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

#define MQTTSERVER "test.mosquitto.org"
#define PORT 1883                     

WiFiClient espClient;
PubSubClient client(espClient);

const int trigPin = 5;
const int echoPin = 18;
#define VELOCIDADE_DO_SOM 0.034 

long duracao;
float distancCm;

void setup() {
  Serial.begin(115200);     
  pinMode(trigPin, OUTPUT);   
  pinMode(echoPin, INPUT);   

  // Conexão Wi-Fi
  WiFi.begin("Wokwi-GUEST", "", 6);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Conectando ao Wi-Fi...");
  }
  Serial.println("Conectado ao Wi-Fi");

  client.setServer(MQTTSERVER, PORT);
}

void loop() {
  if (!client.connected()) {
    establishConnection();
  }

  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duracao = pulseIn(echoPin, HIGH);
  distancCm = duracao * VELOCIDADE_DO_SOM / 2;

  Serial.print("Distancia (cm): ");
  Serial.println(distancCm);

  if (client.connected()) {
    String distanceString = String(distancCm);
    if (client.publish("sensor/distance", distanceString.c_str())) {
      Serial.println("Distância enviada: " + distanceString);
    } else {
      Serial.println("Falha ao enviar distância.");
    }
  }

  client.loop();
  delay(1000); 
}

void establishConnection() {
  while (!client.connected()) {
    Serial.println("Tentando conectar ao broker MQTT...");
    if (client.connect("ESP32_Sensor")) {
      Serial.println("Conectado ao broker MQTT");
    } else {
      Serial.print("Falha na conexão. Código de erro: ");
      Serial.println(client.state());
      delay(2000); 
    }
  }
}