# CharacterFormatter.java

    /*
    ** Module   : CharacterFormatter.java
    ** Abstract : Implements the Progress STRING(value, format) function for characters.
    **
    ** Copyright (c) 2019-2023, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- ---------------------------------Description---------------------------------
    ** 001 VVT 20210408 Created initial version.
    **     VVT 20210427 API changed: the format is now passed to class constructor.
    **                  Method parse() renamed to format()
    ** 002 GBB 20230512 Logging methods replaced by CentralLogger/ConversionStatus.
    */
    /*
    ** 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.util;

    import com.goldencode.p2j.util.logging.*;

    import java.io.*;

    /**
     * Implements the Progress <code>STRING(value, format)</code> function
     * for characters.
     * <p>
     * Example:
     * <p>
     * <pre>
     * CharacterFormatter formatter = new CharacterFormatter("String to format", "x(8)");
     * formatter.parse();
     * String formatted = formatter.getValue(); // "String t"
     * </pre>
     *
     */
    public class CharacterFormatter extends CharacterFormatParser
    {
       /** Logger */
       private static final CentralLogger LOG = CentralLogger.get(CharacterFormatter.class);

       /** The input format specification */
       protected final String format;

       /** The collector for the output formatted value */
       private final StringBuilder out = new StringBuilder();

       /** Reader on the input formatted string */
       private final Reader in;

       /**
        * The constructor.
        *
        * @param format
        *        the format string
        * @param value
        *        the value to format
        */
       public CharacterFormatter(final String format, final String value)
       {
          this.format = format;
          in = new StringReader(value);
       }

       /**
        * Get the formatted value.
        *
        * @return see above
        */
       public String getValue()
       {
          return out.toString();
       }

       /**
        * Do the formatting.
        *
        * @return the formatted string.
        */
       public String format()
       {
          parse(format);
          return out.toString();
       }

       /**
        * This method is called by {@link #format()} for each occurrence of
        * a non-special character in format string.
        *
        * @param ch
        *        the format character
        */
       @Override
       protected void visitFillChar(final char ch)
       {
          out.append(ch);
       }

       /**
        * This method is called by {@link #format()} for each occurrence of
        * the 'a' (letter) special character in format string.
        *
        * @param repeatCount
        *        the special character repeat count
        */
       @Override
       protected void visitLetter(final int repeatCount)
       {
          processCharactersAsIs(repeatCount);
       }

       /**
        * This method is called by {@link #format()} for each occurrence of
        * the 'n' (alphanumeric) special character in format string.
        *
        * @param repeatCount
        *        the special character repeat count
        */
       @Override
       protected void visitAlphanum(final int repeatCount)
       {
          processCharactersAsIs(repeatCount);
       }

       /**
        * This method is called by {@link #format()} for each occurrence of
        * the 'x' (any character) special character in format string.
        *
        * @param repeatCount
        *        the special character repeat count
        */
       @Override
       protected void visitAnyChar(final int repeatCount)
       {
          processCharactersAsIs(repeatCount);
       }

       /**
        * This method is called by {@link #format()} for each occurrence of
        * the '9' (the digit) special character in format string.
        *
        * @param repeatCount
        *        the special character repeat count
        */
       @Override
       protected void visitDigit(final int repeatCount)
       {
          processCharactersAsIs(repeatCount);
       }

       /**
        * This method is called by {@link #format()} for each occurrence of
        * the '!' (upcase) special character in format string.
        *
        * @param repeatCount
        *        the special character repeat count
        */
       @Override
       protected void visitUpperLetter(final int repeatCount)
       {
          processCharacters(Character::toUpperCase, repeatCount);
       }

       /**
        * Process characters with no conversion helper method.
        *
        * @param repeatCount
        *        the character repeat count
        */
       private final void processCharactersAsIs(int repeatCount)
       {
          processCharacters(c -> c, repeatCount);
       }

       /**
        * Process the action associated with a special formatting character.
        *
        * @param converter
        *        the character converter
        * @param repeatCount
        *        the number of times the operation should repeat
        */
       private final void processCharacters(final Convert converter, final int repeatCount)
       {
          try
          {
             for (int i = 0; i < repeatCount; i++)
             {
                final int read = in.read();
                if (read == -1)
                {
                   // No more input characters, pad with spaces
                   out.append(' ');
                   continue;
                }

                out.append(converter.convert((char) read));
             }
          }
          catch (IOException e)
          {
             // Should never happen when reading from a string
             LOG.severe("", e);
          }
       }

       /**
        * Helper method for character testers.
        *
        */
       private static interface Convert
       {
          /**
           * Convert a character.
           *
           * @param c
           *        the character to test
           *
           * @return the result of conversion
           */
          char convert(char c);
       }
    }