// Copyright (c) 2022 Dominic Masters
// 
// This software is released under the MIT License.
// https://opensource.org/licenses/MIT

#pragma once
#include "dawnlibs.hpp"
#include "util/flag.hpp"

namespace Dawn {
  class SceneItem;

  class Transform : public std::enable_shared_from_this<Transform> {
    private:
      // Local (real) values
      glm::vec3 localPosition;
      glm::vec3 localScale;
      glm::quat localRotation;

      // Cached (non-real) values
      glm::mat4 transformLocal;
      glm::mat4 transformWorld;

      // glm::vec3 position;
      // glm::vec3 scale;
      // glm::quat rotation;

      // Heirarchy
      Transform *parent = nullptr;
      std::vector<Transform *> children;

      // Hidden methods
      void updateLocalValuesFromLocalTransform();
      void updateLocalTransformFromLocalValues();
      void updateWorldTransformFromLocalTransform();
      void updateLocalTransformFromWorldTransform();
      void updateChildrenTransforms();

    public:
      SceneItem &item;

      Transform(SceneItem &item);

      void lookAt(glm::vec3 position, glm::vec3 look);
      void lookAt(glm::vec3 position, glm::vec3 look, glm::vec3 up);

      glm::vec3 getLocalPosition();
      void setLocalPosition(glm::vec3 position);

      glm::vec3 getLocalScale();
      void setLocalScale(glm::vec3 scale);
      
      glm::quat getLocalRotation();
      void setLocalRotation(glm::quat rotation);
      

      glm::mat4 getLocalTransform();
      void setLocalTransform(glm::mat4 transform);

      glm::mat4 getWorldTransform();
      void setWorldTransform(glm::mat4 transform);
      

      void setParent(Transform *p);
      Transform * getParent();

      ~Transform();
  };
}