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

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

// MQTT broker
const char* mqttServer = "mqtt.eclipseprojects.io";
WiFiClient espClient;
PubSubClient mqttClient(espClient);

// PWM Fan settings
const int fanPin = 13;
const int pwmFreq = 5000;
const int pwmResolution = 8;
int pwm_duty_cycle = 0;

// Connect to WiFi
void connectToWiFi() {
  Serial.print("Connecting to WiFi");
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println(" connected!");
  Serial.print(" IP address: ");
 Serial.println(WiFi.localIP());
}

// MQTT message callback
void handleMQTTMessage(char* topic, byte* payload, unsigned int length) {
  String message;

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

  if (String(topic) == "esp32/fan/speed") {
    pwm_duty_cycle = message.toInt();
    ledcWrite(fanPin,pwm_duty_cycle );
    Serial.print("setting Pwm duty cycle to: ");
    Serial.println( pwm_duty_cycle);
    Serial.print("recieved pwm duty cycle: ");
    Serial.println( pwm_duty_cycle);
  }
}

// Connect to MQTT broker
void connectToMQTT() {
  while (!mqttClient.connected()) {
    Serial.print("Attempting MQTT CONNECTION...");

    if (mqttClient.connect("ESP32ClientPWM")) {
      Serial.println(" connected");
      mqttClient.subscribe("esp32/fan/speed");
      Serial.println("Subscribed to topic:esp32/fan/speed");
    } else {
      Serial.print(" failed, rc=");
      Serial.print(mqttClient.state());
      Serial.println(" — retrying in 5 seconds");
      delay(5000);
    }
  }
}

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

  connectToWiFi();

  mqttClient.setServer(mqttServer, 1883);
  mqttClient.setCallback(handleMQTTMessage);

  ledcAttach(fanPin, 5000, 8);  // 5kHz frequency, 8-bit resolution

}

void loop() {
  if (!mqttClient.connected()) {
    connectToMQTT();
  }

  mqttClient.loop();
}