package eu.simuline.octave;
   
   import java.util.Collection;
   import java.util.HashSet;
   
   import java.util.regex.Pattern;
   
   import eu.simuline.octave.type.OctaveCell;
   import eu.simuline.octave.type.OctaveString;
  
  /**
   * Small utility functions that can be used with JavaOctave.
   * 
   * Holder class for static functions.
   * @deprecated
   */
  public final class OctaveUtils {
  
  
      private OctaveUtils() {
          throw new UnsupportedOperationException("Do not instantiate");
      }
  
      /**
       * Returns a collection of variables defined 
       * excluding variables like {@link OctaveEngine#NARGIN} and {@link OctaveEngine#ANS} 
       * but also those that are most likely to be created by this software. TBD: clarification 
       * 
       * @param octave
       *    some octave engine. 
       * @return collection of variables
       * @deprecated
       * use {@link OctaveEngine#getVarNames()} instead. 
       */
      public static Collection<String> listVars(final OctaveEngine octave) {
  	// Justification: 3.0 are the earliest versions. 
  	// all later ones don't use '-v' any more 
  	String script = octave.getOctaveVersion().startsWith("3.0.") ? "ans=whos -v()" : "ans=whos()";
  	octave.eval(script);
  	// TBD: clarify: if we use who instead of whos, this can be simplified.  
  	octave.eval("{ans.name}");
  	OctaveCell cell = octave.get(OctaveCell.class, "ans");
  	// TBD: this can be unified with OctaveEngine.getNamesOfPackagesInstalled()
  	int len = cell.dataSize();
  	Collection<String> collection = new HashSet<String>();
  	//cell.getSize(i)
  	for (int idx = 0; idx < len; idx++) {
  	    collection.add(cell.get(OctaveString.class, 1, idx+1).getString());
  	}
  	collection.removeIf(p -> "__nargin__".equals(p));
  	collection.removeIf(p -> "ans".equals(p));
  	// TBD: eliminate magic literal 
  	Pattern pattern = Pattern.compile("javaoctave_[0-9a-f]{12}_eval");
  	collection.removeIf(p -> pattern.matcher(p).matches());
  	return collection;
      }
  
  }