#include "cru/ui/render/FlexLayoutRenderObject.hpp"

#include "cru/platform/graph/util/Painter.hpp"

#include <algorithm>
#include <functional>

namespace cru::ui::render {
Size FlexLayoutRenderObject::OnMeasureContent(
    const MeasureRequirement& requirement, const MeasureSize& preferred_size) {
  // TODO: Rewrite this.
  CRU_UNUSED(requirement);
  CRU_UNUSED(preferred_size);
  throw std::runtime_error("Not implemented.");

  // const bool horizontal = (direction_ == FlexDirection::Horizontal ||
  //                          direction_ == FlexDirection::HorizontalReverse);

  // const auto main_max_length =
  //     horizontal ? requirement.max_width : requirement.max_height;
  // const auto cross_max_length =
  //     horizontal ? requirement.max_height : requirement.max_width;

  // std::function<float(const Size&)> get_main_length;
  // std::function<float(const Size&)> get_cross_length;
  // std::function<void(Size&, const Size&)> calculate_result_size;
  // std::function<MeasureRequirement(MeasureLength main, MeasureLength cross)>
  //     create_requirement;

  // if (horizontal) {
  //   get_main_length = [](const Size& size) { return size.width; };
  //   get_cross_length = [](const Size& size) { return size.height; };
  //   calculate_result_size = [](Size& result, const Size& child_size) {
  //     result.width += child_size.width;
  //     result.height = std::max(result.height, child_size.height);
  //   };
  //   create_requirement = [](MeasureLength main, MeasureLength cross) {
  //     return MeasureRequirement{main, cross};
  //   };
  // } else {
  //   get_main_length = [](const Size& size) { return size.height; };
  //   get_cross_length = [](const Size& size) { return size.width; };
  //   calculate_result_size = [](Size& result, const Size& child_size) {
  //     result.height += child_size.height;
  //     result.width = std::max(result.width, child_size.width);
  //   };
  //   create_requirement = [](MeasureLength main, MeasureLength cross) {
  //     return MeasureRequirement{cross, main};
  //   };
  // }

  // const auto& children = GetChildren();
  // Index children_count = children.size();

  // if (!main_max_length.IsNotSpecify()) {
  //   float remain_main_length = main_max_length.GetLengthOrMax();

  //   for (Index i = 0; i < children_count; i++) {
  //     const auto child = children[i];
  //     child->Measure(create_requirement(remain_main_length,
  //     cross_max_length)); const auto measure_result =
  //     child->GetMeasuredSize(); remain_main_length -=
  //     get_main_length(measure_result);
  //   }

  //   if (remain_main_length > 0) {
  //     std::vector<Index> expand_children;
  //     float total_expand_factor = 0;

  //     for (Index i = 0; i < children_count; i++) {
  //       const auto factor = GetChildLayoutData(i)->expand_factor;
  //       if (factor > 0) {
  //         expand_children.push_back(i);
  //         total_expand_factor += factor;
  //       }
  //     }

  //     for (const Index i : expand_children) {
  //       const float distributed_grow_length =
  //           remain_main_length *
  //           (GetChildLayoutData(i)->expand_factor / total_expand_factor);
  //       const auto child = children[i];
  //       const float new_main_length =
  //           get_main_length(child->GetMeasuredSize()) +
  //           distributed_grow_length;
  //       child->Measure(create_requirement(new_main_length,
  //       cross_max_length));
  //     }
  //   } else if (remain_main_length < 0) {
  //     std::vector<Index> shrink_children;
  //     float total_shrink_factor = 0;

  //     for (Index i = 0; i < children_count; i++) {
  //       const auto factor = GetChildLayoutData(i)->shrink_factor;
  //       if (factor > 0) {
  //         shrink_children.push_back(i);
  //         total_shrink_factor += factor;
  //       }
  //     }

