/**
 * 
 */
package org.vamsas.client;

/**
 * Base class for all Vamsas objects extracted from an IClientDocument. An
 * object maybe registered or unregistered.
 * 
 * @author jimp
 * 
 */
public abstract class object {

  /**
   * unique id for all vamsas objects allows unambiguous referencing to any
   * object in the vamsas document
   */
  protected boolean __stored_in_document = false;

  protected long __last_hash = 0;

  protected boolean registerable = false;

  protected VorbaId vorbaId = null;

  protected IVorbaIdFactory __vorba = null;

  /**
   * 
   */
  protected object() {
    super();
    testInstanceForIdField();
  }

  /**
   * set the isRegisterable flag based on the presence of a 'String id' field in
   * the reflected class instance.
   */
  private void testInstanceForIdField() {
    // look for the id field (should be an NCName string)
    // TODO: decide if 'id' is an appropriate reserved attribute name for the
    // VorbaId
    try {
      java.lang.reflect.Field fd = this.getClass().getField("id");
      if (fd.getType().getClass().equals("astring".getClass())) {
        this.setRegisterable(true);
      }
    } catch (SecurityException e) {
      e.printStackTrace();
    } catch (NoSuchFieldException e) {
      this.setRegisterable(false);
    }
  }

  /**
   * update the object instance's String id field, based on the contents of the
   * VorbaId. Only call this if you mean to do it!
   */
  protected void setInstanceIdField() {
    if (registerable) {
      if (vorbaId != null)
        try {
          java.lang.reflect.Field fd = this.getClass().getField("id");
          fd.set((Object) this, (Object) new String(vorbaId.id));
        } catch (IllegalAccessException e) {
          System.err
              .println("SourceGeneration of "
                  + this.getClass().toString()
                  + "\n has resulted in an inaccessible 'id' field!\nCannot set ID from the vorbaId object.");
          e.printStackTrace(System.err);
        } catch (SecurityException e) {
          e.printStackTrace(System.err);
        } catch (NoSuchFieldException e) {
          this.setRegisterable(false);
        }
    } else {
      System.err.println("Client error. Trying to setInstanceIdField on a "
          + this.getClass().toString() + " (which cannot be given a vorbaId)");
    }
  }

  /**
   * calculate a hash for the object with all housekeeping fields at standard
   * values. (isRegisterable is an immutable attribute property)
   */
  synchronized protected void doHash() {
    __last_hash = 0;
    VorbaId thisid = vorbaId;
    IVorbaIdFactory factory = __vorba;
    boolean stored = __stored_in_document;
    vorbaId = null;
    __vorba = null;
    __last_hash = this.hashCode();
    vorbaId = thisid;
    __vorba = factory;
    __stored_in_document = stored;
  }

  /**
   * TODO: combine two versions of the same collection object to resolve
   * asynchronous updates to the same vamsas object Merges two vamsas objects,
   * one of which is a later version of the earlier (ie they have the same
   * vorbaId but one is a later version recently read from the vamsasDocument
   * collection.
   * 
   * @return
   */
  protected boolean merge(object laterCopy) {
    return true;
  }

  /**
   * 
   * @return true if object is registered
   */
  public boolean isRegistered() {
    return (registerable) ? (vorbaId != null) : false;
  }

  /**
   * Method to get fixed reference for the object in the vamsas document.
   * 
   * @returns null if object is neither registered or not associated with a
   *          properly instantiated VorbaIdFactory.
   */
  public VorbaId getVorbaId() {
    if (registerable && vorbaId == null) {
      // Try to use the associated factory.
      if (__vorba != null)
        if ((vorbaId = __vorba.makeVorbaId()) == null)
          return null; // Factory not valid.
        else {
          this.setInstanceIdField();
          return vorbaId;
        }
    }
    return vorbaId;
  }

  /**
   * used by the IClient implementation to generate unique Id based on client
   * applications current namespace.
   */
  protected void setVorbaId(VorbaId newid) {
    vorbaId = newid;
  }

  /**
   * @return true if object is present in Vamsas Document.
   */
  public boolean is__stored_in_document() {
    return __stored_in_document;
  }

  /**
   * for use by Vorba agent to reflect state of vamsas object to client
   * application.
   * 
   * @param __stored_in_document
   *          The __stored_in_document to set.
   */
  protected void set__stored_in_document(boolean __stored_in_document) {
    this.__stored_in_document = __stored_in_document;
  }

  /**
   * __last_hash is the hash value computed when the object was last checked
   * against a IClientDocument generated by the object's parent IClient
   * instance.
   * 
   * @return Returns the __last_hash.
   */
  public long get__last_hash() {
    return __last_hash;
  }

  /**
   * @return Returns the registerable.
   */
  public boolean isRegisterable() {
    return registerable;
  }

  /**
   * Called during unmarshalling - if object has an id string, it is
   * registerable.
   * 
   * @param registerable
   *          The registerable to set.
   */
  protected void setRegisterable(boolean registerable) {
    this.registerable = registerable;
  }
}