// Copyright 2019 The Cobalt Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "cobalt/cssom/cobalt_ui_nav_focus_transform_function.h"

#include "base/strings/stringprintf.h"
#include "cobalt/cssom/transform_function_visitor.h"
#include "cobalt/math/matrix_interpolation.h"

namespace cobalt {
namespace cssom {

CobaltUiNavFocusTransformFunction::CobaltUiNavFocusTransformFunction(
    float x_translation_scale, float y_translation_scale,
    float progress_to_identity)
    : x_translation_scale_(x_translation_scale),
      y_translation_scale_(y_translation_scale),
      progress_to_identity_(progress_to_identity) {
  traits_ = kTraitIsDynamic | kTraitUsesUiNavFocus;
}

void CobaltUiNavFocusTransformFunction::Accept(
    TransformFunctionVisitor* visitor) const {
  visitor->VisitCobaltUiNavFocusTransform(this);
}

std::string CobaltUiNavFocusTransformFunction::ToString() const {
  return base::StringPrintf("-cobalt-ui-nav-focus-transform(%.7g, %.7g)",
                            x_translation_scale_, y_translation_scale_);
}

math::Matrix3F CobaltUiNavFocusTransformFunction::ToMatrix(
    const math::SizeF& used_size,
    const scoped_refptr<ui_navigation::NavItem>& used_ui_nav_focus) const {
  ui_navigation::NativeMatrix4 matrix;
  if (used_ui_nav_focus && used_ui_nav_focus->GetFocusTransform(&matrix)) {
    return math::InterpolateMatrices(
        math::Matrix3F::FromValues(
            // Since the UI is only rendered in 2D, ignore any scaling or
            // shearing that might be part of a 3D transform.
            1.0f, 0.0f, matrix.m[3] * x_translation_scale_, 0.0f, 1.0f,
            matrix.m[7] * y_translation_scale_, 0.0f, 0.0f, 1.0f),
        math::Matrix3F::Identity(), progress_to_identity_);
  }
  return math::Matrix3F::Identity();
}

}  // namespace cssom
}  // namespace cobalt