// Copyright 2020 Arthur Sonzogni. All rights reserved.
// Use of this source code is governed by the MIT license that can be found in
// the LICENSE file.

#include "ftxui/dom/elements.hpp"
#include "ftxui/dom/node.hpp"

namespace ftxui {

using FlexFunction = void (*)(Requirement&);

void function_flex_grow(Requirement& r) {
  r.flex_grow_x = 1;
  r.flex_grow_y = 1;
}

void function_flex_shrink(Requirement& r) {
  r.flex_shrink_x = 1;
  r.flex_shrink_y = 1;
}

void function_flex(Requirement& r) {
  r.flex_grow_x = 1;
  r.flex_grow_y = 1;
  r.flex_shrink_x = 1;
  r.flex_shrink_y = 1;
}

void function_not_flex(Requirement& r) {
  r.flex_grow_x = 0;
  r.flex_grow_y = 0;
  r.flex_shrink_x = 0;
  r.flex_shrink_y = 0;
}

class Flex : public Node {
 public:
  Flex(FlexFunction f) { f_ = f; }
  Flex(FlexFunction f, Element child) : Node(unpack(std::move(child))), f_(f) {}
  ~Flex() override {}
  void ComputeRequirement() override {
    requirement_.min_x = 0;
    requirement_.min_y = 0;
    if (!children.empty()) {
      children[0]->ComputeRequirement();
      requirement_ = children[0]->requirement();
    }
    f_(requirement_);
  }

  void SetBox(Box box) override {
    if (children.empty())
      return;
    children[0]->SetBox(box);
  }

  FlexFunction f_;
};

Element filler() {
  return std::make_shared<Flex>(function_flex);
}

Element flex(Element child) {
  return std::make_shared<Flex>(function_flex, std::move(child));
}

Element flex_grow(Element child) {
  return std::make_shared<Flex>(function_flex_grow, std::move(child));
}

Element flex_shrink(Element child) {
  return std::make_shared<Flex>(function_flex_shrink, std::move(child));
}

Element notflex(Element child) {
  return std::make_shared<Flex>(function_not_flex, std::move(child));
}

}  // namespace ftxui