#include <Arduino.h>

// Define GPIO pins for the traffic lights
const int green1Pin = 27;
const int yellow1Pin = 25;
const int red1Pin = 23;

const int green2Pin = 14;
const int yellow2Pin = 12;
const int red2Pin = 22;

const int green3Pin = 32;
const int yellow3Pin = 17;
const int red3Pin = 21;

const int green4Pin = 33;
const int yellow4Pin = 16;
const int red4Pin = 19;

// Define timing constants
const unsigned long greenTime = 5000; // 10 seconds
const unsigned long yellowTime = 2000; // 3 seconds

enum TrafficState {
  x_green,
  x_yellow,
  y_green,
  y_yellow,
  z_green,
  z_yellow,
  w_green,
  w_yellow
};

TrafficState currentState;

void setup() {
  // Initialize traffic light pins
  pinMode(green1Pin, OUTPUT);
  pinMode(yellow1Pin, OUTPUT);
  pinMode(red1Pin, OUTPUT);
  
  pinMode(green2Pin, OUTPUT);
  pinMode(yellow2Pin, OUTPUT);
  pinMode(red2Pin, OUTPUT);
  
  pinMode(green3Pin, OUTPUT);
  pinMode(yellow3Pin, OUTPUT);
  pinMode(red3Pin, OUTPUT);
  
  pinMode(green4Pin, OUTPUT);
  pinMode(yellow4Pin, OUTPUT);
  pinMode(red4Pin, OUTPUT);

  // Start with x traffic green
  currentState = x_green;
}

void loop() {
  switch(currentState) {
    case x_green:
      digitalWrite(yellow4Pin, LOW);
      digitalWrite(green4Pin, LOW);
      digitalWrite(red1Pin, LOW);
      digitalWrite(green1Pin, HIGH);
      digitalWrite(red2Pin, HIGH);
      digitalWrite(red3Pin, HIGH);
      digitalWrite(red4Pin, HIGH);
      
      delay(greenTime);
      currentState = x_yellow;
      break;
      
    case x_yellow:
      digitalWrite(green1Pin, LOW);
      digitalWrite(yellow1Pin, HIGH);
      
      delay(yellowTime);
      currentState = y_green;
      break;
      // y traffic green on 
    case y_green:
      digitalWrite(yellow1Pin, LOW);
      digitalWrite(red2Pin, LOW);
      digitalWrite(green2Pin, HIGH);
      digitalWrite(red3Pin, HIGH);
      digitalWrite(red1Pin, HIGH);
      digitalWrite(red4Pin, HIGH);
      
      delay(greenTime);
      currentState = y_yellow;
      break;
      
    case y_yellow:
      digitalWrite(green2Pin, LOW);
      digitalWrite(yellow2Pin, HIGH);
      
      delay(yellowTime);
      currentState = z_green;
      break;
     // z traffic on green
    case z_green:
      digitalWrite(yellow2Pin, LOW);
      digitalWrite(red3Pin, LOW);
      digitalWrite(green3Pin, HIGH);
      digitalWrite(red2Pin, HIGH);
      digitalWrite(red1Pin, HIGH);
      digitalWrite(red4Pin, HIGH);
      
      delay(greenTime);
      currentState = z_yellow;
      break;
      
    case z_yellow:
      digitalWrite(green3Pin, LOW);
      digitalWrite(yellow3Pin, HIGH);
      
      delay(yellowTime);
      currentState = w_green;
      break;
    // w traffic on
    case w_green:
      digitalWrite(yellow3Pin, LOW);
      digitalWrite(red4Pin, LOW);
      digitalWrite(green4Pin, HIGH);
      digitalWrite(red2Pin, HIGH);
      digitalWrite(red1Pin, HIGH);
      digitalWrite(red3Pin, HIGH);
      
      delay(greenTime);
      currentState = w_yellow;
      break;
      
    case w_yellow:
      digitalWrite(green4Pin, LOW);
      digitalWrite(yellow4Pin, HIGH);
      
      delay(yellowTime);
      currentState = x_green;
      break;
  }
}