/*
    * 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.jpeg.iptc;
  
  import static org.apache.commons.imaging.common.BinaryFunctions.read2Bytes;
  import static org.apache.commons.imaging.common.BinaryFunctions.read4Bytes;
  import static org.apache.commons.imaging.common.BinaryFunctions.readByte;
  import static org.apache.commons.imaging.common.BinaryFunctions.readBytes;
  import static org.apache.commons.imaging.common.BinaryFunctions.slice;
  import static org.apache.commons.imaging.common.BinaryFunctions.startsWith;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.nio.ByteOrder;
  import java.nio.charset.Charset;
  import java.nio.charset.StandardCharsets;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Comparator;
  import java.util.List;
  import java.util.Objects;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  import org.apache.commons.imaging.ImagingConstants;
  import org.apache.commons.imaging.ImagingException;
  import org.apache.commons.imaging.ImagingParameters;
  import org.apache.commons.imaging.common.Allocator;
  import org.apache.commons.imaging.common.BinaryFileParser;
  import org.apache.commons.imaging.common.BinaryFunctions;
  import org.apache.commons.imaging.common.BinaryOutputStream;
  import org.apache.commons.imaging.common.ByteConversions;
  import org.apache.commons.imaging.formats.jpeg.JpegConstants;
  import org.apache.commons.imaging.formats.jpeg.JpegImagingParameters;
  import org.apache.commons.imaging.internal.Debug;
  
  public class IptcParser extends BinaryFileParser {
  
      private static final Logger LOGGER = Logger.getLogger(IptcParser.class.getName());
  
      private static final ByteOrder APP13_BYTE_ORDER = ByteOrder.BIG_ENDIAN;
  
      /**
       * Block types (or Image Resource IDs) that are not recommended to be interpreted when libraries process Photoshop IPTC metadata.
       *
       * @see <a href="https://www.adobe.com/devnet-apps/photoshop/fileformatashtml/">Adobe Photoshop File Formats Specification</a>
       * @see <a href="https://issues.apache.org/jira/browse/IMAGING-246">IMAGING-246</a>
       * @since 1.0-alpha2
       */
      private static final List<Integer> PHOTOSHOP_IGNORED_BLOCK_TYPE = Arrays.asList(1084, 1085, 1086, 1087);
  
      private static final Charset DEFAULT_CHARSET = StandardCharsets.ISO_8859_1;
      private static final int ENV_TAG_CODED_CHARACTER_SET = 90;
      private static final byte[] CHARACTER_ESCAPE_SEQUENCE = { '\u001B', '%', 'G' };
  
      public IptcParser() {
          super(ByteOrder.BIG_ENDIAN);
      }
  
      private Charset findCharset(final byte[] codedCharset) {
          final String codedCharsetString = new String(codedCharset, StandardCharsets.ISO_8859_1);
          try {
              if (Charset.isSupported(codedCharsetString)) {
                  return Charset.forName(codedCharsetString);
              }
          } catch (final IllegalArgumentException ignored) {
              // ignored
          }
          // check if encoding is a escape sequence
          // normalize encoding byte sequence
          final byte[] codedCharsetNormalized = Allocator.byteArray(codedCharset.length);
          int j = 0;
          for (final byte element : codedCharset) {
              if (element != ' ') {
                  codedCharsetNormalized[j++] = element;
              }
          }
  
          if (Objects.deepEquals(codedCharsetNormalized, CHARACTER_ESCAPE_SEQUENCE)) {
              return StandardCharsets.UTF_8;
          }
          return DEFAULT_CHARSET;
     }
 
     public boolean isPhotoshopJpegSegment(final byte[] segmentData) {
         if (!startsWith(segmentData, JpegConstants.PHOTOSHOP_IDENTIFICATION_STRING)) {
             return false;
         }
 
         final int index = JpegConstants.PHOTOSHOP_IDENTIFICATION_STRING.size();
         return index + 4 <= segmentData.length && ByteConversions.toInt(segmentData, index, APP13_BYTE_ORDER) == JpegConstants.CONST_8BIM;
     }
 
     protected List<IptcBlock> parseAllBlocks(final byte[] bytes, final boolean strict) throws ImagingException, IOException {
         final List<IptcBlock> blocks = new ArrayList<>();
 
         try (InputStream bis = new ByteArrayInputStream(bytes)) {
 
             // Note that these are unsigned quantities. Name is always an even
             // number of bytes (including the 1st byte, which is the size.)
 
