/* $Id: DefaultOclEvaluator.java 17836 2010-01-12 19:06:55Z linus $

  *****************************************************************************

  * Copyright (c) 2009 Contributors - see below

  * All rights reserved. This program and the accompanying materials

  * are made available under the terms of the Eclipse Public License v1.0

  * which accompanies this distribution, and is available at

  * http://www.eclipse.org/legal/epl-v10.html

  *

  * Contributors:

  *    lepekhine

  *****************************************************************************

  *

  * Some portions of this file was previously release using the BSD License:

  */

 // Copyright (c) 2008 The Regents of the University of California. All

 // Rights Reserved. Permission to use, copy, modify, and distribute this

 // software and its documentation without fee, and without a written

 // agreement is hereby granted, provided that the above copyright notice

 // and this paragraph appear in all copies. This software program and

 // documentation are copyrighted by The Regents of the University of

 // California. The software program and documentation are supplied "AS

 // IS", without any accompanying services from The Regents. The Regents

 // does not warrant that the operation of the program will be

 // uninterrupted or error-free. The end-user understands that the program

 // was developed for research purposes and is advised not to rely

 // exclusively on the program for any reason. IN NO EVENT SHALL THE

 // UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,

 // SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,

 // ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF

 // THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF

 // SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY

 // WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF

 // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE

 // PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF

 // CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,

 // UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 package org.argouml.profile.internal.ocl;

 import java.io.PushbackReader;

 import java.io.StringReader;

 import java.util.Map;

 import org.apache.log4j.Logger;

 import tudresden.ocl.parser.OclParser;

 import tudresden.ocl.parser.lexer.Lexer;

 import tudresden.ocl.parser.node.Start;

 /**

  * Evaluates ocl expressions

  *

  * @author maurelio1234

  */

 public class DefaultOclEvaluator implements OclExpressionEvaluator {

     /**

      * Logger.

      */

     private static final Logger LOG = Logger

             .getLogger(DefaultOclEvaluator.class);

     private static OclExpressionEvaluator instance = null;

     /**

      * @return unique instance

      */

     public static OclExpressionEvaluator getInstance() {

         if (instance == null) {

             instance = new DefaultOclEvaluator();

         }

         return instance;

     }

     /*

      * @see org.argouml.profile.internal.ocl.OclExpressionEvaluator#evaluate(java.util.HashMap, org.argouml.profile.internal.ocl.ModelInterpreter, java.lang.String)

      */

     public Object evaluate(Map<String, Object> vt, ModelInterpreter mi,

             String ocl) throws InvalidOclException {

         // XXX this seems to be a bug of the parser, 

         // it always requires a context

         //LOG.debug("OCL: " + ocl);

         if (ocl.contains("ore")) {

             // TODO: Convert this to some sensible logging

             System.out.println("VOILA!");

         }

         Lexer lexer = new Lexer(new PushbackReader(new StringReader(

                 "context X inv: " + ocl), 2));

         OclParser parser = new OclParser(lexer);

         Start tree = null;

         try {

             tree = parser.parse();

         } catch (Exception e) {

             throw new InvalidOclException(ocl);

         }

         EvaluateExpression ee = new EvaluateExpression(vt, mi);

         tree.apply(ee);

         return ee.getValue();

     }

 }