/*
 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.tools.classfile;

import java.io.IOException;

See JVMS, section 4.8.15.
 
This is NOT part of any supported API.
 If you write code that depends on this, you do so at your own risk.
 This code and its internal interfaces are subject to change or
 deletion without notice.
/**
 * See JVMS, section 4.8.15.
 *
 *  <p><b>This is NOT part of any supported API.
 *  If you write code that depends on this, you do so at your own risk.
 *  This code and its internal interfaces are subject to change or
 *  deletion without notice.</b>
 */
public class ModuleHashes_attribute extends Attribute {
    ModuleHashes_attribute(ClassReader cr, int name_index, int length) throws IOException {
        super(name_index, length);
        algorithm_index = cr.readUnsignedShort();
        hashes_table_length = cr.readUnsignedShort();
        hashes_table = new Entry[hashes_table_length];
        for (int i = 0; i < hashes_table_length; i++)
            hashes_table[i] = new Entry(cr);
    }

    public ModuleHashes_attribute(ConstantPool constant_pool, int algorithm_index, Entry[] hashes_table)
            throws ConstantPoolException {
        this(constant_pool.getUTF8Index(Attribute.ModuleHashes), algorithm_index, hashes_table);
    }

    public ModuleHashes_attribute(int name_index, int algorithm_index, Entry[] hashes_table) {
        super(name_index, 2 + 2 + length(hashes_table));
        this.algorithm_index = algorithm_index;
        this.hashes_table_length = hashes_table.length;
        this.hashes_table = hashes_table;
    }

    @Override
    public <R, D> R accept(Visitor<R, D> visitor, D data) {
        return visitor.visitModuleHashes(this, data);
    }

    private static int length(Entry[] hashes_table) {
        int len = 0;
        for (Entry e: hashes_table) {
            len += e.length();
        }
        return len;
    }

    public final int algorithm_index;
    public final int hashes_table_length;
    public final Entry[] hashes_table;

    public static class Entry {
        Entry(ClassReader cr) throws IOException {
            module_name_index = cr.readUnsignedShort();
            int hash_length = cr.readUnsignedShort();
            hash = new byte[hash_length];
            for (int i=0; i<hash_length; i++) {
                hash[i] = (byte) cr.readUnsignedByte();
            }
        }

        public int length() {
            return 4 + hash.length;
        }

        public final int module_name_index;
        public final byte[] hash;
    }

}