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

RTC_DS1307 rtc;

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
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);
  }

  if (!rtc.isrunning()) {
    Serial.println("RTC is not running");
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }

  display.clearDisplay();
}

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

  display.clearDisplay();
  drawClock(now.hour(), now.minute(), now.second());
  display.display();
}

void drawClock(int hour, int minute, int second) {
  int16_t x0 = SCREEN_WIDTH / 2;
  int16_t y0 = SCREEN_HEIGHT / 2;
  int16_t radius = SCREEN_WIDTH / 4;
  
  // Draw clock face
  display.drawCircle(x0, y0, radius, SSD1306_WHITE);
  display.fillCircle(x0, y0, 2, SSD1306_WHITE);
  
  // Draw hour lines and numbers
  for (int i = 0; i < 12; i++) {
    float angle = PI / 6 * i - PI / 2; // Offset by -90 degrees to start at the top
    int16_t x1 = x0 + cos(angle) * (radius * 0.8);
    int16_t y1 = y0 + sin(angle) * (radius * 0.8);
    int16_t x2 = x0 + cos(angle) * (radius * 0.75); // Move the numbers slightly towards the center
    int16_t y2 = y0 + sin(angle) * (radius * 0.75);
    display.drawLine(x1, y1, x2, y2, SSD1306_WHITE);
    // Print hour number
    display.setTextSize(1);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(x2 - 3, y2 - 3); // Adjust position of the numbers
    if (i == 0) {
      display.setTextSize(1); // Set the size to normal
      display.setCursor(x2 - 4, y2 - 2); // Move the 12 to the top and adjust position
      display.print(12);
    } else {
      display.print(i);
    }
  }
  
  // Draw hour hand
  float angle_hour = PI / 6 * hour + PI / 6 * (minute / 60.0); // Adjust angle calculation
  drawHand(x0, y0, radius * 0.5, angle_hour, SSD1306_WHITE);
  
  // Draw minute hand
  float angle_minute = PI / 30 * minute + PI / 30 * (second / 60.0); // Adjust angle calculation
  drawHand(x0, y0, radius * 0.8, angle_minute, SSD1306_WHITE);
  
  // Draw second hand
  float angle_second = PI / 30 * second;
  drawHand(x0, y0, radius * 0.9, angle_second, SSD1306_WHITE);
}

void drawHand(int16_t x0, int16_t y0, int16_t length, float angle, uint16_t color) {
  int16_t x_end = x0 + cos(angle - PI / 2) * length;
  int16_t y_end = y0 + sin(angle - PI / 2) * length;
  display.drawLine(x0, y0, x_end, y_end, color);
}