/* 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
}

async function run(ctx, argv) {
  const vfs = ctx.vfs
  let showAll = false
  let longFmt = false
  const paths = []
  for (let i = 1; i < argv.length; i++) {
    const a = argv[i]
    if (a === '--') {
      paths.push(...argv.slice(i + 1))
      break
    }
    if (a.startsWith('-') && a.length > 1) {
      for (let j = 1; j < a.length; j++) {
        const c = a[j]
        if (c === 'a') showAll = true
        else if (c === 'l') longFmt = true
        else if (c === '1') longFmt = false
      }
      continue
    }
    paths.push(a)
  }
  const targets = paths.length ? paths : ['.']

  for (const t of targets) {
    if (targets.length > 1) ctx.console.log(t + ':')
    let names
    /** @type {string | null} */
    let singleEntryPath = null
    try {
      const stT = await vfs.lstat(t)
      if (stT && stT.type !== 'directory') {
        const leaf = t
          .replace(/\/+$/, '')
          .split('/')
          .filter(Boolean)
          .pop()
        names = [leaf || t]
        singleEntryPath = t
      } else {
        names = await vfs.readdir(t)
      }
    } catch (e) {
      ctx.console.error('ls: cannot access ' + t + ': ' + (e.message || e))
      continue
    }
    if (!showAll) names = names.filter((n) => !n.startsWith('.'))
    if (!longFmt) {
      ctx.console.log(names.join(' '))
    } else {
      let totalBlocks = 0
      const rows = []
      for (const n of names) {
        const sub =
          singleEntryPath != null
            ? singleEntryPath
            : t === '.' || t === './'
              ? n
              : t.replace(/\/$/, '') + '/' + n
        const st = await vfs.lstat(sub)
        if (!st) {
          rows.push({
            modeStr: '?---------',
            nlink: '?',
            user: '?',
            group: '?',
            size: 0,
            mtimeStr: '?',
            name: n,
            arrow: ''
          })
          continue
        }
        const blocks = barePosixBlocks(st.size || 0)
        totalBlocks += blocks
        const modeStr = bareFormatModeString(st.mode, st.type)
        const nlink = st.nlink != null ? String(st.nlink) : '1'
        const user = st.user != null ? st.user : String(st.uid ?? 0)
        const group = st.group != null ? st.group : String(st.gid ?? 0)
        const size = st.size != null ? String(st.size) : '0'
        const mtimeStr = bareFormatLsMtime(
          typeof st.mtimeMs === 'number' ? st.mtimeMs : Date.now()
        )
        let arrow = ''
        if (st.type === 'symlink' && st.linkname != null) {
          arrow = ' -> ' + st.linkname
        }
        rows.push({
          modeStr,
          nlink,
          user,
          group,
          size,
          mtimeStr,
          name: n,
          arrow
        })
      }
      if (singleEntryPath == null) ctx.console.log('total ' + totalBlocks)
      for (const r of rows) {
        ctx.console.log(
          r.modeStr +
            ' ' +
            r.nlink +
            ' ' +
            r.user +
            ' ' +
            r.group +
            ' ' +
            r.size +
            ' ' +
            r.mtimeStr +
            ' ' +
            r.name +
            r.arrow
        )
      }
    }
  }
}