!include once #1019934 // BCEL

// A = interface we are implementing

sclass ClassMaker<A> {

  gettable S className;

  gettable ClassGen cg;

  JavaClass baked;

  InMemoryClassLoader classLoader;

  Class loadedClass;

  settable bool printDisassembly;

  settable S superClassName = "java.lang.Object";

  settable S fileName;

  *(S className) {

    this(className, null);

  }

  *(S *className, S *superClassName, S[] interfaces) {

    setClassGen(new ClassGen(className, superClassName, fileName,

      Const.ACC_PUBLIC, interfaces));

  }

  *(S *className, S[] interfaces) {

    setClassGen(new ClassGen(className, superClassName, fileName,

      Const.ACC_PUBLIC, interfaces));

  }

  *(Class<A> interfaceToImplement) {

    className = randomClassName();

    setClassGen(new ClassGen(className, "java.lang.Object", null,

      Const.ACC_PUBLIC, new S[] { main className(interfaceToImplement) }));

    addDefaultConstructor();

  }

  void addDefaultConstructor {

    cg.addEmptyConstructor(Const.ACC_PUBLIC);

  }

  void setClassGen(ClassGen cg) {

    this.cg = cg;

    // up the byte code version so we can do ldc of class objects (e.g.)

    cg.setMajor(50); // JDK 6

    //cg.setMajor(55); // JDK 11. can't use yet because StackMapTable became mandatory in JDK 8 and BCEL doesn't generate that

    cg.setMinor(0);

  }

  JavaClass bake() {

    if (baked == null) {

      baked = cg.getJavaClass();

      if (printDisassembly)

        printClassWithMethods();

    }

    ret baked;

  }

  // tabs can look bad in JTextArea, so we're using tabToSingleSpace

  void printClassWithMethods() {

    // print class overview

    print_tabToSingleSpace(bake());

    // print the methods

    for (method : baked.getMethods()) {

      print_tabToSingleSpace("\n" + method);

      print_tabToSingleSpace(method.getCode());

    }

  }

  simplyCached byte[] toBytes aka getBytes() {

    ret bake().getBytes();

  }

  Class<A> load() {

    if (loadedClass == null) {

      var bytes = toBytes();

      classLoader = new InMemoryClassLoader(myClassLoader());

      loadedClass = (Class) classLoader.defineAClass(className, bytes);

    }

    ret loadedClass;

  }

  A newInstance() {

    ret main newInstance(load());

  }

  void addField(FieldGen fg) {

    cg.addField(fg.getField());

  }

  ConstantPoolGen getConstantPool() {

    ret cg.getConstantPool();

  }

}