001/*
002 * jPOS Project [http://jpos.org]
003 * Copyright (C) 2000-2026 jPOS Software SRL
004 *
005 * This program is free software: you can redistribute it and/or modify
006 * it under the terms of the GNU Affero General Public License as
007 * published by the Free Software Foundation, either version 3 of the
008 * License, or (at your option) any later version.
009 *
010 * This program is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
013 * GNU Affero General Public License for more details.
014 *
015 * You should have received a copy of the GNU Affero General Public License
016 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
017 */
018
019package org.jpos.iso;
020
021public class IsoFieldHeaderFormatter {
022
023    private boolean tagFirst;
024
025    public IsoFieldHeaderFormatter(boolean tagFirst) {
026        this.tagFirst = tagFirst;
027    }
028
029
030    public boolean isTagFirst() {
031        return tagFirst;
032    }
033
034    /**
035     *
036     * @param tagPrefixer the tag part prefixer
037     * @param lengthPrefixer the length part prefixer
038     * @param tagData byte array containing the tag value bytes
039     * @param lengthData byte array containing the length value bytes
040     * @return byte array containing the header (tag and length), size of returned bytes is just the header length
041     */
042    public byte[] format(final Prefixer tagPrefixer, final Prefixer lengthPrefixer, final byte[] tagData, final byte[] lengthData) {
043        if (tagPrefixer != null && lengthPrefixer != null && tagData != null && lengthData != null) {
044            final byte[] destinationData = new byte[tagPrefixer.getPackedLength() + lengthPrefixer.getPackedLength()];
045            format(tagPrefixer, lengthPrefixer, tagData, lengthData, destinationData);
046            return destinationData;
047        }
048        return null;
049    }
050
051    public void format(final Prefixer tagPrefixer, final Prefixer lengthPrefixer, final byte[] tagData, final byte[] lengthData, final byte[] destinationData) {
052        if (tagPrefixer != null && lengthPrefixer != null && tagData != null && lengthData != null && destinationData != null) {
053            System.arraycopy(tagData, 0, destinationData, tagFirst ? 0 : lengthPrefixer.getPackedLength(), tagPrefixer.getPackedLength());
054            System.arraycopy(lengthData, 0, destinationData, tagFirst ? tagPrefixer.getPackedLength() : 0, lengthPrefixer.getPackedLength());
055        }
056    }
057
058    public int getTagIndex(Prefixer lengthPrefixer) {
059        return tagFirst ? 0 : lengthPrefixer.getPackedLength();
060    }
061
062    public int getLengthIndex(Prefixer tagPrefixer) {
063        return tagFirst ? tagPrefixer.getPackedLength() : 0;
064    }
065
066    public static IsoFieldHeaderFormatter TAG_FIRST = new IsoFieldHeaderFormatter(true);
067    public static IsoFieldHeaderFormatter LENGTH_FIRST = new IsoFieldHeaderFormatter(false);
068
069    public int getTotalLength(final Prefixer tagPrefixer, final Prefixer prefixer) {
070        if (tagPrefixer == null || prefixer == null) {
071            throw new IllegalArgumentException("Neither tag or length prefixer was provided.");
072        }
073        return tagPrefixer.getPackedLength() + prefixer.getPackedLength();
074    }
075}