/*

 * Copyright (c) 2002, 2012, 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.ByteBuffer;

import java.nio.CharBuffer;

import java.nio.charset.Charset;

import java.nio.charset.CharsetDecoder;

import java.nio.charset.CharsetEncoder;

import java.nio.charset.CoderResult;

import java.nio.charset.CodingErrorAction;

import sun.nio.cs.DelegatableDecoder;

import sun.nio.cs.DoubleByte;

import sun.nio.cs.HistoricallyNamedCharset;

import sun.nio.cs.Surrogate;

import sun.nio.cs.US_ASCII;

import sun.nio.cs.*;

import static sun.nio.cs.CharsetMapping.*;

/*

 * Implementation notes:

 *

 * (1)"Standard based" (ASCII, JIS_X_0201 and JIS_X_0208) ISO2022-JP charset

 * is provided by the base implementation of this class.

 *

 * Three Microsoft ISO2022-JP variants, MS50220, MS50221 and MSISO2022JP

 * are provided via subclasses.

 *

 * (2)MS50220 and MS50221 are assumed to work the same way as Microsoft

 * CP50220 and CP50221's 7-bit implementation works by using CP5022X

 * specific JIS0208 and JIS0212 mapping tables (generated via Microsoft's

 * MultiByteToWideChar/WideCharToMultiByte APIs). The only difference

 * between these 2 classes is that MS50220 does not support singlebyte

 * halfwidth kana (Uff61-Uff9f) shiftin mechanism when "encoding", instead

 * these halfwidth kana characters are converted to their fullwidth JIS0208

 * counterparts.

 *

 * The difference between the standard JIS_X_0208 and JIS_X_0212 mappings

 * and the CP50220/50221 specific are

 *

 * 0208 mapping:

 *              1)0x213d <-> U2015 (compared to U2014)

 *              2)One way mappings for 5 characters below

 *                u2225 (ms) -> 0x2142 <-> u2016 (jis)

 *                uff0d (ms) -> 0x215d <-> u2212 (jis)

 *                uffe0 (ms) -> 0x2171 <-> u00a2 (jis)

 *                uffe1 (ms) -> 0x2172 <-> u00a3 (jis)

 *                uffe2 (ms) -> 0x224c <-> u00ac (jis)

 *                //should consider 0xff5e -> 0x2141 <-> U301c?

 *              3)NEC Row13 0x2d21-0x2d79

 *              4)85-94 ku <-> UE000,UE3AB (includes NEC selected

 *                IBM kanji in 89-92ku)

 *              5)UFF61-UFF9f -> Fullwidth 0208 KANA

 *

 * 0212 mapping:

 *              1)0x2237 <-> UFF5E (Fullwidth Tilde)

 *              2)0x2271 <-> U2116 (Numero Sign)

 *              3)85-94 ku <-> UE3AC - UE757

 *

 * (3)MSISO2022JP uses a JIS0208 mapping generated from MS932DB.b2c

 * and MS932DB.c2b by converting the SJIS codepoints back to their

 * JIS0208 counterparts. With the exception of

 *

 * (a)Codepoints with a resulting JIS0208 codepoints beyond 0x7e00 are

 *    dropped (this includs the IBM Extended Kanji/Non-kanji from 0x9321

 *    to 0x972c)

 * (b)The Unicode codepoints that the IBM Extended Kanji/Non-kanji are

 *    mapped to (in MS932) are mapped back to NEC selected IBM Kanji/

 *    Non-kanji area at 0x7921-0x7c7e.

 *

 * Compared to JIS_X_0208 mapping, this MS932 based mapping has

 * (a)different mappings for 7 JIS codepoints

 *        0x213d <-> U2015

 *        0x2141 <-> UFF5E

 *        0x2142 <-> U2225

 *        0x215d <-> Uff0d

 *        0x2171 <-> Uffe0

 *        0x2172 <-> Uffe1

 *        0x224c <-> Uffe2

 * (b)added one-way c2b mappings for

 *        U00b8 -> 0x2124

 *        U00b7 -> 0x2126

 *        U00af -> 0x2131

 *        U00ab -> 0x2263

 *        U00bb -> 0x2264

 *        U3094 -> 0x2574

 *        U00b5 -> 0x264c

 * (c)NEC Row 13

 * (d)NEC selected IBM extended Kanji/Non-kanji

 *    These codepoints are mapped to the same Unicode codepoints as

 *    the MS932 does, while MS50220/50221 maps them to the Unicode

 *    private area.

