import { computeRucDv } from '@impuestos/rules';
import { describe, expect, it } from 'vitest';
import { lookupNumber } from './index';

const NOW = new Date('2026-09-03T12:00:00Z');

describe('lookupNumber', () => {
  it('validates a RUC and derives the filing day from the base', () => {
    const dv = computeRucDv('4123456');
    const result = lookupNumber(`4123456-${dv}`, NOW);

    expect(result.valid).toBe(true);
    expect(result.docType).toBe('ruc');
    expect(result.base).toBe('4123456');
    expect(result.dv).toBe(dv);
    // Base ends in 6, and RULES.md maps digit 6 to the 19th.
    expect(result.deadlineDigit).toBe(6);
    expect(result.deadlineDay).toBe(19);
  });

  it('returns the next three monthly deadlines in order', () => {
    const dv = computeRucDv('4123456');
    const result = lookupNumber(`4123456-${dv}`, NOW);

    expect(result.nextDeadlines).toHaveLength(3);
    // 2026-09-19 is a Saturday, so the first rolls to the Monday.
    expect(result.nextDeadlines).toEqual(['2026-09-21', '2026-10-19', '2026-11-19']);
    expect([...result.nextDeadlines].sort()).toEqual(result.nextDeadlines);
  });

  it('reads a bare number as a CI, which individuals may type either way', () => {
    const result = lookupNumber('4123456', NOW);
    expect(result.valid).toBe(true);
    expect(result.docType).toBe('ci');
    expect(result.dv).toBeNull();
    expect(result.deadlineDay).toBe(19);
  });

  it('reports a wrong check digit as invalid rather than as an error', () => {
    const dv = computeRucDv('4123456');
    const result = lookupNumber(`4123456-${(dv + 1) % 10}`, NOW);
    expect(result.valid).toBe(false);
    expect(result.base).toBe('4123456');
  });

  it('tolerates the dots and spaces people actually type', () => {
    const dv = computeRucDv('4123456');
    expect(lookupNumber(` 4.123.456-${dv} `, NOW).valid).toBe(true);
  });

  it('rejects letters and over long numbers without throwing', () => {
    for (const value of ['abc', '', '123456789-1', '4123456-', '-1', '4123456-12']) {
      expect(lookupNumber(value, NOW).valid, value).toBe(false);
    }
  });

  it('always returns a well formed shape, even when invalid', () => {
    const result = lookupNumber('nonsense', NOW);
    expect(result.nextDeadlines).toHaveLength(3);
    expect(result.deadlineDay).toBeGreaterThan(0);
  });
});