class SenderInterface {
  async connect() {
    throw new Error('connect() must be implemented by sender classes');
  }

  send(command) {
    throw new Error('send() must be implemented by sender classes');
  }

  getStatus() {
    throw new Error('getStatus() must be implemented by sender classes');
  }

  disconnect() {
    throw new Error('disconnect() must be implemented by sender classes');
  }

  /**
   * Emergency Stop: Bewegung sofort stoppen (best-effort).
   * Standard-Implementierung: no-op (wird übersprungen).
   * Override in TelnetSenderGRBL → sendet '!' (FluidNC Feed Hold).
   * Override in ShellyEmergencyStop → schneidet Strom ab.
   * @returns {Promise<{ok: boolean, skipped?: boolean}>}
   */
  async emergencyStop() { return { ok: true, skipped: true }; }

  /**
   * Alarm-Unlock: Controller nach Strom-Neustart entsperren.
   * Standard-Implementierung: no-op (wird übersprungen).
   * Override in TelnetSenderGRBL → sendet '$X'.
   * @returns {Promise<{ok: boolean, skipped?: boolean}>}
   */
  async alarmUnlock() { return { ok: true, skipped: true }; }
}

module.exports = SenderInterface;