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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
RTC_DS1307 rtc;

void drawTopIcons() {
  // Battery icon (top-right)
  display.drawRect(114, 0, 12, 6, WHITE);   // battery body
  display.drawRect(126, 2, 2, 2, WHITE);    // cap
  display.fillRect(116, 2, 8, 2, WHITE);    // battery fill

  // Network bars (top-left)
  display.drawLine(0, 6, 0, 6, WHITE);
  display.drawLine(3, 4, 3, 6, WHITE);
  display.drawLine(6, 2, 6, 6, WHITE);
  display.drawLine(9, 0, 9, 6, WHITE);
}

void drawBottomUnlockIcon(int x, int y) {
  // Small lock icon
  display.drawRect(x, y + 3, 10, 6, WHITE);         // lock body
  display.drawCircle(x + 5, y, 3, WHITE);           // shackle
  display.drawLine(x + 2, y, x + 8, y, BLACK);      // open part
}

void setup() {
  Wire.begin();
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();

  rtc.begin();
  if (!rtc.isrunning()) {
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__))); // Set to compile time
  }

  display.setTextColor(WHITE);
}

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

  // Draw battery & network icons
  drawTopIcons();

  // Draw big time (HH:MM) in center
  display.setTextSize(3);
  display.setCursor(10, 20);  // Y=20 leaves room above and below

  // Hour
  if (now.hour() < 10) display.print('0');
  display.print(now.hour());

  // Blinking colon
  if (now.second() % 2 == 0) {
    display.print(':');
  } else {
    display.print(' ');
  }

  // Minute
  if (now.minute() < 10) display.print('0');
  display.print(now.minute());

  // Draw date and day in small font at bottom
  display.setTextSize(1);
  display.setCursor(0, 54);
  if (now.day() < 10) display.print('0');
  display.print(now.day());
  display.print('-');
  if (now.month() < 10) display.print('0');
  display.print(now.month());
  display.print('-');
  display.print(now.year());

  // Day of week
  display.setCursor(70, 54);
  const char* days[] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
  display.print(days[now.dayOfTheWeek()]);

  // Unlock icon (bottom right)
  drawBottomUnlockIcon(110, 52);

  display.display();
  delay(1000);
}