// Why this module exists: xterm's public onData stream mixes real keystrokes
// with the parser's synthetic replies to terminal queries a program embedded in
// its output (CPR/DSR cursor + device-status reports, DA device attributes,
// DECRPM mode reports, window/cell pixel-size reports, OSC 10/11 color reports,
// kitty keyboard flag reports, DCS-framed DECRQSS/XTVERSION reports).
// A querying program (e.g. starship/orb) reads these replies synchronously in
// raw mode with a short timeout, so on the remote path they must NOT sit behind
// the input debounce — a late reply lands on the shell prompt in cooked mode,
// which echoes it literally and splices it into the next typed line (#7329).
// This classifier lets the transport send replies immediately while keeping
// ordinary typed input (including bursty arrow-key auto-repeat) coalesced.

const ESC = String.fromCharCode(0x1b)

// Built via new RegExp from \u-escaped strings so no literal control
// characters appear in the source. // Final bytes of xterm's own query-reply grammars:
//   R  — CPR / DECXCPR cursor position report (answer to CSI 6n / CSI ? 6n)
//   n  — DSR device status report (answer to CSI 5n → CSI 0n)
//   c  — DA1/DA2/DA3 device attributes (answer to CSI c / CSI > c / CSI = c)
//   t  — window/cell pixel-size + text-area-size reports (CSI 14t/16t/18t)
//   y  — DECRPM mode report (answer to CSI ? Ps $ p), body ends "$y"
//   u  — kitty keyboard flags report (answer to CSI ? u), carries "?"
/* oxlint-disable no-control-regex -- grammars match terminal ESC/BEL sequences by definition */
// Known accepted collision: xterm.js encodes MODIFIED F3 (Shift/Ctrl/Alt+F3) as
// `CSI 1 ; <mod> R`, which is indistinguishable from a CPR report (a classic
// VT ambiguity). Such a keystroke is sent immediately instead of debounced —
// byte order is still preserved (the immediate path flushes pending input
// first), it just skips input-intent/activity bookkeeping. Harmless, so we
// keep the reply grammar complete rather than special-casing it.
const CPR_OR_DSR_RE = new RegExp('^\\u001b\\[\\??[0-9;]*[Rn]$')
const DEVICE_ATTRIBUTES_RE = new RegExp('^\\u001b\\[[?>=]?[0-9;]*c$')
// 4/6 = pixel-size reports, 8 = text-area size in characters (answer to CSI 18t).
const WINDOW_SIZE_REPORT_RE = new RegExp('^\\u001b\\[[468];[0-9]+;[0-9]+t$')
// `?` optional: private-mode reports carry it (DECRPM), ANSI-mode reports don't.
const DECRPM_RE = new RegExp('^\\u001b\\[\\??[0-9;]*\\$y$')
// Kitty keyboard protocol flags report: CSI ? flags u. The `?` distinguishes it
// from kitty-protocol *keystrokes* (CSI code;mods u), which must stay batched.
const KITTY_FLAGS_RE = new RegExp('^\\u001b\\[\\?[0-9]+u$')
// OSC color/title responses: ESC ] Ps ; body ST (ST = BEL or ESC backslash).
const OSC_RESPONSE_RE = new RegExp('^\\u001b\\][0-9]+;[^\\u0007\\u001b]*(?:\\u0007|\\u001b\\\\)$')
// DCS-framed reports xterm emits: DECRQSS "ESC P 1 $ r Pt ST" / "ESC P 0 $ r ST"
// (vim queries cursor style this way) and XTVERSION "ESC P > | text ST".
const DCS_RESPONSE_RE = new RegExp('^\\u001bP(?:[01]\\$r[^\\u001b]*|>\\|[^\\u001b]*)\\u001b\\\\$')
/* oxlint-enable no-control-regex */

/**
 * True when `data` (from xterm.onData) is a synthetic reply the emulator
 * generated in response to a query — not something the user typed. These are
 * latency-critical and must bypass input coalescing on the remote transport.
 *
 * Conservative by design: matches only complete, well-formed reply grammars so
 * ordinary keystrokes and navigation sequences (arrows CSI A/B/C/D, Home/End,
 * function keys ending in ~, kitty CSI-u keystrokes) are never misclassified
 * as replies — with the single documented modified-F3/CPR collision above.
 */
export function isTerminalQueryReply(data: string): boolean {
  if (data.length < 3 || data[0] !== ESC) {
    return false
  }
  return (
    CPR_OR_DSR_RE.test(data) ||
    DEVICE_ATTRIBUTES_RE.test(data) ||
    WINDOW_SIZE_REPORT_RE.test(data) ||
    DECRPM_RE.test(data) ||
    KITTY_FLAGS_RE.test(data) ||
    OSC_RESPONSE_RE.test(data) ||
    DCS_RESPONSE_RE.test(data)
  )
}