/* 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
}

/**
 * @param {Record<string, unknown>} st
 * @param {string} displayPath
 * @param {string} fmt
 */
function statApplyFormat(st, displayPath, fmt) {
  let out = ''
  for (let i = 0; i < fmt.length; i++) {
    if (fmt[i] === '%' && i + 1 < fmt.length) {
      const c = fmt[++i]
      if (c === 'n')
        out += displayPath.split('/').pop() || displayPath
      else if (c === 'N') out += displayPath
      else if (c === 's') out += String(st.size ?? 0)
      else if (c === 'Y')
        out += String(
          Math.floor(
            (typeof st.mtimeMs === 'number' ? st.mtimeMs : Date.now()) / 1000
          )
        )
      else if (c === 'A')
        out += bareFormatModeString(st.mode, st.type)
      else if (c === 'U') out += String(st.user ?? '')
      else if (c === 'G') out += String(st.group ?? '')
      else if (c === 'u') out += String(st.uid ?? 0)
      else if (c === 'g') out += String(st.gid ?? 0)
      else if (c === '%') out += '%'
      else out += '%' + c
    } else {
      out += fmt[i]
    }
  }
  return out
}

async function run(ctx, argv) {
  /** @type {string | null} */
  let formatStr = null
  /** @type {string[]} */
  const paths = []
  for (let i = 1; i < argv.length; i++) {
    const a = argv[i]
    if (a === '-c' && argv[i + 1]) {
      formatStr = argv[++i]
      continue
    }
    if (a.startsWith('--format=')) {
      formatStr = a.slice('--format='.length)
      continue
    }
    if (a === '--format' && argv[i + 1]) {
      formatStr = argv[++i]
      continue
    }
    if (a.startsWith('-')) {
      ctx.console.error('stat: unsupported option ' + a)
      ctx.exitCode = 1
      return
    }
    paths.push(a)
  }
  if (!paths.length) {
    ctx.console.error('usage: stat [-c FORMAT | --format=FORMAT] FILE...')
    ctx.exitCode = 1
    return
  }
  for (const p of paths) {
    try {
      const st = await ctx.vfs.stat(p)
      if (!st) {
        ctx.console.error('stat: ' + p + ': No such file')
        ctx.exitCode = 1
        continue
      }
      if (formatStr != null) {
        ctx.console.log(statApplyFormat(st, p, formatStr))
        continue
      }
      const modeStr = bareFormatModeString(st.mode, st.type)
      ctx.console.log(
        'File: ' +
          p +
          '\n' +
          'Size: ' +
          (st.size || 0) +
          '\n' +
          'Type: ' +
          st.type +
          '\n' +
          'Mode: ' +
          modeStr +
          '\n' +
          'Uid: ' +
          (st.uid ?? 0) +
          ' Gid: ' +
          (st.gid ?? 0)
      )
    } catch (e) {
      ctx.console.error('stat: ' + p + ': ' + ((e && e.message) || e))
      ctx.exitCode = 1
    }
  }
}