/*

 * 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;

public class CharToByteASCII extends CharToByteConverter {

    // Return the character set ID

    public String getCharacterEncoding()

    {

        return "ASCII";

    }

    private char highHalfZoneCode;

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

        throws MalformedInputException

    {

        if (highHalfZoneCode != 0) {

            highHalfZoneCode = 0;

            throw new MalformedInputException

                ("String ends with <High Half Zone code> of UTF16");

        }

        byteOff = charOff = 0;

        return 0;

    }

    /*

    * Character conversion

    */

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

                       byte[] output, int outOff, int outEnd)

        throws MalformedInputException,

               UnknownCharacterException,

               ConversionBufferFullException

    {

        char    inputChar;          // Input character to be converted

        byte[]  outputByte;         // Output byte written to output

        byte[]  tmpArray = new byte[1];

        int     inputSize;          // Size of input

        int     outputSize;         // Size of output

        // Record beginning offsets

        charOff = inOff;

        byteOff = outOff;

        if (highHalfZoneCode != 0) {

            inputChar = highHalfZoneCode;

            highHalfZoneCode = 0;

            if (input[inOff] >= 0xdc00 && input[inOff] <= 0xdfff) {

                // This is legal UTF16 sequence.

                badInputLength = 1;

                throw new UnknownCharacterException();

            } else {

                // This is illegal UTF16 sequence.

                badInputLength = 0;

                throw new MalformedInputException

                    ("Previous converted string ends with " +

                     "<High Half Zone Code> of UTF16 " +

                     ", but this string is not begin with <Low Half Zone>");

            }

        }

        // Loop until we hit the end of the input

        while(charOff < inEnd) {

            outputByte = tmpArray;

            // Get the input character

            inputChar = input[charOff];

            // default outputSize

            outputSize = 1;

            // Assume this is a simple character

            inputSize = 1;

            // Is this a high surrogate?

            if(inputChar >= '\uD800' && inputChar <= '\uDBFF') {

                // Is this the last character in the input?

                if (charOff + 1 == inEnd) {

                    highHalfZoneCode = inputChar;

                    break;

                }

                // Is there a low surrogate following?

                inputChar = input[charOff + 1];

                if (inputChar >= '\uDC00' && inputChar <= '\uDFFF') {

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

                    //  surrogates.  Is substitution enabled?

                    if (subMode) {

                        outputByte = subBytes;

                        outputSize = subBytes.length;

                        inputSize = 2;

                    } else {

                        badInputLength = 2;

                        throw new UnknownCharacterException();

                    }

                } else {

                    // We have a malformed surrogate pair

                    badInputLength = 1;

                    throw new MalformedInputException();

                }

            }

            // Is this an unaccompanied low surrogate?

            else if (inputChar >= '\uDC00' && inputChar <= '\uDFFF') {

                badInputLength = 1;

                throw new MalformedInputException();

            }

            // Not part of a surrogate, so try to convert

            else {

                // Is this character mappable?

                if (inputChar <= '\u007F') {

                    outputByte[0] = (byte)inputChar;

                } else {

                    // Is substitution enabled?

                    if (subMode) {

                        outputByte = subBytes;

                        outputSize = subBytes.length;

                    } else {

                        badInputLength = 1;

                        throw new UnknownCharacterException();

                    }

                }

            }

            // If we don't have room for the output, throw an exception

            if (byteOff + outputSize > outEnd)

                throw new ConversionBufferFullException();

            // Put the byte in the output buffer

            for (int i = 0; i < outputSize; i++) {

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

            }

            charOff += inputSize;

        }

        // Return the length written to the output buffer

        return byteOff-outOff;

    }

    // Determine if a character is mappable or not

    public boolean canConvert(char ch)

    {

        return (ch <= '\u007F');

    }

    // Reset the converter

    public void reset()

    {

        byteOff = charOff = 0;

        highHalfZoneCode = 0;

    }

    /**

     * returns the maximum number of bytes needed to convert a char

     */

    public int getMaxBytesPerChar()

    {

        return 1;

    }

}