/*
 * Copyright (c) 2014, 2022 Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package com.sun.tdk.jcov.instrument.asm;

import com.sun.tdk.jcov.util.Utils;
import org.objectweb.asm.Attribute;
import org.objectweb.asm.ByteVector;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Label;

/**
 * @author Dmitry Fazunenko
 * @author Alexey Fedorchenko
 */
public class InstrumentedAttributeClassAdapter extends ClassVisitor {

    private boolean isAlreadyInstrumented = false;

    public boolean isAlreadyInstrumented() {
        return isAlreadyInstrumented;
    }

    public InstrumentedAttributeClassAdapter(final ClassVisitor cv) {
        super(ASMUtils.ASM_API_VERSION, cv);
    }

    public void visitAttribute(Attribute attr) {
        System.out.println(attr.type);
        if (attr.type.equals(AttributeInstrumented.INSTRUMENTED)) {
            System.out.println("class is already instrumented");
            isAlreadyInstrumented = true;
        }
        super.visitAttribute(attr);
    }

    @Override
    public void visitEnd() {
        if (!isAlreadyInstrumented) {
            super.visitAttribute(new AttributeInstrumented());
        }
        super.visitEnd();
    }

    private static class AttributeInstrumented extends Attribute {

        final static String INSTRUMENTED = "Instrumented";

        AttributeInstrumented() {
            super(INSTRUMENTED);
        }

        protected Attribute read(
                final ClassReader cr,
                final int off,
                final int len,
                final char[] buf,
                final int codeOff,
                final Label[] labels) {
            return new AttributeInstrumented();
        }

        protected ByteVector write(
                final ClassWriter cw,
                final byte[] code,
                final int len,
                final int maxStack,
                final int maxLocals) {
            return new ByteVector().putShort(cw.newUTF8(INSTRUMENTED));
        }
    }
}
