// 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/jxl/image_bundle.h"

#include <cstddef>

#include <cstdint>

#include <utility>

#include <vector>

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

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

#include "lib/jxl/color_encoding_internal.h"

#include "lib/jxl/image.h"

#include "lib/jxl/image_metadata.h"

namespace jxl {

Status ImageBundle::ShrinkTo(size_t xsize, size_t ysize) {

  if (HasColor()) {

    JXL_RETURN_IF_ERROR(color_.ShrinkTo(xsize, ysize));

  }

  for (ImageF& ec : extra_channels_) {

    JXL_RETURN_IF_ERROR(ec.ShrinkTo(xsize, ysize));

  }

  return true;

}

// Called by all other SetFrom*.

Status ImageBundle::SetFromImage(Image3F&& color,

                                 const ColorEncoding& c_current) {

  JXL_ENSURE(color.xsize() != 0 && color.ysize() != 0);

  JXL_ENSURE(metadata_->color_encoding.IsGray() == c_current.IsGray());

  color_ = std::move(color);

  c_current_ = c_current;

  JXL_RETURN_IF_ERROR(VerifySizes());

  return true;

}

Status ImageBundle::VerifyMetadata() const {

  JXL_ENSURE(!c_current_.ICC().empty());

  JXL_ENSURE(metadata_->color_encoding.IsGray() == IsGray());

  if (metadata_->HasAlpha()) {

    const ImageF* a = alpha();

    if (a->xsize() == 0) {

      return JXL_UNREACHABLE("MD alpha_bits %u IB alpha %" PRIuS " x %" PRIuS

                             "\n",

                             metadata_->GetAlphaBits(), a->xsize(), a->ysize());

    }

  }

  const uint32_t alpha_bits = metadata_->GetAlphaBits();

  JXL_ENSURE(alpha_bits <= 32);

  // metadata_->num_extra_channels may temporarily differ from

  // extra_channels_.size(), e.g. after SetAlpha. They are synced by the next

  // call to VisitFields.

  return true;

}

Status ImageBundle::VerifySizes() const {

  const size_t xs = xsize();

  const size_t ys = ysize();

  if (HasExtraChannels()) {

    JXL_ENSURE(xs != 0 && ys != 0);

    for (const ImageF& ec : extra_channels_) {

      JXL_ENSURE(ec.xsize() == xs);

      JXL_ENSURE(ec.ysize() == ys);

    }

  }

  return true;

}

size_t ImageBundle::DetectRealBitdepth() const {

  return metadata_->bit_depth.bits_per_sample;

  // TODO(lode): let this function return lower bit depth if possible, e.g.

  // return 8 bits in case the original image came from a 16-bit PNG that

  // was in fact representable as 8-bit PNG. Ensure that the implementation

  // returns 16 if e.g. two consecutive 16-bit values appeared in the original

  // image (such as 32768 and 32769), take into account that e.g. the values

  // 3-bit can represent is not a superset of the values 2-bit can represent,

  // and there may be slight imprecisions in the floating point image.

}

const ImageF* ImageBundle::black() const {

  if (!HasBlack()) return nullptr;

  const size_t ec = metadata_->Find(ExtraChannel::kBlack) -

                    metadata_->extra_channel_info.data();

  JXL_DASSERT(ec < extra_channels_.size());

  return &extra_channels_[ec];

}

const ImageF* ImageBundle::alpha() const {

  if (!HasAlpha()) return nullptr;

  const size_t ec = metadata_->Find(ExtraChannel::kAlpha) -

                    metadata_->extra_channel_info.data();

  JXL_DASSERT(ec < extra_channels_.size());

  return &extra_channels_[ec];

}

ImageF* ImageBundle::alpha() {

  if (!HasAlpha()) return nullptr;

  const size_t ec = metadata_->Find(ExtraChannel::kAlpha) -

                    metadata_->extra_channel_info.data();

  JXL_DASSERT(ec < extra_channels_.size());

  return &extra_channels_[ec];

}

Status ImageBundle::SetAlpha(ImageF&& alpha) {

  const ExtraChannelInfo* eci = metadata_->Find(ExtraChannel::kAlpha);

  // Must call SetAlphaBits first, otherwise we don't know which channel index

  JXL_ENSURE(eci != nullptr);

  JXL_ENSURE(alpha.xsize() != 0 && alpha.ysize() != 0);

  if (extra_channels_.size() < metadata_->extra_channel_info.size()) {

    // TODO(jon): get rid of this case

    extra_channels_.insert(

        extra_channels_.begin() + (eci - metadata_->extra_channel_info.data()),

        std::move(alpha));

  } else {

    extra_channels_[eci - metadata_->extra_channel_info.data()] =

        std::move(alpha);

  }

  // num_extra_channels is automatically set in visitor

  JXL_RETURN_IF_ERROR(VerifySizes());

  return true;

}

Status ImageBundle::SetExtraChannels(std::vector<ImageF>&& extra_channels) {

  for (const ImageF& plane : extra_channels) {

    JXL_ENSURE(plane.xsize() != 0 && plane.ysize() != 0);

  }

  extra_channels_ = std::move(extra_channels);

  JXL_RETURN_IF_ERROR(VerifySizes());

  return true;

}

}  // namespace jxl