/*

 * HEIF codec.

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

 *

 * 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/>.

 */

#ifndef LIBHEIF_UNC_DECODER_H

#define LIBHEIF_UNC_DECODER_H

#include <cstdint>

#include <memory>

#include <vector>

#include "error.h"

#include "unc_codec.h"

#include "unc_boxes.h"

class HeifPixelImage;

class MemoryHandle;

struct DataExtent;

struct heif_security_limits;

// Validate the uncC component formats, bit depths and pixel packing. These are

// image-size independent invariants, so this must run on every decode entry

// point -- both the full-image path (unc_decoder::decode_full_image) and the

// per-tile path (UncompressedImageCodec::decode_uncompressed_image_tile).

Error check_hard_limits(const std::shared_ptr<const Box_uncC>& uncC);

class unc_decoder

{

public:

  virtual ~unc_decoder() = default;

  virtual void ensure_channel_list(std::shared_ptr<HeifPixelImage>& img) {}

  // The size of 'tile_data' is charged to 'tile_data_memory_handle', which has to

  // live as long as 'tile_data'.

  Error fetch_tile_data(const DataExtent& dataExtent,

                        const UncompressedImageCodec::unci_properties& properties,

                        uint32_t tile_x, uint32_t tile_y,

                        std::vector<uint8_t>& tile_data,

                        MemoryHandle& tile_data_memory_handle);

  virtual Error decode_tile(const std::vector<uint8_t>& tile_data,

                            std::shared_ptr<HeifPixelImage>& img,

                            uint32_t out_x0, uint32_t out_y0) = 0;

  Error decode_image(const DataExtent& extent,

                     const UncompressedImageCodec::unci_properties& properties,

                     std::shared_ptr<HeifPixelImage>& img);

  static Result<std::shared_ptr<HeifPixelImage>> decode_full_image(

      const UncompressedImageCodec::unci_properties& properties,

      const DataExtent& extent,

      const heif_security_limits* limits);

protected:

  unc_decoder(uint32_t width, uint32_t height,

              const std::shared_ptr<const Box_cmpd>& cmpd,

              const std::shared_ptr<const Box_uncC>& uncC,

              const std::vector<uint32_t>& uncC_index_to_comp_ids);

  virtual Result<std::vector<uint64_t>> get_tile_data_sizes() const = 0;

  const Error get_compressed_image_data_uncompressed(const DataExtent& dataExtent,

                                                     const UncompressedImageCodec::unci_properties& properties,

                                                     std::vector<uint8_t>* data,

                                                     uint64_t range_start_offset, uint64_t range_size,

                                                     uint32_t tile_idx,

                                                     const Box_iloc::Item* item) const;

  // Decompress the complete item. This is used when the compressed units do not give

  // access to the individual tiles (UncompressedImageCodec::TileAccess::whole_item).

  // The item has to decompress to exactly 'expected_size' bytes.

  Result<std::vector<uint8_t>> decompress_whole_item(const DataExtent& dataExtent,

                                                     const UncompressedImageCodec::unci_properties& properties,

                                                     uint64_t expected_size) const;

  Result<std::vector<uint8_t>> do_decompress_data(std::shared_ptr<const Box_cmpC>& cmpC_box,

                                                  const std::vector<uint8_t>& compressed_data,

                                                  const heif_security_limits* limits,

                                                  uint64_t max_output_size = UINT64_MAX) const;

  const uint32_t m_width;

  const uint32_t m_height;

  const std::shared_ptr<const Box_cmpd> m_cmpd;

  const std::shared_ptr<const Box_uncC> m_uncC;

  const std::vector<uint32_t> m_uncC_index_to_comp_ids;

  uint32_t m_tile_height;

  uint32_t m_tile_width;

};

class unc_decoder_factory

{

public:

  virtual ~unc_decoder_factory() = default;

  static Result<std::unique_ptr<unc_decoder>> get_unc_decoder(

      uint32_t width, uint32_t height,

      const std::shared_ptr<const Box_cmpd>& cmpd,

      const std::shared_ptr<const Box_uncC>& uncC,

      const std::vector<uint32_t>& uncC_index_to_comp_ids);

protected:

  static bool check_common_requirements(const std::shared_ptr<const Box_uncC>& uncC);

  static bool has_any_multi_byte_components(const std::shared_ptr<const Box_uncC>& uncC);

  virtual bool can_decode(const std::shared_ptr<const Box_uncC>& uncC) const = 0;

  virtual std::unique_ptr<unc_decoder> create(

      uint32_t width, uint32_t height,

      const std::shared_ptr<const Box_cmpd>& cmpd,

      const std::shared_ptr<const Box_uncC>& uncC,

      const std::vector<uint32_t>& uncC_index_to_comp_ids) const = 0;

};

#endif