package nom.tam.fits;
   
   import java.util.concurrent.ExecutorService;
   import java.util.concurrent.Executors;
   import java.util.concurrent.ThreadFactory;
   
   import nom.tam.fits.header.Standard;
   import nom.tam.fits.header.hierarch.IHierarchKeyFormatter;
   import nom.tam.fits.header.hierarch.StandardIHierarchKeyFormatter;
  import nom.tam.image.compression.hdu.CompressedImageData;
  import nom.tam.image.compression.hdu.CompressedImageHDU;
  import nom.tam.image.compression.hdu.CompressedTableData;
  import nom.tam.image.compression.hdu.CompressedTableHDU;
  
  /*
   * #%L
   * nom.tam FITS library
   * %%
   * Copyright (C) 2004 - 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%
   */
  
  /**
   * Controls the creation of HDUs to encapsulate a variery of data, based on a few configuration switches. The switches
   * allow for toggling support for different conventions to set the desired compatibility level. The default settings
   * produce FITS that are compatibel with version 4.0 of the standard (the latest at the time of writing this). The
   * switches may also be used to make this library more backward compatible with its previous version also.
   */
  public final class FitsFactory {
  
      private static final boolean DEFAULT_USE_ASCII_TABLES = false;
  
      private static final boolean DEFAULT_USE_HIERARCH = true;
  
      private static final boolean DEFAULT_USE_EXPONENT_D = false;
  
      private static final boolean DEFAULT_LONG_STRINGS_ENABLED = true;
  
      private static final boolean DEFAULT_CHECK_ASCII_STRINGS = false;
  
      private static final boolean DEFAULT_ALLOW_TERMINAL_JUNK = true;
  
      private static final boolean DEFAULT_ALLOW_HEADER_REPAIRS = true;
  
      private static final boolean DEFAULT_SKIP_BLANK_AFTER_ASSIGN = false;
  
      private static final boolean DEFAULT_CASE_SENSITIVE_HIERARCH = false;
  
      /**
       * AK: true is the legacy behavior TODO If and when it is changed to false, the corresponding Logger warnings in
       * BinaryTable should also be removed.
       */
      private static final boolean DEFAULT_USE_UNICODE_CHARS = true;
  
      private static final IHierarchKeyFormatter DEFAULT_HIERARCH_FORMATTER = new StandardIHierarchKeyFormatter();
  
      /**
       * An class for aggregating all the settings internal to {@link FitsFactory}.
       * 
       * @author Attila Kovacs
       */
      protected static final class FitsSettings implements Cloneable {
  
          private boolean useAsciiTables;
  
          private boolean useHierarch;
  
          private boolean useExponentD;
  
          private boolean checkAsciiStrings;
  
          private boolean allowTerminalJunk;
  
          private boolean allowHeaderRepairs;
  
          private boolean longStringsEnabled;
 
         private boolean useUnicodeChars;
 
         @Deprecated
         private boolean skipBlankAfterAssign;
 
         private IHierarchKeyFormatter hierarchKeyFormatter = DEFAULT_HIERARCH_FORMATTER;
 
         private FitsSettings() {
             useAsciiTables = DEFAULT_USE_ASCII_TABLES;
             useHierarch = DEFAULT_USE_HIERARCH;
             useUnicodeChars = DEFAULT_USE_UNICODE_CHARS;
             checkAsciiStrings = DEFAULT_CHECK_ASCII_STRINGS;
             useExponentD = DEFAULT_USE_EXPONENT_D;
             allowTerminalJunk = DEFAULT_ALLOW_TERMINAL_JUNK;
             allowHeaderRepairs = DEFAULT_ALLOW_HEADER_REPAIRS;
             longStringsEnabled = DEFAULT_LONG_STRINGS_ENABLED;
             skipBlankAfterAssign = DEFAULT_SKIP_BLANK_AFTER_ASSIGN;
             hierarchKeyFormatter = DEFAULT_HIERARCH_FORMATTER;
             hierarchKeyFormatter.setCaseSensitive(DEFAULT_CASE_SENSITIVE_HIERARCH);
         }
 
