// Define pin numbers for each traffic light color
int G1 = 13; // Green light for intersection 1
int Y1 = 12; // Yellow light for intersection 1
int R1 = 14; // Red light for intersection 1

int G2 = 27; // Green light for intersection 2
int Y2 = 26;  // Yellow light for intersection 2
int R2 = 25;  // Red light for intersection 2

int G3 = 33;  // Green light for intersection 3
int Y3 = 32;  // Yellow light for intersection 3
int R3 = 23;  // Red light for intersection 3

int G4 = 5;  // Green light for intersection 4
int Y4 = 19;  // Yellow light for intersection 4
int R4 = 18;  // Red light for intersection 4

void setup() {
  // Initialize all pins as OUTPUT
  pinMode(G1, OUTPUT);
  pinMode(Y1, OUTPUT);
  pinMode(R1, OUTPUT);
  pinMode(G2, OUTPUT);
  pinMode(Y2, OUTPUT);
  pinMode(R2, OUTPUT);
  pinMode(G3, OUTPUT);
  pinMode(Y3, OUTPUT);
  pinMode(R3, OUTPUT);
  pinMode(G4, OUTPUT);
  pinMode(Y4, OUTPUT);
  pinMode(R4, OUTPUT);
  
  // Initially turn on all red lights and delay for 4 seconds
  digitalWrite(R1, HIGH);
  digitalWrite(R2, HIGH);
  digitalWrite(R3, HIGH);
  digitalWrite(R4, HIGH);
  delay(4000);

  // Turn on yellow light for intersection 1 and delay for 2 seconds
  digitalWrite(Y1, HIGH);
  delay(2000);
}

void loop() {
  // Intersection 4: Green for 5 seconds, blink Green every 500ms
  digitalWrite(Y4, LOW);
  digitalWrite(R4, HIGH);
  digitalWrite(R1, LOW);
  digitalWrite(G1, HIGH);
  digitalWrite(Y1, LOW);
  delay(5000);
  blinkLight(G1, 500);

  // Intersection 1: Switch from green to yellow
  digitalWrite(Y1, HIGH);
  digitalWrite(G1, LOW);
  delay(2000);

  // Intersection 1: Red light and Intersection 2: Green light
  digitalWrite(R1, HIGH);
  digitalWrite(Y1, LOW);
  delay(2000);
  digitalWrite(Y2, HIGH);
  delay(2000);
  digitalWrite(R2, LOW);
  digitalWrite(G2, HIGH);
  digitalWrite(Y2, LOW);
  delay(5000);
  blinkLight(G2, 500);

  // Intersection 2: Switch from green to yellow
  digitalWrite(G2, LOW);
  digitalWrite(Y2, HIGH);
  delay(2000);
  digitalWrite(R2, HIGH);
  digitalWrite(Y2, LOW);
  delay(2000);

  // Intersection 2: Red light and Intersection 3: Green light
  digitalWrite(Y3, HIGH);
  delay(2000);
  digitalWrite(R3, LOW);
  digitalWrite(G3, HIGH);
  digitalWrite(Y3, LOW);
  delay(5000);
  blinkLight(G3, 500);

  // Intersection 3: Switch from green to yellow
  digitalWrite(G3, LOW);
  digitalWrite(Y3, HIGH);
  delay(2000);
  digitalWrite(R3, HIGH);
  digitalWrite(Y3, LOW);
  delay(2000);

  // Intersection 3: Red light and Intersection 4: Green light
  digitalWrite(Y4, HIGH);
  delay(2000);
  digitalWrite(R4, LOW);
  digitalWrite(G4, HIGH);
  digitalWrite(Y4, LOW);
  delay(5000);
  blinkLight(G4, 500);

  // Intersection 4: Switch from green to yellow
  digitalWrite(G4, LOW);
  digitalWrite(Y4, HIGH);
  delay(2000);
  digitalWrite(R4, HIGH);
  digitalWrite(Y4, LOW);
  delay(2000);

  // Intersection 4: Red light and Intersection 1: Green light
  digitalWrite(Y1, HIGH);
  delay(2000);
  digitalWrite(R1, LOW);
  digitalWrite(G1, HIGH);
  digitalWrite(Y1, LOW);
  delay(2000);
}

// Function to blink a light with a specified delay
void blinkLight(int pin, int delayTime) {
  for (int i = 0; i < 6; i++) { // Blink the light 6 times
    digitalWrite(pin, HIGH);
    delay(delayTime);
    digitalWrite(pin, LOW);
    delay(delayTime);
  }
}