/* 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
}

/** Session env map (`vfs.env`, then `ctx.env`). Never throws. */
function bareOsEnv(ctx) {
  const v = ctx && ctx.vfs && ctx.vfs.env
  if (v && typeof v === 'object') return v
  const e = ctx && ctx.env
  if (e && typeof e === 'object') return e
  return {}
}

/**
 * Strict POSIX-ish decimal integer (no octal, no exponent, no empty).
 * @param {unknown} s
 * @returns {number}
 */
function bareOsParseDecInt(s) {
  const t = String(s == null ? '' : s).trim()
  if (!/^[+-]?(?:0|[1-9][0-9]*)$/.test(t)) return NaN
  const n = Number.parseInt(t, 10)
  return Number.isSafeInteger(n) ? n : NaN
}

/** @param {unknown} s */
function bareOsParseNonNegInt(s) {
  const n = bareOsParseDecInt(s)
  return n >= 0 ? n : NaN
}

/**
 * @param {Record<string, unknown>} ctx
 * @param {string} name
 * @param {number} fallback
 * @param {number} [min]
 * @param {number} [max]
 */
function bareOsEnvInt(ctx, name, fallback, min, max) {
  const raw = bareOsEnv(ctx)[name]
  if (raw == null || raw === '') return fallback
  const n = Number.parseInt(String(raw), 10)
  if (!Number.isFinite(n)) return fallback
  let v = n
  if (min != null && v < min) v = min
  if (max != null && v > max) v = max
  return v
}

/**
 * @param {Record<string, unknown>} ctx
 * @param {string} msg
 * @param {number} [code]
 */
function bareOsFail(ctx, msg, code) {
  if (msg) ctx.console.error(msg)
  ctx.exitCode = code == null ? 1 : code
}

/** @param {unknown} e */
function bareOsIsNotFoundErr(e) {
  const code = e && typeof e === 'object' ? e.code : ''
  if (code === 'ENOENT') return true
  const msg = String((e && e.message) || e || '')
  return /ENOENT|No such file|not found/i.test(msg)
}

/**
 * @param {Record<string, unknown>} ctx
 * @param {unknown} buf
 * @returns {Uint8Array}
 */
function bareOsToU8(ctx, buf) {
  if (!buf) return new Uint8Array(0)
  if (buf instanceof Uint8Array) return buf
  if (ctx && ctx.b4a && typeof ctx.b4a.from === 'function') return ctx.b4a.from(buf)
  return new Uint8Array(buf)
}

/** @param {string} dir @param {string} name */
function bareOsJoinPath(dir, name) {
  const d = String(dir || '').replace(/\/+$/, '')
  const n = String(name || '').replace(/^\/+/, '')
  if (!d || d === '/') return '/' + n
  return d + '/' + n
}

/** @param {string} p */
function bareOsBaseName(p) {
  const t = String(p || '').replace(/\/+$/, '')
  if (!t || t === '/') return t === '/' ? '/' : ''
  const i = t.lastIndexOf('/')
  return i < 0 ? t : t.slice(i + 1) || t
}

/** @param {string} p */
function bareOsParentDir(p) {
  const t = String(p || '').replace(/\/+$/, '') || '/'
  if (t === '/') return '/'
  const i = t.lastIndexOf('/')
  return i <= 0 ? '/' : t.slice(0, i) || '/'
}

/** @param {string} p */
function bareOsNormPath(p) {
  return String(p || '').replace(/\/+$/, '') || '/'
}

/**
 * @param {Record<string, unknown>} ctx
 * @param {string} p
 */
function bareOsResolvePath(ctx, p) {
  if (ctx && ctx.vfs && typeof ctx.vfs.resolveLogical === 'function') {
    try {
      return String(ctx.vfs.resolveLogical(p) || p)
    } catch {
      /* fall through */
    }
  }
  return String(p || '')
}

