import { describe, expect, it } from 'vitest';

import { fitFontSize } from './fit';

const options = { available: 500, preferred: 36, minimum: 20 };

describe('fitFontSize', () => {
  it('keeps the preferred size when the text is short', () => {
    expect(fitFontSize('10:00 – 18:30', options)).toBe(36);
  });

  it('shrinks a long line rather than letting it wrap', () => {
    // Three periods, none on a round hour: the case that overflowed.
    const crowded = '09:30 – 12:00 · 13:30 – 16:00 · 17:00 – 19:30';
    const size = fitFontSize(crowded, options);
    expect(size).toBeLessThan(36);
    expect(size * crowded.length * 0.54).toBeLessThanOrEqual(options.available);
  });

  it('never goes below the floor, however long the text', () => {
    expect(fitFontSize('a'.repeat(500), options)).toBe(20);
  });

  it('keeps the preferred size for empty text', () => {
    expect(fitFontSize('', options)).toBe(36);
  });

  it('returns whole pixels', () => {
    expect(Number.isInteger(fitFontSize('10:00 – 13:00 · 14:00', options))).toBe(true);
  });

  it('gives more room a larger size', () => {
    const narrow = fitFontSize('10:00 – 13:00 · 14:00 – 18:30', { ...options, available: 300 });
    const wide = fitFontSize('10:00 – 13:00 · 14:00 – 18:30', { ...options, available: 700 });
    expect(wide).toBeGreaterThan(narrow);
  });
});