/** Shared helpers for drive-resident /bin scripts (prepended before each command). */
function bareStdin(ctx) {
  return typeof ctx.shellStdin === 'string' ? ctx.shellStdin : ''
}

/** @param {number} mode @param {'file' | 'directory' | 'symlink'} type */
function bareFormatModeString(mode, type) {
  const typeChar =
    type === 'directory' ? 'd' : type === 'symlink' ? 'l' : '-'
  const perm = mode & 0o777
  const r = (bit) => (perm & bit ? 'r' : '-')
  const w = (bit) => (perm & bit ? 'w' : '-')
  const x = (bit) => (perm & bit ? 'x' : '-')
  return (
    typeChar +
    r(0o400) +
    w(0o200) +
    x(0o100) +
    r(0o040) +
    w(0o020) +
    x(0o010) +
    r(0o004) +
    w(0o002) +
    x(0o001)
  )
}

/** @param {number} mtimeMs @param {number} [nowMs] */
function bareFormatLsMtime(mtimeMs, nowMs) {
  const now = nowMs != null ? nowMs : Date.now()
  const d = new Date(mtimeMs)
  const months = [
    'Jan',
    'Feb',
    'Mar',
    'Apr',
    'May',
    'Jun',
    'Jul',
    'Aug',
    'Sep',
    'Oct',
    'Nov',
    'Dec'
  ]
  const mon = months[d.getMonth()]
  const day = String(d.getDate()).padStart(2, ' ')
  const sixMo = 180 * 24 * 3600 * 1000
  if (Math.abs(now - mtimeMs) > sixMo) {
    const yr = String(d.getFullYear()).padStart(4, ' ')
    return mon + ' ' + day + '  ' + yr
  }
  const hh = String(d.getHours()).padStart(2, '0')
  const mm = String(d.getMinutes()).padStart(2, '0')
  return mon + ' ' + day + ' ' + hh + ':' + mm
}

/** @param {number} size */
function barePosixBlocks(size) {
  return Math.ceil(Number(size) / 512) || 0
}

function barePrintfFormat(fmt, args) {
  let ai = 0
  let o = ''
  for (let i = 0; i < fmt.length; i++) {
    if (fmt[i] !== '%') {
      o += fmt[i]
      continue
    }
    if (fmt[i + 1] === '%') {
      o += '%'
      i++
      continue
    }
    let j = i + 1
    while (j < fmt.length && /[0-9.#\-+ ]/.test(fmt[j])) j++
    const spec = fmt[j] || 's'
    const arg = args[ai++]
    if (spec === 's') o += String(arg)
    else if (spec === 'd' || spec === 'i') o += String(Math.trunc(Number(arg)))
    else if (spec === 'u') o += String(Math.trunc(Number(arg)) >>> 0)
    else if (spec === 'x') o += (Math.trunc(Number(arg)) >>> 0).toString(16)
    else if (spec === 'X') o += (Math.trunc(Number(arg)) >>> 0).toString(16).toUpperCase()
    else if (spec === 'o') o += (Math.trunc(Number(arg)) >>> 0).toString(8)
    else if (spec === 'c') o += String.fromCharCode(Number(arg) || 0)
    else if (spec === 'f') o += String(Number(arg))
    else o += String(arg)
    i = j
  }
  return o
}

async function run(ctx, argv) {
  if (argv.length < 2) {
    ctx.console.error('usage: printf FORMAT [ARG...]')
    ctx.exitCode = 1
    return
  }
  const fmt = argv[1]
  const args = argv.slice(2)
  let unescaped = fmt
  unescaped = unescaped.replace(/\\n/g, '\n')
  unescaped = unescaped.replace(/\\t/g, '\t')
  unescaped = unescaped.replace(/\\r/g, '\r')
  unescaped = unescaped.replace(/\\\\/g, '\\')
  ctx.console.log(barePrintfFormat(unescaped, args))
}