         @Override
         protected FitsSettings clone() {
             try {
                 return (FitsSettings) super.clone();
             } catch (CloneNotSupportedException e) {
                 return null;
             }
         }
 
         private FitsSettings copy() {
             return clone();
         }
 
         /**
          * Returns the formatter instance for HIERARCH style keywords. Our own standard is to define such keywords
          * internally as starting with the string <code>HIERARCH.</code> followed by a dot-separated hierarchy, or just
          * an unusually long FITS keywords that cannot be represented by a standard 8-byte keyword. The HIERARCH
          * formatted will take such string keywords and will format them according to its rules when writing them to
          * FITS headers.
          * 
          * @return The formatter instance used for HIERARCH-style keywords.
          */
         protected IHierarchKeyFormatter getHierarchKeyFormatter() {
             return hierarchKeyFormatter;
         }
 
         /**
          * Checks if we should use the letter 'D' to mark exponents of double-precision values (in FITS headers and
          * ASCII tables). For ecample, in the typical Java number formatting the String <code>1.37E-13</code> may
          * represent either a <code>float</code> or <code>double</code> value -- which are not exactly the same. For
          * that reason FITS offers the possibility to replace 'E' in the string formatted number with 'D' when the value
          * specifies a double-precision number, thus disambiguating the two.
          * 
          * @return <code>true</code> if we will use 'D' to denote the exponent of double-precision values in FITS
          *             headers and ASCII tables.
          */
         protected boolean isUseExponentD() {
             return useExponentD;
         }
 
         /**
          * Checks if we treat junk after the last properly formed HDU silently withotu generating an exception. When
          * this setting is <code>true</code> we can read corrupted FITS files (at least partially) without raising an
          * alarm.
          * 
          * @return <code>true</code> if we allow additional bytes after the last readable HDU to be present in FITS
          *             files without throwing an exception. Otherwise <code>false</code>.
          */
         protected boolean isAllowTerminalJunk() {
             return allowTerminalJunk;
         }
 
         /**
          * Whether we check if ASCII strings in FITS files conform to the restricted set of characters (0x20 trough
          * 0x7E) allowed by the FITS standard. If the checking is enabled, we will log any such violations so they can
          * be inspected and perhaps fixed.
          * 
          * @return <code>true</code> if we should check and report if string appearing in FITS files do not conform to
          *             specification. Otherwise <code>false</code>
          */
         protected boolean isCheckAsciiStrings() {
             return checkAsciiStrings;
         }
 
         /**
          * Checks if we allow storing long string values (using the OGIP 1.0 convention) in FITS headers. Such long
          * string may span multiple 80-character header records. They are now standard as of FITS 4.0, but they were not
          * in earlier specifications. When long strings are not enabled, we will throw a {@link LongValueException}
          * whenever one tries to add a string value that cannot be contained in a single 80-character header record.
          * 
          * @return <code>true</code> (default) if we allow adding long string values to out FITS headers. Otherwise
          *             <code>false</code>.
          */
         protected boolean isLongStringsEnabled() {
             return longStringsEnabled;
         }
 
         /**
          * @deprecated The FITS standard is very explicit that assignment must be "= " (equals followed by a space). If
          *                 we allow skipping the space, it will result in a non-standard FITS, and may render it
          *                 unreadable for other tools.
          *
          * @return     whether to use only "=", instead of the standard "= " between the keyword and the value.
          */
         @Deprecated
         protected boolean isSkipBlankAfterAssign() {
             return skipBlankAfterAssign;
         }
 
         /**
          * Whether to write tables as ASCII tables automatically if possible. Binary tables are generally always a
          * better option, as they are both more compact and flexible but sometimes we might want to make our table data
          * to be human readable in a terminal without needing any FITS-specific tool -- even though the 1970s is long
          * past...
          * 
          * @return <code>true</code> if we have a preference for writing table data in ASCII format (rather than
          *             binary), whenever that is possible. Otherwise <code>false</code>
          */
         protected boolean isUseAsciiTables() {
             return useAsciiTables;
         }
 
         /**
          * Whether we allow using HIERARCH-style keywords, which may be longer than the standard 8-character FITS
          * keywords, and may specify a hierarchy, and may also allow upper and lower-case characters depending on what
          * formatting rules we use. Our own standard is to define such keywords internally as starting with the string
          * <code>HIERARCH.</code> followed by a dot-separated hierarchy, or just an unusually long FITS keywords that
          * cannot be represented by a standard 8-byte keyword.
          * 
          * @return <code>true</code> if we allow HIERARCH keywords. Otherwise <code>false</code>
          */
         protected boolean isUseHierarch() {
             return useHierarch;
         }
 
