator();
 
         while (iterator.hasNext()) {
             HeaderCard card = iterator.next();
 
             if (!TABLE_COLUMN_KEYS.contains(GenericKey.lookup(card.getKey()))) {
                 CompressedCard.backup(card, imageIterator);
             }
         }
         return header;
     }
 
     /**
      * Performs the actual compression with the selected algorithm(s) and options. When creating a compressed image HDU,
      * e.g using the {@link #fromImageHDU(ImageHDU, int...)} method, the HDU is merely prepared but without actually
      * performing the compression to allow the user to configure the algorithm(S) to be used as well as any specific
      * compression (or quantization) options. See details in the class description.
      * 
      * @throws FitsException if the compression could not be performed
      * 
      * @see                  #fromImageHDU(ImageHDU, int...)
      * @see                  #setCompressAlgorithm(String)
      * @see                  #setQuantAlgorithm(String)
      * @see                  #getCompressOption(Class)
      */
     public void compress() throws FitsException {
         getData().compress(this);
     }
 
     /**
      * Specify an area within the image that will not undergo a lossy compression. This will only have affect it the
      * selected compression (including the options) is a lossy compression. All tiles touched by this region will be
      * handled so that there is no loss of any data, the reconstruction will be exact.
      *
      * @param  x      the x position in the image
      * @param  y      the y position in the image
      * @param  width  the width of the area
      * @param  heigth the height of the area
      *
      * @return        this
      */
     public CompressedImageHDU forceNoLoss(int x, int y, int width, int heigth) {
         getData().forceNoLoss(x, y, width, heigth);
         return this;
     }
 
     /**
      * Returns the compression (or quantization) options for a selected compression option class. It is presumed that
      * the requested options are appropriate for the compression and/or quantization algorithm that was selected. E.g.,
      * if you called <code>setCompressionAlgorithm({@link Compression#ZCMPTYPE_RICE_1})</code>, then you can retrieve
      * options for it with this method as
      * <code>getCompressOption({@link nom.tam.fits.compression.algorithm.rice.RiceCompressOption}.class)</code>.
      * 
      * @param  <T>   The generic type of the compression class
      * @param  clazz the compression class
      * 
      * @return       The current set of options for the requested type, or <code>null</code> if there are no options or
      *                   if the requested type does not match the algorithm(s) selected.
      * 
      * @see          nom.tam.fits.compression.algorithm.hcompress.HCompressorOption
      * @see          nom.tam.fits.compression.algorithm.rice.RiceCompressOption
      * @see          nom.tam.fits.compression.algorithm.quant.QuantizeOption
      */
     public <T extends ICompressOption> T getCompressOption(Class<T> clazz) {
         return getData().getCompressOption(clazz);
     }
 
     @Override
     public CompressedImageData getData() {
         return (CompressedImageData) super.getData();
     }
 
     /**
      * Returns the uncompressed image in serialized form, as it would appear in a stream.
      * 
      * @deprecated               (<i>for internal use</i>) There is no reason why this should be exposed to users. Use
      *                               {@link #asImageHDU()} instead. Future release may restrict the visibility to
      *                               private.
      * 
      * @return                   the buffer containing the serialized form of the uncompressed image.
      * 
      * @throws     FitsException if the decompression could not be performed.
      * 
      * @see                      #asImageHDU()
      */
     @Deprecated
     public Buffer getUncompressedData() throws FitsException {
         return getData().getUncompressedData(getHeader());
     }
 
     @Override
     @Deprecated
     public boolean isHeader() {
         return super.isHeader() && isHeader(myHeader);
     }
 
     /**
      * Sets the compression algorithm used for preserving the blank values in the original image even if the compression
      * is lossy. When compression an integer image, a BLANK header should be defined in its header. You should typically
      * use one of the enum values defined in {@link Compression}.
      *
      * @param  compressionAlgorithm compression algorithm to use for the null pixel mask, see {@link Compression} for
      *                                  recognized names.
      *
      * @return                      itself
      * 
      * @see                         Compression
      * @see                         #setCompressAlgorithm(String)
      * @see                         #setQuantAlgorithm(String)
      */
     public CompressedImageHDU preserveNulls(String compressionAlgorithm) {
         long nullValue = getHeader().getLongValue(BLANK, Long.MIN_VALUE);
         getData().preserveNulls(nullValue, compressionAlgorithm);
         return this;
     }
 
     /**
      * Sets the compression algorithm to use, by its standard FITS name. You should typically use one of the enum values
      * defined in {@link Compression}.
      * 
      * @param  compressAlgorithm compression algorithm to use, see {@link Compression} for recognized names.
      * 
      * @return                   itself
      * 
      * @throws FitsException     if no algorithm is available by the specified name
      * 
      * @see                      Compression
      * @see                      #setQuantAlgorithm(String)
      * @see                      #preserveNulls(String)
      */
     public CompressedImageHDU setCompressAlgorithm(String compressAlgorithm) throws FitsException {
         HeaderCard compressAlgorithmCard = HeaderCard.create(Compression.ZCMPTYPE, compressAlgorithm);
         getData().setCompressAlgorithm(compressAlgorithmCard);
         return this;
     }
 
     /**
      * Sets the quantization algorithm to use, by its standard FITS name. You should typically use one of the enum
      * values defined in {@link Compression}.
      * 
      * @param  quantAlgorithm quantization algorithm to use, see {@link Compression} for recognized names.
      * 
      * @return                itself
      * 
      * @throws FitsException  if no algorithm is available by the specified name
      * 
      * @see                   Compression
      * @see                   #setCompressAlgorithm(String)
      * @see                   #preserveNulls(String)
      */
     public CompressedImageHDU setQuantAlgorithm(String quantAlgorithm) throws FitsException {
         if (quantAlgorithm != null && !quantAlgorithm.isEmpty()) {
             HeaderCard quantAlgorithmCard = HeaderCard.create(Compression.ZQUANTIZ, quantAlgorithm);
             getData().setQuantAlgorithm(quantAlgorithmCard);
         } else {
             getData().setQuantAlgorithm(null);
         }
         return this;
     }
 }