// SPDX-License-Identifier: GPL-2.0-or-later

// included header files

#include "psdimage.hpp"

#include "basicio.hpp"

#include "config.h"

#include "enforce.hpp"

#include "error.hpp"

#include "futils.hpp"

#include "image.hpp"

#include "photoshop.hpp"

#ifdef EXIV2_DEBUG_MESSAGES

#include <iostream>

#endif

// Todo: Consolidate with existing code in struct Photoshop (jpgimage.hpp):

//       Extend this helper to a proper class with all required functionality,

//       then move it here or into a separate file?

//! @cond IGNORE

struct PhotoshopResourceBlock {

  uint32_t resourceType;  // one of the markers in Photoshop::irbId_[]

  uint16_t resourceId;

  unsigned char resourceName[2];  // Pascal string (length byte + characters), padded to an even size -- this assumes

                                  // the empty string

  uint32_t resourceDataSize;

};

//! @endcond

// Photoshop resource IDs (Cf.

// <http://search.cpan.org/~bettelli/Image-MetaData-JPEG-0.15/lib/Image/MetaData/JPEG/TagLists.pod>)

enum kPhotoshopResourceID {

  Photoshop2Info = 0x03e8,  // [obsolete -- Photoshop 2.0 only] General information -- contains five 2-byte values:

                            // number of channels, rows, columns, depth and mode

  MacintoshClassicPrintInfo = 0x03e9,  // [optional] Macintosh classic print record (120 bytes)

  MacintoshCarbonPrintInfo = 0x03ea,   // [optional] Macintosh carbon print info (variable-length XML format)

  Photoshop2ColorTable = 0x03eb,       // [obsolete -- Photoshop 2.0 only] Indexed color table

  ResolutionInfo = 0x03ed,             // PhotoshopResolutionInfo structure (see below)

  AlphaChannelsNames = 0x03ee,         // as a series of Pstrings

  DisplayInfo = 0x03ef,                // see appendix A in Photoshop SDK

  PStringCaption = 0x03f0,             // [optional] the caption, as a Pstring

  BorderInformation = 0x03f1,          // border width and units

  BackgroundColor = 0x03f2,            // see additional Adobe information

  PrintFlags = 0x03f3,                 // labels, crop marks, colour bars, ecc...

  BWHalftoningInfo = 0x03f4,           // Gray-scale and multich. half-toning info

  ColorHalftoningInfo = 0x03f5,        // Colour half-toning information

  DuotoneHalftoningInfo = 0x03f6,      // Duo-tone half-toning information

  BWTransferFunc = 0x03f7,             // Gray-scale and multich. transfer function

  ColorTransferFuncs = 0x03f8,         // Colour transfer function

  DuotoneTransferFuncs = 0x03f9,       // Duo-tone transfer function

  DuotoneImageInfo = 0x03fa,           // Duo-tone image information

  EffectiveBW = 0x03fb,                // two bytes for the effective black and white values

  ObsoletePhotoshopTag1 = 0x03fc,      // [obsolete]

  EPSOptions = 0x03fd,                 // Encapsulated Postscript options

  QuickMaskInfo = 0x03fe,              // Quick Mask information. 2 bytes containing Quick Mask channel ID,

                                       // 1 byte boolean indicating whether the mask was initially empty.

  ObsoletePhotoshopTag2 = 0x03ff,      // [obsolete]

  LayerStateInfo = 0x0400,             // index of target layer (0 means bottom)

  WorkingPathInfo = 0x0401,            // should not be saved to the file

  LayersGroupInfo = 0x0402,            // for grouping layers together

  ObsoletePhotoshopTag3 = 0x0403,      // [obsolete] ??

