// Define pin numbers for ultrasonic sensors
const int trigPins[] = {11, 24, 42};
const int echoPins[] = {12, 23, 41};

// Define pin numbers for PIR sensors
const int pirPins[] = {13, 22, 40};

// Define pin numbers for traffic lights
const int trafficRedPins[] = {10, 25, 43};
const int trafficGreenPins[] = {9, 26, 44};
const int trafficYellowPins[] = {8, 27, 45};

// Define pin numbers for pedestrian lights
const int pedestrianGreenPins[] = {6, 29, 47};
const int pedestrianRedPins[] = {7, 28, 46};

// Timing constants
const unsigned long greenTime = 10000; // 10 seconds
const unsigned long yellowTime = 2000; // 2 seconds
const unsigned long pedestrianCrossTime = 8000; // 8 seconds

void setup() {
  // Initialize pins
  for (int i = 0; i < 3; i++) {
    pinMode(trigPins[i], OUTPUT);
    pinMode(echoPins[i], INPUT);
    pinMode(pirPins[i], INPUT);

    pinMode(trafficRedPins[i], OUTPUT);
    pinMode(trafficYellowPins[i], OUTPUT);
    pinMode(trafficGreenPins[i], OUTPUT);
    pinMode(pedestrianGreenPins[i], OUTPUT);
    pinMode(pedestrianRedPins[i], OUTPUT);
  }

  // Start with default lights (all red for cars, all red for pedestrians)
  for (int i = 0; i < 3; i++) {
    digitalWrite(trafficRedPins[i], HIGH);
    digitalWrite(pedestrianRedPins[i], HIGH);
  }
}

void loop() {
  // Check for vehicles and pedestrians in each direction
  for (int i = 0; i < 3; i++) {
    bool vehicleDetected = isVehicleDetected(i);

    if (vehicleDetected) {
      controlTrafficLights(i);
    } else {
      bool pedestrianDetected = isPedestrianDetected(i);
      if (pedestrianDetected) {
        controlPedestrianLights(i);
      } else {
        defaultTrafficLightState(i);
      }
    }
  }

  delay(1000); // Short delay to avoid rapid switching
}

bool isVehicleDetected(int index) {
  // Send a pulse to the ultrasonic sensor
  digitalWrite(trigPins[index], LOW);
  delayMicroseconds(2);
  digitalWrite(trigPins[index], HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPins[index], LOW);

  // Read the pulse duration
  long duration = pulseIn(echoPins[index], HIGH);

  // Calculate the distance
  float distance = duration * 0.034 / 2;

  // Check if the distance is within the threshold (e.g., 30 cm)
  return (distance < 30.0);
}

bool isPedestrianDetected(int index) {
  // Read the PIR sensor, only detect if no vehicle is present
  return digitalRead(pirPins[index]) == HIGH;
}

void controlTrafficLights(int index) {
  // Vehicle detected sequence
  digitalWrite(trafficGreenPins[index], HIGH);
  digitalWrite(trafficYellowPins[index], LOW);
  digitalWrite(trafficRedPins[index], LOW);
  digitalWrite(pedestrianRedPins[index], HIGH);
  digitalWrite(pedestrianGreenPins[index], LOW);

  delay(greenTime);

  digitalWrite(trafficGreenPins[index], LOW);
  digitalWrite(trafficYellowPins[index], HIGH);

  delay(yellowTime);

  digitalWrite(trafficYellowPins[index], LOW);
  digitalWrite(trafficRedPins[index], HIGH);
}

void controlPedestrianLights(int index) {
  // Pedestrian detected sequence
  digitalWrite(trafficRedPins[index], HIGH);
  digitalWrite(trafficGreenPins[index], LOW);
  digitalWrite(trafficYellowPins[index], LOW);
  digitalWrite(pedestrianRedPins[index], LOW);
  digitalWrite(pedestrianGreenPins[index], HIGH);

  delay(pedestrianCrossTime);

  digitalWrite(pedestrianGreenPins[index], LOW);
  digitalWrite(pedestrianRedPins[index], HIGH);
}

void defaultTrafficLightState(int index) {
  // Default state (no vehicle or pedestrian detected)
  digitalWrite(trafficRedPins[index], HIGH);
  digitalWrite(trafficGreenPins[index], LOW);
  digitalWrite(trafficYellowPins[index], LOW);
  digitalWrite(pedestrianRedPins[index], HIGH);
  digitalWrite(pedestrianGreenPins[index], LOW);
}