import {
  TPIN_LENGTH,
  containsSequentialRun,
  describeTpinProblem,
  isAcceptableNewTpin,
  isValidTpinEntry,
} from './tpinValidation';

describe('isValidTpinEntry', () => {
  it('accepts exactly four digits', () => {
    expect(TPIN_LENGTH).toBe(4);
    expect(isValidTpinEntry('2580')).toBe(true);
    expect(isValidTpinEntry('258')).toBe(false);
    expect(isValidTpinEntry('25801')).toBe(false);
    expect(isValidTpinEntry('25a0')).toBe(false);
  });

  // On a transfer the server decides whether the digits are right, so an
  // entry the create rules would refuse must still be typeable.
  it('does not apply the choosing rules to an entry', () => {
    expect(isValidTpinEntry('1234')).toBe(true);
    expect(isValidTpinEntry('1111')).toBe(true);
  });
});

describe('describeTpinProblem', () => {
  it('says nothing about an empty field', () => {
    expect(describeTpinProblem('')).toBeUndefined();
  });

  it('asks for four digits until there are four', () => {
    expect(describeTpinProblem('25')).toBe('A TPIN is 4 digits');
    expect(describeTpinProblem('2a')).toBe('Digits only');
  });

  it('refuses ascending and descending runs', () => {
    expect(describeTpinProblem('1234')).toMatch(/run of digits/);
    expect(describeTpinProblem('4321')).toMatch(/run of digits/);
    expect(describeTpinProblem('6789')).toMatch(/run of digits/);
  });

  // The policy refuses "a sequence of three digits", so a run of three inside
  // the four counts as much as one spanning all of them.
  it('refuses a run of three anywhere in the TPIN', () => {
    expect(describeTpinProblem('1235')).toMatch(/run of digits/);
    expect(describeTpinProblem('5987')).toMatch(/run of digits/);
    expect(describeTpinProblem('0124')).toMatch(/run of digits/);
    expect(describeTpinProblem('7210')).toMatch(/run of digits/);
  });

  it('allows a TPIN with no run of three', () => {
    expect(describeTpinProblem('1243')).toBeUndefined();
    expect(describeTpinProblem('1357')).toBeUndefined();
    // No wrap-around from 9 to 0.
    expect(describeTpinProblem('8901')).toBeUndefined();
  });

  it('refuses the same digit repeated', () => {
    expect(describeTpinProblem('1111')).toMatch(/same digit/);
  });

  it('refuses the last four digits of the registered mobile', () => {
    expect(describeTpinProblem('0101', '9300000101')).toMatch(/last four digits/);
    expect(describeTpinProblem('0101', '+91 93000 00101')).toMatch(/last four digits/);
    expect(describeTpinProblem('0102', '9300000101')).toBeUndefined();
  });

  it('skips the mobile rule when the number is unknown', () => {
    expect(describeTpinProblem('0101')).toBeUndefined();
    expect(describeTpinProblem('0101', '')).toBeUndefined();
  });
});

describe('isAcceptableNewTpin', () => {
  it('accepts a TPIN that breaks no rule', () => {
    expect(isAcceptableNewTpin('2580', '9300000101')).toBe(true);
  });

  it('refuses one that breaks any rule, or is incomplete', () => {
    expect(isAcceptableNewTpin('258')).toBe(false);
    expect(isAcceptableNewTpin('1234')).toBe(false);
    expect(isAcceptableNewTpin('0101', '9300000101')).toBe(false);
  });
});

describe('containsSequentialRun', () => {
  it('finds a run of three at the start, the end, or spanning the whole value', () => {
    expect(containsSequentialRun('1239')).toBe(true);
    expect(containsSequentialRun('9321')).toBe(true);
    expect(containsSequentialRun('3456')).toBe(true);
  });

  it('does not count a run of two', () => {
    expect(containsSequentialRun('1290')).toBe(false);
    expect(containsSequentialRun('12')).toBe(false);
  });
});