package org.argeo.slc.client.ui.dist.utils;
   
   import org.argeo.eclipse.ui.TreeParent;
   import org.eclipse.jface.viewers.Viewer;
   import org.eclipse.jface.viewers.ViewerComparator;
   
   /**
    * Enable comparison of two names version string with form org.argeo.slc-1.2.x.
    * with following rules and assumptions:
   * <ul>
   * <li>
   * Names are ordered using Lexicographical order</li>
   * <li>
   * Version are parsed and compared segment by segment; doing best effort to
   * convert major, minor and micro to integer and compare them as such (to have
   * 0.1 < 0.9 < 0.10 not 0.1 < 0.10 < 0.9).</li>
   * <li>Version should not contain any dash (-), version segments should be
   * separated by dots (.)</li>
   * </ul>
   */
  
  public class NameVersionComparator extends ViewerComparator {
  	private static final long serialVersionUID = 8290130681918221197L;
  	
  	private VersionComparator vc = new VersionComparator();
  
  	@Override
  	public int category(Object element) {
  		if (element instanceof String) {
  			int lastInd = ((String) element).lastIndexOf('-');
  			if (lastInd > 0)
  				return 10;
  		}
  		// unvalid names always last
  		return 5;
  	}
  
  	@Override
  	public int compare(Viewer viewer, Object e1, Object e2) {
  		int cat1 = category(e1);
  		int cat2 = category(e2);
  
  		if (cat1 != cat2) {
  			return cat1 - cat2;
  		}
  
  		int result = 0;
  
  		String s1, s2;
  
  		if (e1 instanceof TreeParent) {
  			s1 = ((TreeParent) e1).getName();
  			s2 = ((TreeParent) e2).getName();
  		} else {
  			s1 = e1.toString();
  			s2 = e2.toString();
  		}
  
  		int i1 = s1.lastIndexOf('-');
  		int i2 = s2.lastIndexOf('-');
  
  		// Specific cases, unvalid Strings
  		if (i1 < 0)
  			if (i2 < 0)
  				return s1.compareTo(s2);
  			else
  				return 1;
  		else if (i2 < 0)
  			return -1;
  
  		String aName = s1.substring(0, s1.lastIndexOf('-'));
  		String aVersion = s1.substring(s1.lastIndexOf('-'));
  
  		String bName = s2.substring(0, s2.lastIndexOf('-'));
  		String bVersion = s2.substring(s2.lastIndexOf('-'));
  
  		result = aName.compareTo(bName);
  		if (result != 0)
  			return result;
  		else
  			return vc.compare(viewer, aVersion, bVersion);
  	}
  }