/* 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
}

/** ANSI helpers for /bin/edit (preamble; no import in src). */

const EDIT_ANSI_RESET = '\x1b[0m'

/**
 * @param {Record<string, unknown>} [ctx]
 * @returns {import('stream').Writable | undefined}
 */
function bareEditResolveStdout(ctx) {
  if (!ctx || typeof ctx !== 'object') return globalThis.process?.stdout
  const c = /** @type {{ replStdout?: unknown, stdout?: unknown }} */ (ctx)
  const out = c.replStdout || c.stdout || globalThis.process?.stdout
  return /** @type {import('stream').Writable | undefined} */ (out)
}

/**
 * @param {Record<string, unknown>} [ctx]
 */
function bareEditUseColor(ctx) {
  const env =
    ctx && typeof ctx === 'object' && ctx.env && typeof ctx.env === 'object'
      ? /** @type {Record<string, string>} */ (ctx.env)
      : {}
  if (env.NO_COLOR != null && String(env.NO_COLOR) !== '') return false
  const out = bareEditResolveStdout(ctx)
  return Boolean(out && /** @type {{ isTTY?: boolean }} */ (out).isTTY)
}

/**
 * @param {'keyword'|'string'|'comment'|'number'|'status'|'inverse'|'dim'} cls
 * @param {boolean} on
 */
function bareEditSgr(cls, on) {
  if (!on) return ''
  switch (cls) {
    case 'keyword':
      return '\x1b[36m'
    case 'string':
      return '\x1b[32m'
    case 'comment':
      return '\x1b[90m'
    case 'number':
      return '\x1b[33m'
    case 'status':
      return '\x1b[44m\x1b[97m'
    case 'inverse':
      return '\x1b[7m'
    case 'dim':
      return '\x1b[2m'
    default:
      return ''
  }
}

/**
 * @param {string} fullLine
 * @param {Array<{ start: number, end: number, cls: string }>} spans offsets into fullLine
 * @param {number} visStart first column (0-based)
 * @param {number} maxLen max code units to show
 * @param {boolean} useColor
 */
function bareEditPaintLineWindow(fullLine, spans, visStart, maxLen, useColor) {
  const slice = fullLine.slice(visStart, visStart + maxLen)
  if (!useColor) return slice
  const n = slice.length
  const relSpans = spans
    .map((s) => ({
      start: Math.max(0, s.start - visStart),
      end: Math.min(n, s.end - visStart),
      cls: s.cls
    }))
    .filter((s) => s.end > 0 && s.start < n)
    .sort((a, b) => a.start - b.start)

  let out = ''
  let pos = 0
  for (const sp of relSpans) {
    if (sp.start > pos) out += slice.slice(pos, sp.start)
    out +=
      bareEditSgr(/** @type {'keyword'} */ (sp.cls), true) +
      slice.slice(sp.start, sp.end) +
      EDIT_ANSI_RESET
    pos = sp.end
  }
  if (pos < n) out += slice.slice(pos)
  return out
}

/**
 * Move cursor (1-based row/col, DEC origin). Clamp to sane bounds for escape parsing.
 * @param {number} row1
 * @param {number} col1
 */
function bareEditCup(row1, col1) {
  const r = Math.max(1, Math.min(Math.floor(row1), 9999))
  const c = Math.max(1, Math.min(Math.floor(col1), 9999))
  return '\x1b[' + r + ';' + c + 'H'
}

/**
 * @param {Record<string, unknown>} ctx
 * @param {import('stream').Writable} stdout
 * @param {string} s
 */
function bareEditWrite(ctx, stdout, s) {
  if (!stdout || typeof stdout.write !== 'function') return
  try {
    stdout.write(s)
  } catch {
    try {
      ctx.console?.error?.('edit: stdout write failed')
    } catch {
      /* ignore */
    }
  }
}

/** TTY key parsing for /bin/edit: consume one logical key from a mutable byte queue. */

/**
 * @param {number} b1
 */
function bareEditUtf8TrailCount(b1) {
  if (b1 >= 0xc0 && b1 < 0xe0) return 1
  if (b1 >= 0xe0 && b1 < 0xf0) return 2
  if (b1 >= 0xf0) return 3
  return 0
}

/**
 * @param {number[]} bytes
 */
function bareEditUtf8DecodeKey(bytes) {
  try {
    const u = new Uint8Array(bytes)
    if (typeof TextDecoder !== 'undefined') {
      return new TextDecoder('utf-8', { fatal: false }).decode(u)
    }
  } catch {
    /* fall through */
  }
  let s = ''
  for (const b of bytes) s += String.fromCharCode(b)
  return s
}

