/*
    * CSVeed (https://github.com/42BV/CSVeed)
    *
    * Copyright 2013-2023 CSVeed.
    *
    * All rights reserved. This program and the accompanying materials
    * are made available under the terms of The Apache Software License,
    * Version 2.0 which accompanies this distribution, and is available at
    * https://www.apache.org/licenses/LICENSE-2.0.txt
   */
  package org.csveed.bean.conversion;
  
  import static org.csveed.bean.conversion.ConversionUtil.hasLength;
  
  /**
   * The Class CharacterConverter.
   */
  public class CharacterConverter extends AbstractConverter<Character> {
  
      /** The Constant UNICODE_PREFIX. */
      private static final String UNICODE_PREFIX = "\\u";
  
      /** The Constant UNICODE_LENGTH. */
      private static final int UNICODE_LENGTH = 6;
  
      /** The allow empty. */
      private final boolean allowEmpty;
  
      /**
       * Instantiates a new character converter.
       *
       * @param allowEmpty
       *            the allow empty
       */
      public CharacterConverter(boolean allowEmpty) {
          super(Character.class);
          this.allowEmpty = allowEmpty;
      }
  
      @Override
      public Character fromString(String text) throws Exception {
          if (this.allowEmpty && !hasLength(text)) {
              return null;
          }
          if (text == null) {
              throw new IllegalArgumentException("null String cannot be converted to char type");
          }
          if (isUnicodeCharacterSequence(text)) {
              int code = Integer.parseInt(text.substring(UNICODE_PREFIX.length()), 16);
              return (char) code;
          }
          if (text.length() != 1) {
              throw new IllegalArgumentException(
                      "String [" + text + "] with length " + text.length() + " cannot be converted to char type");
          }
          return text.charAt(0);
      }
  
      @Override
      public String toString(Character value) throws Exception {
          return value != null ? value.toString() : "";
      }
  
      /**
       * Checks if is unicode character sequence.
       *
       * @param sequence
       *            the sequence
       *
       * @return true, if is unicode character sequence
       */
      private boolean isUnicodeCharacterSequence(String sequence) {
          return sequence.startsWith(UNICODE_PREFIX) && sequence.length() == UNICODE_LENGTH;
      }
  
  }