package nom.tam.image.compression.hdu;
   
   import java.util.ArrayList;
   import java.util.Arrays;
   import java.util.List;
   import java.util.Locale;
   
   import nom.tam.fits.BinaryTable;
   import nom.tam.fits.FitsException;
  import nom.tam.fits.FitsFactory;
  import nom.tam.fits.Header;
  import nom.tam.fits.header.Compression;
  import nom.tam.fits.header.Standard;
  import nom.tam.image.compression.bintable.BinaryTableTile;
  import nom.tam.image.compression.bintable.BinaryTableTileCompressor;
  import nom.tam.image.compression.bintable.BinaryTableTileDecompressor;
  import nom.tam.image.compression.bintable.BinaryTableTileDescription;
  import nom.tam.util.ColumnTable;
  
  /*
   * #%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.Standard.TFIELDS;
  import static nom.tam.image.compression.bintable.BinaryTableTileDescription.tile;
  
  /**
   * FITS representation of a compressed binary table. It itself is a binary table, but one in which each row represents
   * the compressed image of one or more rows of the original table.
   * 
   * @see CompressedTableHDU
   */
  @SuppressWarnings("deprecation")
  public class CompressedTableData extends BinaryTable {
  
      private static final List<String> ALLOWED_ALGORITHMS = Arrays.asList(Compression.ZCMPTYPE_GZIP_1,
              Compression.ZCMPTYPE_GZIP_2, Compression.ZCMPTYPE_RICE_1, Compression.ZCMPTYPE_NOCOMPRESS);
  
      private int rowsPerTile;
  
      private List<BinaryTableTile> tiles;
  
      private BinaryTable orig;
  
      /** Only add new var-length column in the preparation step once */
      private boolean isPrepped;
  
      private String[] colAlgorithm;
  
      /** For thread synchronization */
      private Object lock = new Object();
  
      /**
       * Creates a new empty compressed table data to be initialized at a later point
       */
      public CompressedTableData() {
      }
  
      /**
       * Creates a new compressed table data based on the prescription of the supplied header.
       * 
       * @param  header        The header that describes the compressed table
       * 
       * @throws FitsException If the header is invalid or could not be accessed.
       */
      public CompressedTableData(Header header) throws FitsException {
          super(header);
          rowsPerTile = header.getIntValue(Compression.ZTILELEN, header.getIntValue(Standard.NAXIS2));
          setColumnCompressionAlgorithms(header);
      }
  
      /**
      * (<i>for internal use</i>) This should only be called by {@link CompressedTableHDU}, and should have reduced
      * visibility accordingly.
      * 
      * @param  header        the compressed header
      * 
      * @throws FitsException if the table cannot be compressed.
      */
     public void compress(Header header) throws FitsException {
         discardVLAs();
 
         // If table has only fixed-length data, we can compress in parallel, and defragment after.
         for (BinaryTableTile tile : tiles) {
             tile.execute(FitsFactory.threadPool());
         }
 
         for (BinaryTableTile tile : tiles) {
             tile.waitForResult();
         }
     }
 
     @Override
     public long defragment() throws FitsException {
         synchronized (lock) {
             if (orig != null && orig.containsHeap()) {
                 // Don't defragment if the original had VLAs, since these are stored on the heap
                 // with a dual-set of descriptors, includeing compressed ones on the heap itself
                 // which are not trivial to de-fragment.
                 return 0L;
             }
             return super.defragment();
         }
     }
 
     @Override
     public void fillHeader(Header h) throws FitsException {
         super.fillHeader(h);
 
         h.setNaxis(2, getData().getNRows());
         h.addValue(Compression.ZTABLE, true);
         h.addValue(Compression.ZTILELEN, getRowsPerTile());
 
         for (int i = 0; i < getNCols(); i++) {
             h.findCard(Compression.ZFORMn.n(i + 1));
             h.addValue(Compression.ZCTYPn.n(i + 1), getAlgorithm(i));
         }
 
         h.deleteKey(Compression.ZIMAGE);
     }
 
     void prepareUncompressedData(BinaryTable fromTable) throws FitsException {
         orig = fromTable;
         prepareUncompressedData(orig.getData());
     }
 
