#include <WiFi.h>
#include <PubSubClient.h>
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "broker.emqx.io";
const int mqtt_port = 1883;
const int ledPin = 21;      
const int buttonPin = 17;  
WiFiClient espClient;
PubSubClient client(espClient);

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

  // Set up the LED pin
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);

  // Set up the button pin
  pinMode(buttonPin, INPUT_PULLUP); // Using internal pull-up resistor

  // Connect to WiFi
  setup_wifi();

  // Set up MQTT
  client.setServer(mqtt_server, mqtt_port);
  client.setCallback(mqttCallback);
}

void setup_wifi() {
  delay(10);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void mqttCallback(char* topic, byte* payload, unsigned int length) {
  // Not used in this example
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect("ESP32Client")) {
      Serial.println("connected");
      // Subscribe to a topic if needed
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

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

  // Read the button state
  int buttonState = digitalRead(buttonPin);

  if (buttonState == LOW) { // Button is pressed (active-low)
    // Blink the LED
    digitalWrite(ledPin, HIGH);
    delay(500);
    digitalWrite(ledPin, LOW);
    delay(500);
  } else {
    // Make sure LED is OFF when button is not pressed
    digitalWrite(ledPin, LOW);
  }
}