/*

 * Copyright (c) 2008, 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.CharsetEncoder;

import java.nio.charset.CharsetDecoder;

import java.nio.charset.CoderResult;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.util.Arrays;

import sun.nio.cs.CharsetMapping;

/*

 *  5 types of entry in SJIS_X_0213/Unicode mapping table

 *

 *  (1)Single-Byte

 *     JIS_X_0213 does not define single-byte character itself, the

 *     JIS_X_0201 entries are added in for sjis implementation.

 *

 *  (2)Double-Byte SJIS <-> BMP Unicode

 *     ex: 0x8140 U+3000    # IDEOGRAPHIC SPACE

 *

 *  (3)Double-Byte SJIS <-> Supplementary

 *     ex: 0xFCF0 U+2A61A   # <cjk> [2000] [Unicode3.1]

 *

 *  (4)Double-Byte SJIS <-> Composite

 *   ex: 0x83F6 U+31F7+309A # [2000]

 *

 *  (5)"Windows-only" special mapping entries

 *     are handled by MS932_0213.

 */

public class SJIS_0213 extends Charset {

    public SJIS_0213() {

        super("x-SJIS_0213", ExtendedCharsets.aliasesFor("SJIS_0213"));

    }

    public boolean contains(Charset cs) {

        return ((cs.name().equals("US-ASCII"))

                || (cs instanceof SJIS)

                || (cs instanceof SJIS_0213));

    }

    public CharsetDecoder newDecoder() {

        return new Decoder(this);

    }

    public CharsetEncoder newEncoder() {

        return new Encoder(this);

    }

    static CharsetMapping mapping = AccessController.doPrivileged(

        new PrivilegedAction<CharsetMapping>() {

            public CharsetMapping run() {

                return CharsetMapping.get(SJIS_0213.class.getResourceAsStream("sjis0213.dat"));

            }

        });

    protected static class Decoder extends CharsetDecoder {

        protected static final char UNMAPPABLE = CharsetMapping.UNMAPPABLE_DECODING;

        protected Decoder(Charset cs) {

            super(cs, 0.5f, 1.0f);

        }

        private CoderResult decodeArrayLoop(ByteBuffer src, CharBuffer dst) {

            byte[] sa = src.array();

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

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

            char[] da = dst.array();

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

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

            try {

                while (sp < sl) {

                    int b1 = sa[sp] & 0xff;

                    char c = decodeSingle(b1);

                    int inSize = 1, outSize = 1;

                    char[] cc = null;

                    if (c == UNMAPPABLE) {

                        if (sl - sp < 2)

                            return CoderResult.UNDERFLOW;

                        int b2 = sa[sp + 1] & 0xff;

                        c = decodeDouble(b1, b2);

                        inSize++;

                        if (c == UNMAPPABLE) {

                            cc = decodeDoubleEx(b1, b2);

                            if (cc == null) {

                                if (decodeSingle(b2) == UNMAPPABLE)

                                    return CoderResult.unmappableForLength(2);

                                else

                                    return CoderResult.unmappableForLength(1);

                            }

                            outSize++;

                        }

                    }

                    if (dl - dp < outSize)

                        return CoderResult.OVERFLOW;

                    if (outSize == 2) {

                        da[dp++] = cc[0];

                        da[dp++] = cc[1];

                    } else {

                        da[dp++] = c;

                    }

                    sp += inSize;

                }

                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();

            try {

                while (src.hasRemaining()) {

                    char[] cc = null;

                    int b1 = src.get() & 0xff;

                    char c = decodeSingle(b1);

                    int inSize = 1, outSize = 1;

                    if (c == UNMAPPABLE) {

                        if (src.remaining() < 1)

                            return CoderResult.UNDERFLOW;

                        int b2 = src.get() & 0xff;

                        inSize++;

                        c = decodeDouble(b1, b2);

                        if (c == UNMAPPABLE) {

                            cc = decodeDoubleEx(b1, b2);

                            if (cc == null) {

                                if (decodeSingle(b2) == UNMAPPABLE)

