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

// WiFi credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// MQTT broker settings
const char* mqttServer = "mqtt.eclipseprojects.io";
const int mqttPort = 1883;
const char* mqttTopic = "LED";

WiFiClient espClient;
PubSubClient client(espClient);

const int ledPin = 5;  // LED on GPIO5 (PWM-capable)

void setup() {
  Serial.begin(115200);
  pinMode(ledPin, OUTPUT);

  // Connect to WiFi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(500);
  }
  Serial.println("\n✅ WiFi connected");

  // Connect to MQTT
  client.setServer(mqttServer, mqttPort);
  client.setCallback(callback);

  while (!client.connected()) {
    Serial.print("Connecting to MQTT...");
    if (client.connect("esp32-client")) {
      Serial.println(" connected!");
      client.subscribe(mqttTopic);
    } else {
      Serial.print(" failed. State=");
      Serial.println(client.state());
      delay(2000);
    }
  }
}

void loop() {
  client.loop();
}

// MQTT callback function to handle incoming messages
void callback(char* topic, byte* payload, unsigned int length) {
  String message;
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }

  Serial.print("📩 Received on topic ");
  Serial.print(topic);
  Serial.print(": ");
  Serial.println(message);

  // Convert incoming value (0-10) to PWM (0-255)
  int sliderValue = message.toInt();
  int pwmValue = map(sliderValue, 0, 10, 0, 255);
  analogWrite(ledPin, pwmValue);

  Serial.printf("🔆 LED brightness set to %d (PWM)\n", pwmValue);
}