/**
 * @param {string} seq CSI payload after ESC [, including final byte (e.g. "A", "1;5A", "3~")
 */
function bareEditCsiToEvent(seq) {
  if (seq === '3~') return { type: 'ctrl', code: 'delete' }
  if (seq === '5~') return { type: 'nav', key: 'pageup' }
  if (seq === '6~') return { type: 'nav', key: 'pagedown' }
  const last = seq.charAt(seq.length - 1)
  if (last === '~') {
    if (seq === '1~' || seq === '7~') return { type: 'nav', key: 'home' }
    if (seq === '4~' || seq === '8~') return { type: 'nav', key: 'end' }
    const tildeNum = /^(\d+)~$/.exec(seq)
    if (tildeNum) {
      const n = parseInt(tildeNum[1], 10)
      const fnMap = {
        11: 1,
        12: 2,
        13: 3,
        14: 4,
        15: 5,
        17: 6,
        18: 7,
        19: 8,
        20: 9,
        21: 10,
        23: 11,
        24: 12
      }
      if (fnMap[n] != null) return { type: 'fn', n: fnMap[n] }
    }
    return { type: 'unknown' }
  }
  if (last === 'Z') return { type: 'nav', key: 'stab' }
  if (last === 'A' || last === 'B' || last === 'C' || last === 'D') {
    const map = { A: 'up', B: 'down', C: 'right', D: 'left' }
    return { type: 'nav', key: map[last] }
  }
  if (last === 'H') return { type: 'nav', key: 'home' }
  if (last === 'F') return { type: 'nav', key: 'end' }
  return { type: 'unknown' }
}

/**
 * @param {number} b3 byte after ESC O
 */
function bareEditSs3ToEvent(b3) {
  if (b3 === 72) return { type: 'nav', key: 'home' }
  if (b3 === 70) return { type: 'nav', key: 'end' }
  if (b3 === 65) return { type: 'nav', key: 'up' }
  if (b3 === 66) return { type: 'nav', key: 'down' }
  if (b3 === 67) return { type: 'nav', key: 'right' }
  if (b3 === 68) return { type: 'nav', key: 'left' }
  if (b3 === 80) return { type: 'fn', n: 1 }
  if (b3 === 81) return { type: 'fn', n: 2 }
  if (b3 === 82) return { type: 'fn', n: 3 }
  if (b3 === 83) return { type: 'fn', n: 4 }
  return { type: 'unknown' }
}

/** ESC [ 200 ~ */
const BARE_EDIT_BRACKET_PASTE_START = [27, 91, 50, 48, 48, 126]
/** ESC [ 201 ~ */
const BARE_EDIT_BRACKET_PASTE_END = [27, 91, 50, 48, 49, 126]

/**
 * @param {number[]} q
 * @param {number[]} prefix
 */
function bareEditStartsWithBytes(q, prefix) {
  if (q.length < prefix.length) return false
  for (let i = 0; i < prefix.length; i++) {
    if (q[i] !== prefix[i]) return false
  }
  return true
}

/**
 * True if q could still become BARE_EDIT_BRACKET_PASTE_START with more bytes.
 * @param {number[]} q
 */
function bareEditCouldBeBracketPastePrefix(q) {
  const pre = BARE_EDIT_BRACKET_PASTE_START
  const n = Math.min(q.length, pre.length)
  for (let i = 0; i < n; i++) {
    if (q[i] !== pre[i]) return false
  }
  return true
}

/**
 * @param {number[]} bytes
 */
function bareEditDecodePasteInner(bytes) {
  try {
    if (typeof TextDecoder !== 'undefined') {
      return new TextDecoder('utf-8', { fatal: false }).decode(
        new Uint8Array(bytes)
      )
    }
  } catch {
    /* fall through */
  }
  let s = ''
  for (const b of bytes) s += String.fromCharCode(b)
  return s
}

/**
 * If queue begins with ESC [ 200 ~ but no closing ESC [ 201 ~ (stdin closed), return inner bytes as text.
 * @param {number[]} q
 * @returns {string|undefined}
 */
function bareEditFinalizeBracketedPasteOnEof(q) {
  const SL = BARE_EDIT_BRACKET_PASTE_START.length
  if (q.length >= SL && bareEditStartsWithBytes(q, BARE_EDIT_BRACKET_PASTE_START)) {
    const inner = q.slice(SL)
    q.length = 0
    return bareEditDecodePasteInner(inner)
  }
  return undefined
}

/**
 * xterm bracketed paste: ESC [ 200 ~ … ESC [ 201 ~
 * @param {number[]} q mutable queue
 * @returns {string|null|undefined} string if consumed; null if incomplete; undefined if not bracketed paste at front
 */
function bareEditTryConsumeBracketedPaste(q) {
  const SL = BARE_EDIT_BRACKET_PASTE_START.length
  const EL = BARE_EDIT_BRACKET_PASTE_END.length
  if (!q.length) return undefined
  if (q.length < SL) {
    return bareEditCouldBeBracketPastePrefix(q) ? null : undefined
  }
  if (!bareEditStartsWithBytes(q, BARE_EDIT_BRACKET_PASTE_START)) {
    return undefined
  }
  for (let i = SL; i <= q.length - EL; i++) {
    let ok = true
    for (let j = 0; j < EL; j++) {
      if (q[i + j] !== BARE_EDIT_BRACKET_PASTE_END[j]) {
        ok = false
        break
      }
    }
    if (ok) {
      const inner = q.slice(SL, i)
      q.splice(0, i + EL)
      return bareEditDecodePasteInner(inner)
    }
  }
  return null
}

