/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * 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 com.sun.org.apache.bcel.internal.generic;

import java.io.DataOutputStream;

import java.io.IOException;

import com.sun.org.apache.bcel.internal.util.ByteSequence;

/**

 * IINC - Increment local variable by constant

 *

 */

public class IINC extends LocalVariableInstruction {

    private boolean wide;

    private int c;

    /**

     * Empty constructor needed for Instruction.readInstruction.

     * Not to be used otherwise.

     */

    IINC() {

    }

    /**

     * @param n index of local variable

     * @param c increment factor

     */

    public IINC(final int n, final int c) {

        super(); // Default behavior of LocalVariableInstruction causes error

        super.setOpcode(com.sun.org.apache.bcel.internal.Const.IINC);

        super.setLength((short) 3);

        setIndex(n); // May set wide as side effect

        setIncrement(c);

    }

    /**

     * Dump instruction as byte code to stream out.

     * @param out Output stream

     */

    @Override

    public void dump( final DataOutputStream out ) throws IOException {

        if (wide) {

            out.writeByte(com.sun.org.apache.bcel.internal.Const.WIDE);

        }

        out.writeByte(super.getOpcode());

        if (wide) {

            out.writeShort(super.getIndex());

            out.writeShort(c);

        } else {

            out.writeByte(super.getIndex());

            out.writeByte(c);

        }

    }

    private void setWide() {

        wide = super.getIndex() > com.sun.org.apache.bcel.internal.Const.MAX_BYTE;

        if (c > 0) {

            wide = wide || (c > Byte.MAX_VALUE);

        } else {

            wide = wide || (c < Byte.MIN_VALUE);

        }

        if (wide) {

            super.setLength(6); // wide byte included

        } else {

            super.setLength(3);

        }

    }

    /**

     * Read needed data (e.g. index) from file.

     */

    @Override

    protected void initFromFile( final ByteSequence bytes, final boolean wide ) throws IOException {

        this.wide = wide;

        if (wide) {

            super.setLength(6);

            super.setIndexOnly(bytes.readUnsignedShort());

            c = bytes.readShort();

        } else {

            super.setLength(3);

            super.setIndexOnly(bytes.readUnsignedByte());

            c = bytes.readByte();

        }

    }

    /**

     * @return mnemonic for instruction

     */

    @Override

    public String toString( final boolean verbose ) {

        return super.toString(verbose) + " " + c;

    }

    /**

     * Set index of local variable.

     */

    @Override

    public final void setIndex( final int n ) {

        if (n < 0) {

            throw new ClassGenException("Negative index value: " + n);

        }

        super.setIndexOnly(n);

        setWide();

    }

    /**

     * @return increment factor

     */

    public final int getIncrement() {

        return c;

    }

    /**

     * Set increment factor.

     */

    public final void setIncrement( final int c ) {

        this.c = c;

        setWide();

    }

    /** @return int type

     */

    @Override

    public Type getType( final ConstantPoolGen cp ) {

        return Type.INT;

    }

    /**

     * 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,

     * i.e., the most specific visitXXX() call comes last.

     *

     * @param v Visitor object

     */

    @Override

    public void accept( final Visitor v ) {

        v.visitLocalVariableInstruction(this);

        v.visitIINC(this);

    }

}