/* 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
}

/**
 * Bubble + cow rendering for baresay (no imports; prepended before src/baresay.js).
 */

/** @param {string} text @param {number} width @param {boolean} noWrap */
function bareBaresayWrap(text, width, noWrap) {
  const t = String(text || '').replace(/\r\n/g, '\n')
  if (noWrap) {
    const line = t.replace(/\n/g, ' ')
    return line.length ? [line] : ['']
  }
  const out = []
  const lim = Math.max(8, Math.min(200, width | 0)) || 40
  for (const para of t.split('\n')) {
    if (!para.trim()) {
      out.push('')
      continue
    }
    let rest = para.trim()
    while (rest.length) {
      if (rest.length <= lim) {
        out.push(rest)
        break
      }
      let cut = rest.lastIndexOf(' ', lim)
      if (cut <= 0) cut = lim
      const piece = rest.slice(0, cut).trimEnd()
      if (!piece.length) {
        out.push(rest.slice(0, lim))
        rest = rest.slice(lim).trimStart()
      } else {
        out.push(piece)
        rest = rest.slice(cut).trimStart()
      }
    }
  }
  return out.length ? out : ['']
}

/**
 * @param {string[]} lines
 * @param {{ think?: boolean, rainbow?: boolean }} opts
 */
function bareBaresayBalloon(lines, opts) {
  const think = !!(opts && opts.think)
  const rainbow = !!(opts && opts.rainbow)
  const rows = lines.map((l) => String(l))
  const n = rows.length
  const longest = Math.max(...rows.map((r) => r.length), 2)
  const padded = rows.map((r) => r.padEnd(longest))

  /** @type {string[]} */
  const mid = []
  if (n === 1) {
    const inner = think
      ? '( ' + padded[0] + ' )'
      : '< ' + padded[0] + ' >'
    mid.push(inner)
  } else if (think) {
    for (let i = 0; i < n; i++) {
      mid.push('( ' + padded[i] + ' )')
    }
  } else {
    for (let i = 0; i < n; i++) {
      let L = '|'
      let R = '|'
      if (i === 0) {
        L = '/'
        R = '\\'
      } else if (i === n - 1) {
        L = '\\'
        R = '/'
      }
      mid.push(L + ' ' + padded[i] + ' ' + R)
    }
  }

  const topUnders = Math.max(0, mid[0].length - 2)
  const botDash = Math.max(0, mid[mid.length - 1].length - 2)
  /** @type {string[]} */
  const out = []
  out.push(' ' + '_'.repeat(topUnders))
  if (rainbow) {
    const ansi = bareBaresayRainbowCodes()
    let k = 0
    for (const line of mid) {
      const c = ansi[k % ansi.length]
      k++
      out.push(c + line + '\x1b[0m')
    }
  } else {
    for (const line of mid) out.push(line)
  }
  out.push(' ' + '-'.repeat(botDash))
  return out
}

function bareBaresayRainbowCodes() {
  return [
    '\x1b[31m',
    '\x1b[91m',
    '\x1b[33m',
    '\x1b[32m',
    '\x1b[36m',
    '\x1b[34m',
    '\x1b[35m'
  ]
}

/** Extract figure body from .bare template text (Perl heredoc or raw). */
function bareBaresayExtractCow(raw) {
  const s = String(raw || '').replace(/^\ufeff/, '')
  // cowsay uses: $the_cow = <<"EOC";  ← semicolon before newline
  const m = s.match(
    /\$the_cow\s*=\s*<<"EOC"\s*;?\s*\r?\n([\s\S]*?)\r?\n\s*EOC\s*(?:\r?\n|$)/m
  )
  if (m)
    return m[1].replace(/\r\n/g, '\n').replace(/\n+$/, '') + '\n'
  return s.replace(/\r\n/g, '\n').trimEnd() + '\n'
}

/**
 * @param {string} template
 * @param {string} eyes two chars
 * @param {string} tongue one char
 * @param {string} thoughts
 */
function bareBaresayFillCow(template, eyes, tongue, thoughts) {
  const e = (eyes || 'oo').slice(0, 2).padEnd(2, 'o')
  const L = e.charAt(0) || 'o'
  const R = e.charAt(1) || 'o'
  const tg = (tongue || ' ').slice(0, 1)
  const th = thoughts || '\\'
  return template
    .replace(/\$thoughts/g, th)
    .replace(/\$eyes/g, e)
    .replace(/\$L/g, L)
    .replace(/\$R/g, R)
    .replace(/\$tongue/g, tg)
}