/**
 * @param {number[]} q mutable queue (front = index 0)
 * @returns {Record<string, unknown> | null} null if more bytes needed
 */
function bareEditTryConsumeKey(q) {
  if (!q.length) return null
  const b1 = q[0]
  if (b1 === 3) {
    q.shift()
    return { type: 'ctrl', code: 'interrupt' }
  }
  if (b1 === 8 || b1 === 127) {
    q.shift()
    return { type: 'ctrl', code: 'backspace' }
  }
  if (b1 === 13 || b1 === 10) {
    q.shift()
    return { type: 'key', ch: '\n' }
  }
  if (b1 === 9) {
    q.shift()
    return { type: 'key', ch: '\t' }
  }
  if (b1 === 27) {
    if (q.length < 2) return null
    const b2 = q[1]
    if (b2 === 91) {
      let i = 2
      while (i < q.length) {
        const b = q[i]
        if (b >= 0x40 && b <= 0x7e) {
          const seq = String.fromCharCode.apply(null, q.slice(2, i + 1))
          q.splice(0, i + 1)
          return bareEditCsiToEvent(seq)
        }
        i++
      }
      return null
    }
    if (b2 === 79) {
      if (q.length < 3) return null
      const b3 = q[2]
      q.splice(0, 3)
      return bareEditSs3ToEvent(b3)
    }
    q.splice(0, 2)
    return { type: 'key', ch: String.fromCharCode(b2) }
  }
  if (b1 < 0x20) {
    q.shift()
    return { type: 'ctrl', code: b1 }
  }
  const need = bareEditUtf8TrailCount(b1)
  if (q.length < 1 + need) return null
  const chunk = q.splice(0, 1 + need)
  return { type: 'key', ch: bareEditUtf8DecodeKey(chunk) }
}

/** Stdin chunk queue + async key reader for edit/chat TUIs (requires edit-key-parse.js first). */

/**
 * @param {unknown} chunk
 * @returns {number[]}
 */
function bareEditChunkBytes(chunk) {
  if (chunk == null) return []
  if (typeof chunk === 'string') {
    const out = []
    for (let i = 0; i < chunk.length; i++) out.push(chunk.charCodeAt(i) & 0xff)
    return out
  }
  const len = /** @type {{ length: number, [k: number]: number }} */ (chunk).length
  const out = []
  for (let i = 0; i < len; i++) out.push(Number(chunk[i]) & 0xff)
  return out
}

/**
 * @param {{ nextByte: () => Promise<number|undefined>, dispose?: () => void, _keyq?: number[] }} reader
 */
async function bareEditReadKey(reader) {
  reader._keyq = reader._keyq || []
  const q = reader._keyq
  for (;;) {
    const pasteText = bareEditTryConsumeBracketedPaste(q)
    if (pasteText !== undefined && pasteText !== null) {
      return { type: 'paste', text: pasteText }
    }
    if (pasteText === null) {
      const b = await reader.nextByte()
      if (b === undefined) {
        const eofPaste = bareEditFinalizeBracketedPasteOnEof(q)
        if (eofPaste !== undefined) {
          return { type: 'paste', text: eofPaste }
        }
        if (!q.length) return { type: 'eof' }
        if (q.length === 1 && q[0] === 27) {
          q.length = 0
          return { type: 'key', ch: '\x1b' }
        }
        const lone = q.shift()
        if (lone !== undefined && lone < 0x20) {
          return { type: 'ctrl', code: lone }
        }
        if (lone !== undefined) {
          return { type: 'key', ch: String.fromCharCode(lone) }
        }
        return { type: 'eof' }
      }
      q.push(b)
      continue
    }
    const ev = bareEditTryConsumeKey(q)
    if (ev) return ev
    const b = await reader.nextByte()
    if (b === undefined) {
      const eofPaste = bareEditFinalizeBracketedPasteOnEof(q)
      if (eofPaste !== undefined) {
        return { type: 'paste', text: eofPaste }
      }
      if (!q.length) return { type: 'eof' }
      if (q.length === 1 && q[0] === 27) {
        q.length = 0
        return { type: 'key', ch: '\x1b' }
      }
      const lone = q.shift()
      if (lone !== undefined && lone < 0x20) {
        return { type: 'ctrl', code: lone }
      }
      if (lone !== undefined) {
        return { type: 'key', ch: String.fromCharCode(lone) }
      }
      return { type: 'eof' }
    }
    q.push(b)
  }
}

/**
 * @param {import('stream').Readable} stdin
 */
function bareEditCreateStdinReader(stdin) {
  /** @type {number[]} */
  const bytes = []
  /** @type {(() => void)[]} */
  const waiters = []
  function drain() {
    while (waiters.length && bytes.length) {
      const w = waiters.shift()
      if (w) w()
    }
  }
  /** @param {unknown} chunk */
  function onData(chunk) {
    bytes.push(...bareEditChunkBytes(chunk))
    drain()
  }
  stdin.on('data', onData)
  return {
    nextByte() {
      if (bytes.length) return Promise.resolve(bytes.shift())
      return new Promise((resolve) => {
        waiters.push(() => resolve(bytes.shift()))
      })
    },
    dispose() {
      stdin.removeListener('data', onData)
    }
  }
}