  IPTC_NAA = 0x0404,                   // IPTC/NAA data

  RawImageMode = 0x0405,               // image mode for raw format files

  JPEGQuality = 0x0406,                // [private]

  GridGuidesInfo = 0x0408,             // see additional Adobe information

  ThumbnailResource = 0x0409,          // see additional Adobe information

  CopyrightFlag = 0x040a,              // true if image is copyrighted

  URL = 0x040b,                        // text string with a resource locator

  ThumbnailResource2 = 0x040c,         // see additional Adobe information

  GlobalAngle = 0x040d,                // global lighting angle for effects layer

  ColorSamplersResource = 0x040e,      // see additional Adobe information

  ICCProfile = 0x040f,                 // see notes from Internat. Color Consortium

  Watermark = 0x0410,                  // one byte

  ICCUntagged = 0x0411,                // 1 means intentionally untagged

  EffectsVisible = 0x0412,             // 1 byte to show/hide all effects layers

  SpotHalftone = 0x0413,               // version, length and data

  IDsBaseValue = 0x0414,               // base value for new layers ID's

  UnicodeAlphaNames = 0x0415,          // length plus Unicode string

  IndexedColourTableCount = 0x0416,    // [Photoshop 6.0 and later] 2 bytes

  TransparentIndex = 0x0417,           // [Photoshop 6.0 and later] 2 bytes

  GlobalAltitude = 0x0419,             // [Photoshop 6.0 and later] 4 bytes

  Slices = 0x041a,                     // [Photoshop 6.0 and later] see additional Adobe info

  WorkflowURL = 0x041b,                // [Photoshop 6.0 and later] 4 bytes length + Unicode string

  JumpToXPEP = 0x041c,                 // [Photoshop 6.0 and later] see additional Adobe info

  AlphaIdentifiers = 0x041d,           // [Photoshop 6.0 and later] 4*(n+1) bytes

  URLList = 0x041e,                    // [Photoshop 6.0 and later] structured Unicode URL's

  VersionInfo = 0x0421,                // [Photoshop 6.0 and later] see additional Adobe info

  ExifInfo = 0x0422,                   // [Photoshop 7.0?] Exif metadata

  XMPPacket = 0x0424,  // [Photoshop 7.0?] XMP packet -- see  http://www.adobe.com/devnet/xmp/pdfs/xmp_specification.pdf

  ClippingPathName = 0x0bb7,  // [Photoshop 6.0 and later] name of clipping path

  MorePrintFlags = 0x2710,    // [Photoshop 6.0 and later] Print flags information. 2 bytes version (=1), 1 byte center

                              // crop  marks, 1 byte (=0), 4 bytes bleed width value, 2 bytes bleed width  scale.

};

// *****************************************************************************

// class member definitions

namespace Exiv2 {

PsdImage::PsdImage(BasicIo::UniquePtr io) : Image(ImageType::psd, mdExif | mdIptc | mdXmp, std::move(io)) {

}  // PsdImage::PsdImage

std::string PsdImage::mimeType() const {

  return "image/x-photoshop";

}

void PsdImage::setComment(const std::string&) {

  // not supported

  throw(Error(ErrorCode::kerInvalidSettingForImage, "Image comment", "Photoshop"));

}

void PsdImage::readMetadata() {

#ifdef EXIV2_DEBUG_MESSAGES

  std::cerr << "Exiv2::PsdImage::readMetadata: Reading Photoshop file " << io_->path() << "\n";

#endif

  if (io_->open() != 0) {

    throw Error(ErrorCode::kerDataSourceOpenFailed, io_->path(), strError());

  }

  IoCloser closer(*io_);

  // Ensure that this is the correct image type

  if (!isPsdType(*io_, false)) {

    if (io_->error() || io_->eof())

      throw Error(ErrorCode::kerFailedToReadImageData);

    throw Error(ErrorCode::kerNotAnImage, "Photoshop");

  }

  clearMetadata();

  /*

    The Photoshop header goes as follows -- all numbers are in big-endian byte order:

    offset  length   name       description

    ======  =======  =========  =========

     0      4 bytes  signature  always '8BPS'

     4      2 bytes  version    always equal to 1

     6      6 bytes  reserved   must be zero

    12      2 bytes  channels   number of channels in the image, including alpha channels (1 to 24)

    14      4 bytes  rows       the height of the image in pixels

    18      4 bytes  columns    the width of the image in pixels

    22      2 bytes  depth      the number of bits per channel

    24      2 bytes  mode       the color mode of the file; Supported values are: Bitmap=0; Grayscale=1;

