#include <DHT.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <WiFi.h>
#include <PubSubClient.h>

// Pin definitions
#define DHTPIN 4          // DHT11 data pin
#define FAN_PIN 5         // GPIO pin controlling the fan via transistor
#define POT_PIN 34        // Potentiometer for manual speed control
#define DHTTYPE DHT11     // DHT11 sensor

// Set up DHT11
DHT dht(DHTPIN, DHTTYPE);

// Set up LCD (I2C)
LiquidCrystal_I2C lcd(0x27, 16, 2);  // Change address if needed

// WiFi and MQTT setup
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "test.mosquitto.org";
WiFiClient espClient;
PubSubClient client(espClient);

// Variables
float temperature = 0.0;
int fanSpeed = 0;
bool autoMode = true;

void setup() {
  Serial.begin(115200);
  Wire.begin();
    Serial.println("Scanning...");
      for (byte i = 8; i < 120; i++) {
          Wire.beginTransmission(i);
              if (Wire.endTransmission() == 0) {
                    Serial.print("I2C device found at address 0x");
                          if (i < 16) {
                                  Serial.print("0");
                                        }
                                              Serial.println(i, HEX);
                                                  }
                                                    }
                                                      Serial.println("Scan complete");

  // Start DHT sensor
  dht.begin();

  // Set up the fan control pin
  pinMode(FAN_PIN, OUTPUT);
  digitalWrite(FAN_PIN, LOW);

  // Set up the LCD
  lcd.begin(16, 2);
  lcd.backlight();

  // Connect to WiFi
  connectToWiFi();

  // Set up MQTT client
  client.setServer(mqtt_server, 1883);
  client.setCallback(mqttCallback);

  // Subscribe to MQTT topics
  client.subscribe("fan/mode");
  client.subscribe("fan/speed");
}

void loop() {
  // Check WiFi connection
  if (!WiFi.isConnected()) {
    connectToWiFi();
  }

  // Read temperature from DHT11 sensor
  temperature = dht.readTemperature();

  // Display temperature and fan speed on LCD
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print(" C");

  lcd.setCursor(0, 1);
  lcd.print("Fan Speed: ");
  lcd.print(fanSpeed);

  // Publish temperature to MQTT
  String tempStr = String(temperature);
  client.publish("home/temperature", tempStr.c_str());

  // MQTT client loop
  if (!client.connected()) {
    reconnectMQTT();
  }
  client.loop();

  // Control fan speed based on temperature
  if (autoMode) {
    if (temperature < 20) {
      fanSpeed = 0;
    } else if (temperature >= 20 && temperature <= 50) {
      fanSpeed = map(temperature, 20, 50, 0, 255);  // Mapping temperature to PWM range
    } else {
      fanSpeed = 255;  // Max speed if temp > 50°C
    }
  } else {
    // Read the potentiometer for manual control
    fanSpeed = analogRead(POT_PIN) / 4;  // Map 0-4095 to 0-255
  }

  // Set fan speed using PWM
  analogWrite(FAN_PIN, fanSpeed);

  // Delay before next loop
  delay(2000);
}

void connectToWiFi() {
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print("Connecting to WiFi...");
    WiFi.begin(ssid, password);
    delay(5000);
  }
  Serial.println("Connected to WiFi");
}

void reconnectMQTT() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect("ESP32Client")) {
      Serial.println("Connected to MQTT broker");
    } else {
      Serial.print("Failed, retrying in 5 seconds...");
      delay(5000);
    }
  }
}

void mqttCallback(char* topic, byte* payload, unsigned int length) {
  String message = "";
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }

  // Control mode: Auto or Manual
  if (String(topic) == "fan/mode") {
    if (message == "auto") {
      autoMode = true;
    } else if (message == "manual") {
      autoMode = false;
    }
  }

  // Set fan speed manually
  if (String(topic) == "fan/speed" && !autoMode) {
    fanSpeed = message.toInt();
  }
}