         /**
          * Checks if we allow storing Java <code>char[]</code> arrays in binary tables as 16-bit <code>short[]</code>.
          * Otherwise we will store them as simple 8-bit ASCII.
          * 
          * @return <code>true</code> if <code>char[]</code> is stored as <code>short[]</code> in binary tables, or
          *             <code>false</code> if we store than as 8-bit ASCII.
          */
         protected boolean isUseUnicodeChars() {
             return useUnicodeChars;
         }
 
         /**
          * Checks if we are tolerant to FITS standard violations when reading 3rd party FITS files.
          * 
          * @return <code>true</code> if we tolerate minor violations of the FITS standard when interpreting headers,
          *             which are unlikely to affect the integrity of the FITS otherwise. The violations will still be
          *             logged, but no exception will be generated. Or, <code>false</code> if we want to generate
          *             exceptions for such error.s
          */
         protected boolean isAllowHeaderRepairs() {
             return allowHeaderRepairs;
         }
 
     }
 
     private static final FitsSettings GLOBAL_SETTINGS = new FitsSettings();
 
     private static final ThreadLocal<FitsSettings> LOCAL_SETTINGS = new ThreadLocal<>();
 
     private static ExecutorService threadPool;
 
     /**
      * the size of a FITS block in bytes.
      */
     public static final int FITS_BLOCK_SIZE = 2880;
 
     /**
      * @deprecated               (<i>for internal use</i>) Will reduce visibility in the future
      *
      * @return                   Given a Header construct an appropriate data.
      *
      * @param      hdr           header to create the data from
      *
      * @throws     FitsException if the header did not contain enough information to detect the type of the data
      */
     @Deprecated
     public static Data dataFactory(Header hdr) throws FitsException {
 
         if (ImageHDU.isHeader(hdr)) {
             if (hdr.getIntValue(Standard.NAXIS, 0) == 0) {
                 return new NullData();
             }
 
             Data d = ImageHDU.manufactureData(hdr);
             // Fix for positioning error noted by V. Forchi
             if (hdr.findCard(Standard.EXTEND) != null) {
                 hdr.nextCard();
             }
             return d;
         }
         if (RandomGroupsHDU.isHeader(hdr)) {
             return RandomGroupsHDU.manufactureData(hdr);
         }
         if (AsciiTableHDU.isHeader(hdr)) {
             return AsciiTableHDU.manufactureData(hdr);
         }
         if (CompressedImageHDU.isHeader(hdr)) {
             return CompressedImageHDU.manufactureData(hdr);
         }
         if (CompressedTableHDU.isHeader(hdr)) {
             return CompressedTableHDU.manufactureData(hdr);
         }
         if (BinaryTableHDU.isHeader(hdr)) {
             return BinaryTableHDU.manufactureData(hdr);
         }
         if (UndefinedHDU.isHeader(hdr)) {
             return UndefinedHDU.manufactureData(hdr);
         }
         throw new FitsException("Unrecognizable header in dataFactory");
     }
 
     /**
      * Whether the letter 'D' may replace 'E' in the exponential notation of doubl-precision values. FITS allows (even
      * encourages) the use of 'D' to indicate double-recision values. For example to disambiguate between 1.37E-3
      * (single-precision) and 1.37D-3 (double-precision), which are not exatly the same value in binary representation.
      * 
      * @return Do we allow automatic header repairs, like missing end quotes?
      *
      * @since  1.16
      * 
      * @see    #setUseExponentD(boolean)
      */
     public static boolean isUseExponentD() {
         return current().isUseExponentD();
     }
 
     /**
      * Whether <code>char[]</code> arrays are written as 16-bit integers (<code>short[]</code>) int binary tables as
      * opposed as FITS character arrays (<code>byte[]</code> with column type 'A'). See more explanation in
      * {@link #setUseUnicodeChars(boolean)}.
      *
      * @return <code>true</code> if <code>char[]</code> get written as 16-bit integers in binary table columns (column
      *             type 'I'), or as FITS 1-byte ASCII character arrays (as is always the case for <code>String</code>)
      *             with column type 'A'.
      *
      * @since  1.16
      * 
      * @see    #setUseUnicodeChars(boolean)
      */
     public static boolean isUseUnicodeChars() {
         return current().isUseUnicodeChars();
     }
 
