/*
 * 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.forms;

import org.apache.commons.compress.harmony.unpack200.bytecode.ByteCode;
import org.apache.commons.compress.harmony.unpack200.bytecode.CodeAttribute;

/**
 * Switch instruction form.
 */
public abstract class SwitchForm extends VariableInstructionForm {

    /**
     * Constructs a new instance with the specified opcode, name, operandType and rewrite.
     *
     * @param opcode  index corresponding to the opcode's value.
     * @param name    String printable name of the opcode.
     */
    public SwitchForm(final int opcode, final String name) {
        super(opcode, name);
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.compress.harmony.unpack200.bytecode.forms.ByteCodeForm#fixUpByteCodeTargets(org.apache.commons
     * .compress.harmony.unpack200.bytecode.ByteCode, org.apache.commons.compress.harmony.unpack200.bytecode.CodeAttribute)
     */
    @Override
    public void fixUpByteCodeTargets(final ByteCode byteCode, final CodeAttribute codeAttribute) {
        // SwitchForms need to fix up the target of label operations
        final int[] originalTargets = byteCode.getByteCodeTargets();
        final int numberOfLabels = originalTargets.length;
        final int[] replacementTargets = new int[numberOfLabels];

        final int sourceIndex = byteCode.getByteCodeIndex();
        final int sourceValue = codeAttribute.byteCodeOffsets.get(sourceIndex).intValue();
        for (int index = 0; index < numberOfLabels; index++) {
            final int absoluteInstructionTargetIndex = sourceIndex + originalTargets[index];
            final int targetValue = codeAttribute.byteCodeOffsets.get(absoluteInstructionTargetIndex).intValue();
            replacementTargets[index] = targetValue - sourceValue;
        }
        final int[] rewriteArray = byteCode.getRewrite();
        for (int index = 0; index < numberOfLabels; index++) {
            setRewrite4Bytes(replacementTargets[index], rewriteArray);
        }
    }

}
