/**
 * [Gitea #136] Elbow-on-the-keyboard guard for push-to-talk: a hold longer
 * than `maxMs` is released as if the key came up. `arm()` on press, `disarm()`
 * on release (a genuine release + re-press restarts the clock). Timers are
 * injectable for tests.
 */
export const PTT_MAX_HOLD_MS = 5 * 60 * 1000;

type Timers = {
  setTimeout: (fn: () => void, ms: number) => unknown;
  clearTimeout: (handle: unknown) => void;
};

const realTimers: Timers = {
  setTimeout: (fn, ms) => setTimeout(fn, ms),
  clearTimeout: (h) => clearTimeout(h as ReturnType<typeof setTimeout>),
};

export const createPttHoldWatchdog = (
  onExpire: () => void,
  maxMs = PTT_MAX_HOLD_MS,
  timers: Timers = realTimers,
) => {
  let handle: unknown;
  const disarm = () => {
    if (handle !== undefined) timers.clearTimeout(handle);
    handle = undefined;
  };
  return {
    arm: () => {
      disarm();
      handle = timers.setTimeout(() => {
        handle = undefined;
        onExpire();
      }, maxMs);
    },
    disarm,
    armed: () => handle !== undefined,
  };
};