#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>
#include <DHT.h>

// Define DHT22 sensor
#define DHTPIN 4           // DHT22 data pin connected to GPIO 4
#define DHTTYPE DHT22      // DHT 22 (AM2302), AM2321
DHT dht(DHTPIN, DHTTYPE);

// Define OLED display
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// Relay pin
#define RELAY_PIN 16      // Relay connected to GPIO 16

// Temperature threshold
float thresholdTemp = 25.0;  // Set the temperature threshold

void setup() {
  // Start serial communication
  Serial.begin(115200);
  
  // Initialize DHT22 sensor
  dht.begin();

  // Initialize OLED display
  if (!display.begin(SSD1306_I2C_ADDRESS, OLED_RESET)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }
  
  // Clear the buffer
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0, 0);
  display.print("Thermostat Initializing");
  display.display();
  
  // Set relay pin as output
  pinMode(RELAY_PIN, OUTPUT);
  
  // Start with the relay off
  digitalWrite(RELAY_PIN, LOW);
  
  delay(2000);
}

void loop() {
  // Read temperature and humidity from DHT22
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();
  
  // Check if any reads failed and exit early (to try again).
  if (isnan(temperature) || isnan(humidity)) {
    Serial.println(F("Failed to read from DHT sensor!"));
    return;
  }

  // Control relay based on temperature threshold
  if (temperature >= thresholdTemp) {
    digitalWrite(RELAY_PIN, HIGH);  // Turn on relay (could mean activating cooling)
  } else {
    digitalWrite(RELAY_PIN, LOW);   // Turn off relay
  }

  // Print data on OLED display
  display.clearDisplay();
  display.setCursor(0, 0);
  display.setTextSize(1);
  display.print("Temp: ");
  display.print(temperature);
  display.println(" C");
  
  display.print("Humidity: ");
  display.print(humidity);
  display.println(" %");
  
  display.print("Relay: ");
  if (digitalRead(RELAY_PIN) == HIGH) {
    display.println("ON");
  } else {
    display.println("OFF");
  }

  display.display();
  
  // Print data to serial monitor
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" *C");
  
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.println(" %");
  
  // Wait a few seconds between measurements
  delay(2000);
}