#define BLYNK_TEMPLATE_ID "TMPL33-ygH834"
#define BLYNK_TEMPLATE_NAME "Smart Traffic"
#define BLYNK_AUTH_TOKEN "lhSWhde6isKGh-AvG99raRkwg7VEhm9D"

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>

const int redLedPin = 25;
const int yellowLedPin = 26;
const int greenLedPin = 27;
const int motionSensorPin = 32;

LiquidCrystal_I2C lcd(0x27, 16, 2);

char auth[] = BLYNK_AUTH_TOKEN;
char ssid[] = "Wokwi-GUEST"; 
char pass[] = "";

enum TrafficLightState {
  RED,
  YELLOW,
  GREEN
};

TrafficLightState currentState = RED;
unsigned long lastChangeTime = 0;
unsigned long interval = 3000; // Default interval

bool isAmbulanceRequested = false;
bool isPedestrianRequested = false;

void setup() {
  Serial.begin(115200);
  Blynk.begin(auth, ssid, pass);
  lcd.init();
  lcd.backlight();
  pinMode(redLedPin, OUTPUT);
  pinMode(yellowLedPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);
  pinMode(motionSensorPin, INPUT);
  
  // Setup Blynk widget for displaying traffic status
  Blynk.virtualWrite(V4, "Normal Traffic");

  // Attach virtual button handlers
  Blynk.virtualWrite(V1, "Ambulance");
  Blynk.virtualWrite(V2, "Pedestrian");

  // Set up interval for normal operation
  currentState = RED;
  lastChangeTime = millis();
}

void loop() {
  Blynk.run();

  unsigned long currentTime = millis();
  if (currentState == RED && currentTime - lastChangeTime >= interval) {
    currentState = GREEN;
    lastChangeTime = currentTime;
  } else if (currentState == GREEN && currentTime - lastChangeTime >= interval) {
    currentState = YELLOW;
    lastChangeTime = currentTime;
  } else if (currentState == YELLOW && currentTime - lastChangeTime >= interval / 2) {
    currentState = RED;
    lastChangeTime = currentTime;
  }

  // Handle special events
  if (isAmbulanceRequested) {
    handleAmbulance();
    isAmbulanceRequested = false;
  } else if (isPedestrianRequested) {
    handlePedestrian();
    isPedestrianRequested = false;
  } else {
    // Normal traffic operation
    updateTrafficLights();
    updateLCD();
  }

  // Update Traffic Light Color on Blynk V3
  updateTrafficLightColorWidget();
  
  delay(1000);
}

void updateTrafficLights() {
  digitalWrite(redLedPin, currentState == RED ? HIGH : LOW);
  digitalWrite(yellowLedPin, currentState == YELLOW ? HIGH : LOW);
  digitalWrite(greenLedPin, currentState == GREEN ? HIGH : LOW);

}

void updateLCD() {
  lcd.clear();
  lcd.setCursor(0, 0);
  switch (currentState) {
    case RED:
      lcd.print("Red");
      lcd.setCursor(0, 1);
      lcd.print("Normal Traffic");
      break;
    case GREEN:
      lcd.print("Green");
      lcd.setCursor(0, 1);
      lcd.print("Normal Traffic");
      break;
    case YELLOW:
      lcd.print("Yellow");
      lcd.setCursor(0, 1);
      lcd.print("Normal Traffic");
      break;
  }
}

void updateTrafficLightColorWidget() {
  String color;
  switch (currentState) {
    case RED:
      color = "Red";
      break;
    case YELLOW:
      color = "Yellow";
      break;
    case GREEN:
      color = "Green";
      break;
  }
  Blynk.virtualWrite(V3, color);
}

BLYNK_WRITE(V1) {
  int value = param.asInt();
  if (value == 1) {
    isAmbulanceRequested = true;
  }
}

BLYNK_WRITE(V2) {
  int value = param.asInt();
  if (value == 1) {
    isPedestrianRequested = true;
  }
}

void handleAmbulance() {
  currentState = RED; // Immediately switch to red for ambulance
  updateTrafficLights();
  Blynk.virtualWrite(V4, "Ambulance Passing");
  Blynk.virtualWrite(V3,"Red");
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Red");
  lcd.setCursor(0, 1);
  lcd.print("Ambulance");
  delay(5000); // Wait for 2 seconds for the ambulance to pass
  currentState = RED; // Switch back to red after ambulance passes
  Blynk.virtualWrite(V4, "Normal Traffic");
  Blynk.virtualWrite(V3,"Red");
  updateTrafficLights();
}

void handlePedestrian() {
  currentState = RED; // Immediately switch to red for pedestrian
  updateTrafficLights();
  Blynk.virtualWrite(V4, "Pedestrian Crossing");
  Blynk.virtualWrite(V3,"Red");
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Red");
  lcd.setCursor(0, 1);
  lcd.print("Pedestrian Crossing");
  delay(10000); // Wait for 15 seconds for the pedestrian to cross
  currentState = RED; // Switch back to green after pedestrian crosses
  Blynk.virtualWrite(V4, "Normal Traffic");
  Blynk.virtualWrite(V3, "Red");
  updateTrafficLights();
}