/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You under the Apache License, Version 2.0
    * (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.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.commons.imaging.formats.tiff.taginfos;
  
  import java.nio.ByteOrder;
  import java.nio.charset.StandardCharsets;
  import java.util.Arrays;
  
  import org.apache.commons.imaging.ImagingException;
  import org.apache.commons.imaging.formats.tiff.TiffField;
  import org.apache.commons.imaging.formats.tiff.constants.TiffDirectoryType;
  import org.apache.commons.imaging.formats.tiff.fieldtypes.AbstractFieldType;
  
  /**
   * Windows XP onwards store some tags using UTF-16LE, but the field type is byte - here we deal with this.
   */
  public class TagInfoXpString extends TagInfo {
      public TagInfoXpString(final String name, final int tag, final TiffDirectoryType directoryType) {
          super(name, tag, AbstractFieldType.BYTE, LENGTH_UNKNOWN, directoryType);
      }
  
      @Override
      public byte[] encodeValue(final AbstractFieldType abstractFieldType, final Object value, final ByteOrder byteOrder) throws ImagingException {
          if (!(value instanceof String)) {
              throw new ImagingException("Text value not String", value);
          }
          final String s = (String) value;
          final byte[] bytes = s.getBytes(StandardCharsets.UTF_16LE);
          return Arrays.copyOf(bytes, bytes.length + 2);
      }
  
      @Override
      public String getValue(final TiffField entry) throws ImagingException {
          if (entry.getFieldType() != AbstractFieldType.BYTE) {
              throw new ImagingException("Text field not encoded as bytes.");
          }
          final byte[] bytes = entry.getByteArrayValue();
          final int length;
          if (bytes.length >= 2 && bytes[bytes.length - 1] == 0 && bytes[bytes.length - 2] == 0) {
              length = bytes.length - 2;
          } else {
              length = bytes.length;
          }
          return new String(bytes, 0, length, StandardCharsets.UTF_16LE);
      }
  }