const int ledPin = 13;     // LED pin
const int buttonPin = 2;   // Button pin
const int cycleTime = 10000; // ON/OFF duration in milliseconds (10s ON, 10s OFF)

bool ledState = false;  // LED state (ON/OFF)
bool systemActive = false; // Tracks whether the LED cycle has started
unsigned long previousMillis = 0; // Stores last toggle time

void setup() {
  pinMode(ledPin, OUTPUT);  // Set LED pin as output
  pinMode(buttonPin, INPUT_PULLUP); // Set button pin as input with pull-up resistor
  Serial.begin(9600);  // Start Serial Monitor
}

void loop() {
  // Check if the button is pressed (LOW due to INPUT_PULLUP)
  if (digitalRead(buttonPin) == LOW && !systemActive) {
    delay(50); // Debounce delay
    if (digitalRead(buttonPin) == LOW) { // Confirm button press
      systemActive = true;  // Start the LED cycle
      ledState = true;  // LED turns ON first
      previousMillis = millis(); // Reset timer
      digitalWrite(ledPin, ledState);
      Serial.println("LED is ON, cycle started");
    }
  }

  // If system is active, follow the blinking cycle
  if (systemActive) {
    unsigned long currentMillis = millis();

    if (currentMillis - previousMillis >= cycleTime) {
      previousMillis = currentMillis; // Update last toggle time
      ledState = !ledState; // Toggle LED state
      digitalWrite(ledPin, ledState);

      // Print LED state to Serial Monitor
      if (ledState) {
        Serial.println("LED is ON");
      } else {
        Serial.println("LED is OFF");
      }
    }
  }
}