#include <wifi.h>
#include <ArduinoMqttClient>

// Wi-Fi credentials (Wokwi provides default SSID and password)
const char* ssid = "FAB LAB MAKANDURA";
const char* password = "fablab2024";

// MQTT broker details (use a public broker like HiveMQ)
const char* mqtt_server = "broker.hivemq.com"; 
const char* mqtt_topic = "wokwi/relay_control";

WiFiClient espClient;
ArduinoMqttClient client(espClient);

const int relayPin = 5; // GPIO pin connected to relay

void setup() {
  Serial.begin(115200);

  // Initialize relay pin as output
  pinMode(relayPin, OUTPUT);
  digitalWrite(relayPin, LOW); // Ensure relay is off initially

  // Connect to Wi-Fi
  connectToWiFi();

  // Set up MQTT client
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);

  // Connect to MQTT broker
  connectToMQTT();
}

void loop() {
  // Ensure the client stays connected
  if (!client.connected()) {
    connectToMQTT();
  }
  client.loop();
}

// Function to connect to Wi-Fi
void connectToWiFi() {
  Serial.print("Connecting to Wi-Fi...");
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("Connected to Wi-Fi!");
}

// Function to connect to MQTT broker
void connectToMQTT() {
  while (!client.connected()) {
    Serial.print("Connecting to MQTT...");
    if (client.connect("ESP32WokwiClient")) {  // Client ID
      Serial.println("Connected to MQTT!");
      client.subscribe(mqtt_topic);
    } else {
      Serial.print("Failed, rc=");
      Serial.print(client.state());
      Serial.println(" Retrying in 5 seconds...");
      delay(5000);
    }
  }
}

// Callback function when a message is received
void callback(char* topic, byte* message, unsigned int length) {
  Serial.print("Message received on topic: ");
  Serial.println(topic);

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

  // Control the relay based on the message
  if (msg == "ON") {
    digitalWrite(relayPin, HIGH); // Turn on relay
    Serial.println("Relay ON");
  } else if (msg == "OFF") {
    digitalWrite(relayPin, LOW); // Turn off relay
    Serial.println("Relay OFF");
  }
}