/*
 * Copyright (c) 2002, 2006, 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.CoderResult;
import sun.nio.cs.Surrogate;

public abstract class DoubleByteEncoder
    extends CharsetEncoder
{

    private short index1[];
    private String index2[];

    private final Surrogate.Parser sgp = new Surrogate.Parser();

    protected DoubleByteEncoder(Charset cs,
                                short[] index1, String[] index2)
    {
        super(cs, 2.0f, 2.0f);
        this.index1 = index1;
        this.index2 = index2;
    }

    protected DoubleByteEncoder(Charset cs,
                                short[] index1, String[] index2,
                                float avg, float max)
    {
        super(cs, avg, max);
        this.index1 = index1;
        this.index2 = index2;
    }

    protected DoubleByteEncoder(Charset cs,
                                short[] index1, String[] index2, byte[] repl)
    {
        super(cs, 2.0f, 2.0f, repl);
        this.index1 = index1;
        this.index2 = index2;
    }


    protected DoubleByteEncoder(Charset cs,
                                short[] index1, String[] index2,
                                byte[] repl, float avg, float max)
    {
        super(cs, avg, max,repl);
        this.index1 = index1;
        this.index2 = index2;
    }

    public boolean canEncode(char c) {
        return (encodeSingle(c) != -1 ||
                encodeDouble(c) != 0);
    }

    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();

        try {
            while (sp < sl) {
                char c = sa[sp];
                if (Character.isSurrogate(c)) {
                    if (sgp.parse(c, sa, sp, sl) < 0)
                        return sgp.error();
                    if (sl - sp < 2)
                        return CoderResult.UNDERFLOW;
                    char c2 = sa[sp + 1];

                    byte[] outputBytes = new byte[2];
                    outputBytes = encodeSurrogate(c, c2);

                    if (outputBytes == null) {
                        return sgp.unmappableResult();
                    }
                    else {
                        if (dl - dp < 2)
                            return CoderResult.OVERFLOW;
                        da[dp++] = outputBytes[0];
                        da[dp++] = outputBytes[1];
                        sp += 2;
                        continue;
                    }
                }
                if (c >= '\uFFFE')
                    return CoderResult.unmappableForLength(1);

                int b = encodeSingle(c);
                if (b != -1) { // Single Byte
                    if (dl - dp < 1)
                        return CoderResult.OVERFLOW;
                    da[dp++] = (byte)b;
                    sp++;
                    continue;
                }

                int ncode  = encodeDouble(c);
                if (ncode != 0 && c != '\u0000' ) {
                    if (dl - dp < 2)
                        return CoderResult.OVERFLOW;
                    da[dp++] = (byte) ((ncode & 0xff00) >> 8);
                    da[dp++] = (byte) (ncode & 0xff);
                    sp++;
                    continue;
                }
                return CoderResult.unmappableForLength(1);
                }
            return CoderResult.UNDERFLOW;
        } finally {
            src.position(sp - src.arrayOffset());
            dst.position(dp - dst.arrayOffset());
        }
    }

    private CoderResult encodeBufferLoop(CharBuffer src, ByteBuffer dst) {
        int mark = src.position();

        try {
            while (src.hasRemaining()) {
                char c = src.get();
                if (Character.isSurrogate(c)) {
                    int surr;
                    if ((surr = sgp.parse(c, src)) < 0)
                        return sgp.error();
                    char c2 = Surrogate.low(surr);
                    byte[] outputBytes = new byte[2];
                    outputBytes = encodeSurrogate(c, c2);

                    if (outputBytes == null) {
                        return sgp.unmappableResult();
                    } else {
                        if (dst.remaining() < 2)
                            return CoderResult.OVERFLOW;
                        mark += 2;
                        dst.put(outputBytes[0]);
                        dst.put(outputBytes[1]);
                        continue;
                    }
                }
                if (c >= '\uFFFE')
                    return CoderResult.unmappableForLength(1);
                int b = encodeSingle(c);

                if (b != -1) { // Single-byte character
                    if (dst.remaining() < 1)
                        return CoderResult.OVERFLOW;
                    mark++;
                    dst.put((byte)b);
                    continue;
                }
                // Double Byte character

                int ncode = encodeDouble(c);
                if (ncode != 0 && c != '\u0000') {
                    if (dst.remaining() < 2)
                        return CoderResult.OVERFLOW;
                    mark++;
                    dst.put((byte) ((ncode & 0xff00) >> 8));
                    dst.put((byte) ncode);
                    continue;
                }
                return CoderResult.unmappableForLength(1);
            }

            return CoderResult.UNDERFLOW;
        } finally {
            src.position(mark);
        }
    }

    protected CoderResult encodeLoop(CharBuffer src, ByteBuffer dst) {
        if (true && src.hasArray() && dst.hasArray())
            return encodeArrayLoop(src, dst);
        else
            return encodeBufferLoop(src, dst);
    }

    /*
     * Can be changed by subclass
     */
    protected int encodeDouble(char ch) {
        int offset = index1[((ch & 0xff00) >> 8 )] << 8;
        return index2[offset >> 12].charAt((offset & 0xfff) + (ch & 0xff));
    }

    /*
     * Can be changed by subclass
     */
    protected int encodeSingle(char inputChar) {
        if (inputChar < 0x80)
            return (byte)inputChar;
        else
            return -1;
    }

    
 Protected method which should be overridden by concrete DBCS
 CharsetEncoder classes which included supplementary characters
 within their mapping coverage.
 null return value indicates surrogate values could not be
 handled or encoded.
/**
     *  Protected method which should be overridden by concrete DBCS
     *  CharsetEncoder classes which included supplementary characters
     *  within their mapping coverage.
     *  null return value indicates surrogate values could not be
     *  handled or encoded.
     */
    protected byte[] encodeSurrogate(char highSurrogate, char lowSurrogate) {
        return null;
    }
}