// Copyright (c) the JPEG XL Project Authors. All rights reserved.

//

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

#include "lib/extras/enc/apng.h"

// Parts of this code are taken from apngdis, which has the following license:

/* APNG Disassembler 2.8

 *

 * Deconstructs APNG files into individual frames.

 *

 * http://apngdis.sourceforge.net

 *

 * Copyright (c) 2010-2015 Max Stepin

 * maxst at users.sourceforge.net

 *

 * zlib license

 * ------------

 *

 * This software is provided 'as-is', without any express or implied

 * warranty.  In no event will the authors be held liable for any damages

 * arising from the use of this software.

 *

 * Permission is granted to anyone to use this software for any purpose,

 * including commercial applications, and to alter it and redistribute it

 * freely, subject to the following restrictions:

 *

 * 1. The origin of this software must not be misrepresented; you must not

 *    claim that you wrote the original software. If you use this software

 *    in a product, an acknowledgment in the product documentation would be

 *    appreciated but is not required.

 * 2. Altered source versions must be plainly marked as such, and must not be

 *    misrepresented as being the original software.

 * 3. This notice may not be removed or altered from any source distribution.

 *

 */

#include <cstring>

#include <string>

#include <vector>

#include "lib/extras/exif.h"

#include "lib/jxl/base/byte_order.h"

#include "lib/jxl/base/printf_macros.h"

#if JPEGXL_ENABLE_APNG

#include "png.h" /* original (unpatched) libpng is ok */

#endif

namespace jxl {

namespace extras {

#if JPEGXL_ENABLE_APNG

namespace {

constexpr unsigned char kExifSignature[6] = {0x45, 0x78, 0x69,

                                             0x66, 0x00, 0x00};

class APNGEncoder : public Encoder {

 public:

  std::vector<JxlPixelFormat> AcceptedFormats() const override {

    std::vector<JxlPixelFormat> formats;

    for (const uint32_t num_channels : {1, 2, 3, 4}) {

      for (const JxlDataType data_type :

           {JXL_TYPE_UINT8, JXL_TYPE_UINT16, JXL_TYPE_FLOAT}) {

        for (JxlEndianness endianness : {JXL_BIG_ENDIAN, JXL_LITTLE_ENDIAN}) {

          formats.push_back(

              JxlPixelFormat{num_channels, data_type, endianness, /*align=*/0});

        }

      }

    }

    return formats;

  }

  Status Encode(const PackedPixelFile& ppf, EncodedImage* encoded_image,

                ThreadPool* pool) const override {

    // Encode main image frames

    JXL_RETURN_IF_ERROR(VerifyBasicInfo(ppf.info));

    encoded_image->icc.clear();

    encoded_image->bitstreams.resize(1);

    JXL_RETURN_IF_ERROR(EncodePackedPixelFileToAPNG(

        ppf, pool, &encoded_image->bitstreams.front()));

    // Encode extra channels

    for (size_t i = 0; i < ppf.extra_channels_info.size(); ++i) {

      encoded_image->extra_channel_bitstreams.emplace_back();

      auto& ec_bitstreams = encoded_image->extra_channel_bitstreams.back();

      ec_bitstreams.emplace_back();

      JXL_RETURN_IF_ERROR(EncodePackedPixelFileToAPNG(

          ppf, pool, &ec_bitstreams.back(), true, i));

    }

    return true;

  }

 private:

  Status EncodePackedPixelFileToAPNG(const PackedPixelFile& ppf,

                                     ThreadPool* pool,

                                     std::vector<uint8_t>* bytes,

                                     bool encode_extra_channels = false,

                                     size_t extra_channel_index = 0) const;

};

void PngWrite(png_structp png_ptr, png_bytep data, png_size_t length) {

  std::vector<uint8_t>* bytes =

      static_cast<std::vector<uint8_t>*>(png_get_io_ptr(png_ptr));

  bytes->insert(bytes->end(), data, data + length);

}

// Stores XMP and EXIF/IPTC into key/value strings for PNG

class BlobsWriterPNG {

 public:

  static Status Encode(const PackedMetadata& blobs,

                       std::vector<std::string>* strings) {

    if (!blobs.exif.empty()) {

      // PNG viewers typically ignore Exif orientation but not all of them do

      // (and e.g. cjxl doesn't), so we overwrite the Exif orientation to the

      // identity to avoid repeated orientation.

      std::vector<uint8_t> exif = blobs.exif;

      ResetExifOrientation(exif);

      // By convention, the data is prefixed with "Exif\0\0" when stored in

      // the legacy (and non-standard) "Raw profile type exif" text chunk

      // currently used here.