                                    return CoderResult.unmappableForLength(2);

                                else

                                    return CoderResult.unmappableForLength(1);

                            }

                            outSize++;

                        }

                    }

                    if (dst.remaining() < outSize)

                        return CoderResult.OVERFLOW;

                    if (outSize == 2) {

                        dst.put(cc[0]);

                        dst.put(cc[1]);

                    } else {

                        dst.put(c);

                    }

                    mark += inSize;

                }

                return CoderResult.UNDERFLOW;

            } finally {

                src.position(mark);

            }

        }

        protected CoderResult decodeLoop(ByteBuffer src, CharBuffer dst) {

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

                return decodeArrayLoop(src, dst);

            else

                return decodeBufferLoop(src, dst);

        }

        protected char decodeSingle(int b) {

            return mapping.decodeSingle(b);

        }

        protected char decodeDouble(int b1, int b2) {

            return mapping.decodeDouble(b1, b2);

        }

        private char[] cc = new char[2];

        private CharsetMapping.Entry comp = new CharsetMapping.Entry();

        protected char[] decodeDoubleEx(int b1, int b2) {

            int db = (b1 << 8) | b2;

            if (mapping.decodeSurrogate(db, cc) != null)

                return cc;

            comp.bs = db;

            if (mapping.decodeComposite(comp, cc) != null)

                return cc;

            return null;

        }

    }

    protected static class Encoder extends CharsetEncoder {

        protected static final int UNMAPPABLE = CharsetMapping.UNMAPPABLE_ENCODING;

        protected static final int MAX_SINGLEBYTE = 0xff;

        protected Encoder(Charset cs) {

            super(cs, 2.0f, 2.0f);

        }

        public boolean canEncode(char c) {

            return (encodeChar(c) != UNMAPPABLE);

        }

        protected int encodeChar(char ch) {

            return mapping.encodeChar(ch);

        }

        protected int encodeSurrogate(char hi, char lo) {

            return mapping.encodeSurrogate(hi, lo);

        }

        private CharsetMapping.Entry comp = new CharsetMapping.Entry();

        protected int encodeComposite(char base, char cc) {

            comp.cp = base;

            comp.cp2 = cc;

            return mapping.encodeComposite(comp);

        }

        protected boolean isCompositeBase(char ch) {

            comp.cp = ch;

            return mapping.isCompositeBase(comp);

        }

        // Unlike surrogate pair, the base character of a base+cc composite

        // itself is a legal codepoint in 0213, if we simply return UNDERFLOW

        // when a base candidate is the last input char in the CharBuffer, like

        // what we do for the surrogte pair, encoding will fail if this base

        // character is indeed the last character of the input char sequence.

        // Keep this base candidate in "leftoverBase" so we can flush it out

        // at the end of the encoding circle.

        char leftoverBase = 0;

        protected CoderResult encodeArrayLoop(CharBuffer src, ByteBuffer dst) {

            char[] sa = src.array();

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

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

            byte[] da = dst.array();

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

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

            try {

                while (sp < sl) {

                    int db;

                    char c = sa[sp];

                    if (leftoverBase != 0) {

                        boolean isComp = false;

                        db = encodeComposite(leftoverBase, c);

                        if (db == UNMAPPABLE)

                            db = encodeChar(leftoverBase);

                        else

                            isComp = true;

                        if (dl - dp < 2)

                            return CoderResult.OVERFLOW;

                        da[dp++] = (byte)(db >> 8);

                        da[dp++] = (byte)db;

                        leftoverBase = 0;

                        if (isComp) {

                            sp++;

                            continue;

                        }

                    }

                    if (isCompositeBase(c)) {

                        leftoverBase = c;

                    } else {

                        db = encodeChar(c);

                        if (db <= MAX_SINGLEBYTE) {      // SingleByte

                            if (dl <= dp)

                                return CoderResult.OVERFLOW;

                            da[dp++] = (byte)db;

                        } else if (db != UNMAPPABLE) {   // DoubleByte

                            if (dl - dp < 2)

