#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <RTClib.h> // Include RTC library suitable for STM32, e.g., RTClib

RTC_DS3231 rtc; // Create an instance of the RTC class, adjust if using a different RTC module

char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};

#define SCREEN_WIDTH 128  // OLED display width, in pixels
#define SCREEN_HEIGHT 64  // OLED display height, in pixels
#define OLED_RESET    -1  // Reset pin # (or -1 if sharing reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

void setup() {
  Serial.begin(9600);

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

  // Check if the current time is valid (RTC is running)
  DateTime now = rtc.now();
  if (now.year() < 2000) {
    Serial.println("RTC is NOT running!");
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__))); // Adjust time if necessary
  }

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;); // Don't proceed, loop forever
  }

  display.display();
  delay(2);
  display.clearDisplay();

  display.clearDisplay();
  display.setTextColor(WHITE);
  display.setTextSize(2);
  display.setCursor(0, 5);
  display.print("  Clock ");
  display.display();
  delay(3000);
}

void loop() {
  DateTime now = rtc.now(); // Get current time from RTC

  display.clearDisplay();
  display.setTextSize(2);
  display.setCursor(75, 0);
  display.println(now.second(), DEC);

  display.setTextSize(2);
  display.setCursor(25, 0);
  display.println(":");

  display.setTextSize(2);
  display.setCursor(65, 0);
  display.println(":");

  display.setTextSize(2);
  display.setCursor(40, 0);
  display.println(now.minute(), DEC);

  display.setTextSize(2);
  display.setCursor(0, 0);
  display.println(now.hour(), DEC);

  display.setTextSize(2);
  display.setCursor(0, 20);
  display.println(now.day(), DEC);

  display.setTextSize(2);
  display.setCursor(25, 20);
  display.println("-");

  display.setTextSize(2);
  display.setCursor(40, 20);
  display.println(now.month(), DEC);

  display.setTextSize(2);
  display.setCursor(55, 20);
  display.println("-");

  display.setTextSize(2);
  display.setCursor(70, 20);
  display.println(now.year(), DEC);

  display.setTextSize(2);
  display.setCursor(0, 40);
  display.print(daysOfTheWeek[now.dayOfTheWeek()]);

  display.display();
}