             final byte[] idString = readBytes("", bis, JpegConstants.PHOTOSHOP_IDENTIFICATION_STRING.size(), "App13 Segment missing identification string");
             if (!JpegConstants.PHOTOSHOP_IDENTIFICATION_STRING.equals(idString)) {
                 throw new ImagingException("Not a Photoshop App13 Segment");
             }
 
             // int index = PHOTOSHOP_IDENTIFICATION_STRING.length;
 
             while (true) {
                 final int imageResourceBlockSignature;
                 try {
                     imageResourceBlockSignature = read4Bytes("", bis, "Image Resource Block missing identification string", APP13_BYTE_ORDER);
                 } catch (final IOException ioEx) {
                     break;
                 }
                 if (imageResourceBlockSignature != JpegConstants.CONST_8BIM) {
                     throw new ImagingException("Invalid Image Resource Block Signature");
                 }
 
                 final int blockType = read2Bytes("", bis, "Image Resource Block missing type", APP13_BYTE_ORDER);
                 Debug.debug("blockType: " + blockType + " (0x" + Integer.toHexString(blockType) + ")");
 
                 // skip blocks that the photoshop spec recommends to, see IMAGING-246
                 if (PHOTOSHOP_IGNORED_BLOCK_TYPE.contains(blockType)) {
                     Debug.debug("Skipping blockType: " + blockType + " (0x" + Integer.toHexString(blockType) + ")");
                     // if there is still data in this block, before the next image resource block
                     // (8BIM), then we must consume these bytes to leave a pointer ready to read
                     // the next block
                     BinaryFunctions.searchQuad(JpegConstants.CONST_8BIM, bis);
                     continue;
                 }
 
                 final int blockNameLength = readByte("Name length", bis, "Image Resource Block missing name length");
                 if (blockNameLength > 0) {
                     Debug.debug("blockNameLength: " + blockNameLength + " (0x" + Integer.toHexString(blockNameLength) + ")");
                 }
                 byte[] blockNameBytes;
                 if (blockNameLength == 0) {
                     readByte("Block name bytes", bis, "Image Resource Block has invalid name");
                     blockNameBytes = ImagingConstants.EMPTY_BYTE_ARRAY;
                 } else {
                     try {
                         blockNameBytes = readBytes("", bis, blockNameLength, "Invalid Image Resource Block name");
                     } catch (final IOException ioEx) {
                         if (strict) {
                             throw ioEx;
                         }
                         break;
                     }
 
                     if (blockNameLength % 2 == 0) {
                         readByte("Padding byte", bis, "Image Resource Block missing padding byte");
                     }
                 }
 
                 final int blockSize = read4Bytes("", bis, "Image Resource Block missing size", APP13_BYTE_ORDER);
                 Debug.debug("blockSize: " + blockSize + " (0x" + Integer.toHexString(blockSize) + ")");
 
