bare-operating-system/kernel/bin/mount

/* 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 printMountTable(ctx) {
  try {
    const buf = await ctx.vfs.readFile('/proc/mounts')
    if (buf) {
      const s = ctx.b4a.toString(buf)
      if (s) {
        ctx.console.log(s.endsWith('\n') ? s.slice(0, -1) : s)
        return
      }
    }
  } catch {
    /* fall through */
  }
  ctx.console.log('(no mounts)')
}

async function run(ctx, argv) {
  const args = argv.slice(1)
  if (!args.length) {
    await printMountTable(ctx)
    return
  }

  let type = 'hyperdrive'
  let opts = ''
  /** @type {string[]} */
  const pos = []
  for (let i = 0; i < args.length; i++) {
    const a = args[i]
    if (a === '-l' || a === '--list') {
      await printMountTable(ctx)
      return
    }
    if (a === '-t') {
      i++
      if (i >= args.length) {
        ctx.console.error('mount: option requires an argument -- t')
        ctx.exitCode = 1
        return
      }
      type = String(args[i] || '')
      continue
    }
    if (a === '-o') {
      i++
      if (i >= args.length) {
        ctx.console.error('mount: option requires an argument -- o')
        ctx.exitCode = 1
        return
      }
      opts = String(args[i] || '')
      continue
    }
    if (a.startsWith('-')) {
      ctx.console.error('mount: unsupported option ' + a)
      ctx.exitCode = 1
      return
    }
    pos.push(a)
  }

  if (type !== 'hyperdrive') {
    ctx.console.error('mount: only -t hyperdrive is supported')
    ctx.exitCode = 1
    return
  }
  if (pos.length < 2) {
    ctx.console.error(
      'usage: mount [-t hyperdrive] [-o ro] <source-key|local> </mnt/label>'
    )
    ctx.exitCode = 1
    return
  }
  const source = String(pos[0] || '').trim()
  const target = String(pos[1] || '').trim()
  const m = /^\/mnt\/([a-zA-Z0-9][a-zA-Z0-9._-]{0,62})$/.exec(target)
  if (!m) {
    ctx.console.error('mount: target must be /mnt/<label>')
    ctx.exitCode = 1
    return
  }
  const label = m[1]
  const ro = opts
    .split(',')
    .map((x) => x.trim())
    .filter(Boolean)
    .includes('ro')

  if (typeof ctx.bareOsSyscall === 'function') {
    try {
      const out = await ctx.bareOsSyscall('mount', {
        source,
        target,
        label,
        readOnly: ro
      })
      if (out && typeof out === 'object' && out.note) {
        ctx.console.log(String(out.note))
      }
      return
    } catch (e) {
      ctx.console.error('mount: ' + (e?.message || String(e)))
      ctx.exitCode = 1
      return
    }
  }

  if (typeof ctx.runHdms !== 'function') {
    ctx.console.error('mount: hdms bridge unavailable')
    ctx.exitCode = 1
    return
  }
  try {
    if (source === 'local') await ctx.runHdms(['hdms', 'create', label])
    else await ctx.runHdms(['hdms', 'add', label, source])
  } catch (e) {
    ctx.console.error('mount: ' + (e?.message || String(e)))
    ctx.exitCode = 1
  }
}