/* 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
}

/**
 * wc — line, word, and byte counts.
 * Default (no flags): -l -w -c. Flags are combinable.
 */

/**
 * @param {string | Uint8Array} input
 * @param {*} b4a
 */
function wcCount(input, b4a) {
  const bytes =
    input instanceof Uint8Array
      ? input.byteLength
      : b4a.from(String(input), 'utf8').length
  const s =
    input instanceof Uint8Array ? b4a.toString(input) : String(input)
  const lines = (s.match(/\n/g) || []).length
  const words = (s.match(/\S+/g) || []).length
  return { lines, words, bytes }
}

async function run(ctx, argv) {
  const vfs = ctx.vfs
  let wantL = false
  let wantW = false
  let wantC = false
  const paths = []
  let i = 1
  while (i < argv.length) {
    const a = argv[i]
    if (a === '--') {
      i++
      break
    }
    if (a === '-l' || a === '--lines') {
      wantL = true
      i++
      continue
    }
    if (a === '-w' || a === '--words') {
      wantW = true
      i++
      continue
    }
    if (a === '-c' || a === '--bytes' || a === '-m') {
      wantC = true
      i++
      continue
    }
    if (a.startsWith('-') && a.length > 1) {
      let j = 1
      let ok = true
      while (j < a.length) {
        const c = a[j++]
        if (c === 'l') wantL = true
        else if (c === 'w') wantW = true
        else if (c === 'c' || c === 'm') wantC = true
        else {
          ok = false
          break
        }
      }
      if (ok) {
        i++
        continue
      }
    }
    paths.push(a)
    i++
  }
  if (!wantL && !wantW && !wantC) {
    wantL = true
    wantW = true
    wantC = true
  }

  function fmt(c, name) {
    const parts = []
    if (wantL) parts.push(String(c.lines))
    if (wantW) parts.push(String(c.words))
    if (wantC) parts.push(String(c.bytes))
    let s = ' ' + parts.join(' ')
    if (name != null) s += ' ' + name
    return s
  }

  if (!paths.length) {
    const s = bareStdin(ctx)
    const c = wcCount(s, ctx.b4a)
    ctx.console.log(fmt(c, null))
    return
  }
  let tLines = 0
  let tWords = 0
  let tBytes = 0
  for (const f of paths) {
    if (f === '-') {
      const s = bareStdin(ctx)
      const c = wcCount(s, ctx.b4a)
      tLines += c.lines
      tWords += c.words
      tBytes += c.bytes
      ctx.console.log(fmt(c, '-'))
      continue
    }
    const buf = await vfs.readFile(f)
    if (!buf) {
      ctx.console.error('wc: ' + f + ': No such file')
      continue
    }
    const u8 = buf instanceof Uint8Array ? buf : ctx.b4a.from(buf)
    const c = wcCount(u8, ctx.b4a)
    tLines += c.lines
    tWords += c.words
    tBytes += c.bytes
    ctx.console.log(fmt(c, f))
  }
  if (paths.length > 1) {
    ctx.console.log(
      fmt({ lines: tLines, words: tWords, bytes: tBytes }, 'total')
    )
  }
}