package org.argeo.eclipse.ui.jcr.lists;
   
   import java.math.BigDecimal;
   import java.util.Calendar;
   
   import javax.jcr.Node;
   import javax.jcr.PropertyType;
   import javax.jcr.RepositoryException;
   import javax.jcr.Value;
  import javax.jcr.ValueFormatException;
  
  import org.argeo.eclipse.ui.EclipseUiException;
  import org.eclipse.jface.viewers.Viewer;
  import org.eclipse.jface.viewers.ViewerComparator;
  
  /**
   * Base comparator to enable ordering on Table or Tree viewer that display Jcr
   * Nodes.
   * 
   * Note that the following snippet must be added before setting the comparator
   * to the corresponding control: <code>
   * // IMPORTANT: initialize comparator before setting it
   * JcrColumnDefinition firstCol = colDefs.get(0);
   * comparator.setColumn(firstCol.getPropertyType(),
   * firstCol.getPropertyName());
   * viewer.setComparator(comparator); </code>
   */
  public class NodeViewerComparator extends ViewerComparator {
  	private static final long serialVersionUID = -7782916140737279027L;
  
  	protected String propertyName;
  
  	protected int propertyType;
  	public static final int ASCENDING = 0, DESCENDING = 1;
  	protected int direction = DESCENDING;
  
  	public NodeViewerComparator() {
  	}
  
  	/**
  	 * e1 and e2 must both be Jcr nodes.
  	 * 
  	 * @param viewer
  	 * @param e1
  	 * @param e2
  	 * @return
  	 */
  	@Override
  	public int compare(Viewer viewer, Object e1, Object e2) {
  		int rc = 0;
  		long lc = 0;
  
  		try {
  			Node n1 = (Node) e1;
  			Node n2 = (Node) e2;
  
  			Value v1 = null;
  			Value v2 = null;
  			if (n1.hasProperty(propertyName))
  				v1 = n1.getProperty(propertyName).getValue();
  			if (n2.hasProperty(propertyName))
  				v2 = n2.getProperty(propertyName).getValue();
  
  			if (v2 == null && v1 == null)
  				return 0;
  			else if (v2 == null)
  				return -1;
  			else if (v1 == null)
  				return 1;
  
  			switch (propertyType) {
  			case PropertyType.STRING:
  				rc = v1.getString().compareTo(v2.getString());
  				break;
  			case PropertyType.BOOLEAN:
  				boolean b1 = v1.getBoolean();
  				boolean b2 = v2.getBoolean();
  				if (b1 == b2)
  					rc = 0;
  				else
  					// we assume true is greater than false
  					rc = b1 ? 1 : -1;
  				break;
  			case PropertyType.DATE:
  				Calendar c1 = v1.getDate();
  				Calendar c2 = v2.getDate();
  				if (c1 == null || c2 == null)
  					// log.trace("undefined date");
  					;
  				lc = c1.getTimeInMillis() - c2.getTimeInMillis();
  				if (lc < Integer.MIN_VALUE)
  					rc = -1;
  				else if (lc > Integer.MAX_VALUE)
  					rc = 1;
  				else
  					rc = (int) lc;
  				break;
  			case PropertyType.LONG:
  				long l1;
 				long l2;
 				// TODO Sometimes an empty string is set instead of a long
 				try {
 					l1 = v1.getLong();
 				} catch (ValueFormatException ve) {
 					l1 = 0;
 				}
 				try {
 					l2 = v2.getLong();
 				} catch (ValueFormatException ve) {
 					l2 = 0;
 				}
 
 				lc = l1 - l2;
 				if (lc < Integer.MIN_VALUE)
 					rc = -1;
 				else if (lc > Integer.MAX_VALUE)
 					rc = 1;
 				else
 					rc = (int) lc;
 				break;
 			case PropertyType.DECIMAL:
 				BigDecimal bd1 = v1.getDecimal();
 				BigDecimal bd2 = v2.getDecimal();
 				rc = bd1.compareTo(bd2);
 				break;
 			case PropertyType.DOUBLE:
 				Double d1 = v1.getDouble();
 				Double d2 = v2.getDouble();
 				rc = d1.compareTo(d2);
 				break;
 			default:
 				throw new EclipseUiException(
 						"Unimplemented comparaison for PropertyType "
 								+ propertyType);
 			}
 			// If descending order, flip the direction
 			if (direction == DESCENDING) {
 				rc = -rc;
 			}
 
 		} catch (RepositoryException re) {
 			throw new EclipseUiException("Unexpected error "
 					+ "while comparing nodes", re);
 		}
 		return rc;
 	}
 
 	/**
 	 * @param propertyType
 	 *            Corresponding JCR type
 	 * @param propertyName
 	 *            name of the property to use.
 	 */
 	public void setColumn(int propertyType, String propertyName) {
 		if (this.propertyName != null && this.propertyName.equals(propertyName)) {
 			// Same column as last sort; toggle the direction
 			direction = 1 - direction;
 		} else {
 			// New column; do an ascending sort
 			this.propertyType = propertyType;
 			this.propertyName = propertyName;
 			direction = ASCENDING;
 		}
 	}
 
 	// Getters and setters
 	protected String getPropertyName() {
 		return propertyName;
 	}
 
 	protected void setPropertyName(String propertyName) {
 		this.propertyName = propertyName;
 	}
 
 	protected int getPropertyType() {
 		return propertyType;
 	}
 
 	protected void setPropertyType(int propertyType) {
 		this.propertyType = propertyType;
 	}
 
 	protected int getDirection() {
 		return direction;
 	}
 
 	protected void setDirection(int direction) {
 		this.direction = direction;
 	}
 }