// Define pin numbers
const int redVehiclePin = 13;
const int yellowVehiclePin = 11;
const int greenVehiclePin = 12;
const int redPedestrianPin = 5;
const int greenPedestrianPin = 3;
const int pedestrianButtonPin = 6;

// Define timings
const int greenVehicleDuration = 20000; // 20 seconds
const int yellowVehicleDuration = 5000; // 5 seconds
const int redVehicleDuration = 5000;    // 5 seconds
const int greenPedestrianDuration = 15000; // 15 seconds
const int blinkingGreenDuration = 5000; // 5 seconds blinking
const int allRedDuration = 3000;       // 3 seconds all red

void setup() {
  pinMode(redVehiclePin, OUTPUT);
  pinMode(yellowVehiclePin, OUTPUT);
  pinMode(greenVehiclePin, OUTPUT);
  pinMode(redPedestrianPin, OUTPUT);
  pinMode(greenPedestrianPin, OUTPUT);
  pinMode(pedestrianButtonPin, INPUT);
}

void loop() {
  // Initial state - Green for vehicles
  digitalWrite(greenVehiclePin, HIGH);
  delay(greenVehicleDuration);

  // Yellow for vehicles
  digitalWrite(greenVehiclePin, LOW);
  digitalWrite(yellowVehiclePin, HIGH);
  delay(yellowVehicleDuration);

  // Red for vehicles
  digitalWrite(yellowVehiclePin, LOW);
  digitalWrite(redVehiclePin, HIGH);
  delay(redVehicleDuration);

  // Check for pedestrian button press during vehicle green
  if (digitalRead(pedestrianButtonPin) == HIGH) {
    // Transition smoothly to next state - Yellow for vehicles
    digitalWrite(redVehiclePin, LOW);
    digitalWrite(redPedestrianPin, LOW);
    digitalWrite(greenPedestrianPin, HIGH);
    delay(greenPedestrianDuration);

    // Blinking green for pedestrians
    for (int i = 0; i < 5; i++) {
      digitalWrite(greenPedestrianPin, HIGH);
      delay(500);
      digitalWrite(greenPedestrianPin, LOW);
      delay(500);
    }

    // Turn on red lights for both pedestrians and vehicles for 3 seconds
    digitalWrite(greenPedestrianPin, LOW);
    digitalWrite(redPedestrianPin, HIGH);
    digitalWrite(redVehiclePin, HIGH);
    delay(allRedDuration);

    // Return to initial state
    digitalWrite(redVehiclePin, LOW);
    digitalWrite(redPedestrianPin, HIGH);
  }
}