#include <WiFi.h>
#include "PubSubClient.h"  // MQTT Library

WiFiClient wifiClient;    // Membuat objek wifiClient
PubSubClient mqttClient(wifiClient); 

const char* ssid = "Wokwi-GUEST";
const char* password = "";

char *mqttServer = "broker.hivemq.com";
int mqttPort = 1883;

#define ECHO_PIN 26
#define TRIG_PIN 27

float distance_cm, duration_us;

void reconnect() {
  Serial.println("Connecting to MQTT Broker...");
  while (!mqttClient.connected()) {
      Serial.println("Reconnecting to MQTT Broker..");
      String clientId = "ESP32Client-";
      clientId += String(random(0xffff), HEX);
      
      if (mqttClient.connect(clientId.c_str())) {
        Serial.println("Connected.");
      }      
  }
}

void setupMQTT() {
  mqttClient.setServer(mqttServer, mqttPort); // Menagtur detail broker yang digunakan
  mqttClient.setCallback(callback);           // jika kita ingin menerima pesan untuk langganan yang dibuat oleh klien
}

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


void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT); 
  
  WiFi.begin(ssid, password);   // Mencoba connect ke Wifi

  // Melakukan pengecekan terhadap status koneksi ke WI-Fi
  while (WiFi.status() != WL_CONNECTED) {
      delay(500);
      Serial.print(".");
    } 
    Serial.println("");
     Serial.println("Connected to Wi-Fi");

  setupMQTT(); // koneksi ke broker
}

void loop() {

  if (!mqttClient.connected())
    reconnect();   // Try to connect with broker
  
  mqttClient.loop();

  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // measure duration of pulse from ECHO pin
  duration_us = pulseIn(ECHO_PIN, HIGH);
  // calculate the distance
  distance_cm = 0.017 * duration_us;

  char distance_cm_string[8];
  dtostrf(distance_cm, 1, 2, distance_cm_string);

  Serial.print("distance: ");
  Serial.print(distance_cm);
  Serial.println(" cm");
  
  mqttClient.publish("lele-dumbo-testing", distance_cm_string);

  

  // put your main code here, to run repeatedly:
  delay(2000); // this speeds up the simulation
}