// 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 <cstring>

#include "lib/extras/codec.h"
#include "lib/jxl/base/span.h"
#include "lib/jxl/codec_in_out.h"
#include "lib/jxl/dec_file.h"
#include "lib/jxl/enc_cache.h"
#include "lib/jxl/enc_color_management.h"
#include "lib/jxl/enc_file.h"

extern "C" {

/* NOTA BENE: see file history to uncover how to decode HDR JPEGs to pixels. */

/** Result: uint32_t 'size' followed by compressed image (JXL). */
uint8_t* jxlCompress(const uint8_t* data, size_t size) {
  jxl::PaddedBytes compressed;
  jxl::CodecInOut io;
  jxl::extras::Codec input_codec;
  if (!jxl::SetFromBytes(jxl::Span<const uint8_t>(data, size), &io, nullptr,
                         &input_codec)) {
    return nullptr;
  }
  jxl::CompressParams params;
  jxl::PassesEncoderState passes_encoder_state;
  if (!jxl::EncodeFile(params, &io, &passes_encoder_state, &compressed,
                       jxl::GetJxlCms(), nullptr, nullptr)) {
    return nullptr;
  }
  uint32_t compressed_size = compressed.size();
  uint8_t* result = reinterpret_cast<uint8_t*>(malloc(compressed_size + 4));
  memcpy(result, &compressed_size, sizeof(compressed_size));
  memcpy(result + 4, compressed.data(), compressed_size);
  return result;
}

/** Result: uint32_t 'size' followed by decompressed image (JPG). */
uint8_t* jxlDecompress(const uint8_t* data, size_t size) {
  std::vector<uint8_t> decompressed;
  jxl::CodecInOut io;
  jxl::DecompressParams params;
  if (!jxl::DecodeFile(params, jxl::Span<const uint8_t>(data, size), &io,
                       nullptr)) {
    return nullptr;
  }
  io.use_sjpeg = false;
  io.jpeg_quality = 100;
  if (!jxl::Encode(io, jxl::extras::Codec::kJPG, io.Main().c_current(), 8,
                   &decompressed, nullptr)) {
    return nullptr;
  }
  uint32_t decompressed_size = decompressed.size();
  uint8_t* result = reinterpret_cast<uint8_t*>(malloc(decompressed_size + 4));
  memcpy(result, &decompressed_size, sizeof(decompressed_size));
  memcpy(result + 4, decompressed.data(), decompressed_size);
  return result;
}

}  // extern "C"