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

RTC_DS1307 rtc;

#define SCREEN_WIDTH 128 // OLED width, in pixels
#define SCREEN_HEIGHT 64 // OLED height, in pixels

// create an OLED display object connected to I2C
Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

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

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

  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("failed to start SSD1306 OLED"));
    while (1);
  }

  delay(2000); // wait two seconds for initializing
}

void loop() {
  DateTime now = rtc.now();

  oled.clearDisplay(); // clear display
  oled.setTextSize(1); // set text size
  oled.setTextColor(WHITE); // set text color

  // Display date
  oled.setCursor(0, 0); // set position to display (x,y)
  oled.print("Date: ");
  oled.print(now.day(), DEC);
  oled.print('/');
  oled.print(now.month(), DEC);
  oled.print('/');
  oled.print(now.year(), DEC);

  // Draw analog clock face
  int centerX = SCREEN_WIDTH / 2;
  int centerY = SCREEN_HEIGHT / 2 + 10;
  int radius = min(SCREEN_WIDTH, SCREEN_HEIGHT) / 4;
  oled.drawCircle(centerX, centerY, radius, WHITE); // Draw the circle face

  // Hour hand
  float hourAngle = (now.hour() % 12) * 30 + now.minute() * 0.5; // Each hour is 30 degrees, each minute adds 0.5 degrees
  drawHand(centerX, centerY, hourAngle, radius * 0.5, WHITE);

  // Minute hand
  float minuteAngle = now.minute() * 6; // Each minute is 6 degrees
  drawHand(centerX, centerY, minuteAngle, radius * 0.75, WHITE);

  // Second hand
  float secondAngle = now.second() * 6; // Each second is 6 degrees
  drawHand(centerX, centerY, secondAngle, radius * 0.9, WHITE);

  oled.display(); // display on OLED
  delay(1000); // update once a second
}

void drawHand(int center_x, int center_y, float angle, int length, uint16_t color) {
  angle = angle - 90; // Adjust for 0 degrees at top
  float angle_rad = angle * (PI / 180.0);
  int endX = center_x + cos(angle_rad) * length;
  int endY = center_y + sin(angle_rad) * length;
  oled.drawLine(center_x, center_y, endX, endY, color);
}