fizzbuzz.phpakefile

<?php

namespace Fizzbuzz;

/**
 * Converts a number into its FizzBuzz equivalent.
 *
 * This function won't be treated as a command because its name starts with
 * an underscore.
 *
 * @param int $n An integer.
 * @return string Fizz, buzz, fizzbuzz, or the number.
 */
function _fizzbuzz(int $n): string {
  $isFizz = ($n % 3 == 0);
  $isBuzz = ($n % 5 == 0);

  if ($isFizz && $isBuzz) {
    return 'fizzbuzz';
  }

  if ($isFizz) {
    return 'fizz';
  }

  if ($isBuzz) {
    return 'buzz';
  }

  return (string) $n;
}

/**
 * Display fizz buzz for a number.
 *
 * Here's how you do Fizz Buzz.
 *
 * If the number is divisible by 3, "fizz" is displayed.
 * If the number is divisible by 5, "buzz" is displayed.
 * If the number is divisible by both, "fizzbuzz" is displayed.
 * If the number is divisible by neither, the number is displayed.
 *
 * See https://en.wikipedia.org/wiki/Fizz_buzz
 *
 * @usage 3
 * @usage 10
 * @usage 13
 * @usage 15
 *
 * @param string $n A positive integer.
 * @param $output
 * @return int|void
 */
function number(string $n, $output) {
  if (!is_numeric($n)) {
    $output->writeln('<error>n must be a positive integer.</error>');
    return 1;
  }

  $result = _fizzbuzz($n);

  if (is_numeric($result)) {
    $output->writeln($result);
    return;
  }

  $output->writeln("<info>$result</info>");
}

/**
 * Display fizz buzz for all numbers from 1 to n.
 *
 * @usage 20
 *
 * @param string $n A positive integer.
 * @param $output
 * @return int|void
 */
function range(string $n, $output) {
  if (!is_numeric($n) || $n < 0) {
    $output->writeln('<error>n must be a positive integer.</error>');
    return 1;
  }

  for ($i = 1; $i <= $n; $i++) {
    number($i, $output);
  }
}