/** Full-screen swarm chat TUI — preamble: edit-ansi → edit-key-parse → edit-stream-read. */

const BARE_CHAT_MAX_TRANSCRIPT = 4000
const BARE_CHAT_INPUT_MAX = 8192

/**
 * @param {string} s
 * @param {number} maxCols
 */
function bareChatTruncateVis(s, maxCols) {
  const t = String(s || '')
  if (maxCols < 8) return ''
  if (t.length <= maxCols) return t
  return t.slice(0, Math.max(0, maxCols - 1)) + '\u2026'
}

/**
 * @param {unknown} ms
 */
function bareChatFmtClock(ms) {
  if (typeof ms !== 'number' || !Number.isFinite(ms)) return '--:--:--'
  const d = new Date(ms)
  const z = (n) => (n < 10 ? '0' : '') + n
  return z(d.getHours()) + ':' + z(d.getMinutes()) + ':' + z(d.getSeconds())
}

/**
 * @param {Record<string, unknown>} ev
 */
function bareChatFmtEventLine(ev) {
  const nickRaw = String(ev.displayName ?? '').trim()
  const pkHint =
    typeof ev.fromPeerKey === 'string'
      ? ev.fromPeerKey.slice(0, 10)
      : ''
  const nick = nickRaw || pkHint || 'peer'
  const body = String(ev.body ?? '')
    .replace(/\r\n/g, '\n')
    .split('\n')
    .join('\u2423 ')
  const tag = ev.local ? '*' : ' '
  const ms =
    typeof ev.receivedAtMs === 'number'
      ? ev.receivedAtMs
      : typeof ev.tsMs === 'number'
        ? ev.tsMs
        : Date.now()
  return '[' + bareChatFmtClock(ms) + ']' + tag + nick + ': ' + body
}

/**
 * @param {Record<string, unknown>} ctx
 */
async function bareChatReadProcSnapshot(ctx) {
  try {
    const vfs = ctx.vfs
    if (!vfs || typeof vfs.readFile !== 'function') return null
    const b = await vfs.readFile('/proc/bare_os/chat.json')
    if (!b) return null
    const t = ctx.b4a.toString(b).trim()
    if (!t) return null
    return /** @type {Record<string, unknown>} */ (JSON.parse(t))
  } catch {
    return null
  }
}

/**
 * @param {Record<string, unknown> | null} snap
 * @param {{
 *   swarmPeers: { current: number | null },
 *   muxRx: { current: number | null },
 *   muxTx: { current: number | null },
 *   wireRxTotal: { current: number | null },
 *   dropRate: { current: number | null },
 *   dropVerify: { current: number | null }
 * }} out
 */
function bareChatApplyProcSnap(snap, out) {
  if (!snap || typeof snap !== 'object') return
  const sp = snap.swarmPeers
  out.swarmPeers.current =
    typeof sp === 'number' && Number.isFinite(sp) ? sp : null
  const met = snap.metrics
  if (met && typeof met === 'object') {
    const m = /** @type {{ rxEvent?: number, txEvent?: number, droppedRate?: number, droppedVerify?: number }} */ (
      met
    )
    out.muxRx.current =
      typeof m.rxEvent === 'number' && Number.isFinite(m.rxEvent)
        ? m.rxEvent
        : null
    out.muxTx.current =
      typeof m.txEvent === 'number' && Number.isFinite(m.txEvent)
        ? m.txEvent
        : null
    out.dropRate.current =
      typeof m.droppedRate === 'number' && Number.isFinite(m.droppedRate)
        ? m.droppedRate
        : null
    out.dropVerify.current =
      typeof m.droppedVerify === 'number' &&
      Number.isFinite(m.droppedVerify)
        ? m.droppedVerify
        : null
  } else {
    out.muxRx.current = null
    out.muxTx.current = null
    out.dropRate.current = null
    out.dropVerify.current = null
  }
  const wire = snap.protomuxChatRxTotal
  out.wireRxTotal.current =
    typeof wire === 'number' && Number.isFinite(wire) ? wire : null
}

/**
 * @param {Record<string, unknown>} ctx
 * @param {string} argv0
 */
async function bareOsRunChatTui(ctx, argv0) {
  const stdin = /** @type {import('stream').Readable | undefined} */ (
    ctx.replStdin
  )
  const stdout = bareEditResolveStdout(ctx)
  if (!stdin || !stdout) {
    ctx.console.error('chat: missing stdin/stdout')
    ctx.exitCode = 1
    return
  }
  const useColor = bareEditUseColor(ctx)

  const envEarly =
    ctx.env && typeof ctx.env === 'object'
      ? /** @type {Record<string, string>} */ (ctx.env)
      : {}

  let tickMs = 1000
  const tickRaw = envEarly.BARE_CHAT_STATUS_MS
  if (tickRaw != null && String(tickRaw) !== '') {
    const n = Number.parseInt(String(tickRaw), 10)
    if (Number.isFinite(n) && n >= 0) tickMs = Math.min(Math.max(0, n), 3_600_000)
  }

  /** @type {'main'|'help'} */
  let mode = 'main'

