/*

 * Copyright (c) 2010, 2013, 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 sun.nio.cs;

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.util.Arrays;

import sun.nio.cs.DoubleByte;

import sun.nio.cs.Surrogate;

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

public class HKSCS {

    public static class Decoder extends DoubleByte.Decoder {

        static int b2Min = 0x40;

        static int b2Max = 0xfe;

        private char[][] b2cBmp;

        private char[][] b2cSupp;

        private DoubleByte.Decoder big5Dec;

        protected Decoder(Charset cs,

                          DoubleByte.Decoder big5Dec,

                          char[][] b2cBmp, char[][] b2cSupp)

        {

            // super(cs, 0.5f, 1.0f);

            // need to extends DoubleByte.Decoder so the

            // sun.io can use it. this implementation

            super(cs, 0.5f, 1.0f, null, null, 0, 0, true);

            this.big5Dec = big5Dec;

            this.b2cBmp = b2cBmp;

            this.b2cSupp = b2cSupp;

        }

        public char decodeSingle(int b) {

            return big5Dec.decodeSingle(b);

        }

        public char decodeBig5(int b1, int b2) {

            return big5Dec.decodeDouble(b1, b2);

        }

        public char decodeDouble(int b1, int b2) {

            return b2cBmp[b1][b2 - b2Min];

        }

        public char decodeDoubleEx(int b1, int b2) {

            /* if the b2cSupp is null, the subclass need

               to override the methold

            if (b2cSupp == null)

                return UNMAPPABLE_DECODING;

             */

            return b2cSupp[b1][b2 - b2Min];

        }

        protected 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_DECODING) {

                        if (sl - sp < 2)

                            return CoderResult.UNDERFLOW;

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

                        inSize++;

                        if (b2 < b2Min || b2 > b2Max)

                            return CoderResult.unmappableForLength(2);

                        c = decodeDouble(b1, b2);           //bmp

                        if (c == UNMAPPABLE_DECODING) {

                            c = decodeDoubleEx(b1, b2);     //supp

                            if (c == UNMAPPABLE_DECODING) {

                                c = decodeBig5(b1, b2);     //big5

                                if (c == UNMAPPABLE_DECODING)

                                    return CoderResult.unmappableForLength(2);

                            } else {

                                // supplementary character in u+2xxxx area

                                outSize = 2;

                            }

                        }

                    }

                    if (dl - dp < outSize)

                        return CoderResult.OVERFLOW;

                    if (outSize == 2) {

                        // supplementary characters

                        da[dp++] = Surrogate.high(0x20000 + c);

                        da[dp++] = Surrogate.low(0x20000 + c);

                    } else {

                        da[dp++] = c;

                    }

                    sp += inSize;

                }

                return CoderResult.UNDERFLOW;

            } finally {

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

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

            }

        }

        protected CoderResult decodeBufferLoop(ByteBuffer src, CharBuffer dst) {

            int mark = src.position();

            try {

                while (src.hasRemaining()) {

                    char[] cc = null;

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

                    int inSize = 1, outSize = 1;

                    char c = decodeSingle(b1);

                    if (c == UNMAPPABLE_DECODING) {

                        if (src.remaining() < 1)

                            return CoderResult.UNDERFLOW;

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

                        inSize++;

                        if (b2 < b2Min || b2 > b2Max)

                            return CoderResult.unmappableForLength(2);

                        c = decodeDouble(b1, b2);           //bmp

                        if (c == UNMAPPABLE_DECODING) {

                            c = decodeDoubleEx(b1, b2);     //supp

                            if (c == UNMAPPABLE_DECODING) {

                                c = decodeBig5(b1, b2);     //big5

                                if (c == UNMAPPABLE_DECODING)

                                    return CoderResult.unmappableForLength(2);

                            } else {

                                outSize = 2;

                            }

                        }

                    }

                    if (dst.remaining() < outSize)

                        return CoderResult.OVERFLOW;

                    if (outSize == 2) {

                        dst.put(Surrogate.high(0x20000 + c));

                        dst.put(Surrogate.low(0x20000 + c));

                    } else {

                        dst.put(c);

                    }

                    mark += inSize;

                }

                return CoderResult.UNDERFLOW;

            } finally {

                src.position(mark);

