/* 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 e = ctx.vfs.env || {}
  const nodename = e.HOSTNAME || e.NAME || 'bare-os'
  let all = false
  let wantS = false
  let wantN = false
  let wantR = false
  let wantM = false
  let wantV = false
  for (let i = 1; i < argv.length; i++) {
    const a = argv[i]
    if (a === '--') break
    if (a === '-a' || a === '--all') {
      all = true
      continue
    }
    if (!a.startsWith('-') || a === '-') {
      ctx.console.error('uname: unexpected argument ' + a)
      ctx.exitCode = 1
      return
    }
    for (let j = 1; j < a.length; j++) {
      const c = a[j]
      if (c === 'a') all = true
      else if (c === 's') wantS = true
      else if (c === 'n') wantN = true
      else if (c === 'r') wantR = true
      else if (c === 'm') wantM = true
      else if (c === 'v') wantV = true
      else {
        ctx.console.error('uname: invalid option -- ' + c)
        ctx.exitCode = 1
        return
      }
    }
  }
  if (all) {
    wantS = wantN = wantR = wantM = wantV = true
  } else if (!wantS && !wantN && !wantR && !wantM && !wantV) {
    wantS = true
  }

  let name = 'BareOS'
  let release = e.BARE_OS_KERNEL_VERSION || e.BARE_OS_RELEASE || '0.1'
  let version = e.BARE_OS_USERLAND_VERSION || e.BARE_OS_BUILD || 'bare-userland'
  let prettyName = ''
  const buf = await ctx.vfs.readFile('/etc/os-release')
  if (buf) {
    const t = ctx.b4a.toString(buf)
    for (const line of t.split('\n')) {
      const keyVal = /^([A-Z0-9_]+)=(.*)$/.exec(line.trim())
      if (!keyVal) continue
      const key = keyVal[1]
      const value = keyVal[2].replace(/^"|"$/g, '')
      if (key === 'NAME' && value) name = value
      if (key === 'VERSION' && value) prettyName = value
      if (key === 'PRETTY_NAME' && value) prettyName = value
      if (key === 'VERSION_ID' && value && !e.BARE_OS_KERNEL_VERSION) release = value
    }
  }
  if (prettyName && !e.BARE_OS_USERLAND_VERSION && !e.BARE_OS_BUILD) {
    version = prettyName
  }
  const machine =
    e.PROCESSOR_ARCHITECTURE || e.MACHINE || e.BARE_OS_ARCH || 'unknown'

  const parts = []
  if (wantS) parts.push(name)
  if (wantN) parts.push(nodename)
  if (wantR) parts.push(release)
  if (wantM) parts.push(machine)
  if (wantV) parts.push(version)

  ctx.console.log(parts.join(' '))
}