/*
 * 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() {
    }

    public MULTIANEWARRAY(final int index, final short dimensions) {
        super(org.apache.bcel.Const.MULTIANEWARRAY, index);
        if (dimensions < 1) {
            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);
    }

    /**
     * @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 = bytes.readByte();
        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;
    }
}
