const int led1 = 12;
const int led2 = 13;
const int buttonPin = 14;

unsigned long previousMillis = 0;
const long interval = 500;
unsigned long lastDebounceTime = 0;
const long debounceDelay = 50;

int mode = 2; 
int buttonState = HIGH;  
int lastButtonState = HIGH; 
bool led1State = LOW;
bool led2State = LOW;

void setup() {
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP);

  Serial.begin(115200);

  digitalWrite(led1, LOW);
  digitalWrite(led2, LOW);

  Serial.println("Waiting for first button press...");
}

void loop() {
  int reading = digitalRead(buttonPin);

  if (reading != lastButtonState) {
    lastDebounceTime = millis(); 
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (reading == LOW && buttonState == HIGH) {
      mode++;
      if (mode > 2) {
        mode = 0;
      }
    }
    buttonState = reading;
  }

  lastButtonState = reading;

  switch (mode) {
    case 0: 
      blinkLED();
      break;
    case 1:
      alternateLED();
      break;
    case 2: 
      turnOffLEDs();
      break;
  }
}

void blinkLED() {
  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;

    led1State = !led1State;
    led2State = led1State; 

    digitalWrite(led1, led1State);
    digitalWrite(led2, led2State);

    if (led1State == HIGH) {
      Serial.print("Blinking On... ");
    } else {
      Serial.println("off");
    }
  }
}

void alternateLED() {
  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;


    led1State = !led1State;
    led2State = !led1State;

    digitalWrite(led1, led2State);
    digitalWrite(led2, led1State);

    if (led1State == HIGH) {
      Serial.print("Alternating on/off... ");
    } else {
      Serial.println("off/on");
    }
  }
}

void turnOffLEDs() {
  digitalWrite(led1, LOW);
  digitalWrite(led2, LOW);
}