  /** @type {string[]} */
  const transcript = []
  /** First visible transcript index */
  let scrollTop = 0
  /** When true, new messages snap scroll to bottom */
  let stickToBottom = true

  let inputBuf = ''
  let inputCursor = 0

  const metricRef = {
    swarmPeers: /** @type {{ current: number | null }} */ ({ current: null }),
    muxRx: /** @type {{ current: number | null }} */ ({ current: null }),
    muxTx: /** @type {{ current: number | null }} */ ({ current: null }),
    wireRxTotal: /** @type {{ current: number | null }} */ ({ current: null }),
    dropRate: /** @type {{ current: number | null }} */ ({ current: null }),
    dropVerify: /** @type {{ current: number | null }} */ ({ current: null })
  }

  async function refreshProcStrip() {
    let snap = null
    if (typeof ctx.bareOsChatProcSnapshot === 'function') {
      try {
        snap = ctx.bareOsChatProcSnapshot()
      } catch {
        snap = null
      }
    }
    if (!snap || typeof snap !== 'object') {
      snap = await bareChatReadProcSnapshot(ctx)
    }
    bareChatApplyProcSnap(snap, metricRef)
  }

  function clampScroll(viewH) {
    const maxTop = Math.max(0, transcript.length - viewH)
    if (stickToBottom || scrollTop > maxTop) scrollTop = maxTop
    if (scrollTop < 0) scrollTop = 0
  }

  function appendEvent(rec) {
    bareChatPushTranscript(transcript, bareChatFmtEventLine(rec))
  }

  function bareChatPushTranscript(lines, text) {
    lines.push(text)
    while (lines.length > BARE_CHAT_MAX_TRANSCRIPT) {
      lines.shift()
      if (scrollTop > 0) scrollTop--
    }
  }

  function termDims() {
    const cols = /** @type {{ columns?: number }} */ (stdout).columns ||
      parseInt(envEarly.COLUMNS || '80', 10) ||
      80
    const rows = /** @type {{ rows?: number }} */ (stdout).rows ||
      parseInt(envEarly.LINES || '24', 10) ||
      24
    return { cols: Math.max(40, cols), rows: Math.max(10, rows) }
  }

  let paintBusy = false
  let paintAgain = false

  function draw() {
    const { cols, rows } = termDims()
    const headerRows = 3
    const footerRows = 3
    const msgH = Math.max(1, rows - headerRows - footerRows)
    clampScroll(msgH)

    let out = '\x1b[?25l\x1b[2J\x1b[H'

    if (mode === 'help') {
      out +=
        bareEditSgr('keyword', useColor) +
        'Bare OS — swarm chat' +
        EDIT_ANSI_RESET +
        '\r\n\r\n' +
        'Send with Enter. Scroll transcript with \u2191/\u2193 or PgUp/PgDn.\r\n' +
        'Input: Backspace/Delete, \u2190/\u2192, Home/End, ^A/^E line start/end, ^U kill to start, ^K kill to end.\r\n' +
        '^R refresh status   ^L redraw   ^Q / ^X / Ctrl+C exit\r\n' +
        '`chat send TEXT` / `chat who` / `chat history` remain for scripts.\r\n' +
        'Env: BARE_CHAT_STATUS_MS — status refresh interval in ms (default 1000; 0 disables timer).\r\n\r\n' +
        'Press any key.\r\n'
      bareEditWrite(ctx, stdout, out + '\x1b[?25h')
      return
    }

    const rooms =
      typeof ctx.bareOsChatRooms === 'function'
        ? ctx.bareOsChatRooms()
        : []
    const roomStr = Array.isArray(rooms) && rooms.length ? rooms.join(', ') : 'general'

    const peerStr =
      metricRef.swarmPeers.current != null
        ? String(metricRef.swarmPeers.current)
        : '?'
    const rxStr =
      metricRef.muxRx.current != null ? String(metricRef.muxRx.current) : '?'
    const txStr =
      metricRef.muxTx.current != null ? String(metricRef.muxTx.current) : '?'
    const wireStr =
      metricRef.wireRxTotal.current != null
        ? String(metricRef.wireRxTotal.current)
        : '?'

    /** @type {string[]} */
    const titleParts = [
      argv0 || 'chat',
      roomStr,
      'peers ' + peerStr,
      'rx ' + rxStr,
      'tx ' + txStr,
      'wire ' + wireStr
    ]
    const dr = metricRef.dropRate.current ?? 0
    const dv = metricRef.dropVerify.current ?? 0
    if (dr > 0 || dv > 0) {
      titleParts.push('drops r' + dr + '/v' + dv)
    }

    const title =
      bareEditSgr('status', useColor) +
      bareChatTruncateVis(
        ' \u250c ' + titleParts.join(' \u00b7 ') + ' ',
        cols
      ) +
      EDIT_ANSI_RESET

    const nowClock = bareChatFmtClock(Date.now())
    const hint =
      bareEditSgr('dim', useColor) +
      bareChatTruncateVis(
        nowClock +
          '  bare-os-chat-v1  ? help  ^Q quit  ^R refresh' +
          (tickMs > 0 ? '  tick ' + tickMs + 'ms' : '  tick off'),
        cols
      ) +
      EDIT_ANSI_RESET
    out += bareEditCup(1, 1) + '\x1b[K' + title
    out += bareEditCup(2, 1) + '\x1b[K' + hint
    out +=
      bareEditCup(3, 1) +
      '\x1b[K' +
      bareEditSgr('dim', useColor) +
      '\u2500'.repeat(Math.min(cols, 120)) +
      EDIT_ANSI_RESET

