/* $Id: OclInterpreter.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:
 *    tfmorris
 *****************************************************************************
 *
 * 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
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// does not warrant that the operation of the program will be
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// was developed for research purposes and is advised not to rely
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// UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
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package org.argouml.profile.internal.ocl;

import java.io.PushbackReader;
import java.io.StringReader;
import java.util.List;
import java.util.Set;

import tudresden.ocl.parser.OclParser;
import tudresden.ocl.parser.lexer.Lexer;
import tudresden.ocl.parser.node.Start;

/**
 * Encapsulates actual interpretation of the OCL expressions for OCL critics
 * provided by a Profile
 * 
 * @author maurelio1234
 */
public class OclInterpreter {

    /**
     * Parser OCL tree
     */
    private Start tree = null;

    /**
     * The model interpreter
     */
    private ModelInterpreter modelInterpreter;

    /**
     * Creates a new OCL interpreter for a given OCL expression
     * 
     * @param ocl expression
     * @param interpreter the interpreter
     * @throws InvalidOclException if the expression is not valid
     */
    public OclInterpreter(String ocl, ModelInterpreter interpreter)
        throws InvalidOclException {
        this.modelInterpreter = interpreter;

        Lexer lexer = new Lexer(new PushbackReader(new StringReader(ocl), 2));

        OclParser parser = new OclParser(lexer);

        try {
            tree = parser.parse();
        } catch (Exception e) {
            e.printStackTrace();
            throw new InvalidOclException(ocl);
        }
    }

    /**
     * Checks whether this OCL expression is applicable to a given model element
     * 
     * @param modelElement the ModelElement
     * @return if is applicable
     */
    public boolean applicable(Object modelElement) {
        ContextApplicable ca = new ContextApplicable(modelElement);
        tree.apply(ca);
        return ca.isApplicable();
    }

    /**
     * Checks if this expression (invariant) is satisfied for the given model
     * element
     * 
     * @param modelElement the ModelElement
     * @return if is satisfied
     */
    public boolean check(Object modelElement) {
        EvaluateInvariant ei = new EvaluateInvariant(modelElement,
                modelInterpreter);
        tree.apply(ei);
        return ei.isOK();
    }

    /**
     * Computes and returns the set of triggers for this constraint.
     * 
     * @see org.argouml.cognitive.Critic#addTrigger(String)
     * @return the set of triggers
     */
    public List<String> getTriggers() {
        ComputeTriggers ct = new ComputeTriggers();
        tree.apply(ct);
        return ct.getTriggers();
    }

    /**
     * @return the design materials to be criticized by this ocl, no metatype
     * is assumed by default.
     */
    public Set<Object> getCriticizedDesignMaterials() {
        ComputeDesignMaterials cdm = new ComputeDesignMaterials();
        tree.apply(cdm);        
        return cdm.getCriticizedDesignMaterials();
    }

}