      // TODO(user): Store Exif data in an eXIf chunk instead, which always

      //             begins with the TIFF header.

      if (exif.size() >= sizeof kExifSignature &&

          memcmp(exif.data(), kExifSignature, sizeof kExifSignature) != 0) {

        exif.insert(exif.begin(), kExifSignature,

                    kExifSignature + sizeof kExifSignature);

      }

      JXL_RETURN_IF_ERROR(EncodeBase16("exif", exif, strings));

    }

    if (!blobs.iptc.empty()) {

      JXL_RETURN_IF_ERROR(EncodeBase16("iptc", blobs.iptc, strings));

    }

    if (!blobs.xmp.empty()) {

      // TODO(user): Store XMP data in an "XML:com.adobe.xmp" text chunk

      //             instead.

      JXL_RETURN_IF_ERROR(EncodeBase16("xmp", blobs.xmp, strings));

    }

    return true;

  }

 private:

  // TODO(eustas): use array

  static JXL_INLINE char EncodeNibble(const uint8_t nibble) {

    if (nibble < 16) {

      return (nibble < 10) ? '0' + nibble : 'a' + nibble - 10;

    } else {

      JXL_DEBUG_ABORT("Internal logic error");

      return 0;

    }

  }

  static Status EncodeBase16(const std::string& type,

                             const std::vector<uint8_t>& bytes,

                             std::vector<std::string>* strings) {

    // Encoding: base16 with newline after 72 chars.

    const size_t base16_size =

        2 * bytes.size() + DivCeil(bytes.size(), static_cast<size_t>(36)) + 1;

    std::string base16;

    base16.reserve(base16_size);

    for (size_t i = 0; i < bytes.size(); ++i) {

      if (i % 36 == 0) base16.push_back('\n');

      base16.push_back(EncodeNibble(bytes[i] >> 4));

      base16.push_back(EncodeNibble(bytes[i] & 0x0F));

    }

    base16.push_back('\n');

    JXL_ENSURE(base16.length() == base16_size);

    char key[30];

    snprintf(key, sizeof(key), "Raw profile type %s", type.c_str());

    char header[30];

    snprintf(header, sizeof(header), "\n%s\n%8" PRIuS, type.c_str(),

             bytes.size());

    strings->emplace_back(key);

    strings->push_back(std::string(header) + base16);

    return true;

  }

};

void MaybeAddCICP(const JxlColorEncoding& c_enc, png_structp png_ptr,

                  png_infop info_ptr) {

  png_byte cicp_data[4] = {};

  png_unknown_chunk cicp_chunk;

  if (c_enc.color_space != JXL_COLOR_SPACE_RGB) {

    return;

  }

  if (c_enc.primaries == JXL_PRIMARIES_P3) {

    if (c_enc.white_point == JXL_WHITE_POINT_D65) {

      cicp_data[0] = 12;

    } else if (c_enc.white_point == JXL_WHITE_POINT_DCI) {

      cicp_data[0] = 11;

    } else {

      return;

    }

  } else if (c_enc.primaries != JXL_PRIMARIES_CUSTOM &&

             c_enc.white_point == JXL_WHITE_POINT_D65) {

    cicp_data[0] = static_cast<png_byte>(c_enc.primaries);

  } else {

    return;

  }

  if (c_enc.transfer_function == JXL_TRANSFER_FUNCTION_UNKNOWN ||

      c_enc.transfer_function == JXL_TRANSFER_FUNCTION_GAMMA) {

    return;

  }

  cicp_data[1] = static_cast<png_byte>(c_enc.transfer_function);

  cicp_data[2] = 0;

  cicp_data[3] = 1;

  cicp_chunk.data = cicp_data;

  cicp_chunk.size = sizeof(cicp_data);

  cicp_chunk.location = PNG_HAVE_IHDR;

  memcpy(cicp_chunk.name, "cICP", 5);

  png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_ALWAYS,

                              reinterpret_cast<const png_byte*>("cICP"), 1);

  png_set_unknown_chunks(png_ptr, info_ptr, &cicp_chunk, 1);

