// --- BEGIN COPYRIGHT BLOCK ---
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; version 2 of the License.
//
// This program 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 for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
// (C) 2007 Red Hat, Inc.
// All rights reserved.
// --- END COPYRIGHT BLOCK ---
package netscape.security.util;

import sun.io.CharToByteConverter;
import sun.io.ConversionBufferFullException;
import sun.io.MalformedInputException;
import sun.io.UnknownCharacterException;

/**
 * Converts a string of ASN.1 PrintableString characters to PrintableString
 * bytes.
 * 
 * @author Lily Hsiao
 * @author Slava Galperin
 */

public class CharToBytePrintable extends CharToByteConverter {
    /*
     * returns the character set id for the conversion.
     * 
     * @return the character set id.
     */
    public String getCharacterEncoding() {
        return "ASN.1 Printable";
    }

    public static boolean isPrintableChar(char c) {
        if ((c < 'A' || c > 'Z') && (c < 'a' || c > 'z')
                && (c < '0' || c > '9') && (c != ' ') && (c != '\'')
                && (c != '(') && (c != ')') && (c != '+') && (c != ',')
                && (c != '-') && (c != '.') && (c != '/') && (c != ':')
                && (c != '=') && (c != '?')) {
            return false;
        } else {
            return true;
        }
    }

    /*
     * Converts an array of Unicode characters into an array of Printable String
     * bytes and returns the total number of characters converted. If conversion
     * cannot be done, UnknownCharacterException is thrown. The character and
     * byte offset will be set to the point of the unknown character.
     * 
     * @param input character array to convert.
     * 
     * @param inStart offset from which to start the conversion.
     * 
     * @param inEnd where to end the conversion.
     * 
     * @param output byte array to store converted bytes.
     * 
     * @param outStart starting offset in the output byte array.
     * 
     * @param outEnd ending offset in the output byte array.
     * 
     * @return the number of characters converted.
     */
    public int convert(char[] input, int inStart, int inEnd, byte[] output,
            int outStart, int outEnd) throws MalformedInputException,
            UnknownCharacterException, ConversionBufferFullException {
        int j = outStart;
        int i;
        for (i = inStart; i < inEnd; i++, j++) {
            if (j >= outEnd) {
                charOff = i;
                byteOff = j;
                throw new ConversionBufferFullException();
            }
            if (!subMode && !isPrintableChar(input[i])) {
                charOff = i;
                byteOff = j;
                badInputLength = 1;
                throw new UnknownCharacterException();
            }
            output[j] = (byte) (input[i] & 0x7f);
        }
        charOff = i;
        byteOff = j;
        return j - outStart;
    }

    public int flush(byte[] output, int outStart, int outEnd)
            throws MalformedInputException, ConversionBufferFullException {
        return 0;
    }

    public void reset() {
    }

    public int getMaxBytesPerChar() {
        return 1;
    }

}