#include <stddef.h>
#include <raylib.h>
#include <raymath.h>
#include <stdio.h>
#include <stdlib.h>
#include "objects.h"

struct global {
  const int scwidth, scheight;
  int fps;
  object *objs[128];
  size_t obj_count;
  double terminal_v;
	double friction;
};

struct global gl = {1600, 900, 144, {}, 0, 15, 0.001};

void addobj(object *obj)
{
  gl.objs[gl.obj_count++] = obj;
}

void drawobjs()
{
  for (int i = 0; i < gl.obj_count; i++)
  {
    object *obj = gl.objs[i];
    DrawSphere(obj->pos, obj->r, obj->color);
    DrawSphereWires(obj->pos, obj->r, 16, 16, ColorBrightness(obj->color, -0.5f));
		DrawLine3D(obj->pos, Vector3Add(obj->pos, obj->vel), PURPLE);
  }
}

void updateobjs()
{
  for (int i = 0; i < gl.obj_count; i++)
  {
    object *obj = gl.objs[i];
    obj->vel.y -= 0 * GetFrameTime();
    //if (obj->vel.y < gl.terminal_yv)
    if (obj->pos.y < obj->r) {
      obj->pos.y = obj->r;
      obj->vel.y *= -obj->restitution;
    }
		for (int j = 0; j < gl.obj_count; j++)
		{
			if (i==j) continue;
			object *obj2 = gl.objs[j];
			integrate_g(obj, obj2, gravitation_force(obj, obj2));
			//float min_dist_delta = Vector3Distance(obj->pos, obj2->pos) - (obj->r+obj2->r);
			//if (min_dist_delta < 0)
			//{
			//	Vector3SubtractValue(obj->pos, min_dist_delta);
			//}
			if (Vector3Distance(obj->pos, obj2->pos) < obj->r+obj2->r+0.01f)
			{
				resolve_collision(obj, obj2);
			}
		}
		float ratio_speed_to_terminal = Vector3Length(obj->vel)/gl.terminal_v;
		if (Vector3Length(obj->vel) > gl.terminal_v)
    {
			obj->vel = Vector3Scale(obj->vel, 1.0f/ratio_speed_to_terminal);
		}
		obj->vel = Vector3Scale(obj->vel, (1.0f-gl.friction));
		obj->pos = Vector3Add(obj->pos, Vector3Scale(obj->vel, GetFrameTime()));
  } 
}

void freeobjs()
{
  for (int i = 0; i < gl.obj_count; i++)
  {
    object *obj = gl.objs[i];
    free(obj);
  } 
}

int main(void) {

  InitWindow(gl.scwidth, gl.scheight, "raylib engine");

  SetTargetFPS(gl.fps);
  addobj(newobj((Vector3){10, 40, 0}, 2, BLUE, 1, 200000));
  addobj(newobj((Vector3){50, 20, 0}, 5, RAYWHITE, 0., 5000000));
  Camera3D camera = {{0, 20, 10}, {0, 20, 0}, {0, 1, 0}, 50, CAMERA_PERSPECTIVE};
	DisableCursor();
	SetWindowMonitor(0);

  while(!WindowShouldClose())
  {

    BeginDrawing();
    {
  		UpdateCamera(&camera, CAMERA_FREE);
      ClearBackground(BLACK);
      BeginMode3D(camera);
			DrawPlane((Vector3){0, 0, 0}, (Vector2){500, 500}, RAYWHITE);
      updateobjs();
      drawobjs();
      EndMode3D();
    }
    EndDrawing();
  }

  freeobjs();

  CloseWindow();

  return 0;

}