     /**
      * Whether extra bytes are tolerated after the end of an HDU. Normally if there is additional bytes present after an
      * HDU, it would be the beginning of another HDU -- which must start with a very specific sequence of bytes. So,
      * when there is data beyond the end of an HDU that does not appear to be another HDU, it's junk. We can either
      * ignore it, or throw an exception.
      * 
      * @return Is terminal junk (i.e., non-FITS data following a valid HDU) allowed.
      * 
      * @see    #setAllowTerminalJunk(boolean)
      */
     public static boolean getAllowTerminalJunk() {
         return current().isAllowTerminalJunk();
     }
 
     /**
      * Whether we allow 3rd party FITS headers to be in violation of the standard, attempting to make sense of corrupted
      * header data as much as possible.
      * 
      * @return Do we allow automatic header repairs, like missing end quotes?
      * 
      * @see    #setAllowHeaderRepairs(boolean)
      */
     public static boolean isAllowHeaderRepairs() {
         return current().isAllowHeaderRepairs();
     }
 
     /**
      * Returns the formatter instance for HIERARCH style keywords. Our own standard is to define such keywords
      * internally as starting with the string <code>HIERARCH.</code> followed by a dot-separated hierarchy, or just an
      * unusually long FITS keywords that cannot be represented by a standard 8-byte keyword. The HIERARCH formatted will
      * take such string keywords and will format them according to its rules when writing them to FITS headers.
      * 
      * @return the formatter to use for hierarch keys.
      * 
      * @see    #setHierarchFormater(IHierarchKeyFormatter)
      */
     public static IHierarchKeyFormatter getHierarchFormater() {
         return current().getHierarchKeyFormatter();
     }
 
     /**
      * Whether we can use HIERARCH style keywords. Such keywords are not part of the current FITS standard, although
      * they constitute a recognised convention. Even if other programs may not process HIRARCH keywords themselves,
      * there is generally no harm to putting them into FITS headers, since the convention is such that these keywords
      * will be simply treated as comments by programs that do not recognise them.
      * 
      * @return <code>true</code> if we are processing HIERARCH style keywords
      * 
      * @see    #setUseHierarch(boolean)
      */
     public static boolean getUseHierarch() {
         return current().isUseHierarch();
     }
 
     /**
      * whether ASCII tables should be used where feasible.
      *
      * @return <code>true</code> if we ASCII tables are allowed.
      *
      * @see    #setUseAsciiTables(boolean)
      */
     public static boolean getUseAsciiTables() {
         return current().isUseAsciiTables();
     }
 
     /**
      * Checks whether we should check and validated ASCII strings that goe into FITS. FITS only allows ASCII characters
      * between 0x20 and 0x7E in ASCII tables.
      * 
      * @return Get the current status for string checking.
      * 
      * @see    #setCheckAsciiStrings(boolean)
      */
     public static boolean getCheckAsciiStrings() {
         return current().isCheckAsciiStrings();
     }
 
     /**
      * Whether we allow storing long string in the header, which do not fit into a single 80-byte header record. Such
      * strings are then wrapped into multiple consecutive header records, OGIP 1.0 standard -- which is nart of FITS
      * 4.0, and was a recognised convention before.
      * 
      * @return <code>true</code> If long string support is enabled.
      * 
      * @see    #setLongStringsEnabled(boolean)
      */
     public static boolean isLongStringsEnabled() {
         return current().isLongStringsEnabled();
     }
 
     /**
      * @return     whether to use only "=", instead of the standard "= " between the keyword and the value.
      *
      * @deprecated The FITS standard is very explicit that assignment must be "= " (equals followed by a blank space).
      *                 If we allow skipping the space, it will result in a non-standard FITS, that is likely to break
      *                 compatibility with other tools.
      * 
      * @see        #setSkipBlankAfterAssign(boolean)
      */
     @Deprecated
     public static boolean isSkipBlankAfterAssign() {
         return current().isSkipBlankAfterAssign();
     }
 
