/*

 * 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

 * particular file as subject to the "Classpath" exception as provided

 *

 * 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.

 *

 */

package sun.io;

import sun.nio.cs.ext.DoubleByte;

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

public abstract class ByteToCharEUC2 extends ByteToCharConverter

{

    private final int G0 = 0;

    private final int G1 = 1;

    private final int SS2 =  0x8E;

    private final int SS3 =  0x8F;

    private int firstByte, state;

    private DoubleByte.Decoder dec;

    public ByteToCharEUC2(DoubleByte.Decoder dec) {

        super();

        state = G0;

        this.dec = dec;

    }

    char decodeSingle(int b) {

        return dec.decodeSingle(b);

    }

    char decodeDouble(int b1, int b2) {

        return dec.decodeDouble(b1, b2);

    }

    /**

      * flush out any residual data and reset the buffer state

      */

    public int flush(char[] output, int outStart, int outEnd)

       throws MalformedInputException

    {

       if (state != G0) {

          reset();

          badInputLength = 0;

          throw new MalformedInputException();

       }

       reset();

       return 0;

    }

    /**

     *  Resets the converter.

     */

    public void reset() {

       state = G0;

       charOff = byteOff = 0;

    }

    /**

     * Character conversion

     */

    public int convert(byte[] input, int inOff, int inEnd,

                       char[] output, int outOff, int outEnd)

        throws UnknownCharacterException, MalformedInputException,

               ConversionBufferFullException

    {

        int       byte1;

        char      outputChar = UNMAPPABLE_DECODING;

        byteOff = inOff;

        charOff = outOff;

        while (byteOff < inEnd) {

            byte1 = input[byteOff] & 0xff;

            switch (state) {

            case G0:

                if (byte1 == SS2 ||                // no general support

                    byte1 == SS3 ) {               //    for g2 or g3

                    badInputLength = 1;

                    throw new MalformedInputException();

                }

                if ( byte1 <= 0x9f )               // < 0x9f has its own table

                    outputChar = decodeSingle(byte1);

                else

                    if (byte1 < 0xa1 || byte1 > 0xfe) {  // byte within range?

                        badInputLength = 1;

                        throw new MalformedInputException();

                    } else {                       // G1 set first byte

                        firstByte = byte1;

                        state = G1;

                    }

                break;

            case G1:

                state = G0;

                if ( byte1 < 0xa1 || byte1 > 0xfe) {  // valid G1 set second byte

                    badInputLength = 1;

                    throw new MalformedInputException();

                }

                outputChar = decodeDouble(firstByte, byte1);

                break;

            }

            if (state == G0) {

                if (outputChar == UNMAPPABLE_DECODING) {

                    if (subMode)

                        outputChar = subChars[0];

                    else {

                        badInputLength = 1;

                        throw new UnknownCharacterException();

                    }

                }

                if (charOff >= outEnd)

                    throw new ConversionBufferFullException();

                output[charOff++] = outputChar;

            }

            byteOff++;

         }

         return charOff - outOff;

    }

}