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

// WiFi credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "mqtt.eclipseprojects.io"; 
const char* mqttTopic = "esp32/pwm";
const char* fan_status_topic = "status/fan/current_speed";

const int ledPin = 13;
const int pwmFreq = 5000;      // 5000 Hz frequency
const int pwmResolution = 8;   // 8-bit resolution
const int pwmChannel = 0;
int pwmValue = 0;              // Initial duty cycle


WiFiClient espClient;
PubSubClient client(espClient);

void setup_wifi() {
  delay(10);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.print(ssid);

  WiFi.begin(ssid, password);

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

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

void callback(char* topic, byte* message, unsigned int length) {
  Serial.println("Message arrived ");
  Serial.print(topic);
  Serial.print(". Message: ");
  String messageTemp;
  
  for (int i = 0; i < length; i++) {
    messageTemp += (char)message[i];
  }
  Serial.println(messageTemp);

  // Check if message is for fan control
  if (String(topic) == "esp32/pwm") {
    int speed = messageTemp.toInt();
   
 
    // Convert percentage to PWM value (0-255)
    int pwm_value = map(speed, 0, 100, 0, 255);
    analogWrite(ledPin, pwm_value);
    
    Serial.print("Recieved Duty Cycle Value: ");
    Serial.println(messageTemp);
    Serial.print("Setting PWM Duty Cycle to: ");
     Serial.println(speed);

  
    
    // Publish current speed back to MQTT
    client.publish(fan_status_topic, messageTemp.c_str());
  }
}

void reconnect() {
  while (!client.connected()) {
    Serial.println("Attempting MQTT connection...");
    String clientId = "ESP32-FanController-";
    clientId += String(random(0xffff), HEX);
    
    if (client.connect(clientId.c_str())) {
      Serial.println("✅connected");
      client.subscribe(mqttTopic);
      Serial.printf("Subscribed to topic: %s\n", mqttTopic);
      
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

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

  Serial.println("PWM Configuration:");
  Serial.printf("Frequency: %d Hz\n", pwmFreq);
  Serial.printf("Resolution: %d-bit (Max Duty:255)\n", pwmResolution);
  Serial.printf("Attached PWM to GPIO %d\n", ledPin);
  Serial.printf("Initial Duty Cycle: %d\n", pwmValue);

  
  // Configure PWM for fan control
  pinMode(ledPin, OUTPUT);
  analogWrite(ledPin, 0); // Start with fan off
  
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

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