     /**
      * @deprecated      (<i>for internal use</i>) This should only be called by {@link CompressedTableHDU}, and its
      *                      visibility will be reduced accordingly in the future, not to mention that it should take a
      *                      BinaryTable as its argument.
      * 
      * @param      data The original (uncompressed) table data.
      */
     @Deprecated
     @SuppressWarnings("javadoc")
     public void prepareUncompressedData(ColumnTable<?> data) throws FitsException {
         tiles = new ArrayList<>();
 
         int nrows = data.getNRows();
         int ncols = data.getNCols();
 
         if (!isPrepped) {
             // Create compressed columns...
             for (int column = 0; column < ncols; column++) {
                 addColumn(BinaryTable.ColumnDesc.createForVariableSize(byte.class));
                 getDescriptor(column).name(null);
             }
 
             // Initialized compressed rows...
             for (int rowStart = 0; rowStart < nrows; rowStart += getRowsPerTile()) {
                 addRow(new byte[ncols][0]);
             }
         }
 
         // Changed tile-order in 1.19.1 to be in row-major table order.
         for (int column = 0; column < ncols; column++) {
             for (int tileIndex = 0, rowStart = 0; rowStart < nrows; tileIndex++, rowStart += getRowsPerTile()) {
 
                 BinaryTableTileDescription td = tile()//
                         .rowStart(rowStart)//
                         .rowEnd(Math.min(nrows, rowStart + getRowsPerTile()))//
                         .column(column)//
                         .tileIndex(tileIndex + 1)//
                         .compressionAlgorithm(getAlgorithm(column));
 
                 BinaryTableTileCompressor tile = (orig == null) ? new BinaryTableTileCompressor(this, data, td) :
                         new BinaryTableTileCompressor(this, orig, td);
 
                 tiles.add(tile);
             }
         }
 
         isPrepped = true;
     }
 
     /**
      * (<i>for internal use</i>) No longer used, and it may be removed in the future.
      */
     @SuppressWarnings("javadoc")
     protected BinaryTable asBinaryTable(BinaryTable toTable, Header compressedHeader, Header targetHeader)
             throws FitsException {
         return asBinaryTable(toTable, compressedHeader, targetHeader, 0);
     }
 
     BinaryTable asBinaryTable(BinaryTable toTable, Header compressedHeader, Header targetHeader, int fromTile)
             throws FitsException {
         int nrows = targetHeader.getIntValue(Standard.NAXIS2);
         int ncols = compressedHeader.getIntValue(TFIELDS);
         int tileSize = compressedHeader.getIntValue(Compression.ZTILELEN, nrows);
 
         ensureData();
         setColumnCompressionAlgorithms(compressedHeader);
 
         BinaryTable.createColumnDataFor(toTable);
 
         List<BinaryTableTile> tileList = new ArrayList<>();
 
         for (int tileIndex = fromTile, rowStart = 0; rowStart < nrows; tileIndex++, rowStart += tileSize) {
             for (int column = 0; column < ncols; column++) {
                 BinaryTableTileDecompressor tile = new BinaryTableTileDecompressor(this, toTable, tile()//
                         .rowStart(rowStart)//
                         .rowEnd(Math.min(nrows, rowStart + tileSize))//
                         .column(column)//
                         .tileIndex(tileIndex + 1)//
                         .compressionAlgorithm(getAlgorithm(column)));
                 tileList.add(tile);
 
                 tile.execute(FitsFactory.threadPool());
             }
         }
 
         for (BinaryTableTile tile : tileList) {
             tile.waitForResult();
         }
 
         return toTable;
     }
 
     Object getColumnData(int col, int fromTile, int toTile, Header compressedHeader, Header targetHeader)
             throws FitsException {
 
