/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.jss.asn1;

import java.io.CharConversionException;

public class IA5String extends CharacterString implements ASN1Value {

    public IA5String(char[] chars) throws CharConversionException {
        super(chars);
    }

    public IA5String(String s) throws CharConversionException {
        super(s);
    }

    @Override
    CharConverter getCharConverter() {
        return new IA5Converter();
    }

    public static final Tag TAG = new Tag(Tag.Class.UNIVERSAL, 22);

    @Override
    public Tag getTag() {
        return TAG;
    }

    public static Template getTemplate() {
        return templateInstance;
    }

    private static final Template templateInstance = new Template();

    // nested class
    public static class Template
            extends CharacterString.Template implements ASN1Template {
        @Override
        public Tag getTag() {
            return IA5String.TAG;
        }

        @Override
        public boolean tagMatch(Tag tag) {
            return (tag.equals(IA5String.TAG));
        }

        @Override
        protected CharConverter getCharConverter() {
            return new IA5Converter();
        }

        @Override
        protected CharacterString generateInstance(char[] chars)
                throws CharConversionException {
            return new IA5String(chars);
        }

        @Override
        protected String typeName() {
            return "IA5String";
        }
    }

    // nested class
    private static class IA5Converter implements CharConverter {

        @Override
        public char[] byteToChar(byte[] bytes, int offset, int len)
                throws CharConversionException {
            char[] chars = new char[len];

            int c; // char index
            int b; // byte index
            for (b = offset, c = 0; c < len; b++, c++) {
                if ((bytes[b] & 0x80) != 0) {
                    throw new CharConversionException("Invalid character: " +
                            bytes[b]);
                }
                chars[c] = (char) (bytes[b] & 0x7f);
            }
            return chars;
        }

        @Override
        public byte[] charToByte(char[] chars, int offset, int len)
                throws CharConversionException {
            byte[] bytes = new byte[len];

            int c; // char index
            int b; // byte index
            for (c = offset, b = 0; b < len; c++, b++) {
                if ((chars[c] & 0x7f) != chars[c]) {
                    throw new CharConversionException("Invalid character: " +
                            chars[c]);
                }
                bytes[b] = (byte) (chars[c] & 0x7f);
            }

            return bytes;
        }
    }

}
