/* 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
}

/**
 * @param {string} line
 * @param {string | null} delim
 * @param {number} start1
 * @param {number | null} end1
 */
function sortKeySlice(line, delim, start1, end1) {
  /** @type {string[]} */
  let fields
  if (delim != null) {
    if (delim === '') fields = line.split('')
    else fields = line.split(delim)
  } else {
    const t = line.trim()
    fields = t.length ? t.split(/\s+/) : []
  }
  const i0 = Math.max(0, start1 - 1)
  const i1 = end1 != null ? end1 : fields.length
  const slice = fields.slice(i0, i1)
  if (delim != null) return slice.join(delim)
  return slice.join(' ')
}

/**
 * @param {object} o
 * @param {string} o.line
 * @param {boolean} o.numeric
 * @param {boolean} o.fold
 * @param {number | null} o.keyStart
 * @param {number | null} o.keyEnd
 * @param {string | null} o.dForKey
 */
function sortKeyObj(o) {
  const keyText =
    o.keyStart != null
      ? sortKeySlice(o.line, o.dForKey, o.keyStart, o.keyEnd)
      : o.line
  if (o.numeric) {
    const m = String(keyText).match(
      /^\s*(-?(?:\d+(?:\.\d*)?|\.\d+)(?:[eE][+-]?\d+)?)/
    )
    if (m) return { n: Number(m[1]), raw: keyText }
    return { n: Number.POSITIVE_INFINITY, raw: keyText }
  }
  if (o.fold) return { n: 0, raw: keyText.toLowerCase() }
  return { n: 0, raw: keyText }
}

/**
 * @param {Record<string, unknown> | undefined} ctx
 */
function sortLocaleTag(ctx) {
  const env =
    ctx && ctx.vfs && ctx.vfs.env && typeof ctx.vfs.env === 'object'
      ? ctx.vfs.env
      : ctx && ctx.env && typeof ctx.env === 'object'
        ? ctx.env
        : {}
  const t = String(
    /** @type {Record<string, string>} */ (env).LC_ALL ||
      /** @type {Record<string, string>} */ (env).LC_COLLATE ||
      'C'
  ).trim()
  return t || 'C'
}

/**
 * @param {Record<string, unknown> | undefined} ctx
 * @param {string} a
 * @param {string} b
 */
function sortLocaleCompareRaw(ctx, a, b) {
  const tag = sortLocaleTag(ctx)
  if (tag === 'C' || tag === 'POSIX') {
    return a < b ? -1 : a > b ? 1 : 0
  }
  try {
    return String(a).localeCompare(String(b), tag, { sensitivity: 'variant' })
  } catch {
    return a < b ? -1 : a > b ? 1 : 0
  }
}

/**
 * @param {string} x
 * @param {string} y
 * @param {object} opts
 * @param {boolean} opts.numeric
 * @param {boolean} opts.reverse
 * @param {boolean} opts.fold
 * @param {number | null} opts.keyStart
 * @param {number | null} opts.keyEnd
 * @param {string | null} opts.dForKey
 * @param {Record<string, unknown> | undefined} [opts.ctx]
 * @returns {number}
 */
function sortCompareLines(x, y, opts) {
  const base = {
    numeric: opts.numeric,
    fold: opts.fold,
    keyStart: opts.keyStart,
    keyEnd: opts.keyEnd,
    dForKey: opts.dForKey
  }
  const kx = sortKeyObj({ ...base, line: x })
  const ky = sortKeyObj({ ...base, line: y })
  if (opts.numeric) {
    if (kx.n !== ky.n) {
      const ord = kx.n < ky.n ? -1 : 1
      return opts.reverse ? -ord : ord
    }
  }
  let cmp = sortLocaleCompareRaw(opts.ctx, kx.raw, ky.raw)
  if (cmp === 0) cmp = sortLocaleCompareRaw(opts.ctx, x, y)
  return opts.reverse ? -cmp : cmp
}

