/*

 * 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.Buffer;

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 static sun.nio.cs.CharsetMapping.*;

public class SingleByte

{

    private static final CoderResult withResult(CoderResult cr,

                                                Buffer src, int sp,

                                                Buffer dst, int dp)

    {

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

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

        return cr;

    }

    public static final class Decoder extends CharsetDecoder

                                      implements ArrayDecoder {

        private final char[] b2c;

        private final boolean isASCIICompatible;

        public Decoder(Charset cs, char[] b2c) {

            super(cs, 1.0f, 1.0f);

            this.b2c = b2c;

            this.isASCIICompatible = false;

        }

        public Decoder(Charset cs, char[] b2c, boolean isASCIICompatible) {

            super(cs, 1.0f, 1.0f);

            this.b2c = b2c;

            this.isASCIICompatible = isASCIICompatible;

        }

        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();

            CoderResult cr = CoderResult.UNDERFLOW;

            if ((dl - dp) < (sl - sp)) {

                sl = sp + (dl - dp);

                cr = CoderResult.OVERFLOW;

            }

            while (sp < sl) {

                char c = decode(sa[sp]);

                if (c == UNMAPPABLE_DECODING) {

                    return withResult(CoderResult.unmappableForLength(1),

                               src, sp, dst, dp);

                }

                da[dp++] = c;

                sp++;

            }

            return withResult(cr, src, sp, dst, dp);

        }

        private CoderResult decodeBufferLoop(ByteBuffer src, CharBuffer dst) {

            int mark = src.position();

            try {

                while (src.hasRemaining()) {

                    char c = decode(src.get());

                    if (c == UNMAPPABLE_DECODING)

                        return CoderResult.unmappableForLength(1);

                    if (!dst.hasRemaining())

                        return CoderResult.OVERFLOW;

                    dst.put(c);

                    mark++;

                }

                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);

        }

        public final char decode(int b) {

            return b2c[b + 128];

        }

        private char repl = '\uFFFD';

        protected void implReplaceWith(String newReplacement) {

            repl = newReplacement.charAt(0);

        }

        @Override

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

            if (len > dst.length)

                len = dst.length;

            int dp = 0;

            while (dp < len) {

                dst[dp] = decode(src[sp++]);

                if (dst[dp] == UNMAPPABLE_DECODING) {

                    dst[dp] = repl;

                }

                dp++;

            }

            return dp;

        }

        @Override

        public boolean isASCIICompatible() {

            return isASCIICompatible;

        }

    }

    public static final class Encoder extends CharsetEncoder

                                      implements ArrayEncoder {

        private Surrogate.Parser sgp;

        private final char[] c2b;

        private final char[] c2bIndex;

        private final boolean isASCIICompatible;

        public Encoder(Charset cs, char[] c2b, char[] c2bIndex, boolean isASCIICompatible) {

            super(cs, 1.0f, 1.0f);

            this.c2b = c2b;

            this.c2bIndex = c2bIndex;

            this.isASCIICompatible = isASCIICompatible;

        }

        public boolean canEncode(char c) {

            return encode(c) != UNMAPPABLE_ENCODING;

        }

        public boolean isLegalReplacement(byte[] repl) {

            return ((repl.length == 1 && repl[0] == (byte)'?') ||

                    super.isLegalReplacement(repl));

        }

        private 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();

            int len  = Math.min(dl - dp, sl - sp);

            while (len-- > 0) {

                char c = sa[sp];

                int b = encode(c);

                if (b == UNMAPPABLE_ENCODING) {

                    if (Character.isSurrogate(c)) {

                        if (sgp == null)

                            sgp = new Surrogate.Parser();

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

                            return withResult(sgp.error(), src, sp, dst, dp);

                        }

                        return withResult(sgp.unmappableResult(), src, sp, dst, dp);

                    }

                    return withResult(CoderResult.unmappableForLength(1),

                               src, sp, dst, dp);

                }

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

                sp++;

            }

            return withResult(sp < sl ? CoderResult.OVERFLOW : CoderResult.UNDERFLOW,

                              src, sp, dst, dp);

