#define LED1 2
#define LED2 3
#define LED3 4
#define LED4 5
#define LED5 6
#define LED6 7
#define LED7 8
#define LED8 9

const int ledPins[] = {LED1, LED2, LED3, LED4, LED5, LED6, LED7, LED8};

const int buttonPin = 10;
bool ledState = false;
bool buttonPressed = false;
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50;

int currentLed = 0;
int direction = 1; // 1 = forward, -1 = backward
unsigned long previousMillis = 0;
const unsigned long interval = 300; // 300ms for each blink

void setup() {
  Serial.begin(115200);
  Serial.println("System Ready. Waiting for button press...");

  for (int i = 0; i < 8; i++) {
    pinMode(ledPins[i], OUTPUT);
    digitalWrite(ledPins[i], LOW);
  }

  pinMode(buttonPin, INPUT_PULLUP);
}

void loop() {
  static bool lastButtonReading = HIGH;
  bool currentReading = digitalRead(buttonPin);

  if (currentReading != lastButtonReading) {
    lastDebounceTime = millis();
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (currentReading == LOW && !buttonPressed) {
      buttonPressed = true;
      ledState = !ledState;

      if (ledState) {
        Serial.println("Button Pressed: Starting blinking sequence...");
        currentLed = 0;
        direction = 1;
      } else {
        Serial.println("Button Pressed: Stopping and turning OFF all LEDs...");
        for (int i = 0; i < 8; i++) {
          digitalWrite(ledPins[i], LOW);
        }
      }
    }

    if (currentReading == HIGH) {
      buttonPressed = false;
    }
  }

  lastButtonReading = currentReading;

  if (ledState) {
    unsigned long currentMillis = millis();
    if (currentMillis - previousMillis >= interval) {
      previousMillis = currentMillis;

      // Turn OFF all LEDs first
      for (int i = 0; i < 8; i++) {
        digitalWrite(ledPins[i], LOW);
      }

      // Turn ON the current LED
      digitalWrite(ledPins[currentLed], HIGH);
      Serial.print("Blinking LED ");
      Serial.println(currentLed + 1);

      // Move to next LED
      currentLed += direction;

      // If we reach the end, reverse direction
      if (currentLed >= 8) {
        currentLed = 7; // Stay at last LED
        direction = -1; // Reverse
      } else if (currentLed < 0) {
        currentLed = 0; // Stay at first LED
        direction = 1;  // Forward again
      }
    }
  }
}