         if (fromTile < 0 || fromTile >= getNRows()) {
             throw new IllegalArgumentException("start tile " + fromTile + " is outof bounds for " + getNRows() + " tiles.");
         }
 
         if (toTile > getNRows()) {
             throw new IllegalArgumentException("end tile " + toTile + " is outof bounds for " + getNRows() + " tiles.");
         }
 
         if (toTile <= fromTile) {
             return null;
         }
 
         setColumnCompressionAlgorithms(compressedHeader);
 
         int nr = targetHeader.getIntValue(Standard.NAXIS2);
 
         int tileSize = compressedHeader.getIntValue(Compression.ZTILELEN, nr);
         int nRows = (toTile - fromTile) * tileSize;
 
         if (nRows > nr) {
             nRows = nr;
         }
 
         ColumnDesc c = getDescriptor(targetHeader, col);
         class UncompressedTable extends BinaryTable {
             @Override
             public void createTable(int nRows) throws FitsException {
                 super.createTable(nRows);
             }
         }
 
         UncompressedTable data = new UncompressedTable();
         data.addColumn(c);
         data.createTable(nRows);
 
         List<BinaryTableTile> tileList = new ArrayList<>();
 
         String algorithm = compressedHeader.getStringValue(Compression.ZCTYPn.n(col + 1));
 
         for (int tileIndex = fromTile, rowStart = 0; rowStart < nRows; tileIndex++, rowStart += tileSize) {
             BinaryTableTileDecompressor tile = new BinaryTableTileDecompressor(this, data, tile()//
                     .rowStart(rowStart)//
                     .rowEnd(Math.min(nr, rowStart + tileSize))//
                     .column(col)//
                     .tileIndex(tileIndex + 1)//
                     .compressionAlgorithm(algorithm));
             tile.decompressToColumn(0);
             tileList.add(tile);
 
             tile.execute(FitsFactory.threadPool());
         }
 
         for (BinaryTableTile tile : tileList) {
             tile.waitForResult();
         }
 
         return data.getColumn(0);
     }
 
     /**
      * Returns the number of original (uncompressed) table rows that are compressed as a block into a single compressed
      * table row.
      * 
      * @return the number of table rows compressed together as a block.
      */
     protected final int getRowsPerTile() {
         synchronized (lock) {
             return rowsPerTile;
         }
     }
 
     private String getAlgorithm(int column) {
         if (colAlgorithm != null && column < colAlgorithm.length && colAlgorithm[column] != null) {
             return colAlgorithm[column];
         }
         return Compression.ZCMPTYPE_GZIP_2;
     }
 
     /**
      * (<i>for internal use</i>) Visibility may be reduced to the package level. This should only be called by
      * {@link CompressedTableHDU}.
      */
     @SuppressWarnings("javadoc")
     protected void setColumnCompressionAlgorithms(String[] columnCompressionAlgorithms) {
         for (String algo : columnCompressionAlgorithms) {
             if (!ALLOWED_ALGORITHMS.contains(algo.toUpperCase(Locale.US))) {
                 throw new IllegalArgumentException(algo + " cannot be used to compress tables.");
             }
         }
 
         this.colAlgorithm = columnCompressionAlgorithms;
     }
 
     private void setColumnCompressionAlgorithms(Header header) {
         int ncols = header.getIntValue(TFIELDS);
 
         // Default compression algorithm, unless specified...
         colAlgorithm = new String[ncols];
 
         // Set the compression algorithms specified.
         for (int column = 0; column < ncols; column++) {
             colAlgorithm[column] = header.getStringValue(Compression.ZCTYPn.n(column + 1));
         }
     }
 
     /**
      * (<i>for internal use</i>) Visibility may be reduced to the package level. This should only be called by
      * {@link CompressedTableHDU}.
      */
     @SuppressWarnings("javadoc")
     protected CompressedTableData setRowsPerTile(int value) {
         synchronized (lock) {
             rowsPerTile = value;
             return this;
         }
     }
 }