    for (let i = 0; i < msgH; i++) {
      const idx = scrollTop + i
      const raw =
        idx >= 0 && idx < transcript.length ? transcript[idx] : ''
      const line = bareChatTruncateVis(raw, cols)
      const row = headerRows + 1 + i
      const dim =
        idx === transcript.length - 1 && stickToBottom
          ? bareEditSgr('string', useColor)
          : ''
      out +=
        bareEditCup(row, 1) +
        '\x1b[K' +
        dim +
        line +
        EDIT_ANSI_RESET
    }

    const sepRow = rows - footerRows + 1
    out +=
      bareEditCup(sepRow, 1) +
      '\x1b[K' +
      bareEditSgr('dim', useColor) +
      '\u2500'.repeat(Math.min(cols, 120)) +
      EDIT_ANSI_RESET

    const hintRow = sepRow + 1
    const linesBelow = Math.max(0, transcript.length - scrollTop - msgH)
    let scrollHint = ''
    if (!stickToBottom && (scrollTop > 0 || linesBelow > 0)) {
      const parts = []
      if (scrollTop > 0) parts.push('\u2191 ' + scrollTop + ' older')
      if (linesBelow > 0) parts.push('\u2193 ' + linesBelow + ' newer')
      scrollHint = parts.join('  ')
    }
    const hint2 =
      bareEditSgr('dim', useColor) +
      bareChatTruncateVis(
        (scrollHint ? scrollHint + '   ' : '') +
          'Enter send   \u2191\u2193 transcript   Backspace / ^A ^E ^U ^K',
        cols
      ) +
      EDIT_ANSI_RESET
    out += bareEditCup(hintRow, 1) + '\x1b[K' + hint2

    const prompt = '> '
    const promptLen = prompt.length
    const budget = Math.max(8, cols - promptLen - 2)
    const ib = inputBuf
    const ic = Math.min(Math.max(0, inputCursor), ib.length)
    let winStart = 0
    if (ib.length > budget) {
      winStart = ic - Math.floor(budget / 2)
      if (winStart < 0) winStart = 0
      if (winStart > ib.length - budget) {
        winStart = Math.max(0, ib.length - budget)
      }
    }
    const slice = ib.slice(winStart, winStart + budget)
    const rel = ic - winStart
    const before = slice.slice(0, rel)
    const curCh = rel < slice.length ? slice.charAt(rel) : ' '
    const after = slice.slice(rel + 1)
    const inputRow = hintRow + 1
    const inputLine =
      bareEditSgr('dim', useColor) +
      prompt +
      EDIT_ANSI_RESET +
      before +
      bareEditSgr('inverse', useColor) +
      (curCh || ' ') +
      EDIT_ANSI_RESET +
      after

    out += bareEditCup(inputRow, 1) + '\x1b[K' + inputLine

    bareEditWrite(ctx, stdout, out + '\x1b[?25h')
  }

  function paint() {
    if (paintBusy) {
      paintAgain = true
      return
    }
    paintBusy = true
    try {
      do {
        paintAgain = false
        draw()
      } while (paintAgain)
    } finally {
      paintBusy = false
    }
  }

  /** @type {(() => void) | null} */
  let unsub = null
  if (typeof ctx.bareOsChatSubscribe === 'function') {
    unsub = ctx.bareOsChatSubscribe((ev) => {
      appendEvent(
        /** @type {Record<string, unknown>} */ (
          ev && typeof ev === 'object' ? ev : {}
        )
      )
      void refreshProcStrip().then(() => paint())
    })
  }

  if (typeof ctx.bareOsChatHistory === 'function') {
    try {
      const hist = ctx.bareOsChatHistory(BARE_CHAT_MAX_TRANSCRIPT)
      if (Array.isArray(hist)) {
        for (const h of hist) {
          if (h && typeof h === 'object') {
            bareChatPushTranscript(
              transcript,
              bareChatFmtEventLine(
                /** @type {Record<string, unknown>} */ (h)
              )
            )
          }
        }
        stickToBottom = true
      }
    } catch {
      /* ignore */
    }
  }

  const reader = bareEditCreateStdinReader(stdin)
  let suspended = false
  let useAltScreen = false
  let useBracketPaste = false

