/*
    * 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.commons.compress.harmony.unpack200.bytecode;
  
  import java.io.DataOutputStream;
  import java.io.IOException;
  import java.util.Objects;
  
  /**
   * Field reference constant pool entry.
   */
  public class CPFieldRef extends ConstantPoolEntry {
  
      CPClass className;
      transient int classNameIndex;
      private final CPNameAndType nameAndType;
      transient int nameAndTypeIndex;
  
      private boolean hashCodeComputed;
  
      private int cachedHashCode;
  
      public CPFieldRef(final CPClass className, final CPNameAndType descriptor, final int globalIndex) {
          super(CP_Fieldref, globalIndex);
          this.className = className;
          this.nameAndType = descriptor;
      }
  
      @Override
      public boolean equals(final Object obj) {
          if (this == obj) {
              return true;
          }
          if (obj == null || getClass() != obj.getClass()) {
              return false;
          }
          final CPFieldRef other = (CPFieldRef) obj;
          return Objects.equals(className, other.className)
                  && Objects.equals(nameAndType, other.nameAndType);
      }
  
      private void generateHashCode() {
          hashCodeComputed = true;
          final int PRIME = 31;
          int result = 1;
          result = PRIME * result + (className == null ? 0 : className.hashCode());
          result = PRIME * result + (nameAndType == null ? 0 : nameAndType.hashCode());
          cachedHashCode = result;
      }
  
      @Override
      protected ClassFileEntry[] getNestedClassFileEntries() {
          return new ClassFileEntry[] { className, nameAndType };
      }
  
      @Override
      public int hashCode() {
          if (!hashCodeComputed) {
              generateHashCode();
          }
          return cachedHashCode;
      }
  
      @Override
      protected void resolve(final ClassConstantPool pool) {
          super.resolve(pool);
          nameAndTypeIndex = pool.indexOf(nameAndType);
          classNameIndex = pool.indexOf(className);
      }
  
      @Override
      public String toString() {
          return "FieldRef: " + className + "#" + nameAndType;
      }
  
      @Override
      protected void writeBody(final DataOutputStream dos) throws IOException {
          dos.writeShort(classNameIndex);
          dos.writeShort(nameAndTypeIndex);
      }
  
  }