/*
 * ProGuardCORE -- library to process Java bytecode.
 *
 * Copyright (c) 2002-2020 Guardsquare NV
 *
 * Licensed 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 proguard.classfile.constant;

import proguard.classfile.*;
import proguard.classfile.constant.visitor.ConstantVisitor;
import proguard.classfile.visitor.MemberVisitor;

/**
 * This {@link Constant} represents a field reference constant in the constant pool.
 *
 * @author Eric Lafortune
 */
public class FieldrefConstant extends RefConstant
{
    /**
     * An extra field optionally pointing to the referenced Field object.
     * This field is typically filled out by the <code>{@link
     * proguard.classfile.util.ClassReferenceInitializer
     * ClassReferenceInitializer}</code>.
     */
    public Field referencedField;


    /**
     * Creates an uninitialized FieldrefConstant.
     */
    public FieldrefConstant()
    {
    }


    /**
     * Creates a new FieldrefConstant with the given name and type indices.
     * @param u2classIndex       the index of the class in the constant pool.
     * @param u2nameAndTypeIndex the index of the name and type entry in the constant pool.
     * @param referencedClass    the referenced class.
     * @param referencedField    the referenced field.
     */
    public FieldrefConstant(int    u2classIndex,
                            int    u2nameAndTypeIndex,
                            Clazz  referencedClass,
                            Field  referencedField)
    {
        this.u2classIndex       = u2classIndex;
        this.u2nameAndTypeIndex = u2nameAndTypeIndex;
        this.referencedClass    = referencedClass;
        this.referencedField    = referencedField;
    }


    /**
     * Lets the referenced class field accept the given visitor.
     */
    public void referencedFieldAccept(MemberVisitor memberVisitor)
    {
        if (referencedField != null)
        {
            referencedField.accept(referencedClass,
                                   memberVisitor);
        }
    }


    // Implementations for RefConstant.

    /**
     * Lets the referenced class member accept the given visitor.
     */
    @Override
    public void referencedMemberAccept(MemberVisitor memberVisitor)
    {
        if (referencedField != null)
        {
            referencedField.accept(referencedClass,
                                   memberVisitor);
        }
    }


    // Implementations for Constant.

    @Override
    public int getTag()
    {
        return Constant.FIELDREF;
    }

    @Override
    public boolean isCategory2()
    {
        return false;
    }

    @Override
    public void accept(Clazz clazz, ConstantVisitor constantVisitor)
    {
        constantVisitor.visitFieldrefConstant(clazz, this);
    }


    // Implementations for Object.

    @Override
    public String toString()
    {
        return "Fieldref(" + u2classIndex + "," + u2nameAndTypeIndex + ")";
    }
}