}

bool MaybeAddSRGB(const JxlColorEncoding& c_enc, png_structp png_ptr,

                  png_infop info_ptr) {

  if (c_enc.transfer_function == JXL_TRANSFER_FUNCTION_SRGB &&

      (c_enc.color_space == JXL_COLOR_SPACE_GRAY ||

       (c_enc.color_space == JXL_COLOR_SPACE_RGB &&

        c_enc.primaries == JXL_PRIMARIES_SRGB &&

        c_enc.white_point == JXL_WHITE_POINT_D65))) {

    png_set_sRGB(png_ptr, info_ptr, c_enc.rendering_intent);

    png_set_cHRM_fixed(png_ptr, info_ptr, 31270, 32900, 64000, 33000, 30000,

                       60000, 15000, 6000);

    png_set_gAMA_fixed(png_ptr, info_ptr, 45455);

    return true;

  }

  return false;

}

void MaybeAddCHRM(const JxlColorEncoding& c_enc, png_structp png_ptr,

                  png_infop info_ptr) {

  if (c_enc.color_space != JXL_COLOR_SPACE_RGB) return;

  if (c_enc.primaries == 0) return;

  png_set_cHRM(png_ptr, info_ptr, c_enc.white_point_xy[0],

               c_enc.white_point_xy[1], c_enc.primaries_red_xy[0],

               c_enc.primaries_red_xy[1], c_enc.primaries_green_xy[0],

               c_enc.primaries_green_xy[1], c_enc.primaries_blue_xy[0],

               c_enc.primaries_blue_xy[1]);

}

void MaybeAddGAMA(const JxlColorEncoding& c_enc, png_structp png_ptr,

                  png_infop info_ptr) {

  switch (c_enc.transfer_function) {

    case JXL_TRANSFER_FUNCTION_LINEAR:

      png_set_gAMA_fixed(png_ptr, info_ptr, PNG_FP_1);

      break;

    case JXL_TRANSFER_FUNCTION_SRGB:

      png_set_gAMA_fixed(png_ptr, info_ptr, 45455);

      break;

    case JXL_TRANSFER_FUNCTION_GAMMA:

      png_set_gAMA(png_ptr, info_ptr, c_enc.gamma);

      break;

    default:;

      // No gAMA chunk.

  }

}

void MaybeAddCLLi(const JxlColorEncoding& c_enc, const float intensity_target,

                  png_structp png_ptr, png_infop info_ptr) {

  if (c_enc.transfer_function != JXL_TRANSFER_FUNCTION_PQ) return;

  const uint32_t max_content_light_level =

      static_cast<uint32_t>(10000.f * Clamp1(intensity_target, 0.f, 10000.f));

  png_byte chunk_data[8] = {};

  png_save_uint_32(chunk_data, max_content_light_level);

  // Leave MaxFALL set to 0.

  png_unknown_chunk chunk;

  memcpy(chunk.name, "cLLi", 5);

  chunk.data = chunk_data;

  chunk.size = sizeof chunk_data;

  chunk.location = PNG_HAVE_IHDR;

  png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_ALWAYS,

                              reinterpret_cast<const png_byte*>("cLLi"), 1);

  png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);

}

Status APNGEncoder::EncodePackedPixelFileToAPNG(

    const PackedPixelFile& ppf, ThreadPool* pool, std::vector<uint8_t>* bytes,

    bool encode_extra_channels, size_t extra_channel_index) const {

  JxlExtraChannelInfo ec_info{};

  if (encode_extra_channels) {

    if (ppf.extra_channels_info.size() <= extra_channel_index) {

      return JXL_FAILURE("Invalid index for extra channel");

    }

    ec_info = ppf.extra_channels_info[extra_channel_index].ec_info;

  }

  bool has_alpha = !encode_extra_channels && (ppf.info.alpha_bits != 0);

  bool is_gray = encode_extra_channels || (ppf.info.num_color_channels == 1);

  size_t color_channels =

      encode_extra_channels ? 1 : ppf.info.num_color_channels;

  size_t num_channels = color_channels + (has_alpha ? 1 : 0);

  if (!ppf.info.have_animation && ppf.frames.size() != 1) {

    return JXL_FAILURE("Invalid number of frames");