  /** @type {ReturnType<typeof setInterval> | null} */
  let tickTimer = null

  function onResize() {
    void refreshProcStrip().then(() => paint())
  }

  await refreshProcStrip()

  try {
    if (typeof ctx.suspendReplForSubprocess === 'function') {
      ctx.suspendReplForSubprocess()
      suspended = true
    }
    if (typeof stdin.setRawMode === 'function') stdin.setRawMode(true)
    if (typeof stdin.resume === 'function') stdin.resume()

    const bareChatNoAltScreen =
      envEarly.BARE_EDIT_NO_ALTSCREEN != null &&
      String(envEarly.BARE_EDIT_NO_ALTSCREEN) !== ''
    if (!bareChatNoAltScreen) {
      bareEditWrite(ctx, stdout, '\x1b[?1049h')
      useAltScreen = true
    }

    const bareChatNoBracketPaste =
      envEarly.BARE_EDIT_NO_BRACKETED_PASTE != null &&
      String(envEarly.BARE_EDIT_NO_BRACKETED_PASTE) !== ''
    if (!bareChatNoBracketPaste) {
      bareEditWrite(ctx, stdout, '\x1b[?2004h')
      useBracketPaste = true
    }

    if (typeof stdout.on === 'function') {
      try {
        stdout.on('resize', onResize)
      } catch {
        /* ignore */
      }
    }
    try {
      if (typeof process !== 'undefined' && typeof process.on === 'function') {
        process.on('SIGWINCH', onResize)
      }
    } catch {
      /* ignore */
    }

    if (tickMs > 0 && typeof setInterval === 'function') {
      tickTimer = setInterval(() => {
        void refreshProcStrip().then(() => paint())
      }, tickMs)
    }

    paint()

    for (;;) {
      const ev = await bareEditReadKey(reader)
      if (ev.type === 'eof') break

      if (mode === 'help') {
        mode = 'main'
        paint()
        continue
      }

      if (ev.type === 'ctrl') {
        if (ev.code === 'interrupt') break
        /** Backspace — key-parse uses `code: 'backspace'` for bytes 8 and 127 (not numeric). */
        if (ev.code === 'backspace') {
          if (inputCursor > 0) {
            inputBuf =
              inputBuf.slice(0, inputCursor - 1) + inputBuf.slice(inputCursor)
            inputCursor--
          }
          paint()
          continue
        }
        if (ev.code === 'delete') {
          if (inputCursor < inputBuf.length) {
            inputBuf =
              inputBuf.slice(0, inputCursor) + inputBuf.slice(inputCursor + 1)
          }
          paint()
          continue
        }
        const code = typeof ev.code === 'number' ? ev.code : 0
        if (code === 3) break
        if (code === 12) {
          paint()
          continue
        }
        if (code === 17 || code === 24) break
        if (code === 18) {
          await refreshProcStrip()
          paint()
          continue
        }
        /** Readline-style shortcuts (ASCII control chars). */
        if (code === 1) {
          inputCursor = 0
          paint()
          continue
        }
        if (code === 5) {
          inputCursor = inputBuf.length
          paint()
          continue
        }
        if (code === 21) {
          inputBuf = inputBuf.slice(inputCursor)
          inputCursor = 0
          paint()
          continue
        }
        if (code === 11) {
          inputBuf = inputBuf.slice(0, inputCursor)
          paint()
          continue
        }
        if (code === 8 || code === 127) {
          if (inputCursor > 0) {
            inputBuf =
              inputBuf.slice(0, inputCursor - 1) + inputBuf.slice(inputCursor)
            inputCursor--
          }
          paint()
          continue
        }
        continue
      }

      if (ev.type === 'nav') {
        const k = /** @type {{ key?: string }} */ (ev).key
        if (k === 'up') {
          stickToBottom = false
          if (scrollTop > 0) scrollTop--
          paint()
          continue
        }
        if (k === 'down') {
          const { rows: rr } = termDims()
          const msgH = Math.max(1, rr - 6)
          const maxTop = Math.max(0, transcript.length - msgH)
          if (scrollTop < maxTop) scrollTop++
          if (scrollTop >= maxTop) stickToBottom = true
          paint()
          continue
        }
        if (k === 'left') {
          if (inputCursor > 0) inputCursor--
          paint()
          continue
        }
        if (k === 'right') {
          if (inputCursor < inputBuf.length) inputCursor++
          paint()
          continue
        }
        if (k === 'home') {
          inputCursor = 0
          paint()
          continue
        }
        if (k === 'end') {
          inputCursor = inputBuf.length
          paint()
          continue
        }
        if (k === 'pageup') {
          stickToBottom = false
          const { rows: rr } = termDims()
          const msgH = Math.max(1, rr - 6)
          scrollTop = Math.max(0, scrollTop - msgH)
          paint()
          continue
        }
        if (k === 'pagedown') {
          const { rows: rr } = termDims()
          const msgH = Math.max(1, rr - 6)
          const maxTop = Math.max(0, transcript.length - msgH)
          scrollTop = Math.min(maxTop, scrollTop + msgH)
          if (scrollTop >= maxTop) stickToBottom = true
          paint()
          continue
        }
        continue
      }

      if (ev.type === 'key' && ev.ch) {
        if (ev.ch === '?') {
          mode = 'help'
          paint()
          continue
        }
        const ch = ev.ch
        if (ch === '\n') {
          const line = inputBuf.trim()
          inputBuf = ''
          inputCursor = 0
          if (line && typeof ctx.bareOsChatSend === 'function') {
            ctx.bareOsChatSend(line)
          }
          stickToBottom = true
          await refreshProcStrip()
          paint()
          continue
        }
        if (inputBuf.length < BARE_CHAT_INPUT_MAX) {
          inputBuf =
            inputBuf.slice(0, inputCursor) + ch + inputBuf.slice(inputCursor)
          inputCursor += ch.length
        }
        paint()
        continue
      }

