/*
    * 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
    *
   *   https://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.
   */
  package org.apache.bcel.verifier.statics;
  
  import org.apache.bcel.classfile.AnnotationDefault;
  import org.apache.bcel.classfile.AnnotationEntry;
  import org.apache.bcel.classfile.Annotations;
  import org.apache.bcel.classfile.BootstrapMethods;
  import org.apache.bcel.classfile.Code;
  import org.apache.bcel.classfile.CodeException;
  import org.apache.bcel.classfile.ConstantClass;
  import org.apache.bcel.classfile.ConstantDouble;
  import org.apache.bcel.classfile.ConstantDynamic;
  import org.apache.bcel.classfile.ConstantFieldref;
  import org.apache.bcel.classfile.ConstantFloat;
  import org.apache.bcel.classfile.ConstantInteger;
  import org.apache.bcel.classfile.ConstantInterfaceMethodref;
  import org.apache.bcel.classfile.ConstantInvokeDynamic;
  import org.apache.bcel.classfile.ConstantLong;
  import org.apache.bcel.classfile.ConstantMethodHandle;
  import org.apache.bcel.classfile.ConstantMethodType;
  import org.apache.bcel.classfile.ConstantMethodref;
  import org.apache.bcel.classfile.ConstantModule;
  import org.apache.bcel.classfile.ConstantNameAndType;
  import org.apache.bcel.classfile.ConstantPackage;
  import org.apache.bcel.classfile.ConstantPool;
  import org.apache.bcel.classfile.ConstantString;
  import org.apache.bcel.classfile.ConstantUtf8;
  import org.apache.bcel.classfile.ConstantValue;
  import org.apache.bcel.classfile.Deprecated;
  import org.apache.bcel.classfile.EnclosingMethod;
  import org.apache.bcel.classfile.ExceptionTable;
  import org.apache.bcel.classfile.Field;
  import org.apache.bcel.classfile.InnerClass;
  import org.apache.bcel.classfile.InnerClasses;
  import org.apache.bcel.classfile.JavaClass;
  import org.apache.bcel.classfile.LineNumber;
  import org.apache.bcel.classfile.LineNumberTable;
  import org.apache.bcel.classfile.LocalVariable;
  import org.apache.bcel.classfile.LocalVariableTable;
  import org.apache.bcel.classfile.LocalVariableTypeTable;
  import org.apache.bcel.classfile.Method;
  import org.apache.bcel.classfile.MethodParameters;
  import org.apache.bcel.classfile.NestMembers;
  import org.apache.bcel.classfile.Node;
  import org.apache.bcel.classfile.ParameterAnnotationEntry;
  import org.apache.bcel.classfile.ParameterAnnotations;
  import org.apache.bcel.classfile.Record;
  import org.apache.bcel.classfile.RecordComponentInfo;
  import org.apache.bcel.classfile.Signature;
  import org.apache.bcel.classfile.SourceFile;
  import org.apache.bcel.classfile.StackMap;
  import org.apache.bcel.classfile.StackMapEntry;
  import org.apache.bcel.classfile.Synthetic;
  import org.apache.bcel.classfile.Unknown;
  import org.apache.bcel.verifier.exc.AssertionViolatedException;
  
  /**
   * BCEL's Node classes (those from the classfile API that {@code accept()} Visitor instances) have {@code toString()}
   * methods that were not designed to be robust, this gap is closed by this class. When performing class file
   * verification, it may be useful to output which entity (for example a {@code Code} instance) is not satisfying the verifier's
   * constraints, but in this case it could be possible for the {@code toString()} method to throw a RuntimeException. A
   * (new StringRepresentation(Node n)).toString() never throws any exception. Note that this class also serves as a
   * placeholder for more sophisticated message handling in future versions of JustIce.
   */
  public class StringRepresentation extends org.apache.bcel.classfile.EmptyVisitor {
  
      /** The string representation, created by a visitXXX() method, output by toString(). */
      private String tostring;
  
      /** The node we ask for its string representation. Not really needed; only for debug output. */
      private final Node n;
  
      /**
       * Creates a new StringRepresentation object which is the representation of n.
       *
       * @param n The node to represent.
       * @see #toString()
       */
      public StringRepresentation(final Node n) {
          this.n = n;
          n.accept(this); // assign a string representation to field 'tostring' if we know n's class.
      }
 
     /**
      * Returns the String representation.
      */
     @Override
     public String toString() {
 // The run-time check below is needed because we don't want to omit inheritance
 // of "EmptyVisitor" and provide a thousand empty methods.
 // However, in terms of performance this would be a better idea.
 // If some new "Node" is defined in BCEL (such as some concrete "Attribute"), we
 // want to know that this class has also to be adapted.
         if (tostring == null) {
             throw new AssertionViolatedException("Please adapt '" + getClass() + "' to deal with objects of class '" + n.getClass() + "'.");
         }
         return tostring;
     }
 