  }

  size_t count = 0;

  size_t anim_chunks = 0;

  for (const auto& frame : ppf.frames) {

    const PackedImage& color = encode_extra_channels

                                   ? frame.extra_channels[extra_channel_index]

                                   : frame.color;

    size_t xsize = color.xsize;

    size_t ysize = color.ysize;

    size_t num_samples = num_channels * xsize * ysize;

    uint32_t bits_per_sample = encode_extra_channels ? ec_info.bits_per_sample

                                                     : ppf.info.bits_per_sample;

    if (!encode_extra_channels) {

      JXL_RETURN_IF_ERROR(VerifyPackedImage(color, ppf.info));

    } else {

      JXL_RETURN_IF_ERROR(VerifyFormat(color.format));

      JXL_RETURN_IF_ERROR(VerifyBitDepth(color.format.data_type,

                                         bits_per_sample,

                                         ec_info.exponent_bits_per_sample));

    }

    const JxlPixelFormat format = color.format;

    const uint8_t* in = reinterpret_cast<const uint8_t*>(color.pixels());

    JXL_RETURN_IF_ERROR(PackedImage::ValidateDataType(format.data_type));

    size_t data_bits_per_sample = PackedImage::BitsPerChannel(format.data_type);

    size_t bytes_per_sample = data_bits_per_sample / 8;

    size_t out_bytes_per_sample = bytes_per_sample > 1 ? 2 : 1;

    size_t out_stride = xsize * num_channels * out_bytes_per_sample;

    size_t out_size = ysize * out_stride;

    std::vector<uint8_t> out(out_size);

    if (format.data_type == JXL_TYPE_UINT8) {

      if (bits_per_sample < 8) {

        float mul = 255.0 / ((1u << bits_per_sample) - 1);

        for (size_t i = 0; i < num_samples; ++i) {

          out[i] = static_cast<uint8_t>(std::lroundf(in[i] * mul));

        }

      } else {

        memcpy(out.data(), in, out_size);

      }

    } else if (format.data_type == JXL_TYPE_UINT16) {

      if (bits_per_sample < 16 || format.endianness != JXL_BIG_ENDIAN) {

        float mul = 65535.0 / ((1u << bits_per_sample) - 1);

        const uint8_t* p_in = in;

        uint8_t* p_out = out.data();

        for (size_t i = 0; i < num_samples; ++i, p_in += 2, p_out += 2) {

          uint32_t val = (format.endianness == JXL_BIG_ENDIAN ? LoadBE16(p_in)

                                                              : LoadLE16(p_in));

          StoreBE16(static_cast<uint32_t>(std::lroundf(val * mul)), p_out);

        }

      } else {

        memcpy(out.data(), in, out_size);

      }

    } else if (format.data_type == JXL_TYPE_FLOAT) {

      constexpr float kMul = 65535.0;

      const uint8_t* p_in = in;

      uint8_t* p_out = out.data();

      for (size_t i = 0; i < num_samples;

           ++i, p_in += sizeof(float), p_out += 2) {

        float val =

            Clamp1(format.endianness == JXL_BIG_ENDIAN ? LoadBEFloat(p_in)

                   : format.endianness == JXL_LITTLE_ENDIAN

                       ? LoadLEFloat(p_in)

                       : *reinterpret_cast<const float*>(p_in),

                   0.f, 1.f);

        StoreBE16(static_cast<uint32_t>(std::lroundf(val * kMul)), p_out);

      }

    }

    png_structp png_ptr;

    png_infop info_ptr;

    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr,

                                      nullptr);

    if (!png_ptr) return JXL_FAILURE("Could not init png encoder");

    info_ptr = png_create_info_struct(png_ptr);

    if (!info_ptr) return JXL_FAILURE("Could not init png info struct");

    png_set_write_fn(png_ptr, bytes, PngWrite, nullptr);

    png_set_flush(png_ptr, 0);

    int width = xsize;

    int height = ysize;

    png_byte color_type = (is_gray ? PNG_COLOR_TYPE_GRAY : PNG_COLOR_TYPE_RGB);

    if (has_alpha) color_type |= PNG_COLOR_MASK_ALPHA;

    png_byte bit_depth = out_bytes_per_sample * 8;

    png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, color_type,

                 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,

                 PNG_FILTER_TYPE_BASE);

    if (count == 0 && !encode_extra_channels) {

      if (!MaybeAddSRGB(ppf.color_encoding, png_ptr, info_ptr)) {

        MaybeAddCICP(ppf.color_encoding, png_ptr, info_ptr);

        if (!ppf.icc.empty()) {

          png_set_benign_errors(png_ptr, 1);

          png_set_iCCP(png_ptr, info_ptr, "1", 0, ppf.icc.data(),

                       ppf.icc.size());

