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

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "bba80a9ee2ed14f0a9e48075be8f89b42.s1.eu.hivemq.cloud"; // e.g., "broker.hivemq.com"
const int mqtt_port = 8883; // default MQTT port
const char* mqtt_user = "hivemq.webclient.1730091698127"; // optional if using HiveMQ Cloud
const char* mqtt_password = "9D18AF4GzaEBcuyl.<$!"; // optional if using HiveMQ Cloud

WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
  Serial.begin(115200);
  
  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected");

  // Set MQTT server and connect
  client.setServer(mqtt_server, mqtt_port);
  client.setCallback(callback);

  reconnect(); // Connect to MQTT broker
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Connecting to MQTT...");
    if (client.connect("ESP32Client", mqtt_user, mqtt_password)) {
      Serial.println("connected");
      client.subscribe("WeatherTest"); // Subscribe to a topic
    } else {
      delay(5000);
    }
  }
}

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

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

  // Publish a test message every 5 seconds
  static unsigned long lastTime = 0;
  if (millis() - lastTime > 5000) {
    lastTime = millis();
    client.publish("WeatherTest", "Hello from ESP32");
  }
}