/**
 * True when dest is src or lives under src (self-copy / self-move).
 * @param {Record<string, unknown>} ctx
 * @param {string} src
 * @param {string} dest
 */
function bareOsDestInsideSrc(ctx, src, dest) {
  const s = bareOsNormPath(bareOsResolvePath(ctx, src))
  const d = bareOsNormPath(bareOsResolvePath(ctx, dest))
  if (s === d) return true
  if (s === '/') return d !== '/'
  return d === s || d.startsWith(s + '/')
}

const BARE_OS_B64_ALPH =
  'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'

/** @param {Uint8Array} u8 */
function bareOsB64Encode(u8) {
  let out = ''
  let i = 0
  for (; i + 2 < u8.length; i += 3) {
    const n = (u8[i] << 16) | (u8[i + 1] << 8) | u8[i + 2]
    out +=
      BARE_OS_B64_ALPH[(n >> 18) & 63] +
      BARE_OS_B64_ALPH[(n >> 12) & 63] +
      BARE_OS_B64_ALPH[(n >> 6) & 63] +
      BARE_OS_B64_ALPH[n & 63]
  }
  const rest = u8.length - i
  if (rest === 1) {
    const n = u8[i] << 16
    out += BARE_OS_B64_ALPH[(n >> 18) & 63] + BARE_OS_B64_ALPH[(n >> 12) & 63] + '=='
  } else if (rest === 2) {
    const n = (u8[i] << 16) | (u8[i + 1] << 8)
    out +=
      BARE_OS_B64_ALPH[(n >> 18) & 63] +
      BARE_OS_B64_ALPH[(n >> 12) & 63] +
      BARE_OS_B64_ALPH[(n >> 6) & 63] +
      '='
  }
  return out
}

/**
 * RFC 4648 Base64 decode (also accepts URL-safe alphabet). Rejects junk.
 * @param {string} s
 * @returns {Uint8Array}
 */
function bareOsB64Decode(s) {
  const t = String(s).replace(/\s+/g, '')
  if (!t) return new Uint8Array(0)
  if (t.length % 4 === 1) throw new Error('invalid base64 length')
  let pad = 0
  if (t.endsWith('==')) pad = 2
  else if (t.endsWith('=')) pad = 1
  const body = pad ? t.slice(0, t.length - pad) : t
  const bytes = []
  let buf = 0
  let bits = 0
  for (let i = 0; i < body.length; i++) {
    const c = body[i]
    let v = BARE_OS_B64_ALPH.indexOf(c)
    if (v < 0) {
      if (c === '-') v = 62
      else if (c === '_') v = 63
      else throw new Error('invalid base64 character')
    }
    buf = (buf << 6) | v
    bits += 6
    if (bits >= 8) {
      bits -= 8
      bytes.push((buf >> bits) & 255)
    }
  }
  if (pad) {
    const want = Math.floor((body.length * 6) / 8)
    if (bytes.length > want) bytes.length = want
  }
  return new Uint8Array(bytes)
}

/**
 * @param {string} s
 * @returns {Uint8Array}
 */
function bareOsHexDecode(s) {
  const t = String(s).replace(/\s+/g, '')
  if (t.length % 2 !== 0) throw new Error('odd hex length')
  const out = new Uint8Array(t.length / 2)
  for (let i = 0; i < out.length; i++) {
    const pair = t.slice(i * 2, i * 2 + 2)
    if (!/^[0-9a-fA-F]{2}$/.test(pair)) throw new Error('invalid hex')
    out[i] = Number.parseInt(pair, 16)
  }
  return out
}

/** @param {Uint8Array} u8 */
function bareOsHexEncode(u8) {
  let s = ''
  for (let i = 0; i < u8.length; i++) s += u8[i].toString(16).padStart(2, '0')
  return s
}

/**
 * GNU-style LS_COLORS string + dircolors(5) database parsing and file classification.
 * Consumed by bare-os-booter (ESM import). Prepended into /bin/ls and /bin/dircolors by bare-os-coreutils build (no import there).
 */

