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

// ---------------- OLED CONFIG ----------------
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
#define OLED_ADDR     0x3C

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// ---------------- DHT CONFIG ----------------
#define DHTPIN   14        // GPIO 14
#define DHTTYPE  DHT22     // DHT22 (AM2302)

DHT dht(DHTPIN, DHTTYPE);

// ---------------- SETUP ----------------
void setup() {
  Serial.begin(115200);

  // I2C pins for ESP32
  Wire.begin(21, 22);   // SDA, SCL

  dht.begin();

  if (!display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR)) {
    Serial.println("SSD1306 allocation failed");
    while (true);
  }

  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0, 0);
  display.println("ESP32 + DHT22");
  display.println("Initializing...");
  display.display();

  delay(2000);
}

// ---------------- LOOP ----------------
void loop() {
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature(); // Celsius

  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // Serial Monitor Output
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.print(" °C  |  Humidity: ");
  Serial.print(humidity);
  Serial.println(" %");

  // OLED Display Output
  display.clearDisplay();
  display.setCursor(0, 0);

  display.setTextSize(1);
  display.println("DHT22 Readings");

  display.setTextSize(2);
  display.setCursor(0, 18);
  display.print(temperature);
  display.println(" C");

  display.setCursor(0, 42);
  display.print(humidity);
  display.println(" %");

  display.display();

  delay(2000);
}