            }

        }

        public int decode(byte[] src, int sp, int len, char[] dst) {

            int dp = 0;

            int sl = sp + len;

            char repl = replacement().charAt(0);

            while (sp < sl) {

                int b1 = src[sp++] & 0xff;

                char c = decodeSingle(b1);

                if (c == UNMAPPABLE_DECODING) {

                    if (sl == sp) {

                        c = repl;

                    } else {

                        int b2 = src[sp++] & 0xff;

                        if (b2 < b2Min || b2 > b2Max) {

                            c = repl;

                        } else if ((c = decodeDouble(b1, b2)) == UNMAPPABLE_DECODING) {

                            c = decodeDoubleEx(b1, b2);     //supp

                            if (c == UNMAPPABLE_DECODING) {

                                c = decodeBig5(b1, b2);     //big5

                                if (c == UNMAPPABLE_DECODING)

                                    c = repl;

                            } else {

                                // supplementary character in u+2xxxx area

                                dst[dp++] = Surrogate.high(0x20000 + c);

                                dst[dp++] = Surrogate.low(0x20000 + c);

                                continue;

                            }

                        }

                    }

                }

                dst[dp++] = c;

            }

            return dp;

        }

        public CoderResult decodeLoop(ByteBuffer src, CharBuffer dst) {

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

                return decodeArrayLoop(src, dst);

            else

                return decodeBufferLoop(src, dst);

        }

        public static void initb2c(char[][]b2c, String[] b2cStr)

        {

            for (int i = 0; i < b2cStr.length; i++) {

                if (b2cStr[i] == null)

                    b2c[i] = DoubleByte.B2C_UNMAPPABLE;

                else

                    b2c[i] = b2cStr[i].toCharArray();

            }

        }

    }

    public static class Encoder extends DoubleByte.Encoder {

        private DoubleByte.Encoder big5Enc;

        private char[][] c2bBmp;

        private char[][] c2bSupp;

        protected Encoder(Charset cs,

                          DoubleByte.Encoder big5Enc,

                          char[][] c2bBmp,

                          char[][] c2bSupp)

        {

            super(cs, null, null, true);

            this.big5Enc = big5Enc;

            this.c2bBmp = c2bBmp;

            this.c2bSupp = c2bSupp;

        }

        public int encodeBig5(char ch) {

            return big5Enc.encodeChar(ch);

        }

        public int encodeChar(char ch) {

            int bb = c2bBmp[ch >> 8][ch & 0xff];

            if (bb == UNMAPPABLE_ENCODING)

                return encodeBig5(ch);

            return bb;

        }

        public int encodeSupp(int cp) {

            if ((cp & 0xf0000) != 0x20000)

                return UNMAPPABLE_ENCODING;

            return c2bSupp[(cp >> 8) & 0xff][cp & 0xff];

        }

        public boolean canEncode(char c) {

            return encodeChar(c) != UNMAPPABLE_ENCODING;

        }

        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) {

                    char c = sa[sp];

                    int inSize = 1;

                    int bb = encodeChar(c);

                    if (bb == UNMAPPABLE_ENCODING) {

                        if (Character.isSurrogate(c)) {

                            int cp;

                            if ((cp = sgp().parse(c, sa, sp, sl)) < 0)

                                return sgp.error();

                            bb = encodeSupp(cp);

                            if (bb == UNMAPPABLE_ENCODING)

                                return CoderResult.unmappableForLength(2);

                            inSize = 2;

                        } else {

                            return CoderResult.unmappableForLength(1);

                        }

                    }

                    if (bb > MAX_SINGLEBYTE) {    // DoubleByte

                        if (dl - dp < 2)

                            return CoderResult.OVERFLOW;

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

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

                    } else {                      // SingleByte

                        if (dl - dp < 1)

                            return CoderResult.OVERFLOW;

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

                    }

                    sp += inSize;

                }

                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 inSize = 1;

                    char c = src.get();

                    int bb = encodeChar(c);

                    if (bb == UNMAPPABLE_ENCODING) {

                        if (Character.isSurrogate(c)) {

                            int cp;

                            if ((cp = sgp().parse(c, src)) < 0)

                                return sgp.error();

                            bb = encodeSupp(cp);

                            if (bb == UNMAPPABLE_ENCODING)

                                return CoderResult.unmappableForLength(2);

                            inSize = 2;

                        } else {

                            return CoderResult.unmappableForLength(1);

