/* BARE_OS_BIN_API 1.0.0 — bump when staged /bin script semantics change (see developer guide). */
/** 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
}

/**
 * Raw stdout for NUL/binary when **`process.stdout.write`** is missing.
 * If **`ctx.bareOsBinWrite(Uint8Array|string)`** is set (tests / host), use it.
 * @param {Record<string, unknown>} ctx
 * @param {string | Uint8Array} chunk
 * @returns {boolean}
 */
function bareOsEmitRaw(ctx, chunk) {
  if (typeof ctx.bareOsBinWrite === 'function') {
    const b4 = ctx.b4a
    const u8 =
      typeof chunk === 'string'
        ? b4 && typeof b4.from === 'function'
          ? b4.from(chunk)
          : new TextEncoder().encode(chunk)
        : chunk
    ctx.bareOsBinWrite(u8 instanceof Uint8Array ? u8 : new Uint8Array(u8))
    return true
  }
  const w = globalThis.process?.stdout?.write
  if (typeof w === 'function') {
    w.call(globalThis.process.stdout, chunk)
    return true
  }
  return false
}

async function run(ctx, argv) {
  const vfs = ctx.vfs
  const b4 = ctx.b4a
  if (!vfs || typeof vfs.readdir !== 'function' || !b4) {
    ctx.console.error('kernel-fsck: vfs unavailable')
    ctx.exitCode = 1
    return
  }
  let json = false
  for (let i = 1; i < argv.length; i++) {
    if (argv[i] === '--json') json = true
  }
  /** @type {string[]} */
  const names = []
  try {
    for await (const n of vfs.readdir('/bin')) names.push(n)
  } catch (e) {
    ctx.console.error('kernel-fsck: ' + ((e && e.message) || String(e)))
    ctx.exitCode = 1
    return
  }
  names.sort()
  let pragmaOk = 0
  let pragmaBad = 0
  for (const n of names) {
    if (!n.endsWith('.js') && !n.includes('.')) {
      try {
        const abs = vfs.resolveLogical('/bin/' + n)
        const buf = await vfs.readFile(abs)
        const head = b4.toString(buf).slice(0, 400)
        if (head.includes('BARE_OS_BIN_API')) pragmaOk++
        else pragmaBad++
      } catch {
        pragmaBad++
      }
    }
  }
  const out = {
    schema: 2,
    ok: pragmaBad === 0,
    binCount: names.length,
    binPragmaOk: pragmaOk,
    binPragmaMissing: pragmaBad,
    sample: names.slice(0, 32),
    note:
      'Integrity pass: /bin listing + BARE_OS_BIN_API pragma probe on runnable entries.'
  }
  if (json) {
    ctx.console.log(JSON.stringify(out, null, 2))
  } else {
    ctx.console.log(
      'kernel-fsck: /bin=' +
        names.length +
        ' pragma_ok=' +
        pragmaOk +
        ' pragma_missing=' +
        pragmaBad
    )
  }
  ctx.exitCode = out.ok ? 0 : 1
}