// Pin Definitions
int red = 8;
int yellow = 7;
int green = 6;
int requestButton = 5; // Button to request pedestrian crossing
int pedestrianWaitingLED = 3; // LED to indicate pedestrian waiting
int pedestrianCrossingLED = 4; // LED to indicate pedestrian crossing

bool pedestrianRequest = false; // Flag to indicate if a pedestrian has requested to cross

void setup() {
  // Initialize traffic light LEDs as outputs
  pinMode(red, OUTPUT);
  pinMode(green, OUTPUT);
  pinMode(yellow, OUTPUT);
  
  // Initialize pedestrian LEDs as outputs
  pinMode(pedestrianWaitingLED, OUTPUT);
  pinMode(pedestrianCrossingLED, OUTPUT);

  // Initialize request button as input with pull-down resistor
  pinMode(requestButton, INPUT); // External pull-down resistor will be used
  
  // Initial LED states
  digitalWrite(red, LOW);
  digitalWrite(green, LOW);
  digitalWrite(yellow, LOW);
  digitalWrite(pedestrianWaitingLED, LOW);
  digitalWrite(pedestrianCrossingLED, LOW);
}

void loop() {
  // Check if the pedestrian has requested to cross by pressing the button
  if (digitalRead(requestButton) == HIGH) { // Button press will read HIGH with pull-down configuration
    pedestrianRequest = true; // Set the pedestrianRequest flag
  }

  // Traffic light sequence
  if (pedestrianRequest) {
    // Handle pedestrian crossing request
    digitalWrite(green, LOW); // Ensure green is off
    digitalWrite(yellow, LOW); // Ensure yellow is off
    digitalWrite(red, HIGH); // Turn on red light

    digitalWrite(pedestrianWaitingLED, HIGH); // Turn on "Pedestrian Waiting" LED
    delay(3000); // Wait for 3 seconds before allowing crossing

    digitalWrite(pedestrianWaitingLED, LOW); // Turn off "Pedestrian Waiting" LED
    digitalWrite(pedestrianCrossingLED, HIGH); // Turn on "Pedestrian Crossing" LED

    delay(8000); // Give pedestrian 8 seconds to cross

    digitalWrite(pedestrianCrossingLED, LOW); // Turn off "Pedestrian Crossing" LED
    pedestrianRequest = false; // Reset pedestrianRequest flag
  } else {
    digitalWrite(green, HIGH);
    delay(900);
    digitalWrite(green, LOW);

    digitalWrite(yellow, HIGH);
    delay(300);
    digitalWrite(yellow, LOW);

    digitalWrite(red, HIGH);
    delay(800);
    digitalWrite(red, LOW);
  }
}