/**
 * tmux send-keys input translation.
 *
 * Translates IC-1 key names (and literal text) into tmux send-keys arguments.
 * Used by the input route (T-1.5) to deliver keystrokes to a pane.
 *
 * Owner: T-1.1
 */

import { execFile } from "node:child_process";
import { promisify } from "node:util";

const execFileAsync = promisify(execFile);

/** Named keys from IC-1 ClientToServer `{ type: "key"; name: string }`. */
const KEY_MAP: Record<string, string> = {
  escape: "Escape",
  tab: "Tab",
  up: "Up",
  down: "Down",
  left: "Left",
  right: "Right",
  enter: "Enter",
  "shift-enter": "S-Enter",
  backspace: "BSpace",
  "ctrl-c": "C-c",
  "ctrl-d": "C-d",
  "ctrl-z": "C-z",
};

/**
 * Send a single named key to a tmux pane.
 * Pane defaults to the first pane of the session (session:0.0).
 */
export async function sendKey(session: string, name: string): Promise<void> {
  const tmuxKey = KEY_MAP[name.toLowerCase()];
  if (!tmuxKey) {
    throw new Error(
      `Unknown key name: "${name}". Supported: ${Object.keys(KEY_MAP).join(", ")}`,
    );
  }
  // Target just the session — tmux selects the active window/pane automatically.
  // Avoids base-index issues (user's tmux.conf may start windows at 1, not 0).
  await execFileAsync("tmux", ["send-keys", "-t", session, tmuxKey]);
}

/**
 * Send literal text to a tmux pane (IC-1 `{ type: "keys"; data: string }`).
 * Uses send-keys -l which sends each character literally.
 */
export async function sendKeys(session: string, data: string): Promise<void> {
  await execFileAsync("tmux", ["send-keys", "-t", session, "-l", data]);
}

/**
 * Send bracketed-paste to a tmux pane (IC-1 `{ type: "paste"; data: string }`).
 * Wraps the data in bracketed-paste sequences then sends literally.
 */
export async function sendPaste(session: string, data: string): Promise<void> {
  const wrapped = `\x1b[200~${data}\x1b[201~`;
  await execFileAsync("tmux", ["send-keys", "-t", session, "-l", wrapped]);
}