import { decodeKittyPrintable, isKeyRelease, matchesKey } from "@earendil-works/pi-tui";

/**
 * Single owner of how a pi TUI key event reaches this extension.
 *
 * Terminals that negotiate the Kitty keyboard protocol — Ghostty among them — send CSI-u
 * sequences instead of the legacy bytes, so `data === "\r"` silently stops matching Enter and
 * an overlay appears frozen. `matchesKey` accepts both encodings regardless of the negotiated
 * protocol, so components must never compare raw bytes themselves.
 */

const ESCAPE_PREFIX = "\u001b";
const DELETE = "\u007f";

export function isEscape(data: string): boolean {
  return matchesKey(data, "escape");
}

export function isEnter(data: string): boolean {
  return matchesKey(data, "enter");
}

export function isUp(data: string): boolean {
  return matchesKey(data, "up");
}

export function isDown(data: string): boolean {
  return matchesKey(data, "down");
}

export function isLeft(data: string): boolean {
  return matchesKey(data, "left");
}

export function isRight(data: string): boolean {
  return matchesKey(data, "right");
}

export function isTab(data: string): boolean {
  return matchesKey(data, "tab");
}

export function isBackTab(data: string): boolean {
  return matchesKey(data, "shift+tab");
}

export function isBackspace(data: string): boolean {
  return matchesKey(data, "backspace");
}

/**
 * The literal text a key event carries, or undefined when it is a control or navigation key.
 * Under the Kitty protocol an ordinary character arrives as a CSI-u sequence, so a plain
 * printable-range test on the raw bytes is not sufficient.
 */
export function printableText(data: string): string | undefined {
  const decoded = decodeKittyPrintable(data);
  if (decoded !== undefined) return decoded.length > 0 ? decoded : undefined;
  if (data.length === 0 || data.startsWith(ESCAPE_PREFIX)) return undefined;
  if (data.includes(DELETE)) return undefined;
  return [...data].every((character) => character >= " ") ? data : undefined;
}

/** True when the event is exactly the given printable character, in either encoding. */
export function isCharacter(data: string, character: string): boolean {
  return printableText(data) === character;
}

/**
 * True for a Kitty key-release event. `matchesKey` deliberately ignores the event type, so a
 * raw terminal-input hook sees both the press and the release of one keystroke and would act
 * twice. The TUI filters releases before reaching a focused component, but `onTerminalInput`
 * receives them unfiltered. Key repeat is a real repeat and must not be filtered.
 */
export function isReleaseEvent(data: string): boolean {
  return isKeyRelease(data);
}