 *

 * # There is also an interesting difference when compared to MS5022X

 *   0208 mapping for JIS codepoint "0x2D60", MS932 maps it to U301d

 *   but MS5022X maps it to U301e, obvious MS5022X is wrong, but...

 */

public class ISO2022_JP

    extends Charset

    implements HistoricallyNamedCharset

{

    private static final int ASCII = 0;                 // ESC ( B

    private static final int JISX0201_1976 = 1;         // ESC ( J

    private static final int JISX0208_1978 = 2;         // ESC $ @

    private static final int JISX0208_1983 = 3;         // ESC $ B

    private static final int JISX0212_1990 = 4;         // ESC $ ( D

    private static final int JISX0201_1976_KANA = 5;    // ESC ( I

    private static final int SHIFTOUT = 6;

    private static final int ESC = 0x1b;

    private static final int SO = 0x0e;

    private static final int SI = 0x0f;

    public ISO2022_JP() {

        super("ISO-2022-JP",

              ExtendedCharsets.aliasesFor("ISO-2022-JP"));

    }

    protected ISO2022_JP(String canonicalName,

                         String[] aliases) {

        super(canonicalName, aliases);

    }

    public String historicalName() {

        return "ISO2022JP";

    }

    public boolean contains(Charset cs) {

        return ((cs instanceof JIS_X_0201)

                || (cs instanceof US_ASCII)

                || (cs instanceof JIS_X_0208)

                || (cs instanceof ISO2022_JP));

    }

    public CharsetDecoder newDecoder() {

        return new Decoder(this);

    }

    public CharsetEncoder newEncoder() {

        return new Encoder(this);

    }

    protected boolean doSBKANA() {

        return true;

    }

    static class Decoder extends CharsetDecoder

        implements DelegatableDecoder {

        final static DoubleByte.Decoder DEC0208 =

            (DoubleByte.Decoder)new JIS_X_0208().newDecoder();

        private int currentState;

        private int previousState;

        private DoubleByte.Decoder dec0208;

        private DoubleByte.Decoder dec0212;

        private Decoder(Charset cs) {

            this(cs, DEC0208, null);

        }

        protected Decoder(Charset cs,

                          DoubleByte.Decoder dec0208,

                          DoubleByte.Decoder dec0212) {

            super(cs, 0.5f, 1.0f);

            this.dec0208 = dec0208;

            this.dec0212 = dec0212;

            currentState = ASCII;

            previousState = ASCII;

        }

        public void implReset() {

            currentState = ASCII;

            previousState = ASCII;

        }

        private CoderResult decodeArrayLoop(ByteBuffer src,

                                            CharBuffer dst)

        {

            int inputSize = 0;

            int b1 = 0, b2 = 0, b3 = 0, b4 = 0;

            char c = UNMAPPABLE_DECODING;

            byte[] sa = src.array();

            int sp = src.arrayOffset() + src.position();

            int sl = src.arrayOffset() + src.limit();

            assert (sp <= sl);

            sp = (sp <= sl ? sp : sl);

            char[] da = dst.array();

            int dp = dst.arrayOffset() + dst.position();

            int dl = dst.arrayOffset() + dst.limit();

            assert (dp <= dl);

            dp = (dp <= dl ? dp : dl);

            try {

                while (sp < sl) {

                    b1 = sa[sp] & 0xff;

                    inputSize = 1;

                    if ((b1 & 0x80) != 0) {

                        return CoderResult.malformedForLength(inputSize);

                    }

                    if (b1 == ESC || b1 == SO || b1 == SI) {

                        if (b1 == ESC) {

                            if (sp + inputSize + 2 > sl)

                                return CoderResult.UNDERFLOW;

                            b2 = sa[sp + inputSize++] & 0xff;

                            if (b2 == '(') {

                                b3 = sa[sp + inputSize++] & 0xff;

                                if (b3 == 'B'){

                                    currentState = ASCII;

                                } else if (b3 == 'J'){

                                    currentState = JISX0201_1976;

                                } else if (b3 == 'I'){

                                    currentState = JISX0201_1976_KANA;

                                } else {

                                    return CoderResult.malformedForLength(inputSize);

                                }

                            } else if (b2 == '$'){

                                b3 = sa[sp + inputSize++] & 0xff;

                                if (b3 == '@'){

                                    currentState = JISX0208_1978;

                                } else if (b3 == 'B'){

                                    currentState = JISX0208_1983;

