import * as THREE from 'three';
import { describe, expect, it } from 'vitest';
import { fitCamera } from '../src/view/fit';

describe('카메라 맞춤 (전체 모델이 화면에 들어옴)', () => {
  const sphere = new THREE.Sphere(new THREE.Vector3(10, 30, 0), 50);

  it('the target moves to the sphere centre and the sphere lies inside the view cone', () => {
    const cam = fitCamera(new THREE.Vector3(1, 1, 1).multiplyScalar(20), new THREE.Vector3(), sphere, 40, 1.6);
    expect(cam.target.distanceTo(sphere.center)).toBeLessThan(1e-9);
    // The distance from the camera to the centre must cover the radius at the vertical half-angle.
    const d = cam.position.distanceTo(sphere.center);
    expect(d * Math.sin(THREE.MathUtils.degToRad(20))).toBeGreaterThanOrEqual(sphere.radius - 1e-6);
  });

  it('a narrow window (aspect < 1) backs off further than a wide one', () => {
    const wide = fitCamera(new THREE.Vector3(0, 0, 100), new THREE.Vector3(), sphere, 40, 2);
    const narrow = fitCamera(new THREE.Vector3(0, 0, 100), new THREE.Vector3(), sphere, 40, 0.5);
    expect(narrow.position.distanceTo(sphere.center)).toBeGreaterThan(wide.position.distanceTo(sphere.center));
  });

  it('a camera already far enough keeps its distance', () => {
    const far = new THREE.Vector3(0, 0, 1000);
    const cam = fitCamera(far, new THREE.Vector3(), sphere, 40, 1.6);
    // The distance is kept from the old target (origin): 1000 m, measured from the new centre.
    expect(cam.position.distanceTo(sphere.center)).toBeCloseTo(1000, 6);
  });
});