import { formatGeneratedNumber } from './number-format';

describe('formatGeneratedNumber', () => {
  // Constructed via local-time components (not an ISO string) so the test
  // is deterministic regardless of the machine's timezone.
  const date = new Date(2026, 2, 7);

  it('substitutes year, month, day and a zero-padded sequence', () => {
    const result = formatGeneratedNumber('WH-{YYYY}-{SEQ:4}', 7, date);

    expect(result).toBe('WH-2026-0007');
  });

  it('supports {YY}, {MM}, {DD} and an unpadded {SEQ}', () => {
    const result = formatGeneratedNumber('{YY}{MM}{DD}-{SEQ}', 3, date);

    expect(result).toBe('260307-3');
  });

  it('does not truncate a sequence wider than the requested padding', () => {
    const result = formatGeneratedNumber('L-{SEQ:2}', 12345, date);

    expect(result).toBe('L-12345');
  });

  it('leaves a format with no placeholders unchanged', () => {
    const result = formatGeneratedNumber('FIXED-NUMBER', 1, date);

    expect(result).toBe('FIXED-NUMBER');
  });

  it('clamps a pathologically large {SEQ:N} width instead of allocating it', () => {
    const result = formatGeneratedNumber('L-{SEQ:999999999}', 7, date);

    expect(result).toBe(`L-${'0'.repeat(19)}7`);
    expect(result.length).toBe(22);
  });
});