     /**
      * .
      * 
      * @deprecated               (<i>for internal use</i>)/ Will reduce visibility in the future
      *
      * @return                   Given Header and data objects return the appropriate type of HDU.
      *
      * @param      hdr           the header, including a description of the data layout.
      * @param      d             the type of data object
      * @param      <DataClass>   the class of the data
      *
      * @throws     FitsException if the operation failed
      */
     @Deprecated
     @SuppressWarnings("unchecked")
     public static <DataClass extends Data> BasicHDU<DataClass> hduFactory(Header hdr, DataClass d) throws FitsException {
         if (d == null) {
             return (BasicHDU<DataClass>) new NullDataHDU(hdr);
         }
         if (d instanceof ImageData) {
             return (BasicHDU<DataClass>) new ImageHDU(hdr, (ImageData) d);
         }
         if (d instanceof CompressedImageData) {
             return (BasicHDU<DataClass>) new CompressedImageHDU(hdr, (CompressedImageData) d);
         }
         if (d instanceof RandomGroupsData) {
             return (BasicHDU<DataClass>) new RandomGroupsHDU(hdr, (RandomGroupsData) d);
         }
         if (d instanceof AsciiTable) {
             return (BasicHDU<DataClass>) new AsciiTableHDU(hdr, (AsciiTable) d);
         }
         if (d instanceof CompressedTableData) {
             return (BasicHDU<DataClass>) new CompressedTableHDU(hdr, (CompressedTableData) d);
         }
         if (d instanceof BinaryTable) {
             return (BasicHDU<DataClass>) new BinaryTableHDU(hdr, (BinaryTable) d);
         }
         if (d instanceof UndefinedData) {
             return (BasicHDU<DataClass>) new UndefinedHDU(hdr, (UndefinedData) d);
         }
         return null;
     }
 
     /**
      * Creates an HDU that wraps around the specified data object. The HDUs header will be created and populated with
      * the essential description of the data. The following HDU types may be returned depending on the nature of the
      * argument:
      * <ul>
      * <li>{@link NullDataHDU} -- if the argument is <code>null</code></li>
      * <li>{@link ImageHDU} -- if the argument is a regular numerical array, such as a <code>double[]</code>,
      * <code>float[][]</code>, or <code>short[][][]</code></li>
      * <li>{@link BinaryTableHDU} -- the the argument is an <code>Object[rows][cols]</code> type array with a regular
      * structure and supported column data types, provided that it cannot be represented by an ASCII table <b>OR</b> if
      * {@link FitsFactory#getUseAsciiTables()} is <code>false</code></li>
      * <li>{@link AsciiTableHDU} -- Like above, but only when the data can be represented by an ASCII table <b>AND</b>
      * {@link FitsFactory#getUseAsciiTables()} is <code>true</code></li>
      * </ul>
      * 
      * @return                   An appropriate HDU to encapsulate the given Java data object
      *
      * @param      o             The object to be described.
      *
      * @throws     FitsException if the parameter could not be converted to a HDU because the binary representation of
      *                               the object is not known..
      * 
      * @deprecated               Use {@link Fits#makeHDU(Object)} instead (this method may either be migrated to
      *                               {@link Fits} entirely or else have visibility reduced to the package level).
      */
     public static BasicHDU<?> hduFactory(Object o) throws FitsException {
         Data d;
         Header h;
 
         if (o == null) {
             return new NullDataHDU();
         } else if (o instanceof Header) {
             h = (Header) o;
             d = dataFactory(h);
         } else if (ImageHDU.isData(o)) {
             d = ImageHDU.encapsulate(o);
             h = ImageHDU.manufactureHeader(d);
         } else if (current().isUseAsciiTables() && AsciiTableHDU.isData(o)) {
             d = AsciiTableHDU.encapsulate(o);
             h = AsciiTableHDU.manufactureHeader(d);
         } else if (BinaryTableHDU.isData(o)) {
             d = BinaryTableHDU.encapsulate(o);
             h = BinaryTableHDU.manufactureHeader(d);
         } else {
             throw new FitsException("This type of data is not supported for FITS representation");
         }
 
         return hduFactory(h, d);
     }
 
     // CHECKSTYLE:OFF
     /**
      * @deprecated               (<i>duplicate method for internal use</i>) Same as {@link #hduFactory(Header, Data)},
      *                               and will be removed in the future.
      *
      * @return                   Given Header and data objects return the appropriate type of HDU.
      *
      * @param      hdr           the header of the date
      * @param      d             the data
      * @param      <DataClass>   the class of the data
      *
      * @throws     FitsException if the operation failed
      */
     @Deprecated
     public static <DataClass extends Data> BasicHDU<DataClass> HDUFactory(Header hdr, DataClass d) throws FitsException {
         return hduFactory(hdr, d);
     }
 
