/*

 * Copyright 1997 Sun Microsystems, Inc.  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.  Sun designates this

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

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package sun.io;

import sun.nio.cs.Surrogate;

import sun.nio.cs.ext.DoubleByte;

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

public abstract class CharToByteDBCS_ASCII extends CharToByteConverter

{

    private char highHalfZoneCode;

    private byte[] outputByte = new byte[2];

    private DoubleByte.Encoder enc;

    public CharToByteDBCS_ASCII(DoubleByte.Encoder enc) {

        super();

        this.enc = enc;

    }

    int encodeChar(char c) {

        return enc.encodeChar(c);

    }

    /**

      * flush out any residual data and reset the buffer state

      */

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

        throws MalformedInputException, ConversionBufferFullException

    {

       if (highHalfZoneCode != 0) {

          reset();

          badInputLength = 0;

          throw new MalformedInputException();

       }

       reset();

       return 0;

    }

    /**

     * Character conversion

     */

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

                       byte[] output, int outOff, int outEnd)

        throws UnknownCharacterException, MalformedInputException,

               ConversionBufferFullException

    {

        char    inputChar;

        int     inputSize;

        byteOff = outOff;

        charOff = inOff;

        while(charOff < inEnd) {

            int   index;

            int   theBytes;

            int   spaceNeeded;

            if (highHalfZoneCode == 0) {

                inputChar = input[charOff];

                inputSize = 1;

            } else {

                inputChar = highHalfZoneCode;

                inputSize = 0;

                highHalfZoneCode = 0;

            }

            // Is this a high surrogate?

                // Is this the last character of the input?

                if (charOff + inputSize >= inEnd) {

                    highHalfZoneCode = inputChar;

                    charOff += inputSize;

                    break;

                }

                // Is there a low surrogate following?

                inputChar = input[charOff + inputSize];

                    // We have a valid surrogate pair.  Too bad we don't do

                    // surrogates.  Is substitution enabled?

                    if (subMode) {

                        if (subBytes.length == 1) {

                            outputByte[0] = 0x00;

                            outputByte[1] = subBytes[0];

                        }

                        else {

                            outputByte[0] = subBytes[0];

                            outputByte[1] = subBytes[1];

                        }

                        inputSize++;

                    } else {

                        badInputLength = 2;

                        throw new UnknownCharacterException();

                    }

                 } else {

                     // We have a malformed surrogate pair

                     badInputLength = 1;

                     throw new MalformedInputException();

                 }

            }

            // Is this an unaccompanied low surrogate?

                badInputLength = 1;

                throw new MalformedInputException();

            } else {

                // We have a valid character, get the bytes for it

                theBytes = encodeChar(inputChar);

                if (theBytes == UNMAPPABLE_ENCODING) {

                    // if there was no mapping - look for substitution characters

                    if (subMode) {

                        if (subBytes.length == 1) {

                            outputByte[0] = 0x00;

                            outputByte[1] = subBytes[0];

                        } else {

                            outputByte[0] = subBytes[0];

                            outputByte[1] = subBytes[1];

                        }

                    } else {

                        badInputLength = 1;

                        throw new UnknownCharacterException();

                    }

                } else {

                    outputByte[0] = (byte)(theBytes >>8);

                    outputByte[1] = (byte)theBytes;

                }

            }

            if (outputByte[0] == 0x00)

                spaceNeeded = 1;

            else

                spaceNeeded = 2;

            if (byteOff + spaceNeeded > outEnd)

                throw new ConversionBufferFullException();

            if (spaceNeeded == 1)

                output[byteOff++] = outputByte[1];

            else {

                output[byteOff++] = outputByte[0];

                output[byteOff++] = outputByte[1];

            }

            charOff += inputSize;

        }

        return byteOff - outOff;

    }

    /**

     * Resets converter to its initial state.

     */

    public void reset() {

       charOff = byteOff = 0;

       highHalfZoneCode = 0;

    }

    /**

     * Returns the maximum number of bytes needed to convert a char.

     */

    public int getMaxBytesPerChar() {

        return 2;

    }

    /**

     * Returns true if the given character can be converted to the

     * target character encoding.

     */

    public boolean canConvert(char c) {

        return encodeChar(c) != UNMAPPABLE_ENCODING;

    }

}