/*

 * HEIF mask image codec.

 *

 * Copyright (c) 2023 Dirk Farin <dirk.farin@gmail.com>

 * Copyright (c) 2023 Brad Hards <bradh@frogmouth.net>

 *

 * This file is part of libheif.

 *

 * libheif is free software: you can redistribute it and/or modify

 * it under the terms of the GNU Lesser General Public License as

 * published by the Free Software Foundation, either version 3 of

 * the License, or (at your option) any later version.

 *

 * libheif is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with libheif.  If not, see <http://www.gnu.org/licenses/>.

 */

#include <cstdint>

#include <cstring>

#include <algorithm>

#include <map>

#include <cstring>

#include "libheif/heif.h"

#include "logging.h"

#include "mask_image.h"

#include "image_item.h"

#include "security_limits.h"

Error Box_mskC::parse(BitstreamRange& range, const heif_security_limits* limits)

{

  parse_full_box_header(range);

  m_bits_per_pixel = range.read8();

  return range.get_error();

}

std::string Box_mskC::dump(Indent& indent) const

{

  std::ostringstream sstr;

  sstr << Box::dump(indent);

  sstr << indent << "bits_per_pixel: " << ((int)m_bits_per_pixel) << "\n";

  return sstr.str();

}

Error Box_mskC::write(StreamWriter& writer) const

{

  size_t box_start = reserve_box_header_space(writer);

  writer.write8(m_bits_per_pixel);

  prepend_header(writer, box_start);

  return Error::Ok;

}

Error MaskImageCodec::decode_mask_image(const HeifContext* context,

                                        heif_item_id ID,

                                        std::shared_ptr<HeifPixelImage>& img,

                                        const std::vector<uint8_t>& data)

{

  auto image = context->get_image(ID, false);

  if (!image) {

    return {heif_error_Invalid_input,

            heif_suberror_Nonexisting_item_referenced};

  }

  std::shared_ptr<Box_ispe> ispe = image->get_property<Box_ispe>();

  std::shared_ptr<Box_mskC> mskC = image->get_property<Box_mskC>();

  if (!ispe || !mskC) {

    return Error(heif_error_Unsupported_feature,

                  heif_suberror_Unsupported_data_version,

                  "Missing required box for mask codec");

  }

  uint32_t width = ispe->get_width();

  uint32_t height = ispe->get_height();

  Error error = check_for_valid_image_size(context->get_security_limits(), width, height);

  if (error) {

    return error;

  }

  if ((mskC->get_bits_per_pixel() != 8) && (mskC->get_bits_per_pixel() != 16))

  {

    return Error(heif_error_Unsupported_feature,

                 heif_suberror_Unsupported_data_version,

                 "Unsupported bit depth for mask item");

  }

  uint32_t bytes_per_pixel = (mskC->get_bits_per_pixel() + 7) / 8;

  if (data.size() / (static_cast<size_t>(width) * bytes_per_pixel) < height) {

    return {heif_error_Invalid_input,

            heif_suberror_Unspecified,

            "Mask image data is too short"};

  }

  img = std::make_shared<HeifPixelImage>();

  img->create(width, height, heif_colorspace_monochrome, heif_chroma_monochrome);

  auto err = img->add_channel(heif_channel_Y, width, height, mskC->get_bits_per_pixel(),

                            context->get_security_limits());

  if (err) {

    return err;

  }

  size_t stride;

  uint8_t* dst = img->get_channel_memory(heif_channel_Y, &stride);

  if (stride == static_cast<size_t>(width) * bytes_per_pixel) {

    memcpy(dst, data.data(), static_cast<size_t>(width) * bytes_per_pixel * height);

  }

  else

  {

    for (size_t i = 0; i < height; i++)

    {

      memcpy(dst + i * stride, data.data() + i * width * bytes_per_pixel, width * bytes_per_pixel);

    }

  }

  return Error::Ok;

}

Result<std::shared_ptr<HeifPixelImage>> ImageItem_mask::decode_compressed_image(const heif_decoding_options& options,

                                                                                bool decode_tile_only, uint32_t tile_x0, uint32_t tile_y0,

                                                                                DecodeTraversalState decode_state) const

{

  std::shared_ptr<HeifPixelImage> img;

  std::vector<uint8_t> data;

  // image data, usually from 'mdat'

  Error error = get_file()->append_data_from_iloc(get_id(), data);

  if (error) {

    return error;

  }

  Error err = MaskImageCodec::decode_mask_image(get_context(),

                                                get_id(),

                                                img,

                                                data);

  if (err) {

    return err;

  }

  else {

    return img;

  }

}

Result<Encoder::CodedImageData> ImageItem_mask::encode(const std::shared_ptr<HeifPixelImage>& image,

                                                       heif_encoder* encoder,

                                                       const heif_encoding_options& options,

                                                       heif_image_input_class input_class)

{

  Encoder::CodedImageData codedImageData;

  if (image->get_colorspace() != heif_colorspace_monochrome)

  {

    return Error(heif_error_Unsupported_feature,

                 heif_suberror_Unsupported_data_version,

                 "Unsupported colourspace for mask region");

  }

  if (image->get_bits_per_pixel(heif_channel_Y) != 8)

  {

    return Error(heif_error_Unsupported_feature,

                 heif_suberror_Unsupported_data_version,

                 "Unsupported bit depth for mask region");

  }

  // TODO: we could add an option to lossless-compress this data

  std::vector<uint8_t> data;

  size_t src_stride;

  uint8_t* src_data = image->get_channel_memory(heif_channel_Y, &src_stride);

  uint32_t w = image->get_width();

  uint32_t h = image->get_height();

  data.resize(w * h);

  if (w == (uint32_t)src_stride) {

    codedImageData.append(src_data, w*h);

  }

  else {

    for (uint32_t y = 0; y < h; y++) {

      codedImageData.append(src_data + y * src_stride, w);

    }

  }

  std::shared_ptr<Box_mskC> mskC = std::make_shared<Box_mskC>();

  uint16_t bpp = image->get_bits_per_pixel(heif_channel_Y);

  if (bpp > 255) {

    return Error{

      heif_error_Invalid_input,

      heif_suberror_Unspecified,

      "Too many bits per pixel for mask image."

    };

  }

  mskC->set_bits_per_pixel(static_cast<uint8_t>(bpp));

  codedImageData.properties.push_back(mskC);

  return codedImageData;

}

int ImageItem_mask::get_luma_bits_per_pixel() const

{

  auto mskC = get_property<Box_mskC>();

  if (!mskC) {

    return -1;

  }

  return mskC->get_bits_per_pixel();

}