/*
 * FindBugs - Find bugs in Java programs
 * Copyright (C) 2008, University of Maryland
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package edu.umd.cs.findbugs.util;

import org.apache.bcel.generic.ReferenceType;
import org.apache.bcel.generic.Type;

import edu.umd.cs.findbugs.ba.ch.Subtypes2;
import edu.umd.cs.findbugs.bcel.BCELUtil;
import edu.umd.cs.findbugs.classfile.ClassDescriptor;
import edu.umd.cs.findbugs.classfile.Global;
import edu.umd.cs.findbugs.classfile.IAnalysisCache;

/**
 * Type matcher that determines if a candidate Type is a subtype of a given
 * Type.
 *
 * @author David Hovemeyer
 */
public class SubtypeTypeMatcher implements TypeMatcher {
    private final ReferenceType supertype;

    /**
     * Constructor.
     *
     * @param supertype
     *            a ReferenceType: this TypeMatcher will test whether or not
     *            candidate Types are subtypes of this Type
     */
    public SubtypeTypeMatcher(ReferenceType supertype) {
        this.supertype = supertype;
    }

    /**
     * Constructor.
     *
     * @param classDescriptor
     *            a ClassDescriptor naming a class: this TypeMatcher will test
     *            whether or not candidate Types are subtypes of the class
     */
    public SubtypeTypeMatcher(ClassDescriptor classDescriptor) {
        this(BCELUtil.getObjectTypeInstance(classDescriptor.toDottedClassName()));
    }

    @Override
    public boolean matches(Type t) {
        if (!(t instanceof ReferenceType)) {
            return false;
        }
        IAnalysisCache analysisCache = Global.getAnalysisCache();
        Subtypes2 subtypes2 = analysisCache.getDatabase(Subtypes2.class);

        try {
            return subtypes2.isSubtype((ReferenceType) t, supertype);
        } catch (ClassNotFoundException e) {
            analysisCache.getErrorLogger().reportMissingClass(e);
            return false;
        }
    }

    @Override
    public String toString() {
        return "+" + supertype.toString();
    }
}
