/*

 * Copyright (c) 2009, 2017, 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

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package java.util.zip;

import java.nio.ByteBuffer;

import java.nio.CharBuffer;

import java.nio.charset.Charset;

import java.nio.charset.CharsetDecoder;

import java.nio.charset.CharsetEncoder;

import java.nio.charset.CharacterCodingException;

import java.nio.charset.CodingErrorAction;

import static java.nio.charset.StandardCharsets.UTF_8;

/**

 * Utility class for zipfile name and comment decoding and encoding

 */

class ZipCoder {

    private static final jdk.internal.misc.JavaLangAccess JLA =

        jdk.internal.misc.SharedSecrets.getJavaLangAccess();

    static final class UTF8 extends ZipCoder {

        UTF8(Charset utf8) {

            super(utf8);

        }

        @Override

        boolean isUTF8() {

            return true;

        }

        @Override

        String toString(byte[] ba, int off, int length) {

            return JLA.newStringUTF8NoRepl(ba, off, length);

        }

        @Override

        byte[] getBytes(String s) {

            return JLA.getBytesUTF8NoRepl(s);

        }

    }

    // UTF_8.ArrayEn/Decoder is stateless, so make it singleton.

    private static ZipCoder utf8 = new UTF8(UTF_8);

    public static ZipCoder get(Charset charset) {

        if (charset == UTF_8)

            return utf8;

        return new ZipCoder(charset);

    }

    String toString(byte[] ba, int off, int length) {

        try {

            return decoder().decode(ByteBuffer.wrap(ba, off, length)).toString();

        } catch (CharacterCodingException x) {

            throw new IllegalArgumentException(x);

        }

    }

    String toString(byte[] ba, int length) {

        return toString(ba, 0, length);

    }

    String toString(byte[] ba) {

        return toString(ba, 0, ba.length);

    }

    byte[] getBytes(String s) {

        try {

            ByteBuffer bb = encoder().encode(CharBuffer.wrap(s));

            int pos = bb.position();

            int limit = bb.limit();

            if (bb.hasArray() && pos == 0 && limit == bb.capacity()) {

                return bb.array();

            }

            byte[] bytes = new byte[bb.limit() - bb.position()];

            bb.get(bytes);

            return bytes;

        } catch (CharacterCodingException x) {

            throw new IllegalArgumentException(x);

        }

    }

    // assume invoked only if "this" is not utf8

    byte[] getBytesUTF8(String s) {

        return utf8.getBytes(s);

    }

    String toStringUTF8(byte[] ba, int len) {

        return utf8.toString(ba, 0, len);

    }

    String toStringUTF8(byte[] ba, int off, int len) {

        return utf8.toString(ba, off, len);

    }

    boolean isUTF8() {

        return false;

    }

    private Charset cs;

    private CharsetDecoder dec;

    private CharsetEncoder enc;

    private ZipCoder(Charset cs) {

        this.cs = cs;

    }

    protected CharsetDecoder decoder() {

        if (dec == null) {

            dec = cs.newDecoder()

              .onMalformedInput(CodingErrorAction.REPORT)

              .onUnmappableCharacter(CodingErrorAction.REPORT);

        }

        return dec;

    }

    protected CharsetEncoder encoder() {

        if (enc == null) {

            enc = cs.newEncoder()

              .onMalformedInput(CodingErrorAction.REPORT)

              .onUnmappableCharacter(CodingErrorAction.REPORT);

        }

        return enc;

    }

}