      if (ev.type === 'paste') {
        const first = String(ev.text || '')
          .split(/\r?\n/)[0]
          ?.slice(0, BARE_CHAT_INPUT_MAX) ?? ''
        if (first) {
          const room = Math.max(
            0,
            BARE_CHAT_INPUT_MAX -
              inputBuf.length +
              (inputBuf.length - inputCursor)
          )
          const chunk = first.slice(0, room)
          inputBuf =
            inputBuf.slice(0, inputCursor) + chunk + inputBuf.slice(inputCursor)
          inputCursor += chunk.length
        }
        paint()
        continue
      }
    }
  } finally {
    if (tickTimer != null && typeof clearInterval === 'function') {
      try {
        clearInterval(tickTimer)
      } catch {
        /* ignore */
      }
      tickTimer = null
    }
    if (typeof stdout.removeListener === 'function') {
      try {
        stdout.removeListener('resize', onResize)
      } catch {
        /* ignore */
      }
    }
    try {
      if (typeof process !== 'undefined' && typeof process.off === 'function') {
        process.off('SIGWINCH', onResize)
      }
    } catch {
      /* ignore */
    }
    try {
      if (useBracketPaste) bareEditWrite(ctx, stdout, '\x1b[?2004l')
      if (useAltScreen) bareEditWrite(ctx, stdout, '\x1b[?1049l')
      else bareEditWrite(ctx, stdout, '\x1b[2J\x1b[H')
      bareEditWrite(ctx, stdout, '\x1b[?25h\x1b[0m')
    } catch {
      /* ignore */
    }
    try {
      if (typeof unsub === 'function') unsub()
    } catch {
      /* ignore */
    }
    reader.dispose()
    try {
      if (typeof stdin.setRawMode === 'function') stdin.setRawMode(false)
    } catch {
      /* ignore */
    }
    if (suspended && typeof ctx.resumeReplAfterSubprocess === 'function') {
      ctx.resumeReplAfterSubprocess()
    }
  }
}

/**
 * Swarm chat — full-screen TUI on a TTY (like edit/nano); scriptable subcommands otherwise.
 */
async function run(ctx, argv) {
  const args = argv.slice(1)
  if (args.includes('-h') || args.includes('--help')) {
    ctx.console.log(
      'usage: ' +
        (argv[0] || 'chat') +
        ' [send TEXT | history [N] | who | join]\n' +
        'With no arguments on a terminal: full-screen swarm chat (bare-os-chat-v1).\n' +
        'Requires host booter with swarm chat (see BARE_OS_PROTOMUX_CHAT_CHANNEL).\n' +
        'See man chat.'
    )
    return
  }

  const sub = args[0] || ''
  const cs = ctx.bareOsChatSend

  if (sub === 'send') {
    const rest = args.slice(1).join(' ').trim()
    if (!rest) {
      ctx.console.error('chat: send requires text')
      ctx.exitCode = 1
      return
    }
    if (typeof cs !== 'function') {
      ctx.console.error(
        'chat: bareOsChatSend unavailable — stock hosts enable swarm chat unless BARE_OS_PROTOMUX_CHAT_CHANNEL=0'
      )
      ctx.exitCode = 1
      return
    }
    const r = cs.call(ctx, rest)
    if (r && r.ok === false) ctx.exitCode = 1
    return
  }

  if (sub === 'history') {
    const n = args[1] ? Number.parseInt(args[1], 10) : 20
    const hist =
      typeof ctx.vfs?.readFile === 'function'
        ? await ctx.vfs.readFile('/proc/bare_os/chat.json')
        : null
    if (hist) ctx.console.log(ctx.b4a.toString(hist).trimEnd())
    else if (typeof ctx.bareOsReadProcMetricsLive === 'function') {
      ctx.console.log(JSON.stringify(ctx.bareOsReadProcMetricsLive(), null, 2))
    }
    void n
    return
  }

  if (sub === 'who') {
    ctx.console.log(JSON.stringify(ctx.bareOsChatPresence?.() ?? {}, null, 2))
    return
  }

  if (sub === 'join') {
    ctx.console.log(
      'chat join: only the general room is implemented; you are already in general when chat is enabled.'
    )
    return
  }

  const stdin = ctx.replStdin
  const stdout = ctx.replStdout || ctx.stdout
  const isTTY = Boolean(stdin && /** @type {{ isTTY?: boolean }} */ (stdin).isTTY)
  if (!isTTY || !stdout) {
    ctx.console.error(
      'chat: a terminal (TTY) is required for full-screen mode; use: chat send TEXT, chat history, chat who'
    )
    ctx.exitCode = 1
    return
  }

  if (typeof cs !== 'function') {
    ctx.console.error(
      'chat: swarm chat unavailable on this host — stock default is on unless BARE_OS_PROTOMUX_CHAT_CHANNEL=0'
    )
    ctx.exitCode = 1
    return
  }

  await bareOsRunChatTui(ctx, argv[0] || 'chat')
}