#include <Wire.h>
#include <RTClib.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ST7789.h>

#define TFT_CS     10
#define TFT_RST    9
#define TFT_DC     8
#define TFT_WIDTH  240
#define TFT_HEIGHT 240

Adafruit_ST7789 tft = Adafruit_ST7789(TFT_CS, TFT_DC, TFT_RST);
RTC_DS3231 rtc;

#define BLACK 0x0000
#define WHITE 0xFFFF

void setup() {
  Serial.begin(9600);
  Serial.println("Initializing...");

  if (!rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }
  if (rtc.lostPower()) {
    Serial.println("RTC lost power, setting the time!");
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }
  tft.init(TFT_WIDTH, TFT_HEIGHT);
  tft.setRotation(1);
  // Clear the screen
  tft.fillScreen(BLACK);
  Serial.println("Display initialized.");
}

void loop() {
  DateTime now = rtc.now();
  // Clear the area where the digital clock will be displayed
  tft.fillRect(0, 0, TFT_WIDTH, TFT_HEIGHT, BLACK);
  // Display digital time on TFT
  tft.setCursor(10, 10);
  tft.setTextSize(4);
  tft.setTextColor(WHITE);

  if (now.hour() < 10)
    // Add leading zero
    tft.print('0');
  tft.print(now.hour());
  tft.print(':');
  // Add leading zero
  if (now.minute() < 10)
    tft.print('0');
  tft.print(now.minute());
  tft.print(':');
  // Add leading zero
  if (now.second() < 10)
    tft.print('0');
  tft.print(now.second());
  // Update every second
  delay(1000);
}