     /**
      * Returns the String representation of the Node object obj; this is obj.toString() if it does not throw any
      * RuntimeException, or else it is a string derived only from obj's class name.
      */
     private String toString(final Node obj) {
         String ret;
         try {
             ret = obj.toString();
         } catch (final RuntimeException e) {
             // including ClassFormatException, trying to convert the "signature" of a ReturnaddressType LocalVariable
             // (shouldn't occur, but people do crazy things)
             String s = obj.getClass().getName();
             s = s.substring(s.lastIndexOf(".") + 1);
             ret = "<<" + s + ">>";
         }
         return ret;
     }
 
     /**
      * @since 6.0
      */
     @Override
     public void visitAnnotation(final Annotations obj) {
         // this is invoked whenever an annotation is found
         // when verifier is passed over a class
         tostring = toString(obj);
     }
 
     /**
      * @since 6.0
      */
     @Override
     public void visitAnnotationDefault(final AnnotationDefault obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.0
      */
     @Override
     public void visitAnnotationEntry(final AnnotationEntry obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.0
      */
     @Override
     public void visitBootstrapMethods(final BootstrapMethods obj) {
         tostring = toString(obj);
     }
 
     ////////////////////////////////
     // Visitor methods start here //
     ////////////////////////////////
     // We don't of course need to call some default implementation:
     // for example we could also simply output "Code" instead of a possibly
     // lengthy Code attribute's toString().
     @Override
     public void visitCode(final Code obj) {
         // tostring = toString(obj);
         tostring = "<CODE>"; // We don't need real code outputs.
     }
 
     @Override
     public void visitCodeException(final CodeException obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitConstantClass(final ConstantClass obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitConstantDouble(final ConstantDouble obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.6.0
      */
     @Override
     public void visitConstantDynamic(final ConstantDynamic obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitConstantFieldref(final ConstantFieldref obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitConstantFloat(final ConstantFloat obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitConstantInteger(final ConstantInteger obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitConstantInterfaceMethodref(final ConstantInterfaceMethodref obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.0
      */
     @Override
     public void visitConstantInvokeDynamic(final ConstantInvokeDynamic obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitConstantLong(final ConstantLong obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.0
      */
     @Override
     public void visitConstantMethodHandle(final ConstantMethodHandle obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitConstantMethodref(final ConstantMethodref obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.0
      */
     @Override
     public void visitConstantMethodType(final ConstantMethodType obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.6.0
      */
     @Override
     public void visitConstantModule(final ConstantModule obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitConstantNameAndType(final ConstantNameAndType obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.6.0
      */
     @Override
     public void visitConstantPackage(final ConstantPackage obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitConstantPool(final ConstantPool obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitConstantString(final ConstantString obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitConstantUtf8(final ConstantUtf8 obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitConstantValue(final ConstantValue obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitDeprecated(final Deprecated obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.0
      */
     @Override
     public void visitEnclosingMethod(final EnclosingMethod obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitExceptionTable(final ExceptionTable obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitField(final Field obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitInnerClass(final InnerClass obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitInnerClasses(final InnerClasses obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitJavaClass(final JavaClass obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitLineNumber(final LineNumber obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitLineNumberTable(final LineNumberTable obj) {
         tostring = "<LineNumberTable: " + toString(obj) + ">";
     }
 
     @Override
     public void visitLocalVariable(final LocalVariable obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitLocalVariableTable(final LocalVariableTable obj) {
         tostring = "<LocalVariableTable: " + toString(obj) + ">";
     }
 
     /**
      * @since 6.0
      */
     @Override
     public void visitLocalVariableTypeTable(final LocalVariableTypeTable obj) {
         // this is invoked whenever a local variable type is found
         // when verifier is passed over a class
         tostring = toString(obj);
     }
 
     @Override
     public void visitMethod(final Method obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.0
      */
     @Override
     public void visitMethodParameters(final MethodParameters obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.4.0
      */
     @Override
     public void visitNestMembers(final NestMembers obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.0
      */
     @Override
     public void visitParameterAnnotation(final ParameterAnnotations obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.0
      */
     @Override
     public void visitParameterAnnotationEntry(final ParameterAnnotationEntry obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitRecord(final Record obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitRecordComponent(final RecordComponentInfo obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitSignature(final Signature obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitSourceFile(final SourceFile obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitStackMap(final StackMap obj) {
         tostring = toString(obj);
     }
 
     /**
      * @since 6.0
      */
     @Override
     public void visitStackMapEntry(final StackMapEntry obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitSynthetic(final Synthetic obj) {
         tostring = toString(obj);
     }
 
     @Override
     public void visitUnknown(final Unknown obj) {
         tostring = toString(obj);
     }
 
 }