/** @param {string} flag */
function bareBaresayPreset(flag) {
  switch (flag) {
    case 'b':
      return { eyes: '==', tongue: ' ' }
    case 'd':
      return { eyes: 'XX', tongue: 'U' }
    case 'g':
      return { eyes: '$$', tongue: ' ' }
    case 'p':
      return { eyes: '@@', tongue: ' ' }
    case 's':
      return { eyes: '**', tongue: ' ' }
    case 't':
      return { eyes: '--', tongue: ' ' }
    case 'w':
      return { eyes: '@@', tongue: ' ' }
    case 'y':
      return { eyes: '..', tongue: ' ' }
    default:
      return { eyes: 'oo', tongue: ' ' }
  }
}

/**
 * @param {string} message
 * @param {string} cowBody filled lines (no vars)
 * @param {{ width: number, noWrap: boolean, think?: boolean, rainbow?: boolean }} opts
 */
function bareBaresayCompose(message, cowBody, opts) {
  const width = opts.width | 0
  const wrapped = bareBaresayWrap(message, width, opts.noWrap)
  const balloon = bareBaresayBalloon(wrapped, {
    think: opts.think,
    rainbow: opts.rainbow
  })
  const cowLines = cowBody.replace(/\s+$/, '').split('\n')
  return balloon.concat(cowLines).join('\n') + '\n'
}

/** Minimal bear if no cowfile on disk (ASCII). */
function bareBaresayFallbackBearTemplate() {
  return [
    ' $thoughts',
    '  $thoughts      __         __',
    '   $thoughts    /  \\.-"""-./  \\',
    '    $thoughts   \\    -   -    /',
    '     $thoughts   |   $L   $R   |',
    '      $thoughts  \\  .-\'\'\'-.  /',
    "       $thoughts   '-\\__Y__/-'",
    '        $thoughts     \u0060---\u0060'
  ].join('\n')
}

async function run(ctx, argv) {
  const raw0 = argv && argv.length ? argv[0] : 'baresay'
  const slash = String(raw0).lastIndexOf('/')
  const prog =
    slash >= 0 ? String(raw0).slice(slash + 1) || 'baresay' : String(raw0)

  /** @param {string} msg */
  const usage = (msg) => {
    if (msg) ctx.console.error(prog + ': ' + msg)
    ctx.console.error(
      'usage: ' +
        prog +
        ' [-h] [-l] [-n] [-W COLS] [-f name|path] [-e XX] [-T C] [-bdgpstwy] [--think] [--rainbow] [-R|--random] [MESSAGE...]\n' +
        '       ' +
        prog +
        ' reads stdin when no MESSAGE and stdin is non-empty.'
    )
    ctx.exitCode = 2
  }

  let width = 40
  let noWrap = false
  let cowKey = 'bear'
  let cowPath = ''
  let listOnly = false
  let eyes = 'oo'
  let tongue = ' '
  let think = false
  let rainbow = false
  let randomPick = false
  /** @type {string[]} */
  const operands = []

