/*

 * Copyright 1999 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.ext.ISCII91;

/*

 * Copyright (c) 1998 International Business Machines.

 * All Rights Reserved.

 *

 * Author : Sunanda Bera, C. Thirumalesh

 * Last Modified : 11,December,1998

 *

 * Purpose : Defines class CharToByteISCII91.

 *

 *

 * Revision History

 * ======== =======

 *

 * Date        By            Description

 * ----        --            -----------

 * March 29, 1999 John Raley Removed MalformedInputException; modified substitution logic

 *

 */

/**

 * Converter class. Converts between ISCII91 encoding and Unicode encoding.

 * ISCII91 is the character encoding as defined in Indian Standard document

 * IS 13194:1991 ( Indian Script Code for Information Interchange ).

 *

 * @see sun.io.CharToByteConverter

 */

/*

 * {jbr} I am not sure this class adheres to code converter conventions.

 * Need to investigate.

 * Might should recode as a subclass of CharToByteSingleByte.

 */

public class CharToByteISCII91 extends CharToByteConverter {

        private static final byte NO_CHAR = (byte)255;

        //private final static ISCII91 nioCoder = new ISCII91();

        private final static byte[] directMapTable = ISCII91.getEncoderMappingTable();

        private static final char NUKTA_CHAR = '\u093c';

        private static final char HALANT_CHAR = '\u094d';

/**

 * @return true for Devanagari and ASCII range and for the special characters

 *              Zero Width Joiner and Zero Width Non-Joiner

 * @see sun.io.CharToByteConverter#canConvert

 *

 */

        public boolean canConvert(char ch) {

        //check for Devanagari range,ZWJ,ZWNJ and ASCII range.

        return ((ch >= 0x0900 && ch <= 0x097f) || (ch == 0x200d || ch == 0x200c)

                                || (ch >= 0x0000 && ch <= 0x007f) );

        } //canConvert()

/**

 * Converts both Devanagari and ASCII range of characters.

 * @see sun.io.CharToByteConverter#convert

 */

    public int convert(char[] input, int inStart, int inEnd, byte[] output, int outStart, int outEnd) throws MalformedInputException, UnknownCharacterException, ConversionBufferFullException {

        charOff = inStart;

        byteOff = outStart;

        for (;charOff < inEnd; charOff++) {

            char inputChar = input[charOff];

            int index = Integer.MIN_VALUE;

            boolean isSurrogatePair = false;

            //check if input is in ASCII RANGE

            if (inputChar >= 0x0000 && inputChar <= 0x007f) {

                if (byteOff >= outEnd) {

                        throw new ConversionBufferFullException();

                }

                output[byteOff++] = (byte) inputChar;

                continue;

            }

            // if inputChar == ZWJ replace it with halant

            // if inputChar == ZWNJ replace it with Nukta

            if (inputChar == 0x200c) {

                inputChar = HALANT_CHAR;

            }

            else if (inputChar == 0x200d) {

                inputChar = NUKTA_CHAR;

            }

            if (inputChar >= 0x0900 && inputChar <= 0x097f) {

                index = ((int)(inputChar) - 0x0900)*2;

            }

            // If input char is a high surrogate, ensure that the following

            // char is a low surrogate.  If not, throw a MalformedInputException.

            // Leave index untouched so substitution or an UnknownCharacterException

            // will result.

            else if (inputChar >= 0xd800 && inputChar <= 0xdbff) {

                if (charOff < inEnd-1) {

                    char nextChar = input[charOff];

                    if (nextChar >= 0xdc00 && nextChar <= 0xdfff) {

                        charOff++;

                        isSurrogatePair = true;

                    }

                }

                if (!isSurrogatePair) {

                    badInputLength = 1;

                    throw new MalformedInputException();

                }

            }

            else if (inputChar >= 0xdc00 && inputChar <= 0xdfff) {

                badInputLength = 1;

                throw new MalformedInputException();

            }

            if (index == Integer.MIN_VALUE || directMapTable[index] == NO_CHAR) {

                if (subMode) {

                    if (byteOff + subBytes.length >= outEnd) {

                            throw new ConversionBufferFullException();

                    }

                    System.arraycopy(subBytes, 0, output, byteOff, subBytes.length);

                    byteOff += subBytes.length;

                } else {

                    badInputLength = isSurrogatePair? 2 : 1;

                    throw new UnknownCharacterException();

                }

            }

            else {

                if(byteOff >= outEnd) {

                    throw new ConversionBufferFullException();

                }

                output[byteOff++] = directMapTable[index++];

                if(directMapTable[index] != NO_CHAR) {

                    if(byteOff >= outEnd) {

                            throw new ConversionBufferFullException();

                    }

                    output[byteOff++] = directMapTable[index];

                }

            }

        } //end for

        return byteOff - outStart;

    } //end of routine convert.

/**

* @see sun.io.CharToByteConverter#flush

*/

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

        throws MalformedInputException, ConversionBufferFullException {

        byteOff = charOff = 0;

        return 0;

        }//flush()

/**

 * @return The character encoding as a String.

 */

        public String getCharacterEncoding() {

        return "ISCII91";

        }//getCharacterEncoding

/**

 * @see sun.io.CharToByteConverter#getMaxBytesPerChar

 */

        public int getMaxBytesPerChar() {

        return 2;

        }//getMaxBytesPerChar()

/**

 * @see sun.io.CharToByteConverter#reset

 */

        public void reset() {

        byteOff = charOff = 0;

        }

} //end of class definition