package uk.ac.ebi.intenz.domain.history;
   
   import uk.ac.ebi.intenz.domain.DomainObject;
   import uk.ac.ebi.intenz.domain.constants.EventConstant;
   
   import java.util.Date;
   
   /**
    * The history event is a structural copy of the corresponding database table, that is attributes of this class
   * correspond to the table's columns.
   * <p/>
   * History events can be deletions, transfers, etc. of enzymes.
   *
   * @author Michael Darsow
   * @version $Revision: 1.2 $ $Date: 2008/01/28 12:33:04 $
   */
  public class HistoryEvent extends DomainObject implements Comparable<HistoryEvent> {
    protected Long groupId;
  
    protected Long eventId;
  
    protected HistoryNode beforeNode;
  
    protected HistoryNode afterNode;
  
    protected EventConstant eventClass;
  
    protected Date date;
  
    protected String note;
  
    /**
     * Nothing special.
     */
    public HistoryEvent() {
      super();
      this.groupId = new Long(0);
      this.eventId = new Long(0);
      this.beforeNode = null;
      this.afterNode = null;
      this.eventClass = EventConstant.CREATION;
      this.date = null;
      this.note = "";
    }
  
    /**
     * Makes instances of this class comparable.
     *
     * @param historyEvent The object to be compared to this instance.
     * @return a pos. integer if this instance is greater than, a neg. integer if it is less than or 0 if it equals o.
     */
    public int compareTo(HistoryEvent historyEvent) {
      if (this.getDate().before(historyEvent.getDate())) return -1;
      if (this.getDate().after(historyEvent.getDate())) return 1;
  
      return 0;
    }
  
    /**
     * Checks if two <code>HistoryEvent</code> objects are equal.
     *
     * @param o The other <code>HistoryEvent</code> to compare with this one.
     * @return <code>true</code>, if the two objects are equal.
     */
    public boolean equals(Object o) {
      if (this == o) return true;
      if (!(o instanceof HistoryEvent)) return false;
      if (!super.equals(o)) return false;
  
      final HistoryEvent event = (HistoryEvent) o;
  
      if (afterNode != null ? !afterNode.equals(event.afterNode) : event.afterNode != null) return false;
      if (beforeNode != null ? !beforeNode.equals(event.beforeNode) : event.beforeNode != null) return false;
      if (date != null ? !date.equals(event.date) : event.date != null) return false;
      if (eventClass != null ? !eventClass.equals(event.eventClass) : event.eventClass != null) return false;
      if (eventId != null ? !eventId.equals(event.eventId) : event.eventId != null) return false;
      if (groupId != null ? !groupId.equals(event.groupId) : event.groupId != null) return false;
      if (note != null ? !note.equals(event.note) : event.note != null) return false;
  
      return true;
    }
  
    /**
     * Calculates a unique hash code.
     *
     * @return the hash code.
     */
    public int hashCode() {
      int result = super.hashCode();
      result = 29 * result + (groupId != null ? groupId.hashCode() : 0);
      result = 29 * result + (eventId != null ? eventId.hashCode() : 0);
      result = 29 * result + (beforeNode != null ? beforeNode.hashCode() : 0);
      result = 29 * result + (afterNode != null ? afterNode.hashCode() : 0);
      result = 29 * result + (eventClass != null ? eventClass.hashCode() : 0);
      result = 29 * result + (date != null ? date.hashCode() : 0);
      result = 29 * result + (note != null ? note.hashCode() : 0);
      return result;
    }
  
   /**
    * Returns <code>true</code> if the given node is the successor of this node.
    *
    * @param node The node to be compared to this node's relatives.
    * @return <code>true</code> if the given node is the successor of this node.
    */
   public boolean isSuccessor(HistoryNode node) {
     if (node == null) return afterNode == null;
     return afterNode.equals(node);
   }
 
 
   // ------------------- GETTER & SETTER ------------------------
 
   /**
    * Returns the relative node of the given node.
    *
    * @param node The node of which the relative is demanded.
    * @return The relative node or <code>null</code> if no relative exists.
    * @throws NullPointerException if the given node is <code>null</code>.
    */
   public HistoryNode getRelative(HistoryNode node) {
     if (node == null) throw new NullPointerException();
 
     if (beforeNode == null || afterNode == null) return null;
 
     if (beforeNode.getEnzymeEntry().getId().equals(node.getEnzymeEntry().getId()) ) return afterNode;
     return beforeNode;
   }
 
   public Long getGroupId() {
     return groupId;
   }
 
   public void setGroupId(Long groupId) {
     if (groupId == null) throw new NullPointerException("Parameter 'groupId' must not be null.");
     this.groupId = groupId;
   }
 
   public Long getEventId() {
     return eventId;
   }
 
   public void setEventId(Long eventId) {
     if (eventId == null) throw new NullPointerException("Parameter 'eventId' must not be null.");
     this.eventId = eventId;
   }
 
   public HistoryNode getBeforeNode() {
     return beforeNode;
   }
 
   public void setBeforeNode(HistoryNode beforeNode) {
     this.beforeNode = beforeNode;
   }
 
   public HistoryNode getAfterNode() {
     return afterNode;
   }
 
   public void setAfterNode(HistoryNode afterNode) {
     this.afterNode = afterNode;
   }
 
   public EventConstant getEventClass() {
     return eventClass;
   }
 
   public void setEventClass(EventConstant eventClass) {
     if (eventClass == null) throw new NullPointerException("Parameter 'eventClass' must not be null.");
     this.eventClass = eventClass;
   }
 
   public Date getDate() {
     return date;
   }
 
   public void setDate(Date date) {
     if (date == null) throw new NullPointerException("Parameter 'date' must not be null.");
     this.date = date;
   }
 
   public String getNote() {
     return note;
   }
 
   public void setNote(String note) {
     if (note == null) throw new NullPointerException("Parameter 'note' must not be null.");
     this.note = note;
   }
 }