     // CHECKSTYLE:ON
 
     // CHECKSTYLE:OFF
     /**
      * @return                   Given an object, create the appropriate FITS header to describe it.
      *
      * @param      o             The object to be described.
      *
      * @throws     FitsException if the parameter could not be converted to a hdu.
      *
      * @deprecated               Use {@link Fits#makeHDU(Object)} instead (will removed in the future. Duplicate of
      *                               {@link #hduFactory(Object)}
      */
     @Deprecated
     public static BasicHDU<?> HDUFactory(Object o) throws FitsException {
         return hduFactory(o);
     }
 
     // CHECKSTYLE:ON
 
     /**
      * Restores all settings to their default values.
      *
      * @since 1.16
      */
     public static void setDefaults() {
         FitsSettings s = current();
         s.useExponentD = DEFAULT_USE_EXPONENT_D;
         s.allowHeaderRepairs = DEFAULT_ALLOW_HEADER_REPAIRS;
         s.allowTerminalJunk = DEFAULT_ALLOW_TERMINAL_JUNK;
         s.checkAsciiStrings = DEFAULT_CHECK_ASCII_STRINGS;
         s.longStringsEnabled = DEFAULT_LONG_STRINGS_ENABLED;
         s.skipBlankAfterAssign = DEFAULT_SKIP_BLANK_AFTER_ASSIGN;
         s.useAsciiTables = DEFAULT_USE_ASCII_TABLES;
         s.useHierarch = DEFAULT_USE_HIERARCH;
         s.useUnicodeChars = DEFAULT_USE_UNICODE_CHARS;
         s.hierarchKeyFormatter = DEFAULT_HIERARCH_FORMATTER;
         s.hierarchKeyFormatter.setCaseSensitive(DEFAULT_CASE_SENSITIVE_HIERARCH);
     }
 
     /**
      * Sets whether 'D' may be used instead of 'E' to mark the exponent for a floating point value with precision beyond
      * that of a 32-bit float.
      *
      * @param allowExponentD if <code>true</code> D will be used instead of E to indicate the exponent of a decimal with
      *                           more precision than a 32-bit float.
      *
      * @since                1.16
      * 
      * @see                  #isUseExponentD()
      */
     public static void setUseExponentD(boolean allowExponentD) {
         current().useExponentD = allowExponentD;
     }
 
     /**
      * Do we allow junk after a valid FITS file?
      *
      * @param allowTerminalJunk value to set
      * 
      * @see                     #getAllowTerminalJunk()
      */
     public static void setAllowTerminalJunk(boolean allowTerminalJunk) {
         current().allowTerminalJunk = allowTerminalJunk;
     }
 
     /**
      * Do we allow automatic header repairs, like missing end quotes?
      *
      * @param allowHeaderRepairs value to set
      * 
      * @see                      #isAllowHeaderRepairs()
      */
     public static void setAllowHeaderRepairs(boolean allowHeaderRepairs) {
         current().allowHeaderRepairs = allowHeaderRepairs;
     }
 
     /**
      * Enable/Disable checking of strings values used in tables to ensure that they are within the range specified by
      * the FITS standard. The standard only allows the values 0x20 - 0x7E with null bytes allowed in one limited
      * context. Disabled by default.
      *
      * @param checkAsciiStrings value to set
      * 
      * @see                     #getCheckAsciiStrings()
      */
     public static void setCheckAsciiStrings(boolean checkAsciiStrings) {
         current().checkAsciiStrings = checkAsciiStrings;
     }
 
     /**
      * There is not a real standard how to write hierarch keys, default we use the one where every key is separated by a
      * blank. If you want or need another format assing the formater here.
      *
      * @param formatter the hierarch key formatter.
      */
     public static void setHierarchFormater(IHierarchKeyFormatter formatter) {
         current().hierarchKeyFormatter = formatter;
     }
 
