import { describe, expect, it } from 'vitest';
import { fmt } from '../src/ui/format';

const stripThin = (s: string) => s.replace(/ /g, ' ');

describe('value formatting', () => {
  it('uses a real minus sign, not a hyphen', () => {
    expect(fmt.db(-12.3)).toContain('−');
    expect(fmt.db(-12.3)).not.toContain('-');
  });

  it('never renders a negative zero', () => {
    // A Doppler ratio a hair under 1 must read "0.0 ¢", not "−0.0 ¢".
    expect(stripThin(fmt.cents(-0.0001))).toBe('0.0 ¢');
    expect(stripThin(fmt.cents(0))).toBe('0.0 ¢');
    expect(stripThin(fmt.speed(-0.004))).toBe('0.0 m/s');
    expect(stripThin(fmt.db(-0.02))).toBe('0.0 dB');
  });

  it('signs real values', () => {
    expect(stripThin(fmt.cents(38.2))).toBe('+38.2 ¢');
    expect(stripThin(fmt.cents(-38.2))).toBe('−38.2 ¢');
  });

  it('renders silence as −∞ rather than a huge number', () => {
    expect(stripThin(fmt.db(-120))).toBe('−∞ dB');
    expect(stripThin(fmt.db(-500))).toBe('−∞ dB');
  });

  it('survives non-finite input', () => {
    for (const formatter of [fmt.metres, fmt.db, fmt.degrees, fmt.seconds, fmt.ms, fmt.speed]) {
      expect(formatter(Number.NaN)).toBe('—');
      expect(formatter(Number.POSITIVE_INFINITY)).toBe('—');
    }
    expect(fmt.hz(Number.NaN)).toBe('—');
    expect(fmt.cents(Number.NaN)).toBe('—');
  });

  it('switches Hz to kHz with three significant figures', () => {
    expect(stripThin(fmt.hz(350))).toBe('350 Hz');
    expect(stripThin(fmt.hz(1700))).toBe('1.70 kHz');
    expect(stripThin(fmt.hz(22050))).toBe('22.1 kHz');
  });

  it('keeps decimals fixed so numbers do not jitter in width', () => {
    expect(stripThin(fmt.metres(5))).toBe('5.00 m');
    expect(stripThin(fmt.metres(12.345))).toBe('12.35 m');
    expect(stripThin(fmt.ratio(1))).toBe('×1.0000');
  });
});