const int displayPins[7] = {2, 3, 4, 5, 6, 7, 8}; // Pins for 7-segment display segments
const int redPin = 9;         // Red LED connected to pin 9
const int yellowPin = 10;     // Yellow LED connected to pin 10
const int greenPin = 11;      // Green LED connected to pin 11
const int countdownDuration = 30; // Countdown duration in seconds

void setup() {
  // Initialize display pins as OUTPUT
  for (int i = 0; i < 7; i++) {
    pinMode(displayPins[i], OUTPUT);
  }
  pinMode(redPin, OUTPUT);
  pinMode(yellowPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
}

void loop() {
  // Red light
  lightLED(3); // Display "red" on the 7-segment display
  digitalWrite(redPin, HIGH);
  digitalWrite(yellowPin, LOW);
  digitalWrite(greenPin, LOW);
  delay(1000); // Red light duration

  // Red and Yellow lights (transition)
  lightLED(4); // Display "r y" on the 7-segment display
  digitalWrite(redPin, HIGH);
  digitalWrite(yellowPin, HIGH);
  digitalWrite(greenPin, LOW);
  delay(1000); // Transition duration

  // Green light
  lightLED(2); // Display "grn" on the 7-segment display
  digitalWrite(redPin, LOW);
  digitalWrite(yellowPin, LOW);
  digitalWrite(greenPin, HIGH);
  delay(1000); // Green light duration

  // Yellow light
  lightLED(1); // Display "yel" on the 7-segment display
  digitalWrite(redPin, LOW);
  digitalWrite(yellowPin, HIGH);
  digitalWrite(greenPin, LOW);
  delay(1000); // Yellow light duration
}

void lightLED(int mode) {
  switch (mode) {
    case 1: // Yellow
      digitalWrite(displayPins[0], LOW); // y
      digitalWrite(displayPins[1], HIGH); // e
      digitalWrite(displayPins[2], HIGH); // l
      digitalWrite(displayPins[3], HIGH); // l
      digitalWrite(displayPins[4], LOW); // o
      digitalWrite(displayPins[5], LOW); // (Blank)
      digitalWrite(displayPins[6], LOW); // (Blank)
      break;
    case 2: // Green
      digitalWrite(displayPins[0], HIGH); // g
      digitalWrite(displayPins[1], LOW); // e
      digitalWrite(displayPins[2], LOW); // l
      digitalWrite(displayPins[3], LOW); // l
      digitalWrite(displayPins[4], LOW); // o
      digitalWrite(displayPins[5], LOW); // (Blank)
      digitalWrite(displayPins[6], LOW); // (Blank)
      break;
    case 3: // Red
      digitalWrite(displayPins[0], LOW); // r
      digitalWrite(displayPins[1], LOW); // e
      digitalWrite(displayPins[2], LOW); // l
      digitalWrite(displayPins[3], LOW); // l
      digitalWrite(displayPins[4], HIGH); // o
      digitalWrite(displayPins[5], LOW); // (Blank)
      digitalWrite(displayPins[6], LOW); // (Blank)
      break;
    case 4: // Red and Yellow (transition)
      digitalWrite(displayPins[0], LOW); // r
      digitalWrite(displayPins[1], HIGH); // e
      digitalWrite(displayPins[2], LOW); // l
      digitalWrite(displayPins[3], LOW); // l
      digitalWrite(displayPins[4], HIGH); // o
      digitalWrite(displayPins[5], LOW); // (Blank)
      digitalWrite(displayPins[6], LOW); // (Blank)
      break;
    default: // Turn off display
      for (int i = 0; i < 7; i++) {
        digitalWrite(displayPins[i], LOW);
      }
      break;
  }
}