# IdUtils.java

    /*
    ** Module   : IdUtils.java
    ** Abstract : A set of useful static routines to handle node IDs.
    **
    ** Copyright (c) 2005-2025, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- --JPRM-- ----------------Description-----------------
    ** 001 SIY 20050303  @20360  Created initial version
    ** 002 SIY 20050328  @20594  Fixed comments.
    ** 003 SIY 20050421  @21013  Added careful name validness check.
    ** 004 SIY 20050505  @21194  Added method upcaseFirst(). Moved splitId()
    **                           from RamRemapper.
    ** 005 GES 20060304  @24889  Added '.' as a valid character in a node id.
    ** 006 SIY 20090712  @43136  Refactoring.
    ** 007 ECF 20150715          Replace StringBuffer with StringBuilder.
    ** 008 SP  20250416          Removed toLowerCase(). Added upper case letters as valid chars.
    */

    /*
    ** This program is free software: you can redistribute it and/or modify
    ** it under the terms of the GNU Affero General Public License as
    ** published by the Free Software Foundation, either version 3 of the
    ** License, or (at your option) any later version.
    **
    ** 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 Affero General Public License for more details.
    **
    ** You may find a copy of the GNU Affero GPL version 3 at the following
    ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
    **
    ** Additional terms under GNU Affero GPL version 3 section 7:
    **
    **   Under Section 7 of the GNU Affero GPL version 3, the following additional
    **   terms apply to the works covered under the License.  These additional terms
    **   are non-permissive additional terms allowed under Section 7 of the GNU
    **   Affero GPL version 3 and may not be removed by you.
    **
    **   0. Attribution Requirement.
    **
    **     You must preserve all legal notices or author attributions in the covered
    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
    **     credit already included within the covered work.
    **
    **   1. No License To Use Trademarks.
    **
    **     This license does not grant any license or rights to use the trademarks
    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
    **     of Golden Code Development Corporation. You are not authorized to use the
    **     name Golden Code, FWD, or the names of any author or contributor, for
    **     publicity purposes without written authorization.
    **
    **   2. No Misrepresentation of Affiliation.
    **
    **     You may not represent yourself as Golden Code Development Corporation or FWD.
    **
    **     You may not represent yourself for publicity purposes as associated with
    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     the covered work, without written authorization.
    **
    **   3. No Misrepresentation of Source or Origin.
    **
    **     You may not represent the covered work as solely your work.  All modified
    **     versions of the covered work must be marked in a reasonable way to make it
    **     clear that the modified work is not originating from Golden Code Development
    **     Corporation or FWD.  All modified versions must contain the notices of
    **     attribution required in this license.
    */

    package com.goldencode.p2j.directory;

    import java.util.*;

    /**
     * A set of useful static routines to handle node and other IDs.
     *
     * @author SIY
     */
    public class IdUtils
    {
       /** Characters allowed in the node name. */
       static final String valid = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_.0123456789";

       /**
        * Generate a list of partial paths starting from root to specified node
        * ID. For example, <code>nodeId</code> <b>/security/users/siy </b> will
        * produce following set: <br>
        * <b>/security </b> <br>
        * <b>/security/users </b> <br>
        * <b>/security/users/siy </b> <br>
        *
        * @param   nodeId
        *          Node ID to normalize.
        *
        * @return  An array of normalized node IDs or <code>null</code> if node
        *          ID is invalid.
        */
       public static String[] listPaths(String nodeId)
       {
          if (nodeId == null)
          {
             return null;
          }
          String[] list = nodeId.split("/", 0);
          if (list == null || list.length == 0)
          {
             return null;
          }
          if (!list[0].isEmpty())
          {
             return null;
          }

          List<String> result = new ArrayList<>();

          StringBuilder res = new StringBuilder(nodeId.length() + 1);

          for (int i = 0; i < list.length; i++)
          {
             if (list[i].isEmpty())
             {
                continue;
             }
             res.append("/");
             res.append(list[i]);

             result.add(res.toString());
          }

          return result.toArray(new String[result.size()]);
       }

       /**
        * This method check nodeId validness and returns it in normalized form
        * <code>/elem0/elem2/&#46;&#46;&#46;/elemN</code>. All redundant
        * forward slashes are removed. If leading slash is omitted then path is
        * assumed invalid.
        *
        * @param   nodeId
        *          Node ID to normalize.
        *
        * @return  Normalized node ID or <code>null</code> if node ID is invalid.
        */
       public static String normalize(String nodeId)
       {
          if (nodeId == null)
          {
             return null;
          }
          //Special case
          if (nodeId.isEmpty())
          {
             return "";
          }

          String[] list = nodeId.split("/", 0);
          if (list == null || list.length == 0)
          {
             return null;
          }

          if (!list[0].isEmpty())
          {
             //No leading slash, relative paths are not allowed.
             return null;
          }

          StringBuilder res = new StringBuilder(nodeId.length() + 1);

          for (int i = 0; i < list.length; i++)
          {
             String link = list[i];

             if (link.isEmpty()) //Intermediate double slash, ignore
             {
                continue;
             }

             if (!verifyChars(link) || link.length() > 256)
             {
                return null;
             }

             res.append("/");
             res.append(link);
          }

          return res.toString();
       }

       /**
        * Uppercase first letter in the given string. If string contains dashes,
        * they are removed and each new part after dash is changed to upper case.
        * <p>
        * For example: <br>
        * <b>xml </b> will be converted to <b>Xml </b> <br>
        * <b>xml-ldap </b> will be converted to <b>XmlLdap </b> <br>
        * <b>xml-ldap-sql </b> will be converted to <b>XmlLdapSql </b> <br>
        *
        * @param   str
        *          Source string.
        *
        * @return  Source string with first character converted to the upper case.
        */
       public static String upcaseFirst(String str)
       {
          if (str.indexOf('-') > 0)
          {
             String[] s = str.split("\\-", 2);

             return upcaseFirst(s[0]) + upcaseFirst(s[1]);
          }
          return str.toUpperCase().charAt(0) + str.substring(1);
       }

       /**
        * Split path into parent id and node name. Note that for root node it
        * returns <code>null</code> since there is no parent for the root node.
        *
        * @param   id
        *          Node id.
        *
        * @return  Array with two elements, first contains id of root node, second
        *          contains node id. If something is wrong with path then
        *          <code>null</code> is returned.
        */
       static String[] splitId(String id)
       {
          id = IdUtils.normalize(id);

          if (id == null)
             return null;

          int pos = id.lastIndexOf("/");

          if (pos < 0)
             return null;

          return new String[] {id.substring(0, pos), id.substring(pos + 1)} ;
       }

       /**
        * Validate string content.
        *
        * @param   string
        *          Source string.
        *
        * @return  <code>true</code> if string contains only allowed characters
        *          and <code>false</code> otherwise.
        */
       private static boolean verifyChars(String string)
       {
          if (string == null)
             return false;

          for (int i = 0; i < string.length(); i++)
             if (valid.indexOf(string.charAt(i)) < 0)
                return false;

          return true;
       }
    }