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

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

// RTC module configuration
RTC_DS3231 rtc;

// Temperature and humidity sensor configuration (DHT22)
#define DHTPIN 2     // Pin to which the data pin of DHT is connected
#define DHTTYPE DHT22   // DHT 22 (AM2302)
DHT dht(DHTPIN, DHTTYPE);

void setup() {
  // Initialize serial communication
  Serial.begin(9600);

  // Initialize OLED display with I2C address 0x3C or 0x3D
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }

  // Clear the display immediately after initialization to avoid showing the splash screen
  display.clearDisplay();
  display.display();

  // Initialize RTC
  if (!rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }

  if (rtc.lostPower()) {
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }

  // Initialize temperature and humidity sensor
  dht.begin();
}

void loop() {
  // Get the current date and time
  DateTime now = rtc.now();

  // Get the temperature and humidity
  float temperatureC = dht.readTemperature();
  float humidity = dht.readHumidity();

  // Clear the display
  display.clearDisplay();

  // Centering the text
  // Display day of the week
  String dayText = dayOfTheWeek(now.dayOfTheWeek());
  int16_t x1, y1;
  uint16_t w, h;
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.getTextBounds(dayText, 0, 0, &x1, &y1, &w, &h);
  display.setCursor((SCREEN_WIDTH - w) / 2, 0);
  display.print(dayText);

  // Display date in DD/MM/YYYY format
  String dateText = String(now.day()) + "/" + String(now.month()) + "/" + String(now.year());
  display.getTextBounds(dateText, 0, 0, &x1, &y1, &w, &h);
  display.setCursor((SCREEN_WIDTH - w) / 2, 10);
  display.print(dateText);

  // Display time in HH:MM:SS format
  String timeText = String(now.hour()) + ":" + String(now.minute()) + ":" + String(now.second());
  display.setTextSize(2);
  display.getTextBounds(timeText, 0, 0, &x1, &y1, &w, &h);
  display.setCursor((SCREEN_WIDTH - w) / 2, 25);
  display.print(timeText);

  // Display temperature and humidity
  String tempHumText = "Temp: " + String(int(temperatureC)) + " C Hum: " + String(int(humidity)) + " %";
  display.setTextSize(1);
  display.getTextBounds(tempHumText, 0, 0, &x1, &y1, &w, &h);
  display.setCursor((SCREEN_WIDTH - w) / 2, 50);
  display.print(tempHumText);

  // Display everything on the screen
  display.display();
  delay(1000);
}

String dayOfTheWeek(uint8_t day) {
  switch(day) {
    case 0: return "Sunday";
    case 1: return "Monday";
    case 2: return "Tuesday";
    case 3: return "Wednesday";
    case 4: return "Thursday";
    case 5: return "Friday";
    case 6: return "Saturday";
    default: return "";
  }
}