/*
    * Copyright (c) 2006 JMockit developers
    * This file is subject to the terms of the MIT license (see LICENSE.txt).
    */
   package mockit.internal.util;
   
   import edu.umd.cs.findbugs.annotations.NonNull;
   
   import java.util.EnumSet;
  import java.util.List;
  
  import mockit.asm.metadata.ClassMetadataReader;
  import mockit.asm.metadata.ClassMetadataReader.Attribute;
  import mockit.asm.metadata.ClassMetadataReader.MethodInfo;
  import mockit.internal.ClassFile;
  import mockit.internal.state.ParameterNames;
  
  public final class ParameterNameExtractor {
      private static final EnumSet<Attribute> PARAMETERS = EnumSet.of(Attribute.Parameters);
  
      private ParameterNameExtractor() {
      }
  
      @NonNull
      public static String extractNames(@NonNull Class<?> classOfInterest) {
          String className = classOfInterest.getName();
          String classDesc = className.replace('.', '/');
  
          if (!ParameterNames.hasNamesForClass(classDesc)) {
              byte[] classfile = ClassFile.readBytesFromClassFile(classDesc);
              ClassMetadataReader cmr = new ClassMetadataReader(classfile, PARAMETERS);
              List<MethodInfo> methods = cmr.getMethods();
  
              for (MethodInfo method : methods) {
                  if (!method.isSynthetic()) {
                      String[] parameters = method.parameters;
  
                      if (parameters != null) {
                          ParameterNames.register(classDesc, method.name, method.desc, parameters);
                      }
                  }
              }
          }
  
          return classDesc;
      }
  }