/*
    * 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 org.apache.commons.imaging.ImagingException;
  import org.apache.commons.imaging.common.Allocator;
  import org.apache.commons.imaging.formats.tiff.constants.TiffDirectoryType;
  import org.apache.commons.imaging.formats.tiff.fieldtypes.AbstractFieldType;
  
  public class TagInfoAscii extends TagInfo {
      public TagInfoAscii(final String name, final int tag, final int length, final TiffDirectoryType directoryType) {
          super(name, tag, AbstractFieldType.ASCII, length, directoryType);
      }
  
      public byte[] encodeValue(final ByteOrder byteOrder, final String... values) throws ImagingException {
          return AbstractFieldType.ASCII.writeData(values, byteOrder);
      }
  
      public String[] getValue(final ByteOrder byteOrder, final byte[] bytes) {
          int nullCount = 0;
          for (int i = 0; i < bytes.length - 1; i++) {
              if (bytes[i] == 0) {
                  nullCount++;
              }
          }
          final String[] strings = Allocator.array(nullCount + 1, String[]::new, 24);
          int stringsAdded = 0;
          strings[0] = ""; // if we have a 0 length string
          int nextStringPos = 0;
          // According to the Exiftool FAQ, [BROKEN URL] http://www.metadataworkinggroup.org
          // specifies that the TIFF ASCII fields are actually UTF-8.
          // Exiftool however allows you to configure the charset used.
          for (int i = 0; i < bytes.length; i++) {
              if (bytes[i] == 0) {
                  final String string = new String(bytes, nextStringPos, i - nextStringPos, StandardCharsets.UTF_8);
                  strings[stringsAdded++] = string;
                  nextStringPos = i + 1;
              }
          }
          if (nextStringPos < bytes.length) {
              // Buggy file, string wasn't null terminated
              final String string = new String(bytes, nextStringPos, bytes.length - nextStringPos, StandardCharsets.UTF_8);
              strings[stringsAdded++] = string;
          }
          return strings;
      }
  }