class Timer {
public:
  void start() { timeStamp = millis(); }
  bool operator()(const uint32_t duration) const { return (millis() - timeStamp >= duration) ? true : false; }

private:
  uint32_t timeStamp {0};
};

enum class ProgramMode : byte { stop, modeA, modeB };
enum class LightStatus : byte { start, on, off };

constexpr uint8_t LED_PIN {4};

// constexpr uint32_t TIME_MODE_A {1000 * 3600UL * 2};   // 2 Hours
// constexpr uint32_t TIME_MODE_B {1000 * 3600UL * 8};   // 8 Hours

// constexpr uint32_t LIGHT_ON_MS {1000 * 5UL};          // 5 Seconds
// constexpr uint32_t LIGHT_OFF_MS {1000 * 60UL * 15};   // 15 Minutes

constexpr uint32_t TIME_MODE_A {1000 * 120UL};   // 2 Minutes
constexpr uint32_t TIME_MODE_B {1000 * 60UL};    // 1 Minute

constexpr uint32_t LIGHT_ON_MS {1000 * 2UL};
constexpr uint32_t LIGHT_OFF_MS {1000 * 4UL};

constexpr uint32_t mainIntervalls[3] {0, TIME_MODE_A, TIME_MODE_B};
constexpr uint32_t ledIntervalls[3] {0, LIGHT_ON_MS, LIGHT_OFF_MS};

Timer ledTimer;
Timer mainTimer;

LightStatus switchLight(LightStatus ls) {
  if (ledTimer(ledIntervalls[static_cast<byte>(ls)])) {
    ledTimer.start();
    digitalWrite(LED_PIN, !digitalRead(LED_PIN));
    ls = (ls != LightStatus::on) ? LightStatus::on : LightStatus::off;
  }
  return ls;
}

void setup() {
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);
  mainTimer.start();
}

void loop() {
  static LightStatus ledStatus {LightStatus::start};
  static ProgramMode mode {ProgramMode::modeB};

  // Depending on the pressed button, the variable mode must be set to either
  // ProgramMode::modeA, ProgramMode::modeB or ProgramMode::stop.
  // When the mode (A or B) is set, mainTimer.start() must also be executed (once).

  if (mainTimer(mainIntervalls[static_cast<byte>(mode)])) {
    if (digitalRead(LED_PIN)) { digitalWrite(LED_PIN, LOW); }
    mode = ProgramMode::stop;
  } else {
    ledStatus = switchLight(ledStatus);
  }
}