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

const char* ssid = "Wokwi-GUEST";  // Wokwi Wi-Fi emulator
const char* mqttServer = "mqtt.eclipseprojects.io";
const int mqttPort = 1883;
const char* mqttTopic = "esp32/pwm";

WiFiClient espClient;
PubSubClient client(espClient);

const int ledPin = 13;
int pwmValue = 0;  // Store received brightness level

void setupWifi() {
  Serial.print("Connecting to Wi-Fi");
  WiFi.begin(ssid);
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(500);
  }
  Serial.println("\n✅ Wi-Fi connected!");
}

void callback(char* topic, byte* payload, unsigned int length) {
  String message = "";

  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }

  pwmValue = message.toInt();
  pwmValue = constrain(pwmValue, 0, 255);  // Ensure valid PWM range

  Serial.printf("✅ Received PWM: %d (%.0f%% brightness)\n", pwmValue, (pwmValue / 255.0) * 100);
  
  analogWrite(ledPin, pwmValue);  // Control LED brightness
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("🔄 Attempting MQTT connection...");
    
    if (client.connect("ESP32Client")) {
      Serial.println("✅ Connected!");
      client.subscribe(mqttTopic);
      Serial.printf("📡 Subscribed to topic: %s\n", mqttTopic);
    } else {
      Serial.printf("❌ Failed, rc=%d. Retrying...\n", client.state());
      delay(2000);
    }
  }
}

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

  pinMode(ledPin, OUTPUT);  // Set LED pin as output

  client.setServer(mqttServer, mqttPort);
  client.setCallback(callback);

  reconnect();
}

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