--description--

Implement a function which:

<ul> <li>takes a positive integer representing a duration in seconds as input (e.g., <code>100</code>), and</li> <li>returns a string which shows the same duration decomposed into weeks, days, hours, minutes, and seconds as detailed below (e.g., <code>1 min, 40 sec</code>).</li> </ul>

Demonstrate that it passes the following three test-cases:

<div style='font-size:115%; font-weight: bold;'>Test Cases</div>

Input number	Output number
7259	<code>2 hr, 59 sec</code>
86400	<code>1 d</code>
6000000	<code>9 wk, 6 d, 10 hr, 40 min</code>

<div style="font-size:115%; font-weight: bold;">Details</div> <ul> <li> The following five units should be used:

Unit	Suffix used in Output	Conversion
week	<code>wk</code>	1 week = 7 days
day	<code>d</code>	1 day = 24 hours
hour	<code>hr</code>	1 hour = 60 minutes
minute	<code>min</code>	1 minute = 60 seconds
second	<code>sec</code>	---

</li> <li> However, <strong>only</strong> include quantities with non-zero values in the output (e.g., return <code>1 d</code> and not <code>0 wk, 1 d, 0 hr, 0 min, 0 sec</code>). </li> <li> Give larger units precedence over smaller ones as much as possible (e.g., return <code>2 min, 10 sec</code> and not <code>1 min, 70 sec</code> or <code>130 sec</code>). </li> <li> Mimic the formatting shown in the test-cases (quantities sorted from largest unit to smallest and separated by comma+space; value and unit of each quantity separated by space). </li> </ul>

--before-each--

const testCases = [7259, 86400, 6000000];
const results = ['2 hr, 59 sec', '1 d', '9 wk, 6 d, 10 hr, 40 min'];

--hints--

convertSeconds should be a function.

assert(typeof convertSeconds === 'function');

convertSeconds(7259) should return 2 hr, 59 sec.

assert.equal(convertSeconds(testCases[0]), results[0]);

convertSeconds(86400) should return 1 d.

assert.equal(convertSeconds(testCases[1]), results[1]);

convertSeconds(6000000) should return 9 wk, 6 d, 10 hr, 40 min.

assert.equal(convertSeconds(testCases[2]), results[2]);

--seed--

--seed-contents--

function convertSeconds(sec) {

  return true;
}

--solutions--

function convertSeconds(sec) {
  const localNames = ['wk', 'd', 'hr', 'min', 'sec'];
  // compoundDuration :: [String] -> Int -> String
  const compoundDuration = (labels, intSeconds) =>
    weekParts(intSeconds)
    .map((v, i) => [v, labels[i]])
    .reduce((a, x) =>
      a.concat(x[0] ? [`${x[0]} ${x[1] || '?'}`] : []), []
    )
    .join(', ');

    // weekParts :: Int -> [Int]
  const weekParts = intSeconds => [0, 7, 24, 60, 60]
    .reduceRight((a, x) => {
      const r = a.rem;
      const mod = x !== 0 ? r % x : r;

      return {
        rem: (r - mod) / (x || 1),
        parts: [mod].concat(a.parts)
      };
    }, {
      rem: intSeconds,
      parts: []
    })
    .parts;

  return compoundDuration(localNames, sec);
}