/*
 * Copyright (c) 2003, 2010, 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 sun.nio.cs.ext;

import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CoderResult;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import sun.nio.cs.HistoricallyNamedCharset;
import sun.nio.cs.SingleByte;
import static sun.nio.cs.CharsetMapping.*;

public class PCK
    extends Charset
    implements HistoricallyNamedCharset
{

    public PCK() {
        super("x-PCK", ExtendedCharsets.aliasesFor("x-PCK"));
    }

    public String historicalName() {
        return "PCK";
    }

    public boolean contains(Charset cs) {
        return ((cs.name().equals("US-ASCII"))
                || (cs instanceof JIS_X_0201)
                || (cs instanceof PCK));
    }

    public CharsetDecoder newDecoder() {
        return new Decoder(this);
    }

    public CharsetEncoder newEncoder() {

        // Need to force the replacement byte to 0x3f
        // because JIS_X_0208_Encoder defines its own
        // alternative 2 byte substitution to permit it
        // to exist as a self-standing Encoder

        byte[] replacementBytes = { (byte)0x3f };
        return new Encoder(this).replaceWith(replacementBytes);
    }

    public static class Decoder extends SJIS.Decoder
        implements DelegatableDecoder {

        private static DoubleByte.Decoder dec0208_sol =
            (DoubleByte.Decoder)new JIS_X_0208_Solaris().newDecoder();

        protected Decoder(Charset cs) {
            super(cs);
        }

        public char decodeDouble(int c1, int c2) {
            char c = super.decodeDouble(c1, c2);
            if (c == '\u2014')  // Map JIS X 0208:1983 0x213D <--> U+2015
                return '\u2015';
            if (c != UNMAPPABLE_DECODING)
                return c;
            int adjust = c2 < 0x9F ? 1 : 0;
            int rowOffset = c1 < 0xA0 ? 0x70 : 0xB0;
            int cellOffset = (adjust == 1) ? (c2 > 0x7F ? 0x20 : 0x1F) : 0x7E;
            int b1 = ((c1 - rowOffset) << 1) - adjust;
            int b2 = c2 - cellOffset;
            return dec0208_sol.decodeDouble(b1, b2);
        }
    }

    public static class Encoder extends SJIS.Encoder {

        private static DoubleByte.Encoder jis0208 =
            (DoubleByte.Encoder)new JIS_X_0208_Solaris().newEncoder();

        protected Encoder(Charset cs) {
            super(cs);
        }

        public int encodeChar(char ch) {
            // PCK uses JIS_X_0208:1983 rather than JIS_X_0208:1997
            switch (ch) {
                case '\u2015':
                    return 0x815C;
                case '\u2014':
                    return UNMAPPABLE_ENCODING;
            }
            int bb = super.encodeChar(ch);
            if (bb != UNMAPPABLE_ENCODING)
                return bb;
            bb = jis0208.encodeChar(ch);
            if (bb == UNMAPPABLE_ENCODING || bb <= MAX_SINGLEBYTE)
                return UNMAPPABLE_ENCODING;
            /*
             * This algorithm for converting from JIS to SJIS comes from
             * Ken Lunde's "Understanding Japanese Information Processing",
             * pg 163.
             */
            int c1 = (bb >> 8) & 0xff;
            int c2 = bb & 0xff;
            int rowOffset = c1 < 0x5F ? 0x70 : 0xB0;
            int cellOffset = (c1 % 2 == 1) ? (c2 > 0x5F ? 0x20 : 0x1F) : 0x7E;
            return ((((c1 + 1 ) >> 1) + rowOffset) << 8) | (c2 + cellOffset);
        }
    }
}