// 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/enc_image_bundle.h"

#include <jxl/cms_interface.h>

#include <jxl/memory_manager.h>

#include <utility>

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

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

#include "lib/jxl/color_encoding_internal.h"

#include "lib/jxl/image_bundle.h"

namespace jxl {

Status ApplyColorTransform(const ColorEncoding& c_current,

                           float intensity_target, const Image3F& color,

                           const ImageF* black, const Rect& rect,

                           const ColorEncoding& c_desired,

                           const JxlCmsInterface& cms, ThreadPool* pool,

                           Image3F* out) {

  ColorSpaceTransform c_transform(cms);

  // Changing IsGray is probably a bug.

  JXL_ENSURE(c_current.IsGray() == c_desired.IsGray());

  bool is_gray = c_current.IsGray();

  JxlMemoryManager* memory_amanger = color.memory_manager();

  if (out->xsize() < rect.xsize() || out->ysize() < rect.ysize()) {

    JXL_ASSIGN_OR_RETURN(

        *out, Image3F::Create(memory_amanger, rect.xsize(), rect.ysize()));

  } else {

    JXL_RETURN_IF_ERROR(out->ShrinkTo(rect.xsize(), rect.ysize()));

  }

  const auto init = [&](const size_t num_threads) -> Status {

    JXL_RETURN_IF_ERROR(c_transform.Init(c_current, c_desired, intensity_target,

                                         rect.xsize(), num_threads));

    return true;

  };

  const auto transform_row = [&](const uint32_t y,

                                 const size_t thread) -> Status {

    float* mutable_src_buf = c_transform.BufSrc(thread);

    const float* src_buf = mutable_src_buf;

    // Interleave input.

    if (is_gray) {

      src_buf = rect.ConstPlaneRow(color, 0, y);

    } else if (c_current.IsCMYK()) {

      if (!black)

        return JXL_FAILURE("Black plane is missing for CMYK transform");

      const float* JXL_RESTRICT row_in0 = rect.ConstPlaneRow(color, 0, y);

      const float* JXL_RESTRICT row_in1 = rect.ConstPlaneRow(color, 1, y);

      const float* JXL_RESTRICT row_in2 = rect.ConstPlaneRow(color, 2, y);

      const float* JXL_RESTRICT row_in3 = rect.ConstRow(*black, y);

      for (size_t x = 0; x < rect.xsize(); x++) {

        // CMYK convention in JXL: 0 = max ink, 1 = white

        mutable_src_buf[4 * x + 0] = row_in0[x];

        mutable_src_buf[4 * x + 1] = row_in1[x];

        mutable_src_buf[4 * x + 2] = row_in2[x];

        mutable_src_buf[4 * x + 3] = row_in3[x];

      }

    } else {

      const float* JXL_RESTRICT row_in0 = rect.ConstPlaneRow(color, 0, y);

      const float* JXL_RESTRICT row_in1 = rect.ConstPlaneRow(color, 1, y);

      const float* JXL_RESTRICT row_in2 = rect.ConstPlaneRow(color, 2, y);

      for (size_t x = 0; x < rect.xsize(); x++) {

        mutable_src_buf[3 * x + 0] = row_in0[x];

        mutable_src_buf[3 * x + 1] = row_in1[x];

        mutable_src_buf[3 * x + 2] = row_in2[x];

      }

    }

    float* JXL_RESTRICT dst_buf = c_transform.BufDst(thread);

    JXL_RETURN_IF_ERROR(

        c_transform.Run(thread, src_buf, dst_buf, rect.xsize()));

    float* JXL_RESTRICT row_out0 = out->PlaneRow(0, y);

    float* JXL_RESTRICT row_out1 = out->PlaneRow(1, y);

    float* JXL_RESTRICT row_out2 = out->PlaneRow(2, y);

    // De-interleave output and convert type.

    if (is_gray) {

      for (size_t x = 0; x < rect.xsize(); x++) {

        row_out0[x] = dst_buf[x];

        row_out1[x] = dst_buf[x];

        row_out2[x] = dst_buf[x];

      }

    } else {

      for (size_t x = 0; x < rect.xsize(); x++) {

        row_out0[x] = dst_buf[3 * x + 0];

        row_out1[x] = dst_buf[3 * x + 1];

        row_out2[x] = dst_buf[3 * x + 2];

      }

    }

    return true;

  };

  JXL_RETURN_IF_ERROR(RunOnPool(pool, 0, rect.ysize(), init, transform_row,

                                "Colorspace transform"));

  return true;

}

namespace {

// Copies ib:rect, converts, and copies into out.

Status CopyToT(const ImageMetadata* metadata, const ImageBundle* ib,

               const Rect& rect, const ColorEncoding& c_desired,

               const JxlCmsInterface& cms, ThreadPool* pool, Image3F* out) {

  return ApplyColorTransform(ib->c_current(), metadata->IntensityTarget(),

                             ib->color(), ib->black(), rect, c_desired, cms,

                             pool, out);

}

}  // namespace

Status ImageBundle::TransformTo(const ColorEncoding& c_desired,

                                const JxlCmsInterface& cms, ThreadPool* pool) {

  JXL_RETURN_IF_ERROR(CopyTo(Rect(color_), c_desired, cms, &color_, pool));

  c_current_ = c_desired;

  return true;

}

Status ImageBundle::CopyTo(const Rect& rect, const ColorEncoding& c_desired,

                           const JxlCmsInterface& cms, Image3F* out,

                           ThreadPool* pool) const {

  return CopyToT(metadata_, this, rect, c_desired, cms, pool, out);

}

Status TransformIfNeeded(const ImageBundle& in, const ColorEncoding& c_desired,

                         const JxlCmsInterface& cms, ThreadPool* pool,

                         ImageBundle* store, const ImageBundle** out) {

  if (in.c_current().SameColorEncoding(c_desired) && !in.HasBlack()) {

    *out = ∈

    return true;

  }

  JxlMemoryManager* memory_manager = in.memory_manager();

  // TODO(janwas): avoid copying via createExternal+copyBackToIO

  // instead of copy+createExternal+copyBackToIO

  JXL_ASSIGN_OR_RETURN(

      Image3F color,

      Image3F::Create(memory_manager, in.color().xsize(), in.color().ysize()));

  JXL_RETURN_IF_ERROR(CopyImageTo(in.color(), &color));

  JXL_RETURN_IF_ERROR(store->SetFromImage(std::move(color), in.c_current()));

  // Must at least copy the alpha channel for use by external_image.

  if (in.HasExtraChannels()) {

    std::vector<ImageF> extra_channels;

    for (const ImageF& extra_channel : in.extra_channels()) {

      JXL_ASSIGN_OR_RETURN(ImageF ec,

                           ImageF::Create(memory_manager, extra_channel.xsize(),

                                          extra_channel.ysize()));

      JXL_RETURN_IF_ERROR(CopyImageTo(extra_channel, &ec));

      extra_channels.emplace_back(std::move(ec));

    }

    JXL_RETURN_IF_ERROR(store->SetExtraChannels(std::move(extra_channels)));

  }

  if (!store->TransformTo(c_desired, cms, pool)) {

    return false;

  }

  *out = store;

  return true;

}

}  // namespace jxl