import {
  MPIN_LENGTH,
  isRepeatedDigits,
  isValidAccountNumber,
  isValidIfsc,
  isValidMmid,
  isValidMpin,
  isValidOtp,
  isValidPhone,
} from './validation';

describe('isValidMpin', () => {
  it('is fixed at four digits', () => {
    expect(MPIN_LENGTH).toBe(4);
    expect(isValidMpin('4271')).toBe(true);
  });

  // The backend would accept six, but this app standardises on four, so a
  // six-digit entry must not slip past the client either.
  it('rejects any other length', () => {
    expect(isValidMpin('427')).toBe(false);
    expect(isValidMpin('42719')).toBe(false);
    expect(isValidMpin('427193')).toBe(false);
    expect(isValidMpin('')).toBe(false);
  });

  // The server refuses this too, but only after decryption — catching it here
  // saves a round trip and a confusing VALIDATION_ERROR.
  it('rejects an all-same-digit MPIN', () => {
    expect(isValidMpin('1111')).toBe(false);
    expect(isValidMpin('0000')).toBe(false);
  });

  it('rejects non-digits', () => {
    expect(isValidMpin('42a1')).toBe(false);
    expect(isValidMpin('4 27')).toBe(false);
  });
});

describe('isRepeatedDigits', () => {
  it('is false for an empty string rather than vacuously true', () => {
    expect(isRepeatedDigits('')).toBe(false);
  });

  it('detects a repeated digit of any length', () => {
    expect(isRepeatedDigits('7')).toBe(true);
    expect(isRepeatedDigits('7777')).toBe(true);
    expect(isRepeatedDigits('7778')).toBe(false);
  });
});

describe('isValidPhone', () => {
  it('accepts exactly ten digits', () => {
    expect(isValidPhone('8871115905')).toBe(true);
    expect(isValidPhone('887111590')).toBe(false);
    expect(isValidPhone('88711159051')).toBe(false);
  });

  it('ignores formatting characters', () => {
    expect(isValidPhone('887-111-5905')).toBe(true);
    expect(isValidPhone('+91 88711 15905')).toBe(false);
  });
});

describe('isValidOtp', () => {
  it('requires exactly six digits', () => {
    expect(isValidOtp('892220')).toBe(true);
    expect(isValidOtp('89222')).toBe(false);
    expect(isValidOtp('8922201')).toBe(false);
  });
});

// The bounds below are the API's, not any single bank's formatting. An IFSC is
// 11 characters in practice, but the endpoint documents 6 to 15.
describe('payee routing fields', () => {
  it('accepts account numbers from 5 to 20 digits', () => {
    expect(isValidAccountNumber('50100')).toBe(true);
    expect(isValidAccountNumber('50100999888777')).toBe(true);
    expect(isValidAccountNumber('5010')).toBe(false);
    expect(isValidAccountNumber('1'.repeat(21))).toBe(false);
    expect(isValidAccountNumber('50100abc')).toBe(false);
  });

  it('accepts IFSC codes from 6 to 15 alphanumerics', () => {
    expect(isValidIfsc('HDFC0001234')).toBe(true);
    expect(isValidIfsc('SIM000')).toBe(true);
    expect(isValidIfsc('SIM00')).toBe(false);
    expect(isValidIfsc('HDFC-0001234')).toBe(false);
  });

  it('requires an MMID of exactly seven digits', () => {
    expect(isValidMmid('1072730')).toBe(true);
    expect(isValidMmid('107273')).toBe(false);
    expect(isValidMmid('10727301')).toBe(false);
  });
});