#include <WiFi.h>
#include <DHT.h>

// Define Wi-Fi credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// DHT sensor setup
#define DHTPIN 15  // Pin where the DHT22 is connected
#define DHTTYPE DHT22  // Define sensor type as DHT22
DHT dht(DHTPIN, DHTTYPE);

// Define relay (fan) pin
#define RELAY_PIN 13  // Pin for relay (fan control)

// Temperature threshold for activating the fan (prediction threshold)
const float TEMP_THRESHOLD = 30.0; // Temperature in Celsius

// Linear regression model parameters
const float slope = 0.05;    // Example slope (m)
const float intercept = -0.5;  // Example intercept (b)

// Setup Wi-Fi client
WiFiServer server(80);

void setup() {
  // Start serial communication
  Serial.begin(115200);

  // Connect to Wi-Fi
  connectToWiFi();

  // Initialize DHT sensor
  dht.begin();

  // Set relay pin as output
  pinMode(RELAY_PIN, OUTPUT);
  
  // Start the server
  server.begin();
}

void loop() {
  // Read the temperature and humidity from the DHT22 sensor
  float temp = dht.readTemperature(); // Get temperature in Celsius
  float humidity = dht.readHumidity(); // Get humidity percentage
  
  // Check if the readings are valid
  if (isnan(temp) || isnan(humidity)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // Print the sensor values
  Serial.print("Temperature: ");
  Serial.print(temp);
  Serial.print("°C, Humidity: ");
  Serial.print(humidity);
  Serial.println("%");

  // Apply the linear regression model to make a decision (whether to turn on the fan)
  float prediction = slope * temp + intercept;  // Predicted output based on temperature
  
  // Print the prediction value
  Serial.print("Predicted Value: ");
  Serial.println(prediction);

  // Simple decision-making: turn on the fan if predicted value exceeds threshold
  if (prediction > 0.5) {  // If predicted value > 0.5, turn on the fan
    digitalWrite(RELAY_PIN, HIGH); // Turn on the fan
    Serial.println("Fan turned ON");
  } else {
    digitalWrite(RELAY_PIN, LOW); // Turn off the fan
    Serial.println("Fan turned OFF");
  }

  // Delay before reading again
  delay(5000);  // Wait for 5 seconds before checking again
}

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

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

  // Print the IP address once connected
  Serial.println();
  Serial.print("Connected to Wi-Fi. IP address: ");
  Serial.println(WiFi.localIP());
}