int RED = 12;        // Vehicle red LED
int YELLOW = 13;     // Vehicle yellow LED
int GREEN = 14;      // Vehicle green LED

int GREEN2 = 25;     // Pedestrian green LED
int RED2 = 26;       // Pedestrian red LED

int BUTTON = 27;     // Pedestrian pushbutton
int BUZZER = 33;     // Buzzer

int crossTime = 5000;          // Pedestrian walk time (5 sec)
unsigned long lastChange = 0;  // Prevent repeated triggers
bool crossing = false;

void setup() {
  pinMode(RED, OUTPUT);
  pinMode(YELLOW, OUTPUT);
  pinMode(GREEN, OUTPUT);
  pinMode(RED2, OUTPUT);
  pinMode(GREEN2, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  pinMode(BUTTON, INPUT);

  // Initial state
  digitalWrite(GREEN, HIGH);   // Traffic green
  digitalWrite(RED, LOW);
  digitalWrite(YELLOW, LOW);

  digitalWrite(RED2, HIGH);    // Pedestrian don't walk
  digitalWrite(GREEN2, LOW);
}

void loop() {
  // Traffic stays green for 5 seconds minimum
  if (!crossing && digitalRead(BUTTON) == HIGH && millis() - lastChange >= 5000) {
    crossing = true;
    changeLights();
    lastChange = millis();
    crossing = false;
  }
}

void changeLights() {
  // Traffic: Green → Yellow
  digitalWrite(GREEN, LOW);
  digitalWrite(YELLOW, HIGH);
  delay(2000); // Yellow = 2 seconds

  // Traffic: Yellow → Red
  digitalWrite(YELLOW, LOW);
  digitalWrite(RED, HIGH);

  // Pedestrian: Walk
  digitalWrite(RED2, LOW);
  digitalWrite(GREEN2, HIGH);
  tone(BUZZER, 1000);      // Buzzer ON
  delay(crossTime);        // Walk = 5 seconds

  noTone(BUZZER);
  delay(500);              // Short pause

  // Pedestrian flashing warning (2 seconds total)
  for (int i = 0; i < 5; i++) {
    digitalWrite(GREEN2, LOW);
    delay(200);
    digitalWrite(GREEN2, HIGH);
    delay(200);
  }

  // Reset to normal traffic flow
  digitalWrite(GREEN2, LOW);
  digitalWrite(RED2, HIGH);

  digitalWrite(RED, LOW);
  digitalWrite(GREEN, HIGH);
}