/* 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
}

/**
 * Shared GNU-style checksum FILE / stdin loop used by *sum commands.
 * @param {Record<string, unknown>} ctx
 * @param {string[]} argv
 * @param {{
 *   cmd: string,
 *   help?: string,
 *   digest: (u8: Uint8Array) => string | Promise<string>
 * }} opts
 */
async function bareChecksumRun(ctx, argv, opts) {
  const cmd = String(opts.cmd || 'checksum')
  const help =
    opts.help ||
    'usage: ' +
      cmd +
      ' [FILE]...\nWith no FILE, or when FILE is -, read standard input.'
  const digest = opts.digest
  const paths = []
  for (let i = 1; i < argv.length; i++) {
    const a = argv[i]
    if (a === '-h' || a === '--help') {
      ctx.console.log(help)
      ctx.exitCode = 0
      return
    }
    if (a.startsWith('-') && a !== '-') {
      ctx.console.error(cmd + ': unsupported option ' + a)
      ctx.exitCode = 1
      return
    }
    paths.push(a)
  }
  const b4 = ctx.b4a
  async function one(name, buf) {
    const u8 = buf instanceof Uint8Array ? buf : new Uint8Array(buf)
    try {
      const hex = await digest(u8)
      ctx.console.log(hex + '  ' + name)
    } catch (e) {
      ctx.console.error(cmd + ': ' + (e.message || e))
      ctx.exitCode = 1
    }
  }
  if (!paths.length || (paths.length === 1 && paths[0] === '-')) {
    await one('-', b4.from(bareStdin(ctx)))
    return
  }
  for (const p of paths) {
    if (p === '-') {
      await one('-', b4.from(bareStdin(ctx)))
      continue
    }
    const b = await ctx.vfs.readFile(p)
    if (!b) {
      ctx.console.error(cmd + ': ' + p + ': No such file')
      ctx.exitCode = 1
      continue
    }
    await one(p, b)
  }
}

/**
 * WebCrypto hex digest; throws the same missing-subtle message as the old *sum files.
 * @param {string} algo
 * @param {string} missingMsg
 * @returns {(u8: Uint8Array) => Promise<string>}
 */
function bareSubtleHexDigest(algo, missingMsg) {
  return async function (u8) {
    const subtle = globalThis.crypto?.subtle
    if (!subtle || typeof subtle.digest !== 'function') {
      throw new Error(missingMsg)
    }
    const hash = await subtle.digest(algo, u8)
    return bareOsHexEncode(new Uint8Array(hash))
  }
}

/**
 * Owner/group name → uid/gid used by chown / chgrp.
 * @param {string} spec
 * @param {Record<string, string>} env
 * @returns {number | null}
 */
function parseGroupSpec(spec, env) {
  const s = String(spec).trim()
  if (!s) return null
  if (/^\d+$/.test(s)) {
    const n = Number.parseInt(s, 10)
    return Number.isFinite(n) ? n : null
  }
  const g = (env.GROUP || env.USER || 'guest').trim()
  if (s === 'root') return 0
  if (s === 'guest' || s === 'nobody') return 65534
  if (g && s === g) {
    const gid = Number.parseInt(String(env.GID ?? '65534'), 10)
    return Number.isFinite(gid) ? gid : 65534
  }
  return null
}

/**
 * User name / numeric uid used by chown.
 * @param {string} spec
 * @param {Record<string, string>} env
 * @returns {{ uid: number | null, gid: number | null }}
 */
function parseIdSpec(spec, env) {
  const s = String(spec).trim()
  if (!s) return { uid: null, gid: null }
  if (/^\d+$/.test(s)) {
    const n = Number.parseInt(s, 10)
    return { uid: Number.isFinite(n) ? n : null, gid: null }
  }
  const u = (env.USER || env.LOGNAME || '').trim()
  if (s === 'root') return { uid: 0, gid: null }
  if (s === 'guest' || s === 'nobody') return { uid: 65534, gid: null }
  if (u && s === u) {
    const uid = Number.parseInt(String(env.UID ?? '65534'), 10)
    return { uid: Number.isFinite(uid) ? uid : 65534, gid: null }
  }
  return { uid: null, gid: null }
}