    Indexed=2; RGB=3; CMYK=4; Multichannel=7; Duotone=8; Lab=9

  */

  byte buf[26];

  if (io_->read(buf, 26) != 26) {

    throw Error(ErrorCode::kerNotAnImage, "Photoshop");

  }

  pixelWidth_ = getLong(buf + 18, bigEndian);

  pixelHeight_ = getLong(buf + 14, bigEndian);

  // immediately following the image header is the color mode data section,

  // the first four bytes of which specify the byte size of the whole section

  if (io_->read(buf, 4) != 4) {

    throw Error(ErrorCode::kerNotAnImage, "Photoshop");

  }

  // skip it

  if (io_->seek(getULong(buf, bigEndian), BasicIo::cur)) {

    throw Error(ErrorCode::kerNotAnImage, "Photoshop");

  }

  // after the color data section, comes a list of resource blocks, preceded by the total byte size

  if (io_->read(buf, 4) != 4) {

    throw Error(ErrorCode::kerNotAnImage, "Photoshop");

  }

  uint32_t resourcesLength = getULong(buf, bigEndian);

  Internal::enforce(resourcesLength < io_->size(), Exiv2::ErrorCode::kerCorruptedMetadata);

  while (resourcesLength > 0) {

    Internal::enforce(resourcesLength >= 8, Exiv2::ErrorCode::kerCorruptedMetadata);

    resourcesLength -= 8;

    if (io_->read(buf, 8) != 8) {

      throw Error(ErrorCode::kerNotAnImage, "Photoshop");

    }

    if (!Photoshop::isIrb(buf)) {

      break;  // bad resource type

    }

    uint16_t resourceId = getUShort(buf + 4, bigEndian);

    uint32_t resourceNameLength = buf[6] & ~1;

    // skip the resource name, plus any padding

    Internal::enforce(resourceNameLength <= resourcesLength, Exiv2::ErrorCode::kerCorruptedMetadata);

    resourcesLength -= resourceNameLength;

    io_->seek(resourceNameLength, BasicIo::cur);

    // read resource size

    Internal::enforce(resourcesLength >= 4, Exiv2::ErrorCode::kerCorruptedMetadata);

    resourcesLength -= 4;

    if (io_->read(buf, 4) != 4) {

      throw Error(ErrorCode::kerNotAnImage, "Photoshop");

    }

    uint32_t resourceSize = getULong(buf, bigEndian);

    const size_t curOffset = io_->tell();

#ifdef EXIV2_DEBUG_MESSAGES

    std::cerr << std::hex << "resourceId: " << resourceId << std::dec << " length: " << resourceSize << std::hex

              << "\n";

#endif

    Internal::enforce(resourceSize <= resourcesLength, Exiv2::ErrorCode::kerCorruptedMetadata);

    readResourceBlock(resourceId, resourceSize);

    resourceSize = (resourceSize + 1) & ~1;  // pad to even

    Internal::enforce(resourceSize <= resourcesLength, Exiv2::ErrorCode::kerCorruptedMetadata);

    resourcesLength -= resourceSize;

    io_->seek(curOffset + resourceSize, BasicIo::beg);

  }

}  // PsdImage::readMetadata

void PsdImage::readResourceBlock(uint16_t resourceId, uint32_t resourceSize) {

  switch (resourceId) {

    case kPhotoshopResourceID::IPTC_NAA: {

      DataBuf rawIPTC(resourceSize);

      io_->read(rawIPTC.data(), rawIPTC.size());

      if (io_->error() || io_->eof())

        throw Error(ErrorCode::kerFailedToReadImageData);

      if (IptcParser::decode(iptcData_, rawIPTC.c_data(), rawIPTC.size())) {

#ifndef SUPPRESS_WARNINGS

        EXV_WARNING << "Failed to decode IPTC metadata.\n";

#endif

        iptcData_.clear();

      }

      break;

