#define BLYNK_TEMPLATE_ID "TMPL31c6Nvniy"
#define BLYNK_TEMPLATE_NAME "smart traffic"
#define BLYNK_AUTH_TOKEN "3Sf3Fp_ChOu9MkaoFpMPPBvN5_XqonU_"

#include <WiFi.h>
#include <PubSubClient.h>
#include <Ultrasonic.h>
#include <BlynkSimpleEsp32.h>

const int TRIG_PIN = 15;
const int ECHO_PIN = 2;
const int RED_PIN = 21;
const int YELLOW_PIN = 19;
const int GREEN_PIN = 18;
const int BUZZER_PIN = 13;

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "test.mosquitto.org";
const char* traffic_light_topic = "/traffic_light";

WiFiClient espClient;
PubSubClient client(espClient);
Ultrasonic ultrasonic(TRIG_PIN, ECHO_PIN);

void setup_wifi()
 {
  delay(100);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) 
  {
    delay(200);
    Serial.print(".");
  }
  Serial.println();
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i = 0; i < length; i++)
  {
    Serial.print((char)payload[i]);
  }
  Serial.println();
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    String clientId = "ESP32Client-";
    clientId += String(random(0xffff), HEX);
    if (client.connect(clientId.c_str()))
    {
      Serial.println("Connected");
      client.publish(traffic_light_topic, "Connected");
      client.subscribe(traffic_light_topic);
    }
    else 
    {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(RED_PIN, OUTPUT);
  pinMode(YELLOW_PIN, OUTPUT);
  pinMode(GREEN_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, password);
}

void buzzerSound()
{
  tone(BUZZER_PIN,1000);  
  delay(500);             
  noTone(BUZZER_PIN);  
}


void manageTrafficLight(long distance) 
{
  if (distance < 150)
  {
    digitalWrite(RED_PIN, HIGH);
    digitalWrite(YELLOW_PIN, LOW);
    digitalWrite(GREEN_PIN, LOW);
    buzzerSound();
    Blynk.virtualWrite(V2, 255);  
    Blynk.virtualWrite(V3, 0);   
    Blynk.virtualWrite(V4, 0);   
  } 
  else if (distance < 250)
  {
    digitalWrite(RED_PIN, LOW);
    digitalWrite(YELLOW_PIN, HIGH);
    digitalWrite(GREEN_PIN, LOW);
    Blynk.virtualWrite(V2, 0);  
    Blynk.virtualWrite(V3, 255);  
    Blynk.virtualWrite(V4, 0);   
  }
  else
  {
    digitalWrite(RED_PIN, LOW);
    digitalWrite(YELLOW_PIN, LOW);
    digitalWrite(GREEN_PIN, HIGH);
    Blynk.virtualWrite(V2, 0);    
    Blynk.virtualWrite(V3, 0);    
    Blynk.virtualWrite(V4, 255); 
  }
}

void loop() {
  if (!client.connected())
  {
    reconnect();
  }
  client.loop();
  Blynk.run();

  long distance = ultrasonic.distanceRead();
  manageTrafficLight(distance);

  String distanceStr = String(distance);
  client.publish(traffic_light_topic, distanceStr.c_str());

  delay(1000);
}