/*
 * FindBugs - Find bugs in Java programs
 * Copyright (C) 2003,2004 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;

import javax.annotation.CheckForNull;

import org.apache.bcel.Repository;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.Method;

import edu.umd.cs.findbugs.ba.AnalysisContext;
import edu.umd.cs.findbugs.ba.XClass;
import edu.umd.cs.findbugs.ba.XFactory;
import edu.umd.cs.findbugs.ba.XMethod;
import edu.umd.cs.findbugs.ba.ch.Subtypes2;
import edu.umd.cs.findbugs.classfile.CheckedAnalysisException;
import edu.umd.cs.findbugs.classfile.ClassDescriptor;
import edu.umd.cs.findbugs.classfile.DescriptorFactory;
import edu.umd.cs.findbugs.classfile.Global;
import edu.umd.cs.findbugs.classfile.MissingClassException;
import edu.umd.cs.findbugs.internalAnnotations.DottedClassName;
import edu.umd.cs.findbugs.internalAnnotations.SlashedClassName;
import edu.umd.cs.findbugs.visitclass.Constants2;

public class Lookup implements Constants2 {

    private static Subtypes2 subtypes2() {
        return AnalysisContext.currentAnalysisContext().getSubtypes2();
    }

    public static XClass getXClass(ClassDescriptor c) throws CheckedAnalysisException {
        return Global.getAnalysisCache().getClassAnalysis(XClass.class, c);
    }

    public static XClass getXClass(@SlashedClassName String className) throws CheckedAnalysisException {
        return Global.getAnalysisCache().getClassAnalysis(XClass.class, DescriptorFactory.createClassDescriptor(className));
    }

    public static XClass findSuperImplementor(XClass clazz, String name, String signature, boolean isStatic,
            BugReporter bugReporter) {

        try {
            return findSuperImplementor(clazz, name, signature, isStatic);
        } catch (MissingClassException e) {
            bugReporter.reportMissingClass(e.getClassDescriptor());
            return clazz;
        } catch (CheckedAnalysisException e) {
            bugReporter.logError("Error finding " + clazz + "." + name + signature, e);
            return clazz;
        }

    }

    public static XClass findImplementor(XClass clazz, String name, String signature, boolean isStatic, BugReporter bugReporter) {

        try {
            return findImplementor(clazz, name, signature, isStatic);
        } catch (MissingClassException e) {
            bugReporter.reportMissingClass(e.getClassDescriptor());
            return clazz;
        } catch (CheckedAnalysisException e) {
            bugReporter.logError("Error finding " + clazz + "." + name + signature, e);
            return clazz;
        }

    }

    public static XClass findSuperImplementor(XClass clazz, String name, String signature, boolean isStatic)
            throws CheckedAnalysisException {

        ClassDescriptor superclassDescriptor = clazz.getSuperclassDescriptor();
        if (superclassDescriptor == null)
            return clazz;
        return findImplementor(getXClass(superclassDescriptor), name, signature, isStatic);
    }

    public static XClass findImplementor(XClass clazz, String name, String signature, boolean isStatic)
            throws CheckedAnalysisException {
        XMethod m = clazz.findMethod(name, signature, isStatic);
        if (m != null)
            return clazz;
        return findSuperImplementor(clazz, name, signature, isStatic);
    }

    public static @CheckForNull
    JavaClass findSuperDefiner(JavaClass clazz, String name, String signature, BugReporter bugReporter) {
        try {
            JavaClass c = clazz;
            while (true) {
                c = c.getSuperClass();
                if (c == null)
                    return null;
                Method m = findImplementation(c, name, signature);
                if (m != null) {
                    return c;
                }
            }
        } catch (ClassNotFoundException e) {
            bugReporter.reportMissingClass(e);
            return null;
        }
    }

    public static @CheckForNull
    JavaClass findSuperImplementor(JavaClass clazz, String name, String signature, BugReporter bugReporter) {
        try {
            JavaClass c = clazz;
            while (true) {
                c = c.getSuperClass();
                if (c == null)
                    return null;
                Method m = findImplementation(c, name, signature);
                if (m != null && !m.isAbstract())
                    return c;

            }
        } catch (ClassNotFoundException e) {
            bugReporter.reportMissingClass(e);
            return null;
        }
    }

    public static @CheckForNull
    XMethod findSuperImplementorAsXMethod(JavaClass clazz, String name, String signature, BugReporter bugReporter) {
        try {
            JavaClass c = clazz;
            while (true) {
                c = c.getSuperClass();
                if (c == null)
                    return null;
                Method m = findImplementation(c, name, signature);
                if (m != null && !m.isAbstract())
                    return XFactory.createXMethod(c, m);

            }
        } catch (ClassNotFoundException e) {
            bugReporter.reportMissingClass(e);
            return null;
        }
    }

    public static @DottedClassName
    String findSuperImplementor(@DottedClassName String clazz, String name, String signature, BugReporter bugReporter) {
        try {
            JavaClass c = findImplementor(Repository.getSuperClasses(clazz), name, signature);
            return (c != null) ? c.getClassName() : clazz;
        } catch (ClassNotFoundException e) {
            bugReporter.reportMissingClass(e);
            return clazz;
        }
    }

    public static @CheckForNull
    JavaClass findImplementor(JavaClass[] clazz, String name, String signature) {

        for (JavaClass aClazz : clazz) {
            Method m = findImplementation(aClazz, name, signature);
            if (m != null && !m.isAbstract())
                return aClazz;

        }
        return null;
    }

    public static Method findImplementation(JavaClass clazz, String name, String signature) {
        Method[] m = clazz.getMethods();
        for (Method aM : m)
            if (aM.getName().equals(name) && aM.getSignature().equals(signature) && !aM.isPrivate() && !aM.isStatic())
                return aM;
        return null;
    }
}