    }

    case kPhotoshopResourceID::ExifInfo: {

      DataBuf rawExif(resourceSize);

      io_->read(rawExif.data(), rawExif.size());

      if (io_->error() || io_->eof())

        throw Error(ErrorCode::kerFailedToReadImageData);

      ByteOrder bo = ExifParser::decode(exifData_, rawExif.c_data(), rawExif.size());

      setByteOrder(bo);

      if (!rawExif.empty() && byteOrder() == invalidByteOrder) {

#ifndef SUPPRESS_WARNINGS

        EXV_WARNING << "Failed to decode Exif metadata.\n";

#endif

        exifData_.clear();

      }

      break;

    }

    case kPhotoshopResourceID::XMPPacket: {

      DataBuf xmpPacket(resourceSize);

      io_->read(xmpPacket.data(), xmpPacket.size());

      if (io_->error() || io_->eof())

        throw Error(ErrorCode::kerFailedToReadImageData);

      xmpPacket_.assign(xmpPacket.c_str(), xmpPacket.size());

      if (!xmpPacket_.empty() && XmpParser::decode(xmpData_, xmpPacket_)) {

#ifndef SUPPRESS_WARNINGS

        EXV_WARNING << "Failed to decode XMP metadata.\n";

#endif

      }

      break;

    }

    // - PS 4.0 preview data is fetched from ThumbnailResource

    // - PS >= 5.0 preview data is fetched from ThumbnailResource2

    case kPhotoshopResourceID::ThumbnailResource:

    case kPhotoshopResourceID::ThumbnailResource2: {

      /*

        Photoshop thumbnail resource header

        offset  length    name            description

        ======  ========  ====            ===========

         0      4 bytes   format          = 1 (kJpegRGB). Also supports kRawRGB (0).

         4      4 bytes   width           Width of thumbnail in pixels.

         8      4 bytes   height          Height of thumbnail in pixels.

        12      4 bytes   widthbytes      Padded row bytes as (width * bitspixel + 31) / 32 * 4.

        16      4 bytes   size            Total size as widthbytes * height * planes

        20      4 bytes   compressedsize  Size after compression. Used for consistency check.

        24      2 bytes   bitspixel       = 24. Bits per pixel.

        26      2 bytes   planes          = 1. Number of planes.

        28      variable  data            JFIF data in RGB format.

                                          Note: For resource ID 1033 the data is in BGR format.

      */

      byte buf[28];

      if (io_->read(buf, 28) != 28) {

        throw Error(ErrorCode::kerNotAnImage, "Photoshop");

      }

      NativePreview nativePreview;

      nativePreview.position_ = io_->tell();

      nativePreview.size_ = getLong(buf + 20, bigEndian);  // compressedsize

      nativePreview.width_ = getLong(buf + 4, bigEndian);

      nativePreview.height_ = getLong(buf + 8, bigEndian);

      const uint32_t format = getLong(buf + 0, bigEndian);

      Internal::enforce(nativePreview.size_ <= static_cast<size_t>(std::numeric_limits<long>::max()),

                        Exiv2::ErrorCode::kerCorruptedMetadata);

      if (nativePreview.size_ > 0 && nativePreview.position_ > 0) {

        io_->seek(static_cast<long>(nativePreview.size_), BasicIo::cur);

        if (io_->error() || io_->eof())

          throw Error(ErrorCode::kerFailedToReadImageData);

        // unsupported format of native preview

        if (format != 1)

          break;

        nativePreview.filter_ = "";

        nativePreview.mimeType_ = "image/jpeg";

        nativePreviews_.push_back(std::move(nativePreview));

      }

      break;

    }

    default:

      break;

  }

}  // PsdImage::readResourceBlock

void PsdImage::writeMetadata() {

  if (io_->open() != 0) {

    throw Error(ErrorCode::kerDataSourceOpenFailed, io_->path(), strError());

  }

  IoCloser closer(*io_);

  MemIo tempIo;

  doWriteMetadata(tempIo);  // may throw

  io_->close();

  io_->transfer(tempIo);  // may throw

}  // PsdImage::writeMetadata

void PsdImage::doWriteMetadata(BasicIo& outIo) {

  if (!io_->isopen())

    throw Error(ErrorCode::kerInputDataReadFailed);

  if (!outIo.isopen())

    throw Error(ErrorCode::kerImageWriteFailed);

