/*
    * 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.generic;
  
  import java.io.DataOutputStream;
  import java.io.IOException;
  
  import org.apache.bcel.ExceptionConst;
  import org.apache.bcel.classfile.ConstantPool;
  import org.apache.bcel.util.ByteSequence;
  
  /**
   * MULTIANEWARRAY - Create new mutidimensional array of references
   *
   * <pre>
   * Stack: ..., count1, [count2, ...] -&gt; ..., arrayref
   * </pre>
   */
  public class MULTIANEWARRAY extends CPInstruction implements LoadClass, AllocationInstruction, ExceptionThrower {
  
      private short dimensions;
  
      /**
       * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
       */
      MULTIANEWARRAY() {
      }
  
      /**
       * Constructs a MULTIANEWARRAY instruction.
       *
       * @param index index into constant pool.
       * @param dimensions number of dimensions.
       */
      public MULTIANEWARRAY(final int index, final short dimensions) {
          super(org.apache.bcel.Const.MULTIANEWARRAY, index);
          if (dimensions < 1 || dimensions > org.apache.bcel.Const.MAX_BYTE) {
              throw new ClassGenException("Invalid dimensions value: " + dimensions);
          }
          this.dimensions = dimensions;
          super.setLength(4);
      }
  
      /**
       * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
       * methods according to the class hierarchy in descending order, that is, the most specific visitXXX() call comes last.
       *
       * @param v Visitor object.
       */
      @Override
      public void accept(final Visitor v) {
          v.visitLoadClass(this);
          v.visitAllocationInstruction(this);
          v.visitExceptionThrower(this);
          v.visitTypedInstruction(this);
          v.visitCPInstruction(this);
          v.visitMULTIANEWARRAY(this);
      }
  
      /**
       * Also works for instructions whose stack effect depends on the constant pool entry they reference.
       *
       * @return Number of words consumed from stack by this instruction.
       */
      @Override
      public int consumeStack(final ConstantPoolGen cpg) {
          return dimensions;
      }
  
      /**
       * Dumps instruction as byte code to stream out.
       *
       * @param out Output stream.
       */
      @Override
      public void dump(final DataOutputStream out) throws IOException {
          out.writeByte(super.getOpcode());
          out.writeShort(super.getIndex());
          out.writeByte(dimensions);
      }
  
      /**
       * Gets the number of dimensions.
      *
      * @return number of dimensions to be created.
      */
     public final short getDimensions() {
         return dimensions;
     }
 
     @Override
     public Class<?>[] getExceptions() {
         return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_CLASS_AND_INTERFACE_RESOLUTION, ExceptionConst.ILLEGAL_ACCESS_ERROR,
             ExceptionConst.NEGATIVE_ARRAY_SIZE_EXCEPTION);
     }
 
     @Override
     public ObjectType getLoadClassType(final ConstantPoolGen cpg) {
         Type t = getType(cpg);
         if (t instanceof ArrayType) {
             t = ((ArrayType) t).getBasicType();
         }
         return t instanceof ObjectType ? (ObjectType) t : null;
     }
 
     /**
      * Reads needed data (that is, no. dimension) from file.
      */
     @Override
     protected void initFromFile(final ByteSequence bytes, final boolean wide) throws IOException {
         super.initFromFile(bytes, wide);
         dimensions = (short) bytes.readUnsignedByte();
         super.setLength(4);
     }
 
     /**
      * @return mnemonic for instruction.
      */
     @Override
     public String toString(final boolean verbose) {
         return super.toString(verbose) + " " + super.getIndex() + " " + dimensions;
     }
 
     /**
      * @return mnemonic for instruction with symbolic references resolved.
      */
     @Override
     public String toString(final ConstantPool cp) {
         return super.toString(cp) + " " + dimensions;
     }
 }