void setup()
{
  Serial.begin(9600);
  pinMode (2, INPUT_PULLUP);
}
void loop()
{
  static unsigned long debounceTime;
  static unsigned long clickTime;
  static bool stateOld;
  static bool press; // long press

  if (millis() - debounceTime >= 50)
  {
    debounceTime = millis(); // update every 50mS

    bool stateNew = !digitalRead(2); // true for press

    if (stateOld != stateNew) // press or release
    {
      stateOld = stateNew;
      if (stateNew == true) // if new state is pressed
      {
        clickTime = millis();
        press = true;
      } else if (press == true) // 50mS later, if released
      {
        press = false;
        Serial.println("pressed short");
      }
    }
  }
  // 1000mS after press
  if (press == true && millis() - clickTime >= 1000 )
  {
    press = false;
    Serial.println("pressed long");
  }

}