                 /*
                  * doesn't catch cases where blocksize is invalid but is still less than bytes.length but will at least prevent OutOfMemory errors
                  */
                 if (blockSize > bytes.length) {
                     throw new ImagingException("Invalid Block Size : " + blockSize + " > " + bytes.length);
                 }
 
                 final byte[] blockData;
                 try {
                     blockData = readBytes("", bis, blockSize, "Invalid Image Resource Block data");
                 } catch (final IOException ioEx) {
                     if (strict) {
                         throw ioEx;
                     }
                     break;
                 }
 
                 blocks.add(new IptcBlock(blockType, blockNameBytes, blockData));
 
                 if (blockSize % 2 != 0) {
                     readByte("Padding byte", bis, "Image Resource Block missing padding byte");
                 }
             }
 
             return blocks;
         }
     }
 
     protected List<IptcRecord> parseIptcBlock(final byte[] bytes) {
         Charset charset = DEFAULT_CHARSET;
         final List<IptcRecord> elements = new ArrayList<>();
 
         int index = 0;
         // Integer recordVersion = null;
         while (index + 1 < bytes.length) {
             final int tagMarker = 0xff & bytes[index++];
             Debug.debug("tagMarker: " + tagMarker + " (0x" + Integer.toHexString(tagMarker) + ")");
 
             if (tagMarker != IptcConstants.IPTC_RECORD_TAG_MARKER) {
                 if (LOGGER.isLoggable(Level.FINE)) {
                     LOGGER.fine("Unexpected record tag marker in IPTC data.");
                 }
                 return elements;
             }
 
             final int recordNumber = 0xff & bytes[index++];
             Debug.debug("recordNumber: " + recordNumber + " (0x" + Integer.toHexString(recordNumber) + ")");
 
             // int recordPrefix = convertByteArrayToShort("recordPrefix", index,
             // bytes);
             // if (verbose)
             // Debug.debug("recordPrefix", recordPrefix + " (0x"
             // + Integer.toHexString(recordPrefix) + ")");
             // index += 2;
             //
             // if (recordPrefix != IPTC_RECORD_PREFIX)
             // {
             // if (verbose)
             // System.out
             // .println("Unexpected record prefix in IPTC data!");
             // return elements;
             // }
 
             // throw new ImageReadException(
             // "Unexpected record prefix in IPTC data.");
 
             final int recordType = 0xff & bytes[index];
             Debug.debug("recordType: " + recordType + " (0x" + Integer.toHexString(recordType) + ")");
             index++;
 
             final int recordSize = ByteConversions.toUInt16(bytes, index, getByteOrder());
             index += 2;
 
             final boolean extendedDataset = recordSize > IptcConstants.IPTC_NON_EXTENDED_RECORD_MAXIMUM_SIZE;
             final int dataFieldCountLength = recordSize & 0x7fff;
             if (extendedDataset) {
                 Debug.debug("extendedDataset. dataFieldCountLength: " + dataFieldCountLength);
             }
             if (extendedDataset) {
                 // ignore extended dataset and everything after.
                 return elements;
             }
 
             final byte[] recordData = slice(bytes, index, recordSize);
             index += recordSize;
 
             // Debug.debug("recordSize", recordSize + " (0x"
             // + Integer.toHexString(recordSize) + ")");
 
             if (recordNumber == IptcConstants.IPTC_ENVELOPE_RECORD_NUMBER && recordType == ENV_TAG_CODED_CHARACTER_SET) {
                 charset = findCharset(recordData);
                 continue;
             }
 
             if (recordNumber != IptcConstants.IPTC_APPLICATION_2_RECORD_NUMBER) {
                 continue;
             }
 
             if (recordType == 0) {
                 if (LOGGER.isLoggable(Level.FINE)) {
                     LOGGER.fine("ignore record version record! " + elements.size());
                 }
                 // ignore "record version" record;
                 continue;
             }
             // if (recordVersion == null)
             // {
             // // The first record in a JPEG/Photoshop IPTC block must be
             // // the record version.
             // if (recordType != 0)
             // throw new ImageReadException("Missing record version: "
             // + recordType);
             // recordVersion = new Integer(convertByteArrayToShort(
             // "recordNumber", recordData));
             //
             // if (recordSize != 2)
             // throw new ImageReadException(
             // "Invalid record version record size: " + recordSize);
             //
             // // JPEG/Photoshop IPTC metadata is always in Record version
             // // 2
             // if (recordVersion.intValue() != 2)
             // throw new ImageReadException(
             // "Invalid IPTC record version: " + recordVersion);
             //
             // // Debug.debug("recordVersion", recordVersion);
             // continue;
             // }
 
             final String value = new String(recordData, charset);
 
             final IptcType iptcType = IptcTypeLookup.getIptcType(recordType);
 