#ifdef EXIV2_DEBUG_MESSAGES

  std::cout << "Exiv2::PsdImage::doWriteMetadata: Writing PSD file " << io_->path() << "\n";

  std::cout << "Exiv2::PsdImage::doWriteMetadata: tmp file created " << outIo.path() << "\n";

#endif

  // Ensure that this is the correct image type

  if (!isPsdType(*io_, true)) {

    if (io_->error() || io_->eof())

      throw Error(ErrorCode::kerInputDataReadFailed);

    throw Error(ErrorCode::kerNoImageInInputData);

  }

  io_->seek(0, BasicIo::beg);  // rewind

  DataBuf lbuf(4096);

  byte buf[8];

  // Get Photoshop header from original file

  byte psd_head[26];

  if (io_->read(psd_head, 26) != 26)

    throw Error(ErrorCode::kerNotAnImage, "Photoshop");

  // Write Photoshop header data out to new PSD file

  if (outIo.write(psd_head, 26) != 26)

    throw Error(ErrorCode::kerImageWriteFailed);

  // Read colorDataLength from original PSD

  if (io_->read(buf, 4) != 4)

    throw Error(ErrorCode::kerNotAnImage, "Photoshop");

  uint32_t colorDataLength = getULong(buf, bigEndian);

  // Write colorDataLength

  ul2Data(buf, colorDataLength, bigEndian);

  if (outIo.write(buf, 4) != 4)

    throw Error(ErrorCode::kerImageWriteFailed);

#ifdef EXIV2_DEBUG_MESSAGES

  std::cerr << std::dec << "colorDataLength: " << colorDataLength << "\n";

#endif

  // Copy colorData

  size_t readTotal = 0;

  while (readTotal < colorDataLength) {

    auto toRead = std::min<size_t>(colorDataLength - readTotal, lbuf.size());

    if (io_->read(lbuf.data(), toRead) != toRead)

      throw Error(ErrorCode::kerNotAnImage, "Photoshop");

    readTotal += toRead;

    if (outIo.write(lbuf.c_data(), toRead) != toRead)

      throw Error(ErrorCode::kerImageWriteFailed);

  }

  if (outIo.error())

    throw Error(ErrorCode::kerImageWriteFailed);

  const size_t resLenOffset = io_->tell();  // remember for later update

  // Read length of all resource blocks from original PSD

  if (io_->read(buf, 4) != 4)

    throw Error(ErrorCode::kerNotAnImage, "Photoshop");

  uint32_t oldResLength = getULong(buf, bigEndian);

  uint32_t newResLength = 0;

  // Write oldResLength (will be updated later)

  ul2Data(buf, oldResLength, bigEndian);

  if (outIo.write(buf, 4) != 4)

    throw Error(ErrorCode::kerImageWriteFailed);

#ifdef EXIV2_DEBUG_MESSAGES

  std::cerr << std::dec << "oldResLength: " << oldResLength << "\n";

#endif

  // Iterate over original resource blocks.

  // Replace or insert IPTC, EXIF and XMP

  // Original resource blocks assumed to be sorted ASC

  bool iptcDone = false;

  bool exifDone = false;

  bool xmpDone = false;

  while (oldResLength > 0) {

    if (io_->read(buf, 8) != 8)

      throw Error(ErrorCode::kerNotAnImage, "Photoshop");

    // read resource type and ID

    uint32_t resourceType = getULong(buf, bigEndian);

    if (!Photoshop::isIrb(buf)) {

      throw Error(ErrorCode::kerNotAnImage, "Photoshop");  // bad resource type

    }

    uint16_t resourceId = getUShort(buf + 4, bigEndian);

    uint32_t resourceNameLength = buf[6];

    uint32_t adjResourceNameLen = resourceNameLength & ~1;

    unsigned char resourceNameFirstChar = buf[7];