/** Default LS_COLORS (subset aligned with GNU dircolors -p essentials + common globs). */
function bareDefaultLsColorsString() {
  return [
    'no=00',
    'fi=00',
    'di=01;34',
    'ln=01;36',
    'pi=40;33',
    'so=01;35',
    'do=01;35',
    'bd=40;33;01',
    'cd=40;33;01',
    'or=40;31;01',
    'mi=00',
    'su=37;41',
    'sg=30;43',
    'ca=30;41',
    'tw=30;42',
    'ow=34;43',
    'st=37;44',
    'ex=01;32',
    'mh=00',
    '*.tar=01;31',
    '*.tgz=01;31',
    '*.arc=01;31',
    '*.arj=01;31',
    '*.taz=01;31',
    '*.lha=01;31',
    '*.lz4=01;31',
    '*.lzh=01;31',
    '*.tlz=01;31',
    '*.txz=01;31',
    '*.tzo=01;31',
    '*.tzst=01;31',
    '*.bz2=01;31',
    '*.bz=01;31',
    '*.tbz=01;31',
    '*.tbz2=01;31',
    '*.tz=01;31',
    '*.deb=01;31',
    '*.rpm=01;31',
    '*.jar=01;31',
    '*.war=01;31',
    '*.ear=01;31',
    '*.sar=01;31',
    '*.rar=01;31',
    '*.alz=01;31',
    '*.ace=01;31',
    '*.zoo=01;31',
    '*.cpio=01;31',
    '*.7z=01;31',
    '*.rz=01;31',
    '*.cab=01;31',
    '*.wim=01;31',
    '*.swm=01;31',
    '*.dwm=01;31',
    '*.esd=01;31',
    '*.jpg=01;35',
    '*.jpeg=01;35',
    '*.mjpg=01;35',
    '*.mjpeg=01;35',
    '*.gif=01;35',
    '*.bmp=01;35',
    '*.pbm=01;35',
    '*.pgm=01;35',
    '*.ppm=01;35',
    '*.tga=01;35',
    '*.xbm=01;35',
    '*.xpm=01;35',
    '*.tif=01;35',
    '*.tiff=01;35',
    '*.png=01;35',
    '*.svg=01;35',
    '*.svgz=01;35',
    '*.mng=01;35',
    '*.pcx=01;35',
    '*.mov=01;35',
    '*.mpg=01;35',
    '*.mpeg=01;35',
    '*.m2v=01;35',
    '*.mkv=01;35',
    '*.webm=01;35',
    '*.ogm=01;35',
    '*.mp4=01;35',
    '*.m4v=01;35',
    '*.mp4v=01;35',
    '*.vob=01;35',
    '*.qt=01;35',
    '*.nuv=01;35',
    '*.wmv=01;35',
    '*.asf=01;35',
    '*.rm=01;35',
    '*.rmvb=01;35',
    '*.flc=01;35',
    '*.avi=01;35',
    '*.fli=01;35',
    '*.flv=01;35',
    '*.gl=01;35',
    '*.dl=01;35',
    '*.xcf=01;35',
    '*.xwd=01;35',
    '*.yuv=01;35',
    '*.cgm=01;35',
    '*.emf=01;35',
    '*.ogv=01;35',
    '*.ogx=01;35',
    '*.aac=00;36',
    '*.au=00;36',
    '*.flac=00;36',
    '*.m4a=00;36',
    '*.mid=00;36',
    '*.midi=00;36',
    '*.mka=00;36',
    '*.mp3=00;36',
    '*.mpc=00;36',
    '*.ogg=00;36',
    '*.ra=00;36',
    '*.wav=00;36',
    '*.oga=00;36',
    '*.opus=00;36',
    '*.spx=00;36',
    '*.xspf=00;36',
    '*.pdf=00;32',
    '*.ps=00;32',
    '*.txt=00;32',
    '*.patch=00;32',
    '*.diff=00;32',
    '*.log=00;32',
    '*.tex=00;32',
    '*.doc=00;32',
    '*.docx=00;32',
    '*.rtf=00;32',
    '*.odt=00;32',
    '*.md=00;32',
    '*.markdown=00;32',
    '*.css=00;32',
    '*.htm=00;32',
    '*.html=00;32',
    '*.xml=00;32',
    '*.json=00;32',
    '*.yaml=00;32',
    '*.yml=00;32',
    '*.c=00;32',
    '*.h=00;32',
    '*.js=00;32',
    '*.mjs=00;32',
    '*.java=00;32',
    '*.py=00;32',
    '*.go=00;32',
    '*.rs=00;32',
    '*.cpp=00;32',
    '*.cc=00;32',
    '*.cxx=00;32',
    '*.hpp=00;32',
    '*.shlib=01;32',
    '*.so=01;32',
    '*.dylib=01;32',
    '*.dll=01;32',
    '*.a=01;32',
    '*.lib=01;32',
    '*.ko=01;32',
    '*.sh=01;32',
    '*.bash=01;32',
    '*.zsh=01;32',
    '*.bat=01;32',
    '*.cmd=01;32',
    '*.exe=01;32',
    '*.com=01;32',
    '*.btm=01;32',
    '*.msi=01;32'
  ].join(':')
}

