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

// UltraSonic
#define TRIGR 2
#define ECHO 4

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

// MQTT Broker
const char* mqtt_server = "broker.emqx.io";
const int mqtt_port = 1883;
const char* mqtt_username = "emqx";
const char* mqtt_password = "public";

//Topic
const char* Topic = "ivansahaja";
float duration_ths, distance_cm;


// WiFi & Client Publish Declaration
WiFiClient espClient;
PubSubClient client(espClient);

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

void setup(){
     // Set software serial baud to 115200;
     pinMode(TRIGR, OUTPUT);
     pinMode(ECHO, INPUT);
    Serial.begin(9600);
    // Connecting to a WiFi network
    WiFi.begin(ssid, password);
    while (WiFi.status() != WL_CONNECTED) {
        //delay(500);
        delay(1000);
        Serial.println("Connecting to WiFi..");
    }
    Serial.println("Connected to the Wi-Fi network");
    Serial.println("IP Address: ");
    Serial.println(WiFi.localIP());
    
    //Connecting to a mqtt server
    client.setServer(mqtt_server, mqtt_port);
    client.setCallback(callback);

    //Connecting Proccess
    while (!client.connected()) {
        String client_id = "esp32-client-";
        client_id += String(WiFi.macAddress());
        Serial.printf("The client %s connects to the public MQTT broker\n", client_id.c_str());

        //WiFi Condition
        if (client.connect(client_id.c_str(), mqtt_username, mqtt_password)) {
            Serial.println("Public EMQX MQTT broker connected");
        } else {
            Serial.print("failed with state ");
            Serial.print(client.state());
            delay(2000);
        }
    }

  
}

void loop() {
  digitalWrite(TRIGR, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGR, LOW);

 
 duration_ths = pulseIn(ECHO, HIGH);

 
  distance_cm = 0.017 * duration_ths;

  Serial.print("distanceR: ");
  Serial.print(distance_cm);
  Serial.println(" cm      ");
  delay(500);

  


    client.publish(Topic, "ivansaja");
    delay(2000);
    client.publish(Topic, "my distance is : ");
    client.publish(Topic, String(distance_cm).c_str());
    delay(2000);

}