package org.apache.maven.coreits.javaagent.mng5669;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *  http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  import java.lang.instrument.ClassFileTransformer;
  import java.lang.instrument.IllegalClassFormatException;
  import java.lang.instrument.Instrumentation;
  import java.security.ProtectionDomain;
  
  import org.objectweb.asm.ClassReader;
  import org.objectweb.asm.ClassVisitor;
  import org.objectweb.asm.ClassWriter;
  import org.objectweb.asm.MethodVisitor;
  import org.objectweb.asm.Opcodes;
  import org.objectweb.asm.commons.AdviceAdapter;
  
  /**
   *
   * @author Robert Scholte
   *
   */
  public class Premain
  {
      public static void premain( String agentArgs, Instrumentation inst )
      {
          inst.addTransformer( new ClassFileTransformer()
          {
  
              public byte[] transform( ClassLoader loader, String className, Class<?> classBeingRedefined,
                                       ProtectionDomain protectionDomain, byte[] classfileBuffer )
                  throws IllegalClassFormatException
              {
                  if ( "org/apache/maven/model/io/DefaultModelReader".equals( className ) )
                  {
                      ClassReader r = new ClassReader( classfileBuffer );
                      final ClassWriter w = new ClassWriter( Opcodes.ASM6 );
  
                      ClassVisitor v = new DefaultModelReaderVisitior( Opcodes.ASM6, w );
  
                      r.accept( v, ClassReader.EXPAND_FRAMES );
                      return w.toByteArray();
                  }
                  else
                  {
                      return classfileBuffer;
                  }
              }
          } );
      }
  
      private static class DefaultModelReaderVisitior
          extends ClassVisitor
      {
          DefaultModelReaderVisitior( int api, org.objectweb.asm.ClassVisitor cv )
          {
              super( api, cv );
          }
  
          @Override
          public MethodVisitor visitMethod( int access, String name, String desc, String signature, String[] exceptions )
          {
              MethodVisitor mv = cv.visitMethod( access, name, desc, signature, exceptions );
              if ( "getSource".equals( name ) )
              {
                  return new GetSourceMethodAdvice( Opcodes.ASM6, mv, access, name, desc );
              }
              else
              {
                  return mv;
              }
          }
      }
  
      // org.apache.maven.model.io.DefaultModelReader.getSource(Map<String, ?>)
      private static class GetSourceMethodAdvice
          extends AdviceAdapter
      {
          GetSourceMethodAdvice( int api, MethodVisitor mv, int access, String name, String desc )
          {
              super( api, mv, access, name, desc );
          }
  
         @Override
         protected void onMethodEnter()
         {
             // System.out.println( options ),
             mv.visitFieldInsn( GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;" );
             mv.visitVarInsn( ALOAD, 1 );
             mv.visitMethodInsn( INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/Object;)V", false );
         }
     }
 }