             // Debug.debug("iptcType", iptcType);
             // debugByteArray("iptcData", iptcData);
             // Debug.debug();
 
             // if (recordType == IPTC_TYPE_CREDIT.type
             // || recordType == IPTC_TYPE_OBJECT_NAME.type)
             // {
             // this.debugByteArray("recordData", recordData);
             // Debug.debug("index", IPTC_TYPE_CREDIT.name);
             // }
 
             final IptcRecord element = new IptcRecord(iptcType, value);
             elements.add(element);
         }
 
         return elements;
     }
 
     public PhotoshopApp13Data parsePhotoshopSegment(final byte[] bytes, final boolean strict) throws ImagingException, IOException {
         final List<IptcRecord> records = new ArrayList<>();
 
         final List<IptcBlock> blocks = parseAllBlocks(bytes, strict);
 
         for (final IptcBlock block : blocks) {
             // Ignore everything but IPTC data.
             if (!block.isIptcBlock()) {
                 continue;
             }
 
             records.addAll(parseIptcBlock(block.getBlockData()));
         }
 
         return new PhotoshopApp13Data(records, blocks);
     }
 
     // private void writeIPTCRecord(BinaryOutputStream bos, )
 
     /*
      * In practice, App13 segments are only used for Photoshop/IPTC metadata. However, we should not treat App13 signatures without Photoshop's signature as
      * Photoshop/IPTC segments.
      *
      * A Photoshop/IPTC App13 segment begins with the Photoshop Identification string.
      *
      * There follows 0-N blocks (Photoshop calls them "Image Resource Blocks").
      *
      * Each block has the following structure:
      *
      * 1. 4-byte type. This is always "8BIM" for blocks in a Photoshop App13 segment. 2. 2-byte id. IPTC data is stored in blocks with id 0x0404, aka.
      * IPTC_NAA_RECORD_IMAGE_RESOURCE_ID 3. Block name as a Pascal String. This is padded to have an even length. 4. 4-byte size (in bytes). 5. Block data. This
      * is also padded to have an even length.
      *
      * The block data consists of a 0-N records. A record has the following structure:
      *
      * 1. 2-byte prefix. The value is always 0x1C02 2. 1-byte record type. The record types are documented by the IPTC. See IptcConstants. 3. 2-byte record size
      * (in bytes). 4. Record data, "record size" bytes long.
      *
      * Record data (unlike block data) is NOT padded to have an even length.
      *
      * Record data, for IPTC record, should always be ISO-8859-1. But according to SANSELAN-33, this isn't always the case.
      *
      * The exception is the first record in the block, which must always be a record version record, whose value is a two-byte number; the value is 0x02.
      *
      * Some IPTC blocks are missing this first "record version" record, so we don't require it.
      */
     public PhotoshopApp13Data parsePhotoshopSegment(final byte[] bytes, final ImagingParameters<JpegImagingParameters> params)
             throws ImagingException, IOException {
         final boolean strict = params != null && params.isStrict();
 
         return parsePhotoshopSegment(bytes, strict);
     }
 
     public byte[] writeIptcBlock(List<IptcRecord> elements) throws ImagingException, IOException {
         Charset charset = DEFAULT_CHARSET;
         for (final IptcRecord element : elements) {
             final byte[] recordData = element.getValue().getBytes(charset);
             if (!new String(recordData, charset).equals(element.getValue())) {
                 charset = StandardCharsets.UTF_8;
                 break;
             }
         }
         final byte[] blockData;
         final ByteArrayOutputStream baos = new ByteArrayOutputStream();
         try (BinaryOutputStream bos = BinaryOutputStream.create(baos, getByteOrder())) {
             if (!charset.equals(DEFAULT_CHARSET)) {
                 bos.write(IptcConstants.IPTC_RECORD_TAG_MARKER);
                 bos.write(IptcConstants.IPTC_ENVELOPE_RECORD_NUMBER);
                 bos.write(ENV_TAG_CODED_CHARACTER_SET);
                 final byte[] codedCharset = CHARACTER_ESCAPE_SEQUENCE;
                 bos.write2Bytes(codedCharset.length);
                 bos.write(codedCharset);
             }
 
