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

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "test.mosquitto.org";
const char* mqtt_topic = "/d3tt"; //Disesuaikan dengan inisial nama

WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;

#define MSG_BUFFER_SIZE (50)
char msg[MSG_BUFFER_SIZE];
int value = 0;

void setup_wifi() {
delay(10);
// We start by connecting to a WiFi network
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);

WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);

while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
Serial.print("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() {
// Loop until we’re reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection…");
// Create a random client ID
String clientId = "ESP32Client-";
clientId += String(random(0xffff), HEX);
// Attempt to connect
if (client.connect(clientId.c_str())) {
Serial.println("Connected");
// Once connected, publish an announcement…
client.publish(mqtt_topic, "D3-TT"); //Nama Server
// … and resubscribe
client.subscribe(mqtt_topic);
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println("try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}

void setup() {
Serial.begin(115200);
setup_wifi();
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
}

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

unsigned long now = millis();
if (now - lastMsg > 2000) {
lastMsg = now;
++value;
snprintf (msg, MSG_BUFFER_SIZE, "Nomor Urut #%ld", value);
Serial.print("Publish message: ");
Serial.println(msg);
client.publish(mqtt_topic, msg);
}
}