/**
 * @param {string} s
 * @returns {Record<string, string>}
 */
function bareParseLsColors(s) {
  const out = /** @type {Record<string, string>} */ ({})
  if (s == null || !String(s).trim()) return out
  for (const part of String(s).split(':')) {
    const p = part.trim()
    if (!p) continue
    const eq = p.indexOf('=')
    if (eq <= 0) continue
    const k = p.slice(0, eq)
    const v = p.slice(eq + 1)
    if (k) out[k] = v
  }
  return out
}

/**
 * @param {Record<string, string>} map
 */
function bareSerializeLsColors(map) {
  const keys = Object.keys(map).sort()
  return keys.map((k) => k + '=' + map[k]).join(':')
}

/**
 * @param {string} code dircolors value (e.g. 01;34)
 * @returns {string} opening SGR including ESC
 */
function bareLscolorsToOpenSgr(code) {
  if (code == null || code === '' || code === '0' || code === '00') return ''
  return '\x1b[' + code + 'm'
}

/**
 * Parse dircolors database (GNU subset): # comments, blank lines, TERM blocks, KEY VALUE pairs.
 * @param {string} text
 * @param {string} termEnv value of TERM
 * @returns {Record<string, string>}
 */
function bareParseDircolorsDatabase(text, termEnv) {
  const term = termEnv != null ? String(termEnv) : ''
  /** @type {Record<string, string>} */
  const out = {}
  let blockActive = true
  const lines = String(text).split(/\r?\n/)
  for (let raw of lines) {
    const line = raw.replace(/#.*$/, '').trim()
    if (!line) continue
    const upper = line.toUpperCase()
    if (upper.startsWith('TERM ')) {
      const rest = line.slice(5).trim()
      if (rest === 'none') blockActive = false
      else
        blockActive =
          rest === '*' || rest === '' || rest === term || term.indexOf(rest) === 0
      continue
    }
    if (upper.startsWith('COLOR ') || upper.startsWith('OPTIONS ')) continue
    if (!blockActive) continue
    const ws = line.search(/\s/)
    if (ws <= 0) continue
    const key = line.slice(0, ws).trim()
    const val = line.slice(ws + 1).trim()
    if (!key || !val) continue
    if (key === 'TERM' || key === 'COLOR' || key === 'OPTIONS') continue
    out[key] = val
  }
  return out
}

