/*
    * 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.
   */
  package org.apache.bcel.classfile;
  
  import java.io.DataInput;
  import java.io.DataOutputStream;
  import java.io.IOException;
  
  import org.apache.bcel.Const;
  
  /**
   * This class represents a inner class attribute, i.e., the class indices of the inner and outer classes, the name and
   * the attributes of the inner class.
   *
   * @see InnerClasses
   */
  public final class InnerClass implements Cloneable, Node {
  
      private int innerClassIndex;
      private int outerClassIndex;
      private int innerNameIndex;
      private int innerAccessFlags;
  
      /**
       * Constructs object from file stream.
       *
       * @param file Input stream
       * @throws IOException if an I/O error occurs.
       */
      InnerClass(final DataInput file) throws IOException {
          this(file.readUnsignedShort(), file.readUnsignedShort(), file.readUnsignedShort(), file.readUnsignedShort());
      }
  
      /**
       * Initialize from another object.
       *
       * @param c Source to copy.
       */
      public InnerClass(final InnerClass c) {
          this(c.getInnerClassIndex(), c.getOuterClassIndex(), c.getInnerNameIndex(), c.getInnerAccessFlags());
      }
  
      /**
       * @param innerClassIndex Class index in constant pool of inner class
       * @param outerClassIndex Class index in constant pool of outer class
       * @param innerNameIndex Name index in constant pool of inner class
       * @param innerAccessFlags Access flags of inner class
       */
      public InnerClass(final int innerClassIndex, final int outerClassIndex, final int innerNameIndex, final int innerAccessFlags) {
          this.innerClassIndex = innerClassIndex;
          this.outerClassIndex = outerClassIndex;
          this.innerNameIndex = innerNameIndex;
          this.innerAccessFlags = innerAccessFlags;
      }
  
      /**
       * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
       * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
       *
       * @param v Visitor object
       */
      @Override
      public void accept(final Visitor v) {
          v.visitInnerClass(this);
      }
  
      /**
       * @return deep copy of this object
       */
      public InnerClass copy() {
          try {
              return (InnerClass) clone();
          } catch (final CloneNotSupportedException e) {
              // TODO should this throw?
          }
          return null;
      }
  
      /**
       * Dump inner class attribute to file stream in binary format.
       *
       * @param file Output file stream
       * @throws IOException if an I/O error occurs.
       */
      public void dump(final DataOutputStream file) throws IOException {
         file.writeShort(innerClassIndex);
         file.writeShort(outerClassIndex);
         file.writeShort(innerNameIndex);
         file.writeShort(innerAccessFlags);
     }
 
     /**
      * @return access flags of inner class.
      */
     public int getInnerAccessFlags() {
         return innerAccessFlags;
     }
 
     /**
      * @return class index of inner class.
      */
     public int getInnerClassIndex() {
         return innerClassIndex;
     }
 
     /**
      * @return name index of inner class.
      */
     public int getInnerNameIndex() {
         return innerNameIndex;
     }
 
     /**
      * @return class index of outer class.
      */
     public int getOuterClassIndex() {
         return outerClassIndex;
     }
 
     /**
      * @param innerAccessFlags access flags for this inner class
      */
     public void setInnerAccessFlags(final int innerAccessFlags) {
         this.innerAccessFlags = innerAccessFlags;
     }
 
     /**
      * @param innerClassIndex index into the constant pool for this class
      */
     public void setInnerClassIndex(final int innerClassIndex) {
         this.innerClassIndex = innerClassIndex;
     }
 
     /**
      * @param innerNameIndex index into the constant pool for this class's name
      */
     public void setInnerNameIndex(final int innerNameIndex) { // TODO unused
         this.innerNameIndex = innerNameIndex;
     }
 
     /**
      * @param outerClassIndex index into the constant pool for the owning class
      */
     public void setOuterClassIndex(final int outerClassIndex) { // TODO unused
         this.outerClassIndex = outerClassIndex;
     }
 
     /**
      * @return String representation.
      */
     @Override
     public String toString() {
         return "InnerClass(" + innerClassIndex + ", " + outerClassIndex + ", " + innerNameIndex + ", " + innerAccessFlags + ")";
     }
 
     /**
      * @return Resolved string representation
      */
     public String toString(final ConstantPool constantPool) {
         String outerClassName;
         String innerName;
         String innerClassName = constantPool.getConstantString(innerClassIndex, Const.CONSTANT_Class);
         innerClassName = Utility.compactClassName(innerClassName, false);
         if (outerClassIndex != 0) {
             outerClassName = constantPool.getConstantString(outerClassIndex, Const.CONSTANT_Class);
             outerClassName = " of class " + Utility.compactClassName(outerClassName, false);
         } else {
             outerClassName = "";
         }
         if (innerNameIndex != 0) {
             innerName = constantPool.getConstantUtf8(innerNameIndex).getBytes();
         } else {
             innerName = "(anonymous)";
         }
         String access = Utility.accessToString(innerAccessFlags, true);
         access = access.isEmpty() ? "" : access + " ";
         return "  " + access + innerName + "=class " + innerClassName + outerClassName;
     }
 }