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

// WiFi Credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";
//const char ssid[] = "Wokwi-GUEST";
//const char pass[] = "";

// HiveMQ Cloud Credentials
const char* mqtt_server = "";  // Your HiveMQ URL
const int mqtt_port = 8883;
const char* mqtt_user = "";  // Replace with your HiveMQ username
const char* mqtt_password = "";  // Replace with your HiveMQ password
const char* mqtt_topic = "";  // Topic for relay control

WiFiClientSecure espClient;
PubSubClient client(espClient);

const int relayPin = 5;  // GPIO Pin for Relay (adjust based on your wiring)

// Function to connect to WiFi
void setup_wifi() {
  delay(10);
  Serial.println("Connecting to WiFi...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi Connected!");
}

// Function to connect to MQTT Broker
void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect("ESP32Client", mqtt_user, mqtt_password)) {
      Serial.println("Connected to HiveMQ!");
      client.subscribe(mqtt_topic);
    } else {
      Serial.print("Failed, rc=");
      Serial.print(client.state());
      Serial.println(" Retrying in 5 seconds...");
      delay(5000);
    }
  }
}

// Callback function for MQTT messages
void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message received [");
  Serial.print(topic);
  Serial.print("]: ");

  String message = "";
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }
  Serial.println(message);

  if (message == "ON") {
    digitalWrite(relayPin, HIGH);
    Serial.println("Relay turned ON");
  } else if (message == "OFF") {
    digitalWrite(relayPin, LOW);
    Serial.println("Relay turned OFF");
  }
}

void setup() {
  Serial.begin(115200);
  pinMode(relayPin, OUTPUT);
  digitalWrite(relayPin, LOW);  // Start with relay OFF

  setup_wifi();
  espClient.setInsecure();  // Allow connection without a certificate
  client.setServer(mqtt_server, mqtt_port);
  client.setCallback(callback);
}

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