  //     for (const Index i : shrink_children) {
  //       const float distributed_shrink_length =  // negative
  //           remain_main_length *
  //           (GetChildLayoutData(i)->shrink_factor / total_shrink_factor);
  //       const auto child = children[i];
  //       float new_main_length = get_main_length(child->GetMeasuredSize()) +
  //                               distributed_shrink_length;
  //       new_main_length = new_main_length > 0 ? new_main_length : 0;
  //       child->Measure(create_requirement(new_main_length,
  //       cross_max_length));
  //     }
  //   }
  // } else {
  //   for (Index i = 0; i < children_count; i++) {
  //     const auto child = children[i];
  //     child->Measure(requirement);
  //   }
  // }

  // Size result;
  // for (auto child : children) {
  //   calculate_result_size(result, child->GetMeasuredSize());
  // }

  // return result;
}

void FlexLayoutRenderObject::OnLayoutContent(const Rect& content_rect) {
  // TODO: Rewrite this.
  CRU_UNUSED(content_rect);
  throw std::runtime_error("Not implemented.");

  // auto calculate_anchor = [](int alignment, float start_point,
  //                            float total_length,
  //                            float content_length) -> float {
  //   switch (alignment) {
  //     case internal::align_start:
  //       return start_point;
  //     case internal::align_center:
  //       return start_point + (total_length - content_length) / 2.0f;
  //     case internal::align_end:
  //       return start_point + total_length - content_length;
  //     default:
  //       return start_point;
  //   }
  // };

  // const auto& children = GetChildren();
  // if (direction_ == FlexDirection::Horizontal ||
  //     direction_ == FlexDirection::HorizontalReverse) {
  //   float actual_content_width = 0;
  //   for (const auto child : children) {
  //     actual_content_width += child->GetMeasuredSize().width;
  //   }

  //   const float content_anchor_x =
  //       calculate_anchor(static_cast<int>(content_main_align_), 0,
  //                        content_rect.width, actual_content_width);

  //   float anchor_x = 0;
  //   for (int i = 0; i < static_cast<int>(children.size()); i++) {
  //     const auto child = children[i];
  //     const auto size = child->GetMeasuredSize();

  //     float real_anchor_x = anchor_x + content_anchor_x;
  //     if (direction_ == FlexDirection::Horizontal)
  //       real_anchor_x = content_rect.left + real_anchor_x;
  //     else
  //       real_anchor_x = content_rect.GetRight() - real_anchor_x;
  //     child->Layout(Rect{
  //         real_anchor_x,
  //         calculate_anchor(
  //             static_cast<int>(GetChildLayoutData(i)->cross_alignment.value_or(
  //                 this->item_cross_align_)),
  //             content_rect.top, content_rect.height, size.height),
  //         size.width, size.height});

  //     anchor_x += size.width;
  //   }
  // } else {
  //   float actual_content_height = 0;
  //   for (const auto child : children) {
  //     actual_content_height = child->GetMeasuredSize().height;
  //   }

  //   const float content_anchor_y =
  //       calculate_anchor(static_cast<int>(content_main_align_), 0,
  //                        content_rect.height, actual_content_height);

  //   float anchor_y = 0;
  //   for (int i = 0; i < static_cast<int>(children.size()); i++) {
  //     const auto child = children[i];
  //     const auto size = child->GetMeasuredSize();

  //     float real_anchor_y = anchor_y + content_anchor_y;
  //     if (direction_ == FlexDirection::Vertical) {
  //       real_anchor_y = content_rect.top + real_anchor_y;
  //     } else {
  //       real_anchor_y = content_rect.GetBottom() - real_anchor_y;
  //     }
  //     child->Layout(Rect{
  //         real_anchor_y,
  //         calculate_anchor(
  //             static_cast<int>(GetChildLayoutData(i)->cross_alignment.value_or(
  //                 this->item_cross_align_)),
  //             content_rect.left, content_rect.width, size.width),
  //         size.width, size.height});

  //     anchor_y += size.height;
  //   }
  // }
}
}  // namespace cru::ui::render