#ifndef CAMERA_SYSTEM_H_D52ADAD3
#define CAMERA_SYSTEM_H_D52ADAD3

#include "consts.h"
#include "system.h"
#include "vector.h"

class Game;

class CameraSystem : public System {
public:

  static constexpr SystemKey Key = SystemKey::Camera;

  CameraSystem(Game& game) : game_(game) {}

  const vec2i& getCameraPosition() const { return pos_; }

  const vec2i& getFieldOfView() const { return fov_; }

  void setFollowingSprite(int spriteId) { followingSprite_ = spriteId; }

  void lockCamera() { locked_ = true; }

  void unlockCamera() { locked_ = false; }

  // Pans over to the provided sprite over the provided amount of time.
  // - length is in milliseconds
  // Automatically locks the camera.
  void panToSprite(int targetId, int length);

  bool isPanning() const { return panning_; }

  void tick(double dt) override;

  void destroySprite(int spriteId) override;

private:

  vec2i calculatePosWithCenter(vec2i center) const;

  Game& game_;

  vec2i pos_;
  vec2i fov_ { CANVAS_WIDTH, CANVAS_HEIGHT };
  int followingSprite_ = -1;
  bool locked_ = true;

  bool panning_ = false;
  vec2i panStart_;
  vec2i panEnd_;
  double panLength_ = 0.0;
  double panThus_ = 0.0;
};

#endif /* end of include guard: CAMERA_SYSTEM_H_D52ADAD3 */