// 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.

#ifndef LIB_EXTRAS_CODEC_JPG_H_
#define LIB_EXTRAS_CODEC_JPG_H_

// Encodes JPG pixels and metadata in memory.

#include <stdint.h>

#include "lib/extras/codec.h"
#include "lib/extras/color_hints.h"
#include "lib/jxl/base/data_parallel.h"
#include "lib/jxl/base/padded_bytes.h"
#include "lib/jxl/base/span.h"
#include "lib/jxl/base/status.h"
#include "lib/jxl/codec_in_out.h"

namespace jxl {
namespace extras {

enum class JpegEncoder {
  kLibJpeg,
  kSJpeg,
};

static inline bool IsJPG(const Span<const uint8_t> bytes) {
  if (bytes.size() < 2) return false;
  if (bytes[0] != 0xFF || bytes[1] != 0xD8) return false;
  return true;
}

// Decodes `bytes` into `io`. color_hints are ignored.
// `elapsed_deinterleave`, if non-null, will be set to the time (in seconds)
// that it took to deinterleave the raw JSAMPLEs to planar floats.
Status DecodeImageJPG(Span<const uint8_t> bytes, const ColorHints& color_hints,
                      ThreadPool* pool, CodecInOut* io,
                      double* elapsed_deinterleave = nullptr);

// Encodes into `bytes`.
Status EncodeImageJPG(const CodecInOut* io, JpegEncoder encoder, size_t quality,
                      YCbCrChromaSubsampling chroma_subsampling,
                      ThreadPool* pool, PaddedBytes* bytes);

// Temporary wrappers to load the JPEG coefficients to a CodecInOut. This should
// be replaced by calling the corresponding JPEG input and output functions on
// the API.

// Decodes the JPEG image coefficients to a CodecIO for lossless recompression.
Status DecodeImageJPGCoefficients(Span<const uint8_t> bytes, CodecInOut* io);

// Reconstructs the JPEG from the coefficients and metadata in CodecInOut.
Status EncodeImageJPGCoefficients(const CodecInOut* io, PaddedBytes* bytes);

}  // namespace extras
}  // namespace jxl

#endif  // LIB_EXTRAS_CODEC_JPG_H_
