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

// WiFi credentials
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

// MQTT Broker
const char *mqtt_broker = "broker.hivemq.com";
const char *mqtt_username = "emqx";
const char *mqtt_password = "public";
const int mqtt_port = 1883;

// MQTT Topics
const char *topic_publish = "emqx/esp32/p";
const char *topic_subsrcibe = "emqx/esp32/s";
const char *topic_subsrcibe2 = "emqx/esp32/s2";

WiFiClient hamada;
PubSubClient client(hamada);

#define LED 2
bool ledState = false;

void setup() {
  // Initialize LED pin
  pinMode(LED, OUTPUT);
  digitalWrite(LED, LOW);  // Turn off LED initially
  
  // Start serial communication
  Serial.begin(115200);
  
  // Connect to Wi-Fi
  WiFi.begin(ssid, pass);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to Wi-Fi!");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());

  // Set MQTT server
  client.setServer(mqtt_broker, mqtt_port);

  // Connect to MQTT broker
  while (!client.connected()) {
    String clientId = "esp32-client-" + String(WiFi.macAddress());
    Serial.printf("Attempting to connect with client ID: %s\n", clientId.c_str());
    if (client.connect(clientId.c_str(), mqtt_username, mqtt_password)) {
      Serial.println("Connected to MQTT broker!");
      client.subscribe(topic_subsrcibe);
      client.subscribe(topic_subsrcibe2);
    } else {
      Serial.print("Failed to connect. State: ");
      Serial.println(client.state());
      delay(5000);  // Retry in 5 seconds
    }
  }

  // Publish a test message
  client.publish(topic_publish, "Hi, I'm ESP32 ^^");
}

void loop() {
  client.loop();  // Ensure to keep the MQTT connection alive
}

void callback(char *topic, byte *payload, unsigned int length) {
  String messageTemp;
  for (int i = 0; i < length; i++) {
    messageTemp += (char)payload[i];
  }
  
  // Example to toggle LED based on incoming message
  if (String(topic) == "emqx/esp32/s" && messageTemp == "ON") {
    digitalWrite(LED, HIGH);
  } else if (String(topic) == "emqx/esp32/s" && messageTemp == "OFF") {
    digitalWrite(LED, LOW);
  }
}