             // first, right record version record
             bos.write(IptcConstants.IPTC_RECORD_TAG_MARKER);
             bos.write(IptcConstants.IPTC_APPLICATION_2_RECORD_NUMBER);
             bos.write(IptcTypes.RECORD_VERSION.type); // record version record
                                                       // type.
             bos.write2Bytes(2); // record version record size
             bos.write2Bytes(2); // record version value
 
             // make a copy of the list.
             elements = new ArrayList<>(elements);
 
             // sort the list. Records must be in numerical order.
             final Comparator<IptcRecord> comparator = (e1, e2) -> e2.iptcType.getType() - e1.iptcType.getType();
             elements.sort(comparator);
             // TODO: make sure order right
 
             // write the list.
             for (final IptcRecord element : elements) {
                 if (element.iptcType == IptcTypes.RECORD_VERSION) {
                     continue; // ignore
                 }
 
                 bos.write(IptcConstants.IPTC_RECORD_TAG_MARKER);
                 bos.write(IptcConstants.IPTC_APPLICATION_2_RECORD_NUMBER);
                 if (element.iptcType.getType() < 0 || element.iptcType.getType() > 0xff) {
                     throw new ImagingException("Invalid record type: " + element.iptcType.getType());
                 }
                 bos.write(element.iptcType.getType());
 
                 final byte[] recordData = element.getValue().getBytes(charset);
                 /*
                  * if (!new String(recordData, charset).equals(element.getValue())) { throw new ImageWriteException( "Invalid record value, not " +
                  * charset.name()); }
                  */
 
                 bos.write2Bytes(recordData.length);
                 bos.write(recordData);
             }
         }
 
         return baos.toByteArray();
     }
 
     public byte[] writePhotoshopApp13Segment(final PhotoshopApp13Data data) throws IOException, ImagingException {
         try (ByteArrayOutputStream os = new ByteArrayOutputStream();
                 BinaryOutputStream bos = BinaryOutputStream.bigEndian(os)) {
 
             JpegConstants.PHOTOSHOP_IDENTIFICATION_STRING.writeTo(bos);
 
             final List<IptcBlock> blocks = data.getRawBlocks();
             for (final IptcBlock block : blocks) {
                 bos.write4Bytes(JpegConstants.CONST_8BIM);
 
                 if (block.getBlockType() < 0 || block.getBlockType() > 0xffff) {
                     throw new ImagingException("Invalid IPTC block type.");
                 }
                 bos.write2Bytes(block.getBlockType());
 
                 final byte[] blockNameBytes = block.getBlockNameBytes();
                 if (blockNameBytes.length > 255) {
                     throw new ImagingException("IPTC block name is too long: " + blockNameBytes.length);
                 }
                 bos.write(blockNameBytes.length);
                 bos.write(blockNameBytes);
                 if (blockNameBytes.length % 2 == 0) {
                     bos.write(0); // pad to even size, including length byte.
                 }
 
                 final byte[] blockData = block.getBlockData();
                 if (blockData.length > IptcConstants.IPTC_NON_EXTENDED_RECORD_MAXIMUM_SIZE) {
                     throw new ImagingException("IPTC block data is too long: " + blockData.length);
                 }
                 bos.write4Bytes(blockData.length);
                 bos.write(blockData);
                 if (blockData.length % 2 == 1) {
                     bos.write(0); // pad to even size
                 }
             }
 
             bos.flush();
             return os.toByteArray();
         }
     }
 
 }