                                } else if (b3 == '(' && dec0212 != null) {

                                    if (sp + inputSize + 1 > sl)

                                        return CoderResult.UNDERFLOW;

                                    b4 = sa[sp + inputSize++] & 0xff;

                                    if (b4 == 'D') {

                                        currentState = JISX0212_1990;

                                    } else {

                                        return CoderResult.malformedForLength(inputSize);

                                    }

                                } else {

                                    return CoderResult.malformedForLength(inputSize);

                                }

                            } else {

                                return CoderResult.malformedForLength(inputSize);

                            }

                        } else if (b1 == SO) {

                            previousState = currentState;

                            currentState = SHIFTOUT;

                        } else if (b1 == SI) {

                            currentState = previousState;

                        }

                        sp += inputSize;

                        continue;

                    }

                    if (dp + 1 > dl)

                        return CoderResult.OVERFLOW;

                    switch (currentState){

                        case ASCII:

                            da[dp++] = (char)(b1 & 0xff);

                            break;

                        case JISX0201_1976:

                          switch (b1) {

                              case 0x5c:  // Yen/tilde substitution

                                da[dp++] = '\u00a5';

                                break;

                              case 0x7e:

                                da[dp++] = '\u203e';

                                break;

                              default:

                                da[dp++] = (char)b1;

                                break;

                            }

                            break;

                        case JISX0208_1978:

                        case JISX0208_1983:

                            if (sp + inputSize + 1 > sl)

                                return CoderResult.UNDERFLOW;

                            b2 = sa[sp + inputSize++] & 0xff;

                            c = dec0208.decodeDouble(b1,b2);

                            if (c == UNMAPPABLE_DECODING)

                                return CoderResult.unmappableForLength(inputSize);

                            da[dp++] = c;

                            break;

                        case JISX0212_1990:

                            if (sp + inputSize + 1 > sl)

                                return CoderResult.UNDERFLOW;

                            b2 = sa[sp + inputSize++] & 0xff;

                            c = dec0212.decodeDouble(b1,b2);

                            if (c == UNMAPPABLE_DECODING)

                                return CoderResult.unmappableForLength(inputSize);

                            da[dp++] = c;

                            break;

                        case JISX0201_1976_KANA:

                        case SHIFTOUT:

                            if (b1 > 0x5f) {

                                return CoderResult.malformedForLength(inputSize);

                            }

                            da[dp++] = (char)(b1 + 0xff40);

                            break;

                    }

                    sp += inputSize;

                }

                return CoderResult.UNDERFLOW;

            } finally {

                src.position(sp - src.arrayOffset());

                dst.position(dp - dst.arrayOffset());

            }

        }

        private CoderResult decodeBufferLoop(ByteBuffer src,

                                             CharBuffer dst)

        {

            int mark = src.position();

            int b1 = 0, b2 = 0, b3 = 0, b4=0;

            char c = UNMAPPABLE_DECODING;

            int inputSize = 0;

            try {

                while (src.hasRemaining()) {

                    b1 = src.get() & 0xff;

                    inputSize = 1;

                    if ((b1 & 0x80) != 0)

                        return CoderResult.malformedForLength(inputSize);

                    if (b1 == ESC || b1 == SO || b1 == SI) {

                        if (b1 == ESC) {  // ESC

                            if (src.remaining() < 2)

                                return CoderResult.UNDERFLOW;

                            b2 = src.get() & 0xff;

                            inputSize++;

                            if (b2 == '(') {

                                b3 = src.get() & 0xff;

                                inputSize++;

                                if (b3 == 'B'){

                                    currentState = ASCII;

                                } else if (b3 == 'J'){

                                    currentState = JISX0201_1976;

                                } else if (b3 == 'I'){

                                    currentState = JISX0201_1976_KANA;

                                } else {

                                   return CoderResult.malformedForLength(inputSize);

                                }

                            } else if (b2 == '$'){

                                b3 = src.get() & 0xff;

                                inputSize++;

                                if (b3 == '@'){

                                    currentState = JISX0208_1978;

                                } else if (b3 == 'B'){

                                    currentState = JISX0208_1983;

                                } else if (b3 == '(' && dec0212 != null) {

                                    if (!src.hasRemaining())

                                        return CoderResult.UNDERFLOW;

                                    b4 = src.get() & 0xff;

                                    inputSize++;

                                    if (b4 == 'D') {

                                        currentState = JISX0212_1990;

