// 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 <limits>

#include <utility>

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

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

#include "lib/jxl/fields.h"

namespace jxl {

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

  if (HasColor()) color_.ShrinkTo(xsize, ysize);

  for (ImageF& ec : extra_channels_) {

    ec.ShrinkTo(xsize, ysize);

  }

}

// Called by all other SetFrom*.

void ImageBundle::SetFromImage(Image3F&& color,

                               const ColorEncoding& c_current) {

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

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

  color_ = std::move(color);

  c_current_ = c_current;

  VerifySizes();

}

void ImageBundle::VerifyMetadata() const {

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

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

  if (metadata_->HasAlpha() && alpha().xsize() == 0) {

    JXL_UNREACHABLE("MD alpha_bits %u IB alpha %" PRIuS " x %" PRIuS "\n",

                    metadata_->GetAlphaBits(), alpha().xsize(),

                    alpha().ysize());

  }

  const uint32_t alpha_bits = metadata_->GetAlphaBits();

  JXL_CHECK(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.

}

void ImageBundle::VerifySizes() const {

  const size_t xs = xsize();

  const size_t ys = ysize();

  if (HasExtraChannels()) {

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

    for (const ImageF& ec : extra_channels_) {

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

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

    }

  }

}

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 {

  JXL_ASSERT(HasBlack());

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

                    metadata_->extra_channel_info.data();

  JXL_ASSERT(ec < extra_channels_.size());

  return extra_channels_[ec];

}

const ImageF& ImageBundle::alpha() const {

  JXL_ASSERT(HasAlpha());

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

                    metadata_->extra_channel_info.data();

  JXL_ASSERT(ec < extra_channels_.size());

  return extra_channels_[ec];

}

ImageF* ImageBundle::alpha() {

  JXL_ASSERT(HasAlpha());

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

                    metadata_->extra_channel_info.data();

  JXL_ASSERT(ec < extra_channels_.size());

  return &extra_channels_[ec];

}

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

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

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

  JXL_CHECK(eci != nullptr);

  JXL_CHECK(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

  VerifySizes();

}

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

  for (const ImageF& plane : extra_channels) {

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

  }

  extra_channels_ = std::move(extra_channels);

  VerifySizes();

}

}  // namespace jxl