        }

        MaybeAddCHRM(ppf.color_encoding, png_ptr, info_ptr);

        MaybeAddGAMA(ppf.color_encoding, png_ptr, info_ptr);

      }

      MaybeAddCLLi(ppf.color_encoding, ppf.info.intensity_target, png_ptr,

                   info_ptr);

      std::vector<std::string> textstrings;

      JXL_RETURN_IF_ERROR(BlobsWriterPNG::Encode(ppf.metadata, &textstrings));

      for (size_t kk = 0; kk + 1 < textstrings.size(); kk += 2) {

        png_text text;

        text.key = const_cast<png_charp>(textstrings[kk].c_str());

        text.text = const_cast<png_charp>(textstrings[kk + 1].c_str());

        text.compression = PNG_TEXT_COMPRESSION_zTXt;

        png_set_text(png_ptr, info_ptr, &text, 1);

      }

      png_write_info(png_ptr, info_ptr);

    } else {

      // fake writing a header, otherwise libpng gets confused

      size_t pos = bytes->size();

      png_write_info(png_ptr, info_ptr);

      bytes->resize(pos);

    }

    if (ppf.info.have_animation) {

      if (count == 0) {

        png_byte adata[8];

        png_save_uint_32(adata, ppf.frames.size());

        png_save_uint_32(adata + 4, ppf.info.animation.num_loops);

        png_byte actl[5] = "acTL";

        png_write_chunk(png_ptr, actl, adata, 8);

      }

      png_byte fdata[26];

      // TODO(jon): also make this work for the non-coalesced case

      png_save_uint_32(fdata, anim_chunks++);

      png_save_uint_32(fdata + 4, width);

      png_save_uint_32(fdata + 8, height);

      png_save_uint_32(fdata + 12, 0);

      png_save_uint_32(fdata + 16, 0);

      png_save_uint_16(fdata + 20, frame.frame_info.duration *

                                       ppf.info.animation.tps_denominator);

      png_save_uint_16(fdata + 22, ppf.info.animation.tps_numerator);

      fdata[24] = 1;

      fdata[25] = 0;

      png_byte fctl[5] = "fcTL";

      png_write_chunk(png_ptr, fctl, fdata, 26);

    }

    std::vector<uint8_t*> rows(height);

    for (int y = 0; y < height; ++y) {

      rows[y] = out.data() + y * out_stride;

    }

    png_write_flush(png_ptr);

    const size_t pos = bytes->size();

    png_write_image(png_ptr, rows.data());

    png_write_flush(png_ptr);

    if (count > 0) {

      std::vector<uint8_t> fdata(4);

      png_save_uint_32(fdata.data(), anim_chunks++);

      size_t p = pos;

      while (p + 8 < bytes->size()) {

        size_t len = png_get_uint_32(bytes->data() + p);

        JXL_ENSURE(bytes->operator[](p + 4) == 'I');

        JXL_ENSURE(bytes->operator[](p + 5) == 'D');

        JXL_ENSURE(bytes->operator[](p + 6) == 'A');

        JXL_ENSURE(bytes->operator[](p + 7) == 'T');

        fdata.insert(fdata.end(), bytes->data() + p + 8,

                     bytes->data() + p + 8 + len);

        p += len + 12;

      }

      bytes->resize(pos);

      png_byte fdat[5] = "fdAT";

      png_write_chunk(png_ptr, fdat, fdata.data(), fdata.size());

    }

    count++;

    if (count == ppf.frames.size() || !ppf.info.have_animation) {

      png_write_end(png_ptr, nullptr);

    }

    png_destroy_write_struct(&png_ptr, &info_ptr);

  }

  return true;

}

}  // namespace

#endif

std::unique_ptr<Encoder> GetAPNGEncoder() {

#if JPEGXL_ENABLE_APNG

  return jxl::make_unique<APNGEncoder>();

#else

  return nullptr;

#endif

}

}  // namespace extras

}  // namespace jxl