                                    } else {

                                        return CoderResult.malformedForLength(inputSize);

                                    }

                                } else {

                                    return CoderResult.malformedForLength(inputSize);

                                }

                            } else {

                                return CoderResult.malformedForLength(inputSize);

                            }

                        } else if (b1 == SO) {

                            previousState = currentState;

                            currentState = SHIFTOUT;

                        } else if (b1 == SI) { // shift back in

                            currentState = previousState;

                        }

                        mark += inputSize;

                        continue;

                    }

                    if (!dst.hasRemaining())

                        return CoderResult.OVERFLOW;

                    switch (currentState){

                        case ASCII:

                            dst.put((char)(b1 & 0xff));

                            break;

                        case JISX0201_1976:

                            switch (b1) {

                              case 0x5c:  // Yen/tilde substitution

                                dst.put('\u00a5');

                                break;

                              case 0x7e:

                                dst.put('\u203e');

                                break;

                              default:

                                dst.put((char)b1);

                                break;

                            }

                            break;

                        case JISX0208_1978:

                        case JISX0208_1983:

                            if (!src.hasRemaining())

                                return CoderResult.UNDERFLOW;

                            b2 = src.get() & 0xff;

                            inputSize++;

                            c = dec0208.decodeDouble(b1,b2);

                            if (c == UNMAPPABLE_DECODING)

                                return CoderResult.unmappableForLength(inputSize);

                            dst.put(c);

                            break;

                        case JISX0212_1990:

                            if (!src.hasRemaining())

                                return CoderResult.UNDERFLOW;

                            b2 = src.get() & 0xff;

                            inputSize++;

                            c = dec0212.decodeDouble(b1,b2);

                            if (c == UNMAPPABLE_DECODING)

                                return CoderResult.unmappableForLength(inputSize);

                            dst.put(c);

                            break;

                        case JISX0201_1976_KANA:

                        case SHIFTOUT:

                            if (b1 > 0x5f) {

                                return CoderResult.malformedForLength(inputSize);

                            }

                            dst.put((char)(b1 + 0xff40));

                            break;

                    }

                    mark += inputSize;

                }

                return CoderResult.UNDERFLOW;

            } finally {

                src.position(mark);

            }

        }

        // Make some protected methods public for use by JISAutoDetect

        public CoderResult decodeLoop(ByteBuffer src, CharBuffer dst) {

            if (src.hasArray() && dst.hasArray())

                return decodeArrayLoop(src, dst);

            else

                return decodeBufferLoop(src, dst);

        }

        public CoderResult implFlush(CharBuffer out) {

            return super.implFlush(out);

        }

    }

    static class Encoder extends CharsetEncoder {

        final static DoubleByte.Encoder ENC0208 =

            (DoubleByte.Encoder)new JIS_X_0208().newEncoder();

        private static byte[] repl = { (byte)0x21, (byte)0x29 };

        private int currentMode = ASCII;

        private int replaceMode = JISX0208_1983;

        private DoubleByte.Encoder enc0208;

        private DoubleByte.Encoder enc0212;

        private boolean doSBKANA;

        private Encoder(Charset cs) {

            this(cs, ENC0208, null, true);

        }

        Encoder(Charset cs,

                DoubleByte.Encoder enc0208,

                DoubleByte.Encoder enc0212,

                boolean doSBKANA) {

            super(cs, 4.0f, (enc0212 != null)? 9.0f : 8.0f, repl);

            this.enc0208 = enc0208;

            this.enc0212 = enc0212;

            this.doSBKANA = doSBKANA;

        }

        protected int encodeSingle(char inputChar) {

            return -1;

        }

        protected void implReset() {

            currentMode = ASCII;

        }

        protected void implReplaceWith(byte[] newReplacement) {

            /* It's almost impossible to decide which charset they belong

               to. The best thing we can do here is to "guess" based on

               the length of newReplacement.

             */

            if (newReplacement.length == 1) {

                replaceMode = ASCII;

            } else if (newReplacement.length == 2) {

                replaceMode = JISX0208_1983;

            }

        }

        protected CoderResult implFlush(ByteBuffer out) {

            if (currentMode != ASCII) {

                if (out.remaining() < 3)

                    return CoderResult.OVERFLOW;

                out.put((byte)0x1b);

                out.put((byte)0x28);

                out.put((byte)0x42);

                currentMode = ASCII;

            }

            return CoderResult.UNDERFLOW;

        }

        public boolean canEncode(char c) {