  for (let i = 1; i < argv.length; i++) {
    const a = argv[i]
    if (a === '--') {
      operands.push(...argv.slice(i + 1))
      break
    }
    if (a === '-h' || a === '--help') {
      usage('')
      return
    }
    if (a === '-l') {
      listOnly = true
      continue
    }
    if (a === '-n') {
      noWrap = true
      continue
    }
    if (a === '--think' || a === '-th') {
      think = true
      continue
    }
    if (a === '--rainbow') {
      rainbow = true
      continue
    }
    if (a === '-R' || a === '--random') {
      randomPick = true
      continue
    }
    if (a === '-W' || a === '--width') {
      const v = argv[++i]
      const n = v != null ? parseInt(String(v), 10) : NaN
      if (!Number.isFinite(n) || n < 1) {
        usage('invalid width')
        return
      }
      width = n
      continue
    }
    if (a.startsWith('-W') && a.length > 2) {
      const n = parseInt(a.slice(2), 10)
      if (!Number.isFinite(n) || n < 1) {
        usage('invalid width')
        return
      }
      width = n
      continue
    }
    if (a === '-f' || a === '--file') {
      const v = argv[++i]
      if (v == null) {
        usage('missing character file')
        return
      }
      if (v.startsWith('/') || v.startsWith('.')) cowPath = v
      else cowKey = v.replace(/\.(bare|cow)$/i, '')
      continue
    }
    if (a.startsWith('-f') && a.length > 2) {
      const v = a.slice(2)
      if (v.startsWith('/') || v.startsWith('.')) cowPath = v
      else cowKey = v.replace(/\.(bare|cow)$/i, '')
      continue
    }
    if (a === '-e') {
      const v = argv[++i]
      if (v == null || String(v).length < 1) {
        usage('missing eyes')
        return
      }
      eyes = String(v).slice(0, 2).padEnd(2, ' ')
      continue
    }
    if (a.startsWith('-e') && a.length > 2) {
      eyes = a.slice(2, 4).padEnd(2, ' ')
      continue
    }
    if (a === '-T') {
      const v = argv[++i]
      tongue = v != null && String(v).length ? String(v).slice(0, 1) : ' '
      continue
    }
    if (a.startsWith('-T') && a.length > 2) {
      tongue = a.slice(2, 3) || ' '
      continue
    }
    {
      const mm = a.match(/^-([bdgpstwy])$/)
      if (mm) {
        const p = bareBaresayPreset(mm[1])
        eyes = p.eyes
        tongue = p.tongue
        continue
      }
    }
    if (a.startsWith('-') && a.length > 1) {
      usage('unknown option: ' + a)
      return
    }
    operands.push(a)
  }

  const vfs = ctx.vfs
  const b4 = ctx.b4a

  /** @returns {Promise<string[]>} */
  async function listShareCows() {
    const dir = '/share/baresay'
    /** @type {string[]} */
    const names = []
    if (!vfs || typeof vfs.readdir !== 'function') return names
    try {
      for await (const n of vfs.readdir(dir)) {
        if (typeof n === 'string' && /\.bare$/i.test(n)) {
          names.push(n.replace(/\.bare$/i, ''))
        }
      }
    } catch {
      /* ignore */
    }
    return names.sort()
  }

  if (listOnly) {
    const names = await listShareCows()
    for (const n of names) ctx.console.log(n)
    ctx.exitCode = 0
    return
  }

  /** @type {string} */
  let message = operands.join(' ')
  if (!message.trim()) {
    message = bareStdin(ctx).replace(/\r\n/g, '\n').trimEnd()
  }
  if (randomPick) {
    const names = await listShareCows()
    const pool = names.length ? names : ['bear']
    cowKey = pool[Math.floor(Math.random() * pool.length)]
    cowPath = ''
  }

  /** @returns {Promise<string | null>} */
  async function readCowAt(path) {
    if (!vfs || typeof vfs.readFile !== 'function') return null
    try {
      const buf = await vfs.readFile(path)
      if (!buf) return null
      return b4 ? b4.toString(buf) : String(buf)
    } catch {
      return null
    }
  }

  let rawCow = ''
  if (cowPath) {
    rawCow = (await readCowAt(cowPath)) || ''
  } else {
    const p = '/share/baresay/' + cowKey + '.bare'
    rawCow = (await readCowAt(p)) || ''
  }
  if (!rawCow.trim()) {
    if (cowKey === 'bear' && !cowPath) {
      rawCow = bareBaresayFallbackBearTemplate()
    } else {
      ctx.console.error(
        prog +
          ': character file not found: ' +
          (cowPath || '/share/baresay/' + cowKey + '.bare')
      )
      ctx.exitCode = 1
      return
    }
  }

  const template = bareBaresayExtractCow(rawCow)
  const filled = bareBaresayFillCow(template, eyes, tongue, '\\')
  const out = bareBaresayCompose(message, filled, {
    width,
    noWrap,
    think,
    rainbow
  })

  const w = globalThis.process?.stdout?.write
  if (typeof w === 'function') {
    w.call(globalThis.process.stdout, out)
  } else {
    ctx.console.log(out.replace(/\n$/, ''))
  }
  ctx.exitCode = 0
}