    // read rest of resource name, plus any padding

    DataBuf resName(256);

    if (io_->read(resName.data(), adjResourceNameLen) != adjResourceNameLen)

      throw Error(ErrorCode::kerNotAnImage, "Photoshop");

    // read resource size (actual length w/o padding!)

    if (io_->read(buf, 4) != 4)

      throw Error(ErrorCode::kerNotAnImage, "Photoshop");

    uint32_t resourceSize = getULong(buf, bigEndian);

    uint32_t pResourceSize = (resourceSize + 1) & ~1;  // padded resource size

    const size_t curOffset = io_->tell();

    // Write IPTC_NAA resource block

    if (resourceId >= kPhotoshopResourceID::IPTC_NAA && !iptcDone) {

      newResLength += writeIptcData(iptcData_, outIo);

      iptcDone = true;

    }

    // Write ExifInfo resource block

    else if (resourceId >= kPhotoshopResourceID::ExifInfo && !exifDone) {

      newResLength += writeExifData(exifData_, outIo);

      exifDone = true;

    }

    // Write XMPpacket resource block

    else if (resourceId >= kPhotoshopResourceID::XMPPacket && !xmpDone) {

      newResLength += writeXmpData(xmpData_, outIo);

      xmpDone = true;

    }

    // Copy all other resource blocks

    if (resourceId != kPhotoshopResourceID::IPTC_NAA && resourceId != kPhotoshopResourceID::ExifInfo &&

        resourceId != kPhotoshopResourceID::XMPPacket) {

#ifdef EXIV2_DEBUG_MESSAGES

      std::cerr << std::hex << "copy : resourceType: " << resourceType << "\n";

      std::cerr << std::hex << "copy : resourceId: " << resourceId << "\n";

      std::cerr << std::dec;

#endif

      // Copy resource block to new PSD file

      ul2Data(buf, resourceType, bigEndian);

      if (outIo.write(buf, 4) != 4)

        throw Error(ErrorCode::kerImageWriteFailed);

      us2Data(buf, resourceId, bigEndian);

      if (outIo.write(buf, 2) != 2)

        throw Error(ErrorCode::kerImageWriteFailed);

      // Write resource name as Pascal string

      buf[0] = resourceNameLength & 0x00ff;

      if (outIo.write(buf, 1) != 1)

        throw Error(ErrorCode::kerImageWriteFailed);

      buf[0] = resourceNameFirstChar;

      if (outIo.write(buf, 1) != 1)

        throw Error(ErrorCode::kerImageWriteFailed);

      if (outIo.write(resName.c_data(), adjResourceNameLen) != static_cast<size_t>(adjResourceNameLen))

        throw Error(ErrorCode::kerImageWriteFailed);

      ul2Data(buf, resourceSize, bigEndian);

      if (outIo.write(buf, 4) != 4)

        throw Error(ErrorCode::kerImageWriteFailed);

      readTotal = 0;

      while (readTotal < pResourceSize) {

        /// \todo almost same code as in lines 403-410. Factor out & reuse!

        auto toRead = std::min<size_t>(pResourceSize - readTotal, lbuf.size());

        if (io_->read(lbuf.data(), toRead) != toRead) {

          throw Error(ErrorCode::kerNotAnImage, "Photoshop");

        }

        readTotal += toRead;

        if (outIo.write(lbuf.c_data(), toRead) != toRead)

          throw Error(ErrorCode::kerImageWriteFailed);

      }

      if (outIo.error())

        throw Error(ErrorCode::kerImageWriteFailed);

      newResLength += pResourceSize + adjResourceNameLen + 12;

    }

    io_->seek(curOffset + pResourceSize, BasicIo::beg);

    oldResLength -= (12 + adjResourceNameLen + pResourceSize);

  }

  // Append IPTC_NAA resource block, if not yet written

  if (!iptcDone) {

    newResLength += writeIptcData(iptcData_, outIo);

    iptcDone = true;

  }

  // Append ExifInfo resource block, if not yet written

  if (!exifDone) {

    newResLength += writeExifData(exifData_, outIo);

  }

  // Append XmpPacket resource block, if not yet written

  if (!xmpDone) {

    newResLength += writeXmpData(xmpData_, outIo);

  }

  // Populate the fake data, only make sense for remoteio, httpio and sshio.

