import { describe, expect, it } from 'vitest';
import { pitchForZoom, smoothstep, PITCH_ZOOM_MIN, PITCH_ZOOM_MAX, MAX_PITCH_DEG } from './camera';

describe('smoothstep', () => {
  it('clamps outside the edges and is 0.5 at the midpoint', () => {
    expect(smoothstep(0, 1, -5)).toBe(0);
    expect(smoothstep(0, 1, 2)).toBe(1);
    expect(smoothstep(0, 1, 0.5)).toBeCloseTo(0.5);
  });
});

describe('pitchForZoom', () => {
  it('is 0 at and below the lower zoom threshold', () => {
    expect(pitchForZoom(PITCH_ZOOM_MIN)).toBe(0);
    expect(pitchForZoom(4)).toBe(0);
    expect(pitchForZoom(0)).toBe(0);
  });

  it('is max pitch at and above the upper zoom threshold', () => {
    expect(pitchForZoom(PITCH_ZOOM_MAX)).toBe(MAX_PITCH_DEG);
    expect(pitchForZoom(15)).toBe(MAX_PITCH_DEG);
  });

  it('rises smoothly between thresholds (monotonic, midpoint = half max)', () => {
    expect(pitchForZoom((PITCH_ZOOM_MIN + PITCH_ZOOM_MAX) / 2)).toBeCloseTo(MAX_PITCH_DEG / 2);
    let prev = -1;
    for (let z = PITCH_ZOOM_MIN; z <= PITCH_ZOOM_MAX; z += 0.25) {
      const p = pitchForZoom(z);
      expect(p).toBeGreaterThan(prev);
      prev = p;
    }
  });
});