                        }

                    }

                    if (bb > MAX_SINGLEBYTE) {  // DoubleByte

                        if (dst.remaining() < 2)

                            return CoderResult.OVERFLOW;

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

                        dst.put((byte)(bb));

                    } else {

                        if (dst.remaining() < 1)

                        return CoderResult.OVERFLOW;

                        dst.put((byte)bb);

                    }

                    mark += inSize;

                }

                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);

        }

        private byte[] repl = replacement();

        protected void implReplaceWith(byte[] newReplacement) {

            repl = newReplacement;

        }

        public int encode(char[] src, int sp, int len, byte[] dst) {

            int dp = 0;

            int sl = sp + len;

            while (sp < sl) {

                char c = src[sp++];

                int bb = encodeChar(c);

                if (bb == UNMAPPABLE_ENCODING) {

                    if (!Character.isHighSurrogate(c) || sp == sl ||

                        !Character.isLowSurrogate(src[sp]) ||

                        (bb = encodeSupp(Character.toCodePoint(c, src[sp++])))

                        == UNMAPPABLE_ENCODING) {

                        dst[dp++] = repl[0];

                        if (repl.length > 1)

                            dst[dp++] = repl[1];

                        continue;

                    }

                }

                if (bb > MAX_SINGLEBYTE) {        // DoubleByte

                    dst[dp++] = (byte)(bb >> 8);

                    dst[dp++] = (byte)bb;

                } else {                          // SingleByte

                    dst[dp++] = (byte)bb;

                }

            }

            return dp;

        }

        public int encodeFromUTF16(byte[] src, int sp, int len, byte[] dst) {

            int dp = 0;

            int sl = sp + len;

            int dl = dst.length;

            while (sp < sl) {

                char c = StringUTF16.getChar(src, sp++);

                int bb = encodeChar(c);

                if (bb == UNMAPPABLE_ENCODING) {

                    if (!Character.isHighSurrogate(c) || sp == sl ||

                        !Character.isLowSurrogate(StringUTF16.getChar(src,sp)) ||

                        (bb = encodeSupp(Character.toCodePoint(c, StringUTF16.getChar(src, sp++))))

                        == UNMAPPABLE_ENCODING) {

                        dst[dp++] = repl[0];

                        if (repl.length > 1)

                            dst[dp++] = repl[1];

                        continue;

                    }

                }

                if (bb > MAX_SINGLEBYTE) { // DoubleByte

                    dst[dp++] = (byte)(bb >> 8);

                    dst[dp++] = (byte)bb;

                } else {                   // SingleByte

                    dst[dp++] = (byte)bb;

                }

            }

            return dp;

        }

        static char[] C2B_UNMAPPABLE = new char[0x100];

        static {

            Arrays.fill(C2B_UNMAPPABLE, (char)UNMAPPABLE_ENCODING);

        }

        public static void initc2b(char[][] c2b, String[] b2cStr, String pua) {

            // init c2b/c2bSupp from b2cStr and supp

            int b2Min = 0x40;

            Arrays.fill(c2b, C2B_UNMAPPABLE);

            for (int b1 = 0; b1 < 0x100; b1++) {

                String s = b2cStr[b1];

                if (s == null)

                    continue;

                for (int i = 0; i < s.length(); i++) {

                    char c = s.charAt(i);

                    if (c == UNMAPPABLE_DECODING)

                        continue;

                    int hi = c >> 8;

                    if (c2b[hi] == C2B_UNMAPPABLE) {

                        c2b[hi] = new char[0x100];

                        Arrays.fill(c2b[hi], (char)UNMAPPABLE_ENCODING);

                    }

                    c2b[hi][c & 0xff] = (char)((b1 << 8) | (i + b2Min));

                }

            }

            if (pua != null) {        // add the compatibility pua entries

                char c = '\ue000';    //first pua character

                for (int i = 0; i < pua.length(); i++) {

                    char bb = pua.charAt(i);

                    if (bb != UNMAPPABLE_DECODING) {

                        int hi = c >> 8;

                        if (c2b[hi] == C2B_UNMAPPABLE) {

                            c2b[hi] = new char[0x100];

                            Arrays.fill(c2b[hi], (char)UNMAPPABLE_ENCODING);

                        }

                        c2b[hi][c & 0xff] = bb;

                    }

                    c++;

                }

            }

        }

    }

}