/**
 * SHA-224 (FIPS 180-4) — same compression as SHA-256, distinct IV, output first 224 bits.
 * Bundled because many runtimes (incl. Node Web Crypto) omit SHA-224 in subtle.digest.
 */
function bareSha224DigestBytes(u8) {
  const K = new Uint32Array([
    0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4,
    0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe,
    0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f,
    0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
    0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc,
    0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
    0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116,
    0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
    0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7,
    0xc67178f2
  ])
  const W = new Uint32Array(64)
  const n = u8.length
  const bits = BigInt(n) * 8n
  const bitLenHi = Number((bits >> 32n) & 0xffffffffn)
  const bitLenLo = Number(bits & 0xffffffffn)
  const padLen = (56 - ((n + 1) % 64) + 64) % 64
  const total = n + 1 + padLen + 8
  const buf = new Uint8Array(total)
  buf.set(u8)
  buf[n] = 0x80
  const view = new DataView(buf.buffer)
  view.setUint32(total - 8, bitLenHi, false)
  view.setUint32(total - 4, bitLenLo, false)

  let h0 = 0xc1059ed8
  let h1 = 0x367cd507
  let h2 = 0x3070dd17
  let h3 = 0xf70e5939
  let h4 = 0xffc00b31
  let h5 = 0x68581511
  let h6 = 0x64f98fa7
  let h7 = 0xbefa4fa4

  const rotr = (x, c) => ((x >>> c) | (x << (32 - c))) >>> 0
  for (let off = 0; off < total; off += 64) {
    for (let i = 0; i < 16; i++) W[i] = view.getUint32(off + i * 4, false)
    for (let i = 16; i < 64; i++) {
      const s0 = rotr(W[i - 15], 7) ^ rotr(W[i - 15], 18) ^ (W[i - 15] >>> 3)
      const s1 = rotr(W[i - 2], 17) ^ rotr(W[i - 2], 19) ^ (W[i - 2] >>> 10)
      W[i] = (W[i - 16] + s0 + W[i - 7] + s1) >>> 0
    }
    let a = h0
    let b = h1
    let c = h2
    let d = h3
    let e = h4
    let f = h5
    let g = h6
    let h = h7
    for (let i = 0; i < 64; i++) {
      const S1 = rotr(e, 6) ^ rotr(e, 11) ^ rotr(e, 25)
      const ch = (e & f) ^ (~e & g)
      const t1 = (h + S1 + ch + K[i] + W[i]) >>> 0
      const S0 = rotr(a, 2) ^ rotr(a, 13) ^ rotr(a, 22)
      const maj = (a & b) ^ (a & c) ^ (b & c)
      const t2 = (S0 + maj) >>> 0
      h = g
      g = f
      f = e
      e = (d + t1) >>> 0
      d = c
      c = b
      b = a
      a = (t1 + t2) >>> 0
    }
    h0 = (h0 + a) >>> 0
    h1 = (h1 + b) >>> 0
    h2 = (h2 + c) >>> 0
    h3 = (h3 + d) >>> 0
    h4 = (h4 + e) >>> 0
    h5 = (h5 + f) >>> 0
    h6 = (h6 + g) >>> 0
    h7 = (h7 + h) >>> 0
  }

  const out = new Uint8Array(28)
  const ov = new DataView(out.buffer)
  ov.setUint32(0, h0, false)
  ov.setUint32(4, h1, false)
  ov.setUint32(8, h2, false)
  ov.setUint32(12, h3, false)
  ov.setUint32(16, h4, false)
  ov.setUint32(20, h5, false)
  ov.setUint32(24, h6, false)
  return [...out].map((b) => b.toString(16).padStart(2, '0')).join('')
}

/**
 * sha224sum — compute SHA-224 checksums (hex), GNU-like output line.
 * Uses bundled SHA-224 (many runtimes omit SHA-224 in crypto.subtle.digest).
 */
async function run(ctx, argv) {
  await bareChecksumRun(ctx, argv, {
    cmd: 'sha224sum',
    digest: (u8) => bareSha224DigestBytes(u8)
  })
}