#define OLC_PGE_APPLICATION
#include "olcPixelGameEngine.h"
#include "olcUTIL_Camera2D.h"
#define OLC_PGEX_TRANSFORMEDVIEW
#include "olcPGEX_TransformedView.h"

using namespace olc;
using namespace olc::utils;

const vi2d WINDOW_SIZE={24*8,24*8};

struct Player{
	vf2d pos;
	float moveSpd;
	Player(){};
	Player(vf2d pos,float moveSpd):
		pos(pos),moveSpd(moveSpd){};
};

class Crawler : public olc::PixelGameEngine
{
	const vi2d WORLD_SIZE={64,64};
	Camera2D camera;
	TileTransformedView view;
	Player player=Player{{},100};

public:
	Crawler()
	{
		sAppName = "Crawler Concept";
	}

public:
	bool OnUserCreate() override
	{
		camera=Camera2D{WINDOW_SIZE};
		camera.SetMode(olc::utils::Camera2D::Mode::LazyFollow);
		camera.SetTarget(player.pos);
		camera.SetWorldBoundary({0,0},WORLD_SIZE*24);
		camera.EnableWorldBoundary(false);
		view=TileTransformedView{GetScreenSize(),{1,1}};
		return true;
	}

	bool OnUserUpdate(float fElapsedTime) override
	{
		HandleUserInput(fElapsedTime);
		UpdateCamera(fElapsedTime);
		RenderWorld();
		return true;
	}

	void HandleUserInput(float fElapsedTime){
		if(GetKey(RIGHT).bHeld){
			player.pos.x+=fElapsedTime*player.moveSpd;
		}
		if(GetKey(LEFT).bHeld){
			player.pos.x-=fElapsedTime*player.moveSpd;
		}
		if(GetKey(UP).bHeld){
			player.pos.y-=fElapsedTime*player.moveSpd;
		}
		if(GetKey(DOWN).bHeld){
			player.pos.y+=fElapsedTime*player.moveSpd;
		}
	}

	void UpdateCamera(float fElapsedTime){
		camera.Update(fElapsedTime);
		view.SetWorldOffset(vi2d(camera.GetViewPosition()));
	}

	void RenderWorld(){
		Clear(BLACK);
		for (int x = view.GetTopLeftTile().x/24-1; x <= view.GetBottomRightTile().x/24; x++){
			for (int y = view.GetTopLeftTile().y/24-1; y <= view.GetBottomRightTile().y/24; y++){
				view.DrawRect(vi2d{x,y}*24,{24,24},VERY_DARK_GREY);
			}
		}
		view.DrawCircle(player.pos,8);
	}
};


int main()
{
	Crawler demo;
	if (demo.Construct(WINDOW_SIZE.x, WINDOW_SIZE.y, 4, 4))
		demo.Start();

	return 0;
}