        }

        private CoderResult encodeBufferLoop(CharBuffer src, ByteBuffer dst) {

            int mark = src.position();

            try {

                while (src.hasRemaining()) {

                    char c = src.get();

                    int b = encode(c);

                    if (b == UNMAPPABLE_ENCODING) {

                        if (Character.isSurrogate(c)) {

                            if (sgp == null)

                                sgp = new Surrogate.Parser();

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

                                return sgp.error();

                            return sgp.unmappableResult();

                        }

                        return CoderResult.unmappableForLength(1);

                    }

                    if (!dst.hasRemaining())

                        return CoderResult.OVERFLOW;

                    dst.put((byte)b);

                    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);

        }

        public final int encode(char ch) {

            char index = c2bIndex[ch >> 8];

            if (index == UNMAPPABLE_ENCODING)

                return UNMAPPABLE_ENCODING;

            return c2b[index + (ch & 0xff)];

        }

        private byte repl = (byte)'?';

        protected void implReplaceWith(byte[] newReplacement) {

            repl = newReplacement[0];

        }

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

            int dp = 0;

            int sl = sp + Math.min(len, dst.length);

            while (sp < sl) {

                char c = src[sp++];

                int b = encode(c);

                if (b != UNMAPPABLE_ENCODING) {

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

                    continue;

                }

                if (Character.isHighSurrogate(c) && sp < sl &&

                    Character.isLowSurrogate(src[sp])) {

                    if (len > dst.length) {

                        sl++;

                        len--;

                    }

                    sp++;

                }

                dst[dp++] = repl;

            }

            return dp;

        }

        @Override

        public int encodeFromLatin1(byte[] src, int sp, int len, byte[] dst) {

            int dp = 0;

            int sl = sp + Math.min(len, dst.length);

            while (sp < sl) {

                char c = (char)(src[sp++] & 0xff);

                int b = encode(c);

                if (b == UNMAPPABLE_ENCODING) {

                    dst[dp++] = repl;

                } else {

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

                }

            }

            return dp;

        }

        @Override

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

            int dp = 0;

            int sl = sp + Math.min(len, dst.length);

            while (sp < sl) {

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

                int b = encode(c);

                if (b != UNMAPPABLE_ENCODING) {

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

                    continue;

                }

                if (Character.isHighSurrogate(c) && sp < sl &&

                    Character.isLowSurrogate(StringUTF16.getChar(src, sp))) {

                    if (len > dst.length) {

                        sl++;

                        len--;

                    }

                    sp++;

                }

                dst[dp++] = repl;

            }

            return dp;

        }

        @Override

        public boolean isASCIICompatible() {

            return isASCIICompatible;

        }

    }

    // init the c2b and c2bIndex tables from b2c.

    public static void initC2B(char[] b2c, char[] c2bNR,

                               char[] c2b, char[] c2bIndex) {

        for (int i = 0; i < c2bIndex.length; i++)

            c2bIndex[i] = UNMAPPABLE_ENCODING;

        for (int i = 0; i < c2b.length; i++)

            c2b[i] = UNMAPPABLE_ENCODING;

        int off = 0;

        for (int i = 0; i < b2c.length; i++) {

            char c = b2c[i];

            if (c == UNMAPPABLE_DECODING)

                continue;

            int index = (c >> 8);

            if (c2bIndex[index] == UNMAPPABLE_ENCODING) {

                c2bIndex[index] = (char)off;

                off += 0x100;

            }

            index = c2bIndex[index] + (c & 0xff);

            c2b[index] = (char)((i>=0x80)?(i-0x80):(i+0x80));

        }

        if (c2bNR != null) {

            // c-->b nr entries

            int i = 0;

            while (i < c2bNR.length) {

                char b = c2bNR[i++];

                char c = c2bNR[i++];

                int index = (c >> 8);

                if (c2bIndex[index] == UNMAPPABLE_ENCODING) {

                    c2bIndex[index] = (char)off;

                    off += 0x100;

                }

                index = c2bIndex[index] + (c & 0xff);

                c2b[index] = b;

            }

        }

    }

}