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

#pragma once
#include "SceneItemComponent.hpp"

namespace Dawn {
  typedef int32_t sceneitemid_t;

  class Scene;

  class SceneItem :
    public std::enable_shared_from_this<SceneItem>
  {
    private:
      std::vector<std::shared_ptr<SceneItemComponent>> components;

    public:
      std::weak_ptr<Scene> scene;
      sceneitemid_t id;

      /**
       * Constructor for a SceneItem. Scene Items should only be called and
       * initialized by the scene itself.
       * 
       * @param scene Weak pointer to the Scene that this SceneItem belongs to.
       * @param id Scene Item ID that the Scene assigned this SceneItem.
       */
      SceneItem(std::weak_ptr<Scene> scene, sceneitemid_t id);
      
      /**
       * Called by the Scene the frame after we were constructed so we can begin
       * existing.
       */
      void init();

      /**
       * Adds a component to this scene item. Components will only have their
       * init methods invoked on the first frame we enter the scene. If you add
       * a component to this item after this time you will either need to try
       * manually invoking its' init method, or ensure the component is aware of
       * the entire SceneItem lifecycle and listen for added callbacks.
       * 
       * @tparam T Type of component being added to this scene item.
       * @return A shared pointer to the newly added component.
       */
      template<class T>
      std::shared_ptr<T> addComponent() {
        auto component = std::make_shared<T>(weak_from_this());
        this->components.push_back(component);
        return component;
      }

      /**
       * Returns a component attached to this SceneItem. This method will return
       * either a shared pointer to the component, or nullptr if the item does
       * not have the queried component.
       * 
       * @tparam T Type of component to be fetched.
       * @return A shared pointer to the component, or nullptr if not found.
       */
      template<class T>
      std::shared_ptr<T> getComponent() {
        auto it = this->components.begin();
        while(it != this->components.end()) {
          auto castedAs = std::dynamic_pointer_cast<T>(*it);
          if(castedAs != nullptr) return castedAs;
          ++it;
        }
        return nullptr;
      }
      
      /**
       * Destroy this SceneItem.
       */
      ~SceneItem();
  };
}