async function run(ctx, argv) {
  const vfs = ctx.vfs
  let numeric = false
  let reverse = false
  let uniq = false
  let fold = false
  /** @type {'off' | 'verbose' | 'quiet'} */
  let checkMode = 'off'
  let stable = false
  /** @type {string | null} */
  let outFile = null
  /** @type {string | undefined} */
  let delim
  /** @type {number | null} */
  let keyStart = null
  /** @type {number | null} */
  let keyEnd = null
  let i = 1
  while (i < argv.length) {
    const a = argv[i]
    if (a === '--') {
      i++
      break
    }
    if (a === '--check' || a === '--check=diagnose-first') {
      checkMode = 'verbose'
      i++
      continue
    }
    if (a === '--check=silent' || a === '--check=quiet') {
      checkMode = 'quiet'
      i++
      continue
    }
    if (a === '-C') {
      checkMode = 'quiet'
      i++
      continue
    }
    if (a === '-c') {
      checkMode = 'verbose'
      i++
      continue
    }
    if (a === '-s' || a === '--stable') {
      stable = true
      i++
      continue
    }
    if (a === '-o' || a === '--output') {
      const f = argv[++i]
      if (f === undefined) {
        ctx.console.error('sort: option requires an argument -- output')
        ctx.exitCode = 1
        return
      }
      outFile = f
      i++
      continue
    }
    if (a.startsWith('--output=')) {
      outFile = a.slice('--output='.length) || null
      if (!outFile) {
        ctx.console.error('sort: option requires an argument -- output')
        ctx.exitCode = 1
        return
      }
      i++
      continue
    }
    if (a === '-n' || a === '--numeric-sort' || a === '-g') {
      numeric = true
      i++
      continue
    }
    if (a === '-r' || a === '--reverse') {
      reverse = true
      i++
      continue
    }
    if (a === '-u' || a === '--unique') {
      uniq = true
      i++
      continue
    }
    if (a === '-f' || a === '--ignore-case') {
      fold = true
      i++
      continue
    }
    if (a === '-t' || a === '--field-separator') {
      const d = argv[++i]
      if (d === undefined) {
        ctx.console.error('sort: option requires an argument -- t')
        ctx.exitCode = 1
        return
      }
      delim = d === '\\t' ? '\t' : d
      i++
      continue
    }
    if (a.startsWith('-t') && a.length > 2) {
      delim = a.slice(2) === 't' ? '\t' : a.slice(2)
      i++
      continue
    }
    if (a === '-k' || a === '--key') {
      const spec = argv[++i]
      if (spec === undefined) {
        ctx.console.error('sort: option requires an argument -- k')
        ctx.exitCode = 1
        return
      }
      const parts = String(spec).split(',')
      keyStart = Number.parseInt(parts[0], 10)
      keyEnd =
        parts[1] !== undefined && parts[1] !== ''
          ? Number.parseInt(parts[1], 10)
          : null
      if (!Number.isFinite(keyStart) || keyStart < 1) {
        ctx.console.error('sort: invalid key specification')
        ctx.exitCode = 1
        return
      }
      if (
        keyEnd != null &&
        (!Number.isFinite(keyEnd) || keyEnd < keyStart)
      ) {
        ctx.console.error('sort: invalid key specification')
        ctx.exitCode = 1
        return
      }
      i++
      continue
    }
    if (/^-k\d/.test(a)) {
      const spec = a.slice(2)
      const parts = String(spec).split(',')
      keyStart = Number.parseInt(parts[0], 10)
      keyEnd =
        parts[1] !== undefined && parts[1] !== ''
          ? Number.parseInt(parts[1], 10)
          : null
      if (!Number.isFinite(keyStart) || keyStart < 1) {
        ctx.console.error('sort: invalid key specification')
        ctx.exitCode = 1
        return
      }
      i++
      continue
    }
    if (a.startsWith('-') && a.length > 1) {
      let j = 1
      let ok = true
      while (j < a.length) {
        const c = a[j++]
        if (c === 'n') numeric = true
        else if (c === 'r') reverse = true
        else if (c === 'u') uniq = true
        else if (c === 'f') fold = true
        else if (c === 'c') checkMode = 'verbose'
        else if (c === 'C') checkMode = 'quiet'
        else if (c === 's') stable = true
        else {
          ok = false
          break
        }
      }
      if (ok) {
        i++
        continue
      }
    }
    break
  }

  const files = argv.slice(i).filter((x) => x !== '--')
  /** @type {string[]} */
  let lines = []
  if (!files.length) {
    const s = bareStdin(ctx)
    lines = s.length ? s.split('\n') : []
    if (lines.length && lines[lines.length - 1] === '') lines.pop()
  } else {
    for (const f of files) {
      if (f === '-') {
        const s = bareStdin(ctx)
        const part = s.length ? s.split('\n') : []
        if (part.length && part[part.length - 1] === '') part.pop()
        lines.push(...part)
        continue
      }
      const buf = await vfs.readFile(f)
      if (!buf) {
        ctx.console.error('sort: ' + f + ': No such file')
        ctx.exitCode = 1
        continue
      }
      const part = ctx.b4a.toString(buf).split('\n')
      if (part.length && part[part.length - 1] === '') part.pop()
      lines.push(...part)
    }
  }

  const dForKey = delim === undefined ? null : delim
  const cmpOpts = {
    numeric,
    reverse,
    fold,
    keyStart,
    keyEnd,
    dForKey,
    ctx
  }

  if (checkMode !== 'off') {
    const checkLabel = files.length === 1 ? files[0] : '-'
    for (let li = 0; li < lines.length - 1; li++) {
      const aLine = lines[li]
      const bLine = lines[li + 1]
      const c = sortCompareLines(aLine, bLine, cmpOpts)
      if (uniq && c === 0) {
        ctx.exitCode = 1
        if (checkMode === 'verbose') {
          ctx.console.error(
            'sort: ' +
              checkLabel +
              ':' +
              (li + 2) +
              ': disorder: ' +
              bLine
          )
        }
        return
      }
      if (c > 0) {
        ctx.exitCode = 1
        if (checkMode === 'verbose') {
          ctx.console.error(
            'sort: ' +
              checkLabel +
              ':' +
              (li + 2) +
              ': disorder: ' +
              bLine
          )
        }
        return
      }
    }
    ctx.exitCode = 0
    return
  }

  /** @param {string} x
   * @param {string} y */
  function cmpPair(x, y) {
    const primary = sortCompareLines(x, y, cmpOpts)
    if (primary !== 0 || !stable) return primary
    return 0
  }

  if (stable) {
    const decorated = lines.map((line, idx) => ({ line, idx }))
    decorated.sort((a, b) => {
      const p = sortCompareLines(a.line, b.line, cmpOpts)
      if (p !== 0) return p
      return a.idx - b.idx
    })
    lines = decorated.map((d) => d.line)
  } else {
    lines.sort(cmpPair)
  }

  if (uniq) {
    const out = []
    let prev = null
    for (const ln of lines) {
      if (prev != null && sortCompareLines(prev, ln, cmpOpts) === 0) continue
      out.push(ln)
      prev = ln
    }
    lines = out
  }

  const body = lines.length ? lines.join('\n') + '\n' : ''

  if (outFile != null) {
    try {
      await vfs.writeFile(outFile, ctx.b4a.from(body))
    } catch (e) {
      ctx.console.error('sort: ' + outFile + ': ' + (e.message || e))
      ctx.exitCode = 1
      return
    }
  } else if (lines.length) {
    ctx.console.log(lines.join('\n'))
  }
}