/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is part of dcm4che, an implementation of DICOM(TM) in
 * Java(TM), hosted at https://github.com/gunterze/dcm4che.
 *
 * The Initial Developer of the Original Code is
 * Agfa Healthcare.
 * Portions created by the Initial Developer are Copyright (C) 2011
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * See @authors listed below
 *
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 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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package org.dcm4che3.util;

import org.dcm4che3.data.Tag;

/**
 * @author Gunter Zeilinger <gunterze@gmail.com>
 */
public class TagUtils {

    private static char[] HEX_DIGITS = {
        '0', '1', '2', '3', '4', '5', '6', '7',
        '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
    };

    public static String shortToHexString(int n) {
        char[] s = {
                HEX_DIGITS[(n >>> 12) & 0xF],
                HEX_DIGITS[(n >>> 8) & 0xF],
                HEX_DIGITS[(n >>> 4) & 0xF],
                HEX_DIGITS[(n >>> 0) & 0xF] };
        return new String(s);
    }

    public static String toHexString(int tag) {
        char[] s = {
                HEX_DIGITS[(tag >>> 28)],
                HEX_DIGITS[(tag >>> 24) & 0xF],
                HEX_DIGITS[(tag >>> 20) & 0xF],
                HEX_DIGITS[(tag >>> 16) & 0xF],
                HEX_DIGITS[(tag >>> 12) & 0xF],
                HEX_DIGITS[(tag >>> 8) & 0xF],
                HEX_DIGITS[(tag >>> 4) & 0xF],
                HEX_DIGITS[(tag >>> 0) & 0xF] };
        return new String(s);
    }

    public static String toHexString(byte[] b) {
        char[] s = new char[b.length << 1];
        for (int i = 0, j = 0; i < b.length; i++) {
            s[j++] = HEX_DIGITS[(b[i] >>> 4) & 0xF];
            s[j++] = HEX_DIGITS[b[i] & 0xF];
        }
        return new String(s);
    }

    public static String toString(int tag) {
        char[] s = {
                '(',
                HEX_DIGITS[(tag >>> 28)],
                HEX_DIGITS[(tag >>> 24) & 0xF],
                HEX_DIGITS[(tag >>> 20) & 0xF],
                HEX_DIGITS[(tag >>> 16) & 0xF],
                ',',
                HEX_DIGITS[(tag >>> 12) & 0xF],
                HEX_DIGITS[(tag >>> 8) & 0xF],
                HEX_DIGITS[(tag >>> 4) & 0xF],
                HEX_DIGITS[(tag >>> 0) & 0xF],
                ')'};
        return new String(s);
    }

    public static int groupNumber(int tag) {
        return tag >>> 16;
    }

    public static int elementNumber(int tag) {
        return tag & 0xFFFF;
    }

    public static boolean isGroupLength(int tag) {
        return elementNumber(tag) == 0;
    }

    public static boolean isPrivateCreator(int tag) {
        return (tag & 0x00010000) != 0
            && (tag & 0x0000FF00) == 0
            && (tag & 0x000000F0) != 0;
    }

    public static boolean isPrivateGroup(int tag) {
        return (tag & 0x00010000) != 0;
    }

    public static boolean isPrivateTag(int tag) {
        return (tag & 0x00010000) != 0
            && (tag & 0x0000FF00) != 0;
    }

    public static int toTag(int groupNumber, int elementNumber) {
        return groupNumber << 16 | elementNumber;
    }

    public static int toPrivateTag(int creatorTag, int elementNumber) {
        return (creatorTag & 0xffff0000) 
             | ((creatorTag & 0xff) << 8
             | (elementNumber & 0xff));
    }

    public static int creatorTagOf(int tag) {
        return (tag & 0xffff0000) | ((tag >>> 8) & 0xff);
    }

    public static int groupLengthTagOf(int tag) {
        return tag & 0xffff0000;
    }

    public static boolean isItem(int tag) {
        return tag == Tag.Item
            || tag == Tag.ItemDelimitationItem
            || tag == Tag.SequenceDelimitationItem;
    }

    public static boolean isFileMetaInformation(int tag) {
        return (tag & 0xffff0000) == 0x00020000;
    }

    public static int normalizeRepeatingGroup(int tag) {
        int gg000000 = tag & 0xffe00000;
        return (gg000000 == 0x50000000
             || gg000000 == 0x60000000)
                    ? tag & 0xffe0ffff
                    : tag;
    }

    public static int forName(String name) {
        try {
            return Integer.parseInt(name, 16);
        } catch (NumberFormatException nfe) {
            try {
                return Tag.class.getField(name).getInt(null);
            } catch (Exception e) {
                return -1;
            }
        }
    }

    public static int[] parseTagPath(String tagPath) {
        String[] names = StringUtils.split(tagPath, '.');
        int[] tags = new int[names.length];
        for (int i = 0; i < tags.length; i++)
            if ((tags[i] = forName(names[i])) == -1)
                throw new IllegalArgumentException("tagPath: " + tagPath);
        return tags;
    }

}