  // it avoids allocating memory for parts of the file that contain image-date.

  io_->populateFakeData();

  // Copy remaining data

  size_t readSize = io_->read(lbuf.data(), lbuf.size());

  while (readSize != 0) {

    if (outIo.write(lbuf.c_data(), readSize) != readSize)

      throw Error(ErrorCode::kerImageWriteFailed);

    readSize = io_->read(lbuf.data(), lbuf.size());

  }

  if (outIo.error())

    throw Error(ErrorCode::kerImageWriteFailed);

    // Update length of resources

#ifdef EXIV2_DEBUG_MESSAGES

  std::cerr << "newResLength: " << newResLength << "\n";

#endif

  outIo.seek(resLenOffset, BasicIo::beg);

  ul2Data(buf, newResLength, bigEndian);

  if (outIo.write(buf, 4) != 4)

    throw Error(ErrorCode::kerImageWriteFailed);

}  // PsdImage::doWriteMetadata

uint32_t PsdImage::writeIptcData(const IptcData& iptcData, BasicIo& out) {

  uint32_t resLength = 0;

  byte buf[8];

  if (!iptcData.empty()) {

    DataBuf rawIptc = IptcParser::encode(iptcData);

    if (!rawIptc.empty()) {

#ifdef EXIV2_DEBUG_MESSAGES

      std::cerr << std::hex << "write: resourceId: " << kPhotoshopResourceID::IPTC_NAA << "\n";

      std::cerr << std::dec << "Writing IPTC_NAA: size: " << rawIptc.size() << "\n";

#endif

      if (out.write(reinterpret_cast<const byte*>(Photoshop::irbId_.front()), 4) != 4)

        throw Error(ErrorCode::kerImageWriteFailed);

      us2Data(buf, kPhotoshopResourceID::IPTC_NAA, bigEndian);

      if (out.write(buf, 2) != 2)

        throw Error(ErrorCode::kerImageWriteFailed);

      us2Data(buf, 0, bigEndian);  // NULL resource name

      if (out.write(buf, 2) != 2)

        throw Error(ErrorCode::kerImageWriteFailed);

      ul2Data(buf, static_cast<uint32_t>(rawIptc.size()), bigEndian);

      if (out.write(buf, 4) != 4)

        throw Error(ErrorCode::kerImageWriteFailed);

      // Write encoded Iptc data

      if (out.write(rawIptc.c_data(), rawIptc.size()) != rawIptc.size())

        throw Error(ErrorCode::kerImageWriteFailed);

      resLength += static_cast<uint32_t>(rawIptc.size()) + 12;

      if (rawIptc.size() & 1)  // even padding

      {

        buf[0] = 0;

        if (out.write(buf, 1) != 1)

          throw Error(ErrorCode::kerImageWriteFailed);

        resLength++;

      }

    }

  }

  return resLength;

}  // PsdImage::writeIptcData

uint32_t PsdImage::writeExifData(ExifData& exifData, BasicIo& out) {

  uint32_t resLength = 0;

  byte buf[8];

  if (!exifData.empty()) {

    Blob blob;

    ByteOrder bo = byteOrder();

    if (bo == invalidByteOrder) {

      bo = littleEndian;

      setByteOrder(bo);

    }

    ExifParser::encode(blob, bo, exifData);

    if (!blob.empty()) {

#ifdef EXIV2_DEBUG_MESSAGES

      std::cerr << std::hex << "write: resourceId: " << kPhotoshopResourceID::ExifInfo << "\n";

      std::cerr << std::dec << "Writing ExifInfo: size: " << blob.size() << "\n";

#endif

      if (out.write(reinterpret_cast<const byte*>(Photoshop::irbId_.front()), 4) != 4)

        throw Error(ErrorCode::kerImageWriteFailed);

      us2Data(buf, kPhotoshopResourceID::ExifInfo, bigEndian);

      if (out.write(buf, 2) != 2)

        throw Error(ErrorCode::kerImageWriteFailed);

      us2Data(buf, 0, bigEndian);  // NULL resource name

      if (out.write(buf, 2) != 2)

        throw Error(ErrorCode::kerImageWriteFailed);

      ul2Data(buf, static_cast<uint32_t>(blob.size()), bigEndian);

      if (out.write(buf, 4) != 4)

        throw Error(ErrorCode::kerImageWriteFailed);