     /**
      * Enable/Disable longstring support.
      *
      * @param longStringsEnabled value to set
      * 
      * @see                      #isLongStringsEnabled()
      */
     public static void setLongStringsEnabled(boolean longStringsEnabled) {
         current().longStringsEnabled = longStringsEnabled;
     }
 
     /**
      * If set to true the blank after the assign in the header cards in not written. The blank is stronly recommendet
      * but in some cases it is important that it can be ommitted.
      *
      * @param      skipBlankAfterAssign value to set
      *
      * @deprecated                      The FITS standard is very explicit that assignment must be "= " (equals followed
      *                                      by a blank space). It is also very specific that string values must have
      *                                      their opening quote in byte 11 (counted from 1). If we allow skipping the
      *                                      space, we will violate both standards in a way that is likely to break
      *                                      compatibility with other tools.
      * 
      * @see                             #isSkipBlankAfterAssign()
      */
     @Deprecated
     public static void setSkipBlankAfterAssign(boolean skipBlankAfterAssign) {
         current().skipBlankAfterAssign = skipBlankAfterAssign;
     }
 
     /**
      * Indicate whether ASCII tables should be used where feasible.
      *
      * @param useAsciiTables value to set
      */
     public static void setUseAsciiTables(boolean useAsciiTables) {
         current().useAsciiTables = useAsciiTables;
     }
 
     /**
      * Enable/Disable hierarchical keyword processing.
      *
      * @param useHierarch value to set
      */
     public static void setUseHierarch(boolean useHierarch) {
         current().useHierarch = useHierarch;
     }
 
     /**
      * <p>
      * Enable/Disable writing <code>char[]</code> arrays as <code>short[]</code> in FITS binary tables (with column type
      * 'I'), instead of as standard FITS 1-byte ASCII characters (with column type 'A'). The old default of this library
      * has been to use unicode, and that behavior remains the default &mdash; the same as setting the argument to
      * <code>true</code>. On the flipside, setting it to <code>false</code> provides more convergence between the
      * handling of <code>char[]</code> columns and the nearly identical <code>String</code> columns, which have already
      * been restricted to ASCII before.
      * </p>
      *
      * @param value <code>true</code> to write <code>char[]</code> arrays as if <code>short[]</code> with column type
      *                  'I' to binary tables (old behaviour, and hence default), or else <code>false</code> to write
      *                  them as <code>byte[]</code> with column type 'A', the same as for <code>String</code> (preferred
      *                  behaviour)
      *
      * @since       1.16
      *
      * @see         #isUseUnicodeChars()
      */
     public static void setUseUnicodeChars(boolean value) {
         current().useUnicodeChars = value;
     }
 
     /**
      * Returns the common thread pool that we use for processing FITS files.
      * 
      * @return the thread pool for processing FITS files.
      */
     public static ExecutorService threadPool() {
         if (threadPool == null) {
             initializeThreadPool();
         }
         return threadPool;
     }
 
     /**
      * Use thread local settings for the current thread instead of the global ones if the parameter is set to true, else
      * use the shared global settings.
      *
      * @param useThreadSettings true if the thread should not share the global settings.
      */
     public static void useThreadLocalSettings(boolean useThreadSettings) {
         if (useThreadSettings) {
             LOCAL_SETTINGS.set(GLOBAL_SETTINGS.copy());
         } else {
             LOCAL_SETTINGS.remove();
         }
     }
 
     private static void initializeThreadPool() {
         synchronized (GLOBAL_SETTINGS) {
             if (threadPool == null) {
                 threadPool = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors() * 2, //
                         new ThreadFactory() {
                             private int counter = 1;
 
                             @Override
                             public Thread newThread(Runnable r) {
                                 Thread thread = new Thread(r, "nom-tam-fits worker " + counter++);
                                 thread.setDaemon(true);
                                 return thread;
                             }
                         });
             }
         }
     }
 
     /**
      * Returns the current settings that guide how we read or produce FITS files.
      * 
      * @return the current active settings for generating or interpreting FITS files.
      */
     protected static FitsSettings current() {
         FitsSettings settings = LOCAL_SETTINGS.get();
         if (settings == null) {
             return GLOBAL_SETTINGS;
         }
         return settings;
     }
 
     private FitsFactory() {
     }
 }