/*

 * 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.

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package com.sun.org.apache.bcel.internal.classfile;

import java.io.DataInput;

import java.io.DataOutputStream;

import java.io.IOException;

import com.sun.org.apache.bcel.internal.Const;

/**

 * This class represents an entry in the requires table of the Module attribute.

 * Each entry describes a module on which the parent module depends.

 *

 * @see   Module

 * @since 6.4.0

 */

public final class ModuleRequires implements Cloneable, Node {

    private final int requiresIndex;  // points to CONSTANT_Module_info

    private final int requiresFlags;

    private final int requiresVersionIndex;  // either 0 or points to CONSTANT_Utf8_info

    /**

     * Construct object from file stream.

     *

     * @param file Input stream

     * @throws IOException if an I/O Exception occurs in readUnsignedShort

     */

    ModuleRequires(final DataInput file) throws IOException {

        requiresIndex = file.readUnsignedShort();

        requiresFlags = file.readUnsignedShort();

        requiresVersionIndex = file.readUnsignedShort();

    }

    /**

     * Called by objects that are traversing the nodes of the tree implicitely

     * defined by the contents of a Java class. I.e., the hierarchy of methods,

     * fields, attributes, etc. spawns a tree of objects.

     *

     * @param v Visitor object

     */

    @Override

    public void accept( final Visitor v ) {

        v.visitModuleRequires(this);

    }

    // TODO add more getters and setters?

    /**

     * Dump table entry to file stream in binary format.

     *

     * @param file Output file stream

     * @throws IOException if an I/O Exception occurs in writeShort

     */

    public void dump( final DataOutputStream file ) throws IOException {

        file.writeShort(requiresIndex);

        file.writeShort(requiresFlags);

        file.writeShort(requiresVersionIndex);

    }

    /**

     * @return String representation

     */

    @Override

    public String toString() {

        return "requires(" + requiresIndex + ", " + String.format("%04x", requiresFlags) + ", " + requiresVersionIndex + ")";

    }

    /**

     * @return Resolved string representation

     */

    public String toString( final ConstantPool constant_pool ) {

        final StringBuilder buf = new StringBuilder();

        final String module_name = constant_pool.constantToString(requiresIndex, Const.CONSTANT_Module);

        buf.append(Utility.compactClassName(module_name, false));

        buf.append(", ").append(String.format("%04x", requiresFlags));

        final String version = requiresVersionIndex == 0 ? "0" : constant_pool.getConstantString(requiresVersionIndex, Const.CONSTANT_Utf8);

        buf.append(", ").append(version);

        return buf.toString();

    }

    /**

     * @return deep copy of this object

     */

    public ModuleRequires copy() {

        try {

            return (ModuleRequires) clone();

        } catch (final CloneNotSupportedException e) {

            // TODO should this throw?

        }

        return null;

    }

}