toHMS.coffee

# Convert int|float from seconds into formatted
# duration timestamp
#
# deps: underscore or lodash or any other library
#       that takes over window._ and provides a
#       #.compact() method. dep could ultimately
#       be removed...
#
# uses double bitwise not `~~` as `Math.floor`
# uses `+` as type coercion to `int`
Util.toHMS = (seconds, options={}) ->
  {padding, withSeconds} = options

  h = ~~(+seconds / 3600)
  m = ~~((+seconds - (h * 3600)) / 60)
  s = ~~(+seconds - (h * 3600) - (m * 60)) if withSeconds

  # apply pre-padding
  if padding
    h = (Array(padding + 1).join('0') + h) if h < 10 and h
    m = (Array(padding + 1).join('0') + m) if m < 10
    s = (Array(padding + 1).join('0') + s) if s < 10 and withSeconds

  _.compact([h, m, s]).join(':')