      // Write encoded Exif data

      if (out.write(blob.data(), blob.size()) != blob.size())

        throw Error(ErrorCode::kerImageWriteFailed);

      resLength += static_cast<long>(blob.size()) + 12;

      if (blob.size() & 1)  // even padding

      {

        buf[0] = 0;

        if (out.write(buf, 1) != 1)

          throw Error(ErrorCode::kerImageWriteFailed);

        resLength++;

      }

    }

  }

  return resLength;

}  // PsdImage::writeExifData

uint32_t PsdImage::writeXmpData(const XmpData& xmpData, BasicIo& out) const {

  std::string xmpPacket;

  uint32_t resLength = 0;

  byte buf[8];

#ifdef EXIV2_DEBUG_MESSAGES

  std::cerr << "writeXmpFromPacket(): " << writeXmpFromPacket() << "\n";

#endif

  //        writeXmpFromPacket(true);

  if (!writeXmpFromPacket() && XmpParser::encode(xmpPacket, xmpData) > 1) {

#ifndef SUPPRESS_WARNINGS

    EXV_ERROR << "Failed to encode XMP metadata.\n";

#endif

  }

  if (!xmpPacket.empty()) {

#ifdef EXIV2_DEBUG_MESSAGES

    std::cerr << std::hex << "write: resourceId: " << kPhotoshopResourceID::XMPPacket << "\n";

    std::cerr << std::dec << "Writing XMPPacket: size: " << xmpPacket.size() << "\n";

#endif

    if (out.write(reinterpret_cast<const byte*>(Photoshop::irbId_.front()), 4) != 4)

      throw Error(ErrorCode::kerImageWriteFailed);

    us2Data(buf, kPhotoshopResourceID::XMPPacket, bigEndian);

    if (out.write(buf, 2) != 2)

      throw Error(ErrorCode::kerImageWriteFailed);

    us2Data(buf, 0, bigEndian);  // NULL resource name

    if (out.write(buf, 2) != 2)

      throw Error(ErrorCode::kerImageWriteFailed);

    ul2Data(buf, static_cast<uint32_t>(xmpPacket.size()), bigEndian);

    if (out.write(buf, 4) != 4)

      throw Error(ErrorCode::kerImageWriteFailed);

    // Write XMPPacket

    if (out.write(reinterpret_cast<const byte*>(xmpPacket.data()), xmpPacket.size()) != xmpPacket.size())

      throw Error(ErrorCode::kerImageWriteFailed);

    if (out.error())

      throw Error(ErrorCode::kerImageWriteFailed);

    resLength += static_cast<uint32_t>(xmpPacket.size()) + 12;

    if (xmpPacket.size() & 1)  // even padding

    {

      buf[0] = 0;

      if (out.write(buf, 1) != 1)

        throw Error(ErrorCode::kerImageWriteFailed);

      resLength++;

    }

  }

  return resLength;

}  // PsdImage::writeXmpData

// *************************************************************************

// free functions

Image::UniquePtr newPsdInstance(BasicIo::UniquePtr io, bool /*create*/) {

  auto image = std::make_unique<PsdImage>(std::move(io));

  if (!image->good()) {

    return nullptr;

  }

  return image;

}

bool isPsdType(BasicIo& iIo, bool advance) {

  const int32_t len = 6;

  const std::array<byte, len> PsdHeader{'8', 'B', 'P', 'S', 0, 1};

  std::array<byte, len> buf;

  iIo.read(buf.data(), len);

  if (iIo.error() || iIo.eof()) {

    return false;

  }

  bool matched = buf == PsdHeader;

  if (!advance || !matched) {

    iIo.seek(-len, BasicIo::cur);

  }

  return matched;

}

}  // namespace Exiv2