                                return CoderResult.OVERFLOW;

                            da[dp++] = (byte)(db >> 8);

                            da[dp++] = (byte)db;

                        } else if (Character.isHighSurrogate(c)) {

                            if ((sp + 1) == sl)

                                return CoderResult.UNDERFLOW;

                            char c2 = sa[sp + 1];

                            if (!Character.isLowSurrogate(c2))

                                return CoderResult.malformedForLength(1);

                            db = encodeSurrogate(c, c2);

                            if (db == UNMAPPABLE)

                                return CoderResult.unmappableForLength(2);

                            if (dl - dp < 2)

                                return CoderResult.OVERFLOW;

                            da[dp++] = (byte)(db >> 8);

                            da[dp++] = (byte)db;

                            sp++;

                        } else if (Character.isLowSurrogate(c)) {

                            return CoderResult.malformedForLength(1);

                        } else {

                            return CoderResult.unmappableForLength(1);

                        }

                    }

                    sp++;

                }

                return CoderResult.UNDERFLOW;

            } finally {

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

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

            }

        }

        protected CoderResult encodeBufferLoop(CharBuffer src, ByteBuffer dst) {

            int mark = src.position();

            try {

                while (src.hasRemaining()) {

                    int db;

                    char c = src.get();

                    if (leftoverBase != 0) {

                        boolean isComp = false;

                        db = encodeComposite(leftoverBase, c);

                        if (db == UNMAPPABLE)

                            db = encodeChar(leftoverBase);

                        else

                            isComp = true;

                        if (dst.remaining() < 2)

                            return CoderResult.OVERFLOW;

                        dst.put((byte)(db >> 8));

                        dst.put((byte)(db));

                        leftoverBase = 0;

                        if (isComp) {

                            mark++;

                            continue;

                        }

                    }

                    if (isCompositeBase(c)) {

                        leftoverBase = c;

                    } else {

                        db = encodeChar(c);

                        if (db <= MAX_SINGLEBYTE) {    // Single-byte

                            if (dst.remaining() < 1)

                                return CoderResult.OVERFLOW;

                            dst.put((byte)db);

                        } else if (db != UNMAPPABLE) {   // DoubleByte

                            if (dst.remaining() < 2)

                                return CoderResult.OVERFLOW;

                            dst.put((byte)(db >> 8));

                            dst.put((byte)(db));

                        } else if (Character.isHighSurrogate(c)) {

                            if (!src.hasRemaining())     // Surrogates

                                return CoderResult.UNDERFLOW;

                            char c2 = src.get();

                            if (!Character.isLowSurrogate(c2))

                                return CoderResult.malformedForLength(1);

                            db = encodeSurrogate(c, c2);

                            if (db == UNMAPPABLE)

                                return CoderResult.unmappableForLength(2);

                            if (dst.remaining() < 2)

                                return CoderResult.OVERFLOW;

                            dst.put((byte)(db >> 8));

                            dst.put((byte)(db));

                            mark++;

                        } else if (Character.isLowSurrogate(c)) {

                            return CoderResult.malformedForLength(1);

                        } else {

                            return CoderResult.unmappableForLength(1);

                        }

                    }

                    mark++;

                }

                return CoderResult.UNDERFLOW;

            } finally {

                src.position(mark);

            }

        }

        protected CoderResult encodeLoop(CharBuffer src, ByteBuffer dst) {

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

                return encodeArrayLoop(src, dst);

            else

                return encodeBufferLoop(src, dst);

        }

        protected CoderResult implFlush(ByteBuffer dst) {

            if (leftoverBase > 0) {

                if (dst.remaining() < 2)

                    return CoderResult.OVERFLOW;

                int db = encodeChar(leftoverBase);

                dst.put((byte)(db >> 8));

                dst.put((byte)(db));

                leftoverBase = 0;

            }

            return CoderResult.UNDERFLOW;

        }

        protected void implReset() {

            leftoverBase = 0;

        }

    }

}