/**
 * @param {string} filename basename only
 * @param {Record<string, string>} map
 */
function bareLsColorsGlobMatch(filename, map) {
  const keys = Object.keys(map).filter((k) => k.startsWith('*.'))
  keys.sort((a, b) => b.length - a.length)
  const lower = filename.toLowerCase()
  for (const k of keys) {
    const suf = k.slice(1).toLowerCase()
    if (lower.endsWith(suf)) return map[k]
  }
  return null
}

/**
 * @param {{ type?: string, mode?: number, linkname?: string, targetMissing?: boolean, nlink?: number, capabilities?: boolean } | null} st
 * @param {string} filename basename
 * @param {Record<string, string>} map from LS_COLORS
 * @returns {string} SGR open sequence or ''
 */
function bareLsColorOpenSgrFromMap(st, filename, map) {
  if (!st) {
    const no = map.no
    return no ? bareLscolorsToOpenSgr(no) : ''
  }
  const mode = Number(st.mode) || 0
  const perm = mode & 0o777
  const t = st.type
  let key = 'fi'

  if (t === 'symlink') {
    key = st.targetMissing ? 'or' : 'ln'
  } else if (t === 'directory') {
    const ow = (perm & 0o002) !== 0
    const sticky = (mode & 0o1000) !== 0
    if (ow && sticky) key = 'tw'
    else if (ow) key = 'ow'
    else if (sticky) key = 'st'
    else key = 'di'
  } else if (t === 'file') {
    if (st.capabilities) key = 'ca'
    else if (mode & 0o4000) key = 'su'
    else if (mode & 0o2000) key = 'sg'
    else if (perm & 0o111) key = 'ex'
    else {
      const nlink = Number(st.nlink)
      if (nlink > 1 && map.mh != null && String(map.mh).trim() !== '') {
        const mhOpen = bareLscolorsToOpenSgr(map.mh)
        if (mhOpen) return mhOpen
      }
      const g = bareLsColorsGlobMatch(filename, map)
      if (g != null) return bareLscolorsToOpenSgr(g)
      key = 'fi'
    }
  }

  const code = map[key] != null ? map[key] : map.fi
  return code ? bareLscolorsToOpenSgr(code) : ''
}

/**
 * @returns {string} multiline dircolors database (default colors)
 */
function bareDefaultDircolorsDatabase() {
  const pairs = bareParseLsColors(bareDefaultLsColorsString())
  const lines = ['# Bare OS default dircolors (GNU-like)', 'TERM *', '']
  for (const k of Object.keys(pairs).sort()) {
    lines.push(k + ' ' + pairs[k])
  }
  return lines.join('\n') + '\n'
}

async function run(ctx, argv) {
  const env = ctx.env || {}
  let bourne = false
  let printDefault = false
  /** @type {string | null} */
  let file = null
  for (let i = 1; i < argv.length; i++) {
    const a = argv[i]
    if (a === '--') continue
    if (a === '-b' || a === '--sh' || a === '--bourne-shell') bourne = true
    else if (a === '-p' || a === '--print-database') printDefault = true
    else if (a.startsWith('-')) {
      ctx.console.error('dircolors: unrecognized option: ' + a)
      ctx.exitCode = 2
      return
    } else file = a
  }
  if (printDefault) {
    ctx.console.log(bareDefaultDircolorsDatabase())
    return
  }
  let text = bareDefaultDircolorsDatabase()
  if (file) {
    const buf = await ctx.vfs.readFile(file)
    if (!buf) {
      ctx.console.error('dircolors: cannot read ' + file)
      ctx.exitCode = 2
      return
    }
    text = ctx.b4a.toString(buf)
  }
  const term = env.TERM || ''
  const db = bareParseDircolorsDatabase(text, term)
  const ls = bareSerializeLsColors(db)
  if (bourne) {
    const q = "'" + ls.replace(/'/g, "'\\''") + "'"
    ctx.console.log('LS_COLORS=' + q)
    ctx